stockcar engineering spring 2013

NASCAR steps into the futureGeneration 6

FROM THE PUBLISHERS OF

Issue 09 • Spring 2013 • www.racecar-engineering.com/stockcar

www.racecar-engineering.com

RUNNING HEAD

4 NEWSNASCAR looking to the future with digital dashes, lasers in tech inspection, and Ferrari to go stockcar racing?

8 NEW LOOK NASCARHow the Generation 6 Sprint Cup bodwork was developed with the help of the four manufacturers

14 WONKY WHEELSAs well as new body styles, Sprint Cup teams are now able to run far more camber on the new cars

16 EAKERS PLACEThe Aerodyn wind tunnel in North Carolina was instrumental in the creation of the Gen 6 cars

20 UNFAIR ADVANTAGESA new gearbox from the UK, Microsoft teams up with Toyota, a golden heatshield and 3D printing

26 THE TWO CAR TANGOSimulating two car drafting

27 LUBRICATIONHow engine oil will help some teams race to the front at Daytona, Talladega and Indianapolis

28 OPINIONChassis consultant Mark Ortiz discusses setup on dirt tracks and Ricardo Divila learns to cheat

CONTENTS

Stockcar racing changed forever on one chilly Saturday night in

February in 2013. As the pace car peeled off at the start of the

NASCAR Sprint Unlimited race at Daytona the ‘Generation 6’ cars

made their long awaited debut, but that’s not what has changed.

As the green waved, not one of the crews knew what type of pit

stop they would have to make at the end of the first 30-lap segment.

Indeed it was the fans who would decide. They were given the chance

to vote online or via a smartphone app about whether the cars would

make a a four-tyre pit stop, a two-tyre pit stop or no pit stop at all.

Indeed everything about the race would be decided by online voting,

and while it may seem

to be a gimmick, this fan

involvement is crucial to

the future of the sport.

The Sprint Unlimited

ran in front of largely

empty grandstands, a

problem that has become

an increasing trend

in stockcar racing as

spectator numbers have

dwindled. NASCAR has

realised that it needs to appeal to a new generation of fans, and that

means going digital with races streamed online, open information and

fan interaction using social media.

This all has a knock on impact on the engineering aspects of the

sport. Lets not forget what made the guys at NASCAR Marketing realise

how important this digital stuff is; a single picture tweeted out by Brad

Keselowski during the seemingly endless 2012 Daytona 500. It was

not an especially good, or interesting, picture but the reaction of the

fans was huge, as the bored driver replied to fans from the cockpit of

his stationary Dodge, more than 100,000 people added his feed.

But something was bugging me. Why did Brad have a smartphone

in his car anyway? Its not like he was going to use it to call the crew

to get instructions. He had a radio. When you think of what makes up

a modern smart phone you start to realise that they are all fitted with

pretty good GPS, accelerometers, gyroscopes and in some, like the new

Blackberry Z10, they come with a Magnetometer.

In a tightly contested series, where in race data acquisition is strictly

outlawed, the data that could be derived from smart phone could

be that crucial unfair advantage. Indeed, it could easily be streamed

realtime to a similar device or laptop back in the hauler, giving the crew

a rudimentary form of telemetry. At Daytona, NASCAR took no action

over Keselowski’s usage of the ‘phone in the race, perhaps because it

was great publicity for the series. Another possibility was that Brian

Helton and his squad had not yet figured out what these devices could

do. By the time Keselowski arrived at Phoenix for the penultimate race

of the series, the technical inspectors had got wise. He was hit with

a $25,000 fine and placed on probation for carrying his phone in the

car. Did it make a difference? Perhaps that will come out over time, but

a single $25,000 fine is irrelevant when you consider that Keselowski

took the Sprint Cup at the following race.

Phones are small and, short of patting down every driver, you

have no chance of finding them. In tech inspection NASCAR never

looks inside the radio housing. It would be easy to hide at least the

functionality of a smartphone in that box and it remain undetected. As

NASCAR Marketing has had to change its thinking to deal with a post

digital revolution, so do engineers and NASCAR R&D.

Sam CollinsEditor

NASCAR has realised that it

needs to appeal to a new generation of fans through

social media


STOCKCAR NEWS

NEWS

Advanced technology is set to change the face

of stockcar racing, as NASCAR modernises its

racing series. Digital dashboards and substantial

engine changes are on the horizon according to

many in the garage.

‘You look at where consumers are today –

they’re getting younger and attention spans are

getting shorter,’ said NASCAR senior vice president

of racing operations Steve O’Donnell, ‘so we know

it’s imperative for us to innovate every day.’

‘We’re looking at the dashboard in each of the

cars and how we could bring technology into the

cars. We are working with our partner Sprint to do

that in a smart way and utilise Facebook, Twitter

– whatever it may be that’s out there to bring

in a younger audience and use the technology,

because at the end of the day we feel like we’ve

got the best story to tell when it comes to

technology and involving fans, so whatever we

can do in that realm, we’re going to go after it. I

think you’re going to see a heavy emphasis on

that in everything we do moving forward.’

The arrival of EFI last year was widely seen

as a first step on a road that will eventually lead

to the cars using smaller capacity direct injection

V8 engines in future. Restrictor plates are also

thought to be on the way out as the McLaren ECU

can fulfil the same role electronically.

It is thought that cars running prototype digital

dashboards will run at some point in 2013.

New manufacturers considering NASCARNew nameplates could appear in Sprint Cup in future, according to a senior NASCAR source. Porsche, Audi, KIA, Jaguar and Honda have all been rumoured to be evaluating participation in stockcar racing, but so far none have confirmed a programme.

‘Occasionally we’ll get a cold call from another manufacturer, and we’ll sit down and talk to them,’ says VP of Competition at NASCAR Robin Pemberton. ‘We explain how things work and what our garage area is and how it exists and what we expect out of manufacturers that come in. I’m sure there’s some that are taking a serious look at moving forward, but there shouldn’t be anything new for, say, the next year or two.’

Dodge has hinted on more than one occasion that it may well return to Cup as early as 2014, subject to finding the right teams to partner with.

Generation 6 could open the technological floodgates


STOCKCAR NEWS

NASCAR’s new laser platform for

technical inspection did not make

the best debut, with the system

failing during its first real world

usage. The new system has been

introduced along with the new

Sprint Cup cars in order to ensure

teams stay on the right side of the

regulations. ‘A lot of the gadgets

and trickery we had going on

underneath the back ends of the

cars – the sideways stuff – will be

much easier for us to control,’ said

NASCAR’s John Darby.

The platform, which was

developed by NASCAR with

the help of some outside

sources, does not provide a

scan of the car body, instead

it details components on the

underside. It will position the

car exactly to check the location

of various components.

‘The way it does that is that,

as the car rolls up on to the

platform, it will identify the car

from one of the RFID chips that

was put on it at certification. It

will then go through the entire

database of all the cars that have

been certified, find that car, pull

the certification file, look at it and

position the car on the platform

exactly in the location that it was

certified,’ Darby explains.

‘Where it excels is that

the process erases any doubt

by providing more exact

measurements,’ he said. ‘In

the past we used probably

10 different gauges or pieces

of equipment to do the same

measurements that the platform

does, especially when they

are put on at two separate

stations. Wheels are turning,

cars are getting pushed – you

don’t have a guarantee. We

felt pretty good about where

we were, but this eliminates

any questions.’

A back-up system was

employed at Daytona after the

laser platform failed, though

it was put back in place ahead

of the 500.

NASCAR has a weakness, a

force of nature it struggles to

overcome. That weakness is

rain and sometimes even snow.

But for 2013 there is a new

weapon in the war against the

weather. Less than eight months

ago, NASCAR chairman and CEO

Brian France tasked the team

at the NASCAR Research and

Development Center in Concord,

NC, with developing a means to

shorten the delays caused by rain

by 80 per cent. The first result

of this project was revealed at

Daytona ahead of Speedweeks:

the Air Titan track drying system.

If you can get past the somewhat

over dramatic name the new

device is in essence a giant

Dyson air blade.

‘The system basically works

by having compressors feed air

at a high rate of speed through

a hose to the Air Titan modules,’

explains NASCAR senior vice

president of racing operations

Steve O’Donnell. ‘It is able

to blow air in narrow, highly

pressurised sheets over the race

surface down on to the apron,

and then on the apron we’ve

got a regenerative air vacuum

truck, which obviously absorbs

the water, and then we’ll have

jet dryers behind each cycle,

we’ll have five of those, that

will move at a rate of speed at

approximately 3 to 5 miles per

hour. It is important for them to

maintain a consistent speed.”

As part of the Air Titan’s

testing process, NASCAR

enlisted the expertise of the

National Center for Asphalt

Technology (NCAT) in Auburn,

Alabama, International Speedway

Corporation’s track construction

group, Racing Surface

Technologies and QualPro Inc.

Additionally, Elgin Sweeper

Company, Sullair and Ring Power

CAT also provided equipment

during the testing, and will be

part of the track-drying process

at Daytona during Speedweeks.

For the immediate future, jet

dryers and vacuum trucks will

continue to be used during track-

drying efforts. The next evolution

in the innovative technology will

be to optimise the power source,

but it is clear that the new system

is very much a prototype and its

use will be limited initially. ‘I think

we want to see how it goes,’ says

O’Donnell. ‘Keep in mind that this

has never been tested during a

race or during full rain conditions

at a track, so we’ve still got some

work to do once we see it, if we

do see it in play, and we’ll learn

from there and make sure we’ve

got the best model going forward

possible for other tracks.

‘I think if everything works

where we see it going in the

future, you could see jet dryers

being a thing of the past. You

could see the model of tracks

that purchae jet dryers – they

could now purchase the Air

Titans and have their own air

supply at each track, because

obviously they host more than

just NASCAR events.’

NASCAR develops new

track dryer in-house

Laser-guided tech inspection has bumpy start


STOCKCAR NEWS

John Monsam has been hired as

crew chief at Tri Star Motorsports,

replacing Wes Ward for driver

Eric McClure in the NASCAR

Nationwide Series. Monsam

last worked for McDonald

Motorsports and has previously

acted as crew chief at Dale

Earnhardt Inc, Roush Fenway

Racing and Kevin Harvick Inc.

Adam Stevens will be

crew chief at Joe Gibbs Racing

for driver Kyle Busch in the

NASCAR Nationwide Series, the

announcement coming after

Busch was signed to a long-term

contract extension. Chris Gayle –

former team engineer for Busch’s

Sprint Cup team at JGR – has

been promoted to crew chief

for a third JGR Nationwide team

driven by Elliott Sadler.

Chris Rice has been named

crew chief for rookie driver

Alex Bowman at RAB Racing,

Rice served in the same capacity

for RAB’s NASCAR Truck Series

team in 2012.

Mike Bumgarner has

been hired as crew chief in the

NASCAR Nationwide Series at

JR Motorsports for drivers Kasey

Kahne and Brad Sweet. Greg Ives

has been hired in a similar position

for the Chevrolet, driven by Regan

Smith. Both crew chiefs are former

Hendrick Motorsports personnel.

Mike Hester has returned

as crew chief for Ricky Benton

Racing Enterprises and driver

Scott Riggs in the NASCAR Truck

Series for 2013. Hester had a

brief hiatus due to ill health.

Also in the Truck Series,

veteran crew chief Gary Cogswell has joined T3R2

Motorsports as crew chief for

driver Brian Silas.

Chad Walter has been hired

by Michael Waltrip Racing as

director of race engineering for its

three Sprint Cup teams. Walter left

his post as crew chief at Penske

Racing for driver Sam Hornish

in the Nationwide Series. Walter

was replaced by Greg Erwin at

the end of 2012 and replaces

Steve Bowyer, who has returned

to a position outside racing for

the second time. Long-time

Penske Racing technical director

Tom German has departed the

company to take the position of

chief technical officer at MWR.

Current MWR technical director

Nick Hughes will be moving

back his native Australia at some

point during the year following

five years at MWR.

In addition to the drivers

name in the centre ‘shade band’

area of the windshield, all of

the Gen-6 NASCAR Sprint Cup cars will also have the car

manufacturer’s logo on either

side of the windshield in an effort

to further give brand identity.

Team owner Tommy Baldwin will return to a crew chief role

within his two-car NASCAR Sprint

Cup team and will serve in that

position for Dave Blaney. The

team also hired long-time Hendrick

Motorsports employee Charlie Langenstein as competition

director and Joe Lax as crew chief

for driver JJ Yeley’s Chevrolet.

SR2 Motorsports is

growing its Nationwide

Series operation purchasing

its neighbour in Mooresville,

North Carolina MacDonald Motorsports. The Toyota team

will become a three car operation.

Driver/owner Joe Nemechek’s

NEMCO Motorsports has joined

forces with Jay Robinson Racing, combining efforts to

field Toyota’s in the Sprint Cup

and Nationwide Series driven

by Nemechek and with engines

leased from Race Engines Plus.

Bill Romanowski, a veteran

16 seasons NFL player, has

become a minority owner of

the Brandon Davis owned Swan

Racing in the NASCAR Sprint

Cup Series. Romanowski’s

dietary supplement company,

Nutrition53 will also be the

primary sponsor of the David

Stremme driven Toyotas in 10

races, and have an associate role

in the remaining 26 events.

The latest Race Moves

Europe’s leading oval racing category is evaluating its own next generation cars. The NHRPA National Hot Rods could use sportscar bodies in place of the current hatchback and coupe designs currently racing.

‘No manufacturer is prepared to put the investment in for new National Hot Rod body shapes,’ series owner Deane Wood said. ‘There’s no guarantee that when you’ve put anything up to £40,000 investment in to come up with a new body, that you’re going to have a car that beats what’s already out there – the Tigra – so why would you?

‘I’ve got hold of a Ferrari that we may use to build a car up from. I think we’ve got to do something to change the formula a bit, and get the kids excited about the cars. Like Ferraris and Porsches – exotic cars racing on a stockcar track. We’re not doing anything about it yet, the climate is wrong at the moment. But I could easily see 2-litre Hot Rods [the NHRPA’s equivalent of the Nationwide series] being the ordinary cars and Nationals being the supercar class.’

Chassis builder SHP has released a concept rendering of what it feels the new cars could look like, based on the Mazda RX-8.

Ferrari stockcars in England?

The Mazda RX8 could be the first of

the new breed of stockars

“All Gen-6 NASCAR Sprint Cup cars will have the car manufacturer’s

logo on each side of the windshield to further give brand identity”

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SPRINT CUP CARS

It is probably the first time that the

NASCAR rulebook has been influenced by

an Australian touring car championship,

but the new look Sprint Cup cars were

introduced as a result of GM executive’s

work in V8 Supercars. Mark Reuss, now

president of General Motors North America,

served as managing director of Holden from

February 2008 to September 2009.

When Reuss returned to GM in the United

States, unifying the brand identity between

the Cup car and a street car was at the top

of his to-do list. He met with NASCAR

president Mike Helton and NASCAR principals

Lesa France Kennedy and Jim France. The

agenda featured only one item: a new car.

‘The first thing I did when I came back from

Australia was to sit down with Mike, Lesa and

Jim,’ said Reuss. ‘The racecar had little to do

with an Impala. The car before that had little

to do with a Monte Carlo. We hadn’t been

doing this right for a long time.’

While GM never threatened to quit the

sport, the writing was on the wall, according

to team boss Rick Hendrick. ‘I think Mark

Reuss said that if we can’t be relevant, we

don’t race,’ he said. ‘So we had a lot riding

on that. I think that’s when everybody

started talking, along with Ford and Toyota.

But Mark pushed the button with NASCAR,

and I’m glad he did. It’s sure paid off.’

Indeed, Reuss was not alone. The Car

of Tomorrow (aka Generation 5) was an

ugly thing. This was the sentiment that was

almost universally held from the moment

NASCAR introduced it in 2007. It became

even more apparent when a new, better

looking version of the concept was rolled

out for the second tier Nationwide series

in 2010. It was clear that something would

have to change.

‘Once we got the Nationwide car

finished, everyone looked at it and realised

that we could build a better looking, more

representative Cup car,’ explains Howard

Comstock, manager of engineering for

Chrysler Group’s Street and Racing Technology

Motorsports division. ‘The Car of Tomorrow

was a huge technological advance. They

were a lot stronger, safer, and many things

about it were better. But it was not a good

looking racecar in any shape or form and,

quite frankly, it turned the fans off. We

needed to get the fans back on our side.

The proportions, in my opinion, were not

good, and were not representative of current

passenger car design. For example, I don’t

think the roof was anywhere close to being

racecar-like and the C-posts were splayed to

keep air off the spoiler, which hurt our ability

to move the tail forward.’

All of the manufacturers were unhappy

with the almost total lack of brand identity

on the Cup cars. Stockcars has always had at

Following a raft of well-received rulebook changes, NASCAR hope a new look and renewed relevance will make 2013’s Sprint Cup cars a huge hit both on and off the track

The sixth Generation


SPRINT CUP CARS

least a nod to the shape of the production

cars they emulate, but the introduction of

the CoT meant every car on the track was

essentially an identical shape beneath the

stickers. They also wanted to go further

than they did with the Nationwide car.‘

On the Nationwide car, from the middle of

the bumper upwards to the base of the

windshield is the area we were allowed

to put in brand identity. The rest of the

car is common, which is basically from the

windshield base rearward, including the

sides and tail, and then the lower nose,’ said

Bernie Marcus, Ford Racing’s aerodynamicist

who has worked on every NASCAR vehicle

since the 2004 Taurus. ‘We were able to

put on the upper nose with the grille,

headlights and then a hood bonnet. We went

away from true Stockcar racing and got

to a point where the cars we were racing in

Sprint Cup were very vanilla.’

It was something that irritated senior

figures within the manufacturers, and was

genuinely raising questions about future

participation. ‘My management was making

it very clear that our car had to have more

Dodge identity. It had to look like a Dodge

or they would be far less interested in

continuing with racing in the series,’ said

Comstock. ‘It was something echoed by

all of the manufacturers, and we all went

separately to NASCAR and said we need a

better looking Cup car. They quickly sent

that up the line and the management there

agreed wholeheartedly, so their technical

people and ours got together. As a result,

NASCAR made the pretty big decision to let

the four OEMs go a long way down the path

to see where we ended up.’

MANAGEMENT STRATEGYBut to achieve what the senior management

of ‘the big three’ and Toyota all wanted,

the technical departments of the four

manufacturers would all have to work together.

‘There was a group of four of us – one

from each manufacturer,’ continued Comstock.

‘We know each other and we see each other

every week. We wanted to start out by

correcting the errors on the car as it is

now. We thought the nose was too short,

so we lengthened it by three inches. The

tail was way too long, so we put an extra

six inches into the centre of the vehicle.

The car now has the short tail, longer hood

look that we think is representative of more

current passenger cars.’ Once the broad

parameters of the new design were set, the

manufacturers each went their own way

with the car design, developing their own

range of body panels and shapes.

‘NASCAR encouraged us to put a lot of

identity into the front of our cars without

limiting us to designated shapes. We moved

the base of the windshield ahead by five

inches, and made it look sleeker, longer and

lower, even though the centre roof height is

the same, and the car would have the same

chassis, the same track, the same wheelbase

and the same wheel and tyre combo.

‘The upper and lower fascia are unique to

each manufacturer, the tail is also different

for each make and – for the first time ever –

NASCAR has opened up the sides of the car

for us to put identity into the sides, as well as

adding wheel arch flares. So we can closely

emulate trends in performance car design.

Pretty much any production performance car

has flares. We all made a pact that we were

going to listen to the stylists first, then we

would dump the problem on the aero guys.

‘Fortunately, NASCAR wanted to keep

the downforce/drag balance and side force

close to the existing car. Not exactly the

same, but close. They wanted to give

enough latitude that the cars would be

different, and they thought we could shift

some of the balance if we needed.’

Once these sections were decided, the

stylists were essentially given free rein over

the look of the car, and each manufacturer

tackled it in their own way. For Ford, the

process behind developing the 2013 body

was significantly different to some of

the previous models, where race teams

such as Penske and Roush Racing actually

built, designed and did the majority of the

development on the Ford Taurus, prior to its

debut for the 1998 season.

‘We started by going back to our design

community and nosed around with guys that

have been with the company the longest.

We can’t remember the last time designers

were involved with helping NASCAR,’ said

Ford Racing NASCAR operations manager

Andy Slankard. ‘This time, we had the luxury

of support from the Ford Design Center to

give us these sleek shapes and new look.

Only designers could do that, not a bunch of

engineers or racecar guys.’

One of the people heading up the Design

Center part of the project is Garen Nicoghosian,

design manager for specialty vehicles. A

self-professed race fan, he embraced this

opportunity and called it one of the highlights of

his time so far at Ford. Some of the challenges

the design team faced centred around various

NASCAR rules, and common areas such as

Ford used its long proven production

car body styling process to get the look of

its Generation 6 car just right, including

making this full-scale mock up in clay

Ford conducted aero testing at full scale in

the AeroDyn wind tunnel in North Carolina

“The Car of Tomorrow was a huge technical advance, but it wasn’t a good looking racecar”


SPRINT CUP CARS

the greenhouse that all of the manufacturer

vehicles share. But there were other, more

obvious ones that had to be overcome.

‘There is a size difference between

the production and the racecar, and the

proportions are so different,’ explained

Nicoghosian. ‘The street Fusion is a front-

wheel drive, front engine car, and the racecar

is a front-engine, rear-wheel drive car with a

really long hood, and a much lower and wider

stance. The fundamentally different profiles

and proportions of the two vehicles, as well

as other constraints, presented a bigger

challenge than simply taking a Fusion and

putting NASCAR stickers on it.

‘The challenge was to design a racecar

with the look and feel of the production car.

To do this, you have to rely on design identity.

We paid close attention to the way we

shaped the details on the racer, such as the

headlights, grille and fog light openings, as

well as the body side sections, character lines

and overall surface language. When parked

side by side, the racer and the street car

“feel” the same, even though the two share

absolutely no common surfaces.’

‘We’ve really embraced the Design Center’s

philosophy and process of how they would

design a car for the street,’ explains Ford

Racing NASCAR programme manager Pat

DiMarco. ‘We started with some conceptual

drawings that our design team did, and

worked with the aerodynamicists to see

what was feasible and what was not.’ That

resulted in some 40 per cent clay models that

helped assess the car’s overall look and how

it would react aerodynamically in the wind

tunnel. Eventually, a full-size clay model was

constructed and reviewed.

Dodge, on the other hand, took a rather

more pragmatic approach to the car’s design:

‘We wanted to see a car go past and be able

to tell what it is just from the side,’ explains

Dodge Motorsports’ Dave Bailey. ‘We had a

lot of fun doing that, because we grafted the

body of a current production Charger on to a

CoT. It wasn’t all lined up properly or anything,

but that was the first concept we showed to

NASCAR. It was really a production car sat on a

racecar chassis, and we made a model of it and

showed it to Robin Pemberton, NASCAR’s vice

president for competition. I remember he liked

it and that meeting went well!’

FINAL DESIGNSOnce all the designs were ready from a

manufacturer perspective, they then had to

present the final designs to Pemberton and

his team at NASCAR R&D, who would then

work with all four designs to ensure a level

playing field, from an aerodynamic standpoint.

‘When we ran the car for the first time

in the tunnel, we were quite surprised that

we were within a reasonable range of what

NASCAR was looking for, and with only minor

corrections we were able to meet the balance

they required,’ said Comstock. ‘NASCAR put

aero targets on all four OEMs and, by June,

we had to hit targets for drag, horsepower,

downforce and side force.’

Unusually, for a competitive series with

multiple manufacturers, all four used the

same base car to do the official aerodynamic

tests, both at Dodge’s full-scale wind tunnel in

Detroit and at the similarly sized but specially

designed tunnel at AeroDyn in North Carolina.

‘NASCAR built a chassis with universal

body mounts, which they sent to us as a

CAD file,’ added Comstock. ‘What we have

done is make body panels. As the greenhouse

is common, they put that on and it was

fixed. Each of us then made a set of bits

and took them to the wind tunnel. We ran

Substantial amounts of aerodynamic work

was conducted using both scale models

and full-scale cars. Here we see the Dodge

under development at the ARC wind tunnel

“NASCAR encouraged us to put a lot of identity into the front of our cars without limiting us

to designated shapes”


a control body first, then each of

us ran our kit of bits on the car.

Once that was done, they took

the car out and scanned it for

each manufacturer.’

Part of the aerodynamic

programme was to develop the

car to work in the real world, but

also to ensure no manufacturer

was at an advantage.

‘We not only ran at inspection

height and attitudes, we ran

in the wind tunnel at real world

ride heights,’ said Comstock.

‘There are some universally

accepted numbers about what

the car runs at when it is on the

race track, and we put the car

at those heights and checked

the cars at the attitudes and yaw

angles you would experience

in reality. So now we have a

good idea on the aero.

‘We found that with a shorter

tail we needed to do a fair bit

of work on the greenhouse,

and we quit expelling air off the

side of the car so it didn’t get

to the spoiler. We now had to

encourage air to the spoiler so

we could keep the same amount

of rear downforce, as we don’t

want the cars to be aero loose

flat out at Talladega.’

OPEN BOOK DEVELOPMENTThe manufacturers had an open

book on each other’s aerodynamic

figures on the test car and – as you

would expect – there was some

discord about balancing the cars.

‘Some were draggier and some

had more downforce than others,

so NASCAR had to decide what

the targets were going to be.

Some people cried, some people

cheered. But it’s NASCAR’s game

and we have to play to their

rules. We were all smiling though,’

enthuses Comstock. ‘We found

that what we expected was really the case.

CFD is a hugely useful tool for production

car design and we kinda stole those guys in

Detroit to work on the racecar, so we had a

pretty good idea it would work. And it did.’

The arrival of the new bodies for the

2013 Daytona 500 will see most Cup teams

having to rethink the way they work. Instead

of the bodies being largely fabricated by

the teams from sheet metal, most of the

body will be supplied to the teams ready

to fit. The roof, bonnet, wings and sides

will be supplied as stamped steel parts,

while there will be a ‘new’ material for the

nose, tail and boot lid – something that

may surprise many when they see it

employed in NASCAR bodies – carbon fibre.

Or at least that’s the plan…

However, this does not mean that

North Carolina will suddenly be awash with

unemployed sheet metal workers. Indeed,

Comstock believes that there will actually

be more demand for them: ‘I think there will

be more fabricators on it,’ he

said. ‘Whatever anyone supplies,

the teams will always find

a way to make it better. We

will do what NASCAR asks –

supply the panels and the

teams will no doubt then try

to make them better.’

This ‘making it better’

can often stray beyond what

is strictly allowed in the

regulations, and new bodies,

new methods and new materials

will mean NASCAR’s technical

inspection process will also

have to change. ‘We all did our

final wind tunnel runs in June

and, once everyone passed,

NASCAR scanned all of the cars

and will use that as an electronic

record,’ added Comstock. ‘It’s all

so much easier in the electronic

age. They have every square

millimetre of our surfaces in

there. As a result of that, the

templating process will be very

different. There will be fewer

big, shaped aluminium claws

and more fibreglass moulded

plugs to fit over areas of the car

to keep the teams honest.

‘Scanning, too, is a

tremendously successful tool,

but we may not see it on

Friday inspection. Now though,

if you win a race, the car goes

back to the tech centre on

Monday for a detailed scan of

the body surfaces, and NASCAR

knows exactly what is required

of the cars and exactly what

the tolerances are!’

The new bodies will not

be limited to Sprint Cup for

long, and the new processes

being implemented will have

significant impact on lower

level classes such as ARCA

and Late Model Series. ‘I

think there is no end to how

much better we can make the cars look

in a whole range of series,’ said Comstock.

‘The one-piece fibreglass body on the

Dodge at the launch [at the Las Vegas Motor

Speedway] showed how easy it is now.

With the improvements in the way we can

make one-piece bodies, it seems to me

that a lot of the lower series could instantly

have better identities, so the ARCA guys

could just leapfrog over the CoT and go

direct to the Generation 6 car.’

SPRINT CUP CARS

Manufacturer identity can now be found all over the new bodies,

which is the key part of the Generation 6 concept

Another huge change is that – for the first time in years – manufacturers

are able to have different sides on their cars to one another


SPRINT CUP CARS

The 2013 cars made their debut at

Daytona for the Sprint Unlimited race in

mid-February with – perhaps fittingly – a

Chevrolet taking the flag. But the new cars

came too late for one manufacturer, Dodge,

which pulled out of the series at the end of

2012, despite having designed a Generation 6

car. Perhaps it will return, but the rumour mill

suggests that others from the Far East may

also be on the way thanks to the new cars.

TUNING THE CONCEPTEven once NASCAR had finalised the overall

bodies for the Generation 6 cars, there were

still plenty of small changes made, a process

that is still ongoing.

‘We knew where last year’s car was and

the input that we got about aerodynamics

and how cars act around each other. We

set out to make a car that works better

than that,’ explained Pemberton. ‘As a

result – and we have given the teams more

under the underbody to work with – we’ve

extended the splitters a little bit, so they

should react a little bit better in the draft.

Our goal was to start better than we left

the last models, and we do have better

numbers on the car. I think the drivers’

confidence that they can hustle these a

little bit more will be there once they get

their setups fine-tuned.

‘We have worked on where we get our

downforce, how we evacuate air from up

under the car if a team chooses to do so with

different ductwork, cooling hoses and so

forth. That’s all in an effort to make the cars

run a little bit better in groups or in packs.’

It seems to have worked. The debut race

at Daytona showed that the cars could run

in a pack as well as pass each other, though

the feedback from the drivers was somewhat

mixed. ‘The car drives well,’ mused Greg Biffle.

‘Maybe we will work on the aero package

… the car stalls out fast here, it’s got a lot

of drag.’ One thing that remains somewhat

unknown territory for the drivers is bump

drafting, as Sprint Unlimited winner Kevin

Harvick explained. ‘There is still a lot to be

learned with a full pack of cars,’ he said, ‘and

we’ll kind of ease into that with the Duels

and then on to the 500.’ The debut race and

some of the practice sessions saw a number

of crashes caused by drivers losing control

when in contact with other cars. ‘The front

bumpers have a very small contact patch

in as far as how you can push and how you

can’t,’ Harvick continued. ‘When things don’t

line up correctly, you see what happens.

You just have to be patient. It reminds me

of how we raced 10 or 11 years ago with

those types of cars and that type of package.’

“There’s no end to how much better we can make the cars look in a whole range of series”

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GENERATION 6 CAMBER

A fresh startGeneration 6 cars don’t just look different – rules on camber mean they’ll behave differently too

The changes to the

Sprint Cup car aren’t

limited to the new

bodies – there have

been many detail

changes to the car mechanically,

most important of which is a

decrease in weight allied to a

substantial change to the rules

governing allowable camber.

‘I had my list of everything

that I didn’t really like about the

Car of Tomorrow and things that

I wished we could change,’ says

Sprint Cup series director John

Darby. ‘Some of those changes

were not practical to do in the

middle of a run of a style of car

– it just creates too much chaos.

So when we started putting all

the parts and pieces together

for the Gen-6 car, it was time to

look at introducing a lot of those

things, and with the help of our

engineers at the tech centre –

and a lot of sessions, talks and

comparing notes – there’s so

many things that have changed

beyond the bodywork. We put

more toolbox drawers full of

tools back in the crew chiefs’

hands. There’s more things

for them to work with,

to adjust, to move

around, and to

experiment with.

‘Teams now have a whole list

of goodies now that everybody is

playing and experimenting with,

changing the mousetrap just a

little bit. But from leaving last

year’s car and working on this

new one, there’s enough that’s

different, and a lot of the changes

have all been pointing to making

life easier and more adjustable for

the guys in the garage as well as

enhancing the actual performance

of the car on the racetrack.’

The car weight is one of those

factors. While the Generation 6

cars retain the CoT or Generation

5 chassis, the minimum weight

has been reduced by 68kg and

new spindle designs have been

approved. Largely throwing out

much of the tyre and setup data

accumulated over the years

by the teams, this

becomes apparent when you

consider that the rule defining

camber limits has changed.

‘At Daytona, for example,

the front wheels look like

they’re pretty much straight

up-and-down, versus going to

Martinsville where the wheel

looks like it’s going to fall off.

That’s camber when you move

in and out,’ explains Darby. ‘It’s

a very adjustable component on

the front of all the cars and has

been for years. When the radial

tyre was introduced, the value

of camber on the rear axle also

started being experimented with.

‘Back in the 1990s, as teams

learned about camber, they

started to show up at Martinsville

with a whole bunch of rear

camber. Half a dozen cars dropped

out of the race with broken axles,

because the technology of doing

all that probably wasn’t

as researched and

refined as well as

it should

have been. So NASCAR put a rule

in that said you could only have

1.8 degrees of camber, which has

been in place right up until the

start of this season.

‘Today the materials are better,

the engineering is better, and your

ability to make all of that happen

without breaking parts is better.

So realising how much of the

tyre we weren’t really using, we

decided to change that rule. On

the Generation 6 car, the teams

are now allowed 3.5 degrees

of rear camber – you will see it

especially clearly on the right

rear.’ This change will put a lot of

stresses on the axle shaft as well

as the suppliers and teams trying

to get components designed and

approved by NASCAR in time for

the races on the paperclip.

‘The teams will be running

a lot of durability testing at the

moment,’ adds Darby. ‘They do that

in a lot of different ways. They can

simulate that type of loading and

rigs on a machine right at their

shop, but a lot of teams like to just

simply put the miles on the car to

get a really good picture of all of

that. If you watch the tyre with an

onboard camera, especially when

goes into a corner, it’s incredible

how much those tyres move when

they’re under load. Adding camber

to match the banking of the turns

helps stabilise that load and

stabilise that tyre, so the footprint

stays flatter on the racetrack.’

“In the 90s, teams showed up at Martinsville with a whole bunch of rear camber, and half a dozen cars dropped out with broken axles”

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SUSPENSIONS END FITTINGS


TECHNOLOGY BODYWORK

The introduction of the

Generation 6 cars to

NASCAR has meant

a reliance on the

expertise of the wind tunnel

specialists, and in particular

the AeroDyn facility in North

Carolina that was chosen by

NASCAR to make the final

verification for the bodies ahead

of their introduction at Daytona.

AeroDyn will this year

celebrate its 10th anniversary,

having accepted its first paying

client in April 2003. Since then,

it has seen business expand

rapidly in the first five years,

before the financial crash in 2008

that led to a gradual decline in

trade over the next two.

However, since 2010,

business has picked up once

again, and its reputation has

strengthened considerably.

In the company’s early years,

their main tunnel – which

offers a boundary layer control,

spinning wheels and an

automatic ride height

adjustment that is accurate

to the third decimal percentile –

was in use 24 hours a day,

five days a week, plus extra

time on Saturday. They’re

now running 18 hours a day, five

days a week, which is –

says general manager Steve

Dickert – a more comfortable

position to be in, allowing

engineers time to maintain the

facility between sessions.

‘AeroDyn was the first

wind tunnel in the United

States designed specifically

for NASCAR race series,’ says

Dickert. ‘Of late, we have been

able to offer some testing

capability to OEM manufacturers

that they don’t get in their

own wind tunnel – very

controlled and accurate boundary

layer system, and automated

ride height control system

that is accurate to the third

decimal place. Those are

functionalities that wind tunnels

at GM, Ford and Chrysler don’t

have, all at the same time.’

The move to the new cars,

coupled with the official sanction

from NASCAR, has meant that

the tunnel is busy enough, and

the work is becoming more

complicated. Teams have to start

from scratch with their aero

figures as there is no baseline

from which to work with the

Gen-6 cars. It has been six years

since the last big rule change to

stockcar racing, and the engineers

are, from an aerodynamic point of

view, pretty much starting afresh.

‘The cup teams are

extremely sensitive to security,’

adds Dickert, ‘so we can’t have us

be a conduit for one cup team’s

advantage to another cup team’s

advantage. We provide and

operate a precision laboratory

that meets or exceeds the needs

of our customers.’

The Gen-6 cars have

required much the same

aerodynamic development

as previous generations, but

have to immediately be on the

pace in a closely contested

environment. Much as Formula

1 is looking ahead to the

rule changes in 2014 with

apprehension after one of its

closest seasons ever in 2012,

the pressure is on for the

NASCAR teams to get it right

first time out in 2013.

‘It is interesting that the

level of teamwork between

NASCAR and manufacturers

is unprecedented with the

development of the new cars,’

Setting the standardBased in the heart of NASCAR country, the AeroDyn wind tunnel in Mooresville, North Carolina has been picked out to validate the figures for the new Generation 6 cars

“The level of teamwork between NASCAR and manufacturers is

unprecented with the new cars”

The 2013 Lowe’s Chevrolet SS

during wind tunnel testing


TECHNOLOGY BODYWORK

says Dickert. ‘The development

has always been driven by

NASCAR, but this time it really is

a team effort.’

The AeroDyn tunnel is built to

accommodate full-scale cars

only, with speeds up to 130mph.

The loads from 130-200mph

are linear with dynamic pressure.

‘With scale model testing,

there is a significant Reynolds

number mismatch – for example

a half-scale model must be

tested at twice the full-scale

speed. By using the full-scale

car you can appreciate the

deflections,’ says aerodynamic

consultant Gary Romberg.

‘We think that gives a better

simulation to what you get on

the track. Our normal testing

is 130mph, but we can run

other speeds below that, and

even a few speeds above it.

The general speed is 130mph,

which is almost 40lbs/sqft in

kinetic energy.’

Also on site is the second

wind tunnel – A2. This tunnel is

a smaller, economical solution for

customer teams that are involved

in everything, from land speed

record attempts to road racing, and

karting. Available at $490/hour,

the company also offers

aerodynamic expertise through

its own dedicated staff says David

Salazar, general manager of A2.

‘It is a smaller tunnel, of

the same design as AeroDyn

with an 85mph maximum wind

speed. It does not have spinning

wheels, active boundary layer

control or ride height control,’ says

Salazar. ‘What is does

have is a greatly reduced rate,

so that smaller teams and

privateers – and by privateers I

mean people who are attempting

land speed records on salt flats,

they come there quite regularly.

They can get large gross aero

advantages for very little money

in a very controlled laboratory.’

This can be essential to them,

and, for a series were the winner

gets a hat or a T-shirt, not prize

money, this proves to be a great

tool when on that kind of out

of pocket budget.

Most of A2’s customers come in

as first time users and have never

set foot inside a wind tunnel. As

such, Aerodyn offers assistance

for these teams to help point

them in the right direction and

teach them how to understand the

wind tunnel data. This assistance

is valuable because most people

are intimidated by testing in a

wind tunnel for the first time and

don’t normally know where to

begin. Along with this help is the

understanding that AeroDyn do

not develop the cars or tell them

what other customers are doing

with their aero programmes. As

many low budget teams don’t have

an engineer, the firm can offer

some assistance in guiding

them along until they better

understand the process.

DEVELOPMENT PROGRAMMESince opening for business in

April 2003, AeroDyn believes

that it has tested more racecars

than any other independent wind

tunnel in the world. It has tripled

the amount of data customers

collect in a single test session,

improved repeatability from

1 per cent to 0.8 per cent, and

decreased fault-related down

time by a factor of six.

In the period since 2006,

AeroDyn has added the following

upgrades to the facility:

Ride Height System

Installed in November 2006,

the new system is completely

computer operated. To increase

testing efficiency, teams provide

a complete map of heights they

would like to run for a given

The management team at the AeroDyn facilty do not consider the rise of Computational Flow Dynamics (CFD) to be a

threat to its wind tunnel business, having investigated with teams and manufacturers the viability of providing in-house expertise. Most of the teams and manufacturers have their own capabilities, and even the smaller NASCAR teams on the grid have access to such data.

‘Nasa has said that CFD and wind tunnels are not at odds,’ says aerodynamic consultant Gary Romberg. ‘They are complementary.’

A last generation car on the move in the main AeroDyn tunnel

Having developed a strong reputation within NASCAR, AeroDyn is now looking to expand beyond the confines of stockcar

racing, and has started working with teams in Indycar, Grand-Am, and the American Le Mans Series, already with promising results.

‘We’ve had some data with an Indycar team which correlates very closely with what was achieved on the track,’ says general manager Steve Dickert. Although European tunnels are looking more to alternatives to motorsport, AeroDyn is looking more at OEMs. ‘Manufacturers do have their own tunnels, but most of them don’t have the capabilities of the rotating wheels, extensive boundary layers, and precise ride height settings, so we think this is the area we can expand into,’ says Dickert.

There are no plans to build a third tunnel, however.

“With NASCAR’s new cars, the rules are so tight that teams look

for microscopic changes”

www.racecar-engineering.com • June 2008S10

STOCK CAR TECHNOLOGY AERODYNAMICS

Tomorrow. ‘Now we are limited to about two inches of front shock travel – before we had four, so with the CoT we lost half our available room to work.’

But there is still variation, as Grubb explains: ‘There is not really a different body for every track but they will do different components that augment the stock shape. Say if you go to Martinsville you’ll have to have a lot more cooling because of the demands of the brakes. There will be more NACA ducts, more open areas to keep the tyres cool – things like that that you won’t see at a big track where there is more airfl ow to think about.’THE RISE OF CFDFormula 1 teams are

pretty much reliant on Computational Fluid Dynamics (CFD) for aero development, and increasingly, top NASCAR teams are turning to this technology to develop the CoT.

‘It is the next big step, using wind tunnels and building models is expensive,’ explains Romberg. ‘The next

big thing over here is more thorough use of CFD, but we have a different set of parameters to work to than the F1 guys.’

Alan Gustafson elaborates a little more. ‘It is something we are getting into. As technology standardises it fi lters down. We are still doing a lot of development work with it, a lot of correlation work and Pratt & Miller are helping us with that.’

While no NASCAR team is yet close to the stage where Formula 1 is today with world class super-computers in house, it looks like that is the direction the wind is blowing. It will certainly not be a great shock when a big team announces the acquisition of a powerful system.

LOWER LEVEL AERO

Some of the advanced aero technology is starting to fi lter down to the lower levels, as Gustafson explains: ‘Last year I ran the number fi ve car in the Busch series and we had a lot of aero support from the top guys. There is a lot you can do still with those cars, but as you move down the ladder there is a lot less understanding of what is going on. Some of the smaller guys will look at what we are doing on the cars and will try to mimic that as best they can.’

Kurt Romberg has the following advice for smaller teams using the old-style cars in Late Models.

‘Everything we did to the old cars in Cup you can do to those cars,’ he explains. ‘Offset the cars, offset the noses, offset the tails, work everything you can to get the roof down and get more air to the spoiler, use your suspension guys as much as you can because nose down-tail up is a great way to make downforce, plant the nose, raise the tail – it’s about the best thing you can get.’

While Windshear, AeroDyn and Audi may be out of the price range of smaller teams, facilities like the new A2 tunnel in Mooresville are aimed

squarely at them. Aerodyn’s little brother is situated next to the main tunnel and is aimed at a lower level

market. While also full-scale, ‘A2’ runs at a slower speed than the main tunnel and is not as advanced but can still give teams valuable data.

Opened: 2006Scale: 100%Type: Closed Jet with adaptable ceiling Rolling Road: NoneMax Airspeed: 85mph

While Windshear, AeroDyn

squarely at them. Aerodyn’s little brother is situated next to the main tunnel and is aimed at a lower level

market. While also full-scale,

A2The new ‘baby’ tunnel at Aerodyn is not as advanced as the main tunnel and wheels are not rotated

explains Romberg. ‘The next

VIRTUAL WIND TUNNELSIncreasingly, CFD is used by teams – here the COY is compared to the CoT in a GM ‘gaffer dazzler’

S6_RE18N6_Aero.shs.indd 10 22/4/08 13:46:43

Wheels are not rotated in A2, the smaller alternative to the main tunnel

CFD CAPABILITIES

EXPANSION PROGRAMME


TECHNOLOGY BODYWORK

AERODYNAlso known as ‘Eaker’s place’, AeroDyn was built expressly for the purpose of testing stockcars, and its Mooresville, North Carolina location means that many teams frequent it primarily for the cataloguing of cars. ‘We built the walls for stockcars, not for everything from Formula 1 to karts and everything in-between,’ explains the tunnel’s creator Gary Eaker. ‘We originally defined that we deal with stockcars and trucks only – we lock these walls and leave them where they are at.’Opened: 2003Scale: 100 per centType: Closed Jet with slotted wallsRolling Road: None, wheels spun on rollersMax airspeed: 130mph (147mph possible with recalibration)

A2 TunnelOpened: 2006Scale: 100 per centType: Closed Jet with adaptable ceilingRolling Road: NoneMax Airspeed: 85mph

ARCThe most popular scale tunnel

for NASCAR teams is surprisingly not in North Carolina. In fact it is some distance away in Indianapolis. Auto Research Centre (ARC) not only provides its 50 per cent scale tunnel for use, but also makes many of the models used by teams, often in collaboration with C&R Racing.Scale: 50 per centType: Open JetRolling Road: Belt

WINDSHEARWindshear (see also left) is a very large three-quarter open jet rolling roadtunnel situated on the edge of Concord Airport in North Carolina.

The facility is capable of running at speeds of up to 180mph, and is climatically controlled. Emphasis has been placed on the full-scale tunnel being used by NASCAR teams though IRL and Formula 1 teams have also used the tunnel. Reliability and repeatability are the focus of the technical team behind the facility.Opened: 2008Scale: 100 per centType: ¾ Open JetRolling Road: Steel beltMax airspeed: 180mph

test. The height tables are

imported into AeroDyn’s system.

This has dramatically increased

the efficiency of ride height

studies, as well as controlling

heights within 0.001-inch.

Automated Yaw System

This system, added in January

2008, is completely computer

operated and uses the latest

in measurement technology

to assure accuracy and

repeatability. Standard yaw

increments are pre-programmed,

based on the customer test

schedule. Additional yaw

increments can be input with

resolution to 0.1 degrees. The

accuracy and speed of establishing

each yaw setting has increased

testing productivity significantly.

New Test Section Floor

Based on the introduction of

the Car of Tomorrow, the test

section floor was redesigned

in June 2008 to increase the

performance of the floor

boundary layer control. The

splitter and front end under-body

is an extremely sensitive area on

the car. As such, the boundary

layer system was significantly

improved and offers a very good

simulation. The total power in

the boundary system is now four

times what it used to be.

Active Boundary Layer control This system, added to the

facility in January 2010, is

completely computer controlled.

By changing the boundary layer

control from a ‘passive’ speed

setting to an ‘active’ pressure

setting, the system very

accurately matches the boundary

layer conditions to actual free-

stream dynamic pressure in

order to maintain a constant

Cp ratio. As a result, the overall

tunnel sensitivity is extremely

high and the smallest, most

subtle changes to a test model

can be measured.

HD Camera System

Incorporated in February 2010,

this is a completely new system

and again is 100 per cent

computer controlled. Most

tunnels simply provide viewing

of the test model through a

window, and often only one

side view of the model is

available. AeroDyn’s customers

have the ability now to view

the model in real-time, in HD

(1080p) resolution, and eight

different camera angles.

This system is valuable for

studying panel deflections,

flow vis, and model integrity

during a test. The data

collection system is programmed

to automatically capture a

snapshot of all eight camera

angles at the beginning and of

each data point.

Additionally, the customer

has the ability to record video

in 1080p of any camera angle.

The video is then downloaded

to an external hard drive for the

customer at the end of the test.

Increase Yaw Sweep

The original yaw system was

+3 to -3 degrees. With the

advent of the new car design, it

became necessary to gather

data to -5 degrees. This

upgrade, added in November

2010, required significant

modifications to the tunnel

floor, balance, actuation system

and data collection.

The test section floor was redesigned in 2008 to increase the

performance of the floor boundary layer control

Windshear was formed in 2006 to provide full-scale rolling road wind tunnel access to North American and international teams. Their facility opened in September, 2008, the first facility of its kind in North America, and the third rolling road wind tunnel that operates on this scale. It was also the first full-width rolling road that supports full scale vehicle testing.

The project was funded by Haas Automation, the company that owns Windshear. Facility design and construction were overseen by Jacobs Technology, whose engineers manage the day-to-day operation of the tunnel.

The air in this closed-circuit wind tunnel covers and area of 160,000 square feet, its main fan is 22 feet in diameter and rated at 5,100 horsepower, capable of producing air speeds of up to 180mph. Air temperature is tightly controlled to within 1degF.

The MTS Flat-Trac Rolling Road measures 10.5 feet wide by 29.5 feet long. It easily keeps pace with the wind, accelerating from zero to 180mph in less than a minute. This ‘road’ is actually a continuous stainless-steel belt just one millimetre thick. During testing, the through-the-belt sensors precisely measure the aerodynamic downforce under each tyre.

The facility’s 40-hour weekly operating schedule is filled with NASCAR and Indycar racing teams from all over North America. Teams from Europe and Asia are also bringing their wind tunnel testing to Windshear.

THE OPPOSITION NASCAR WIND TUNNELS


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lubrication partners – in

NASCAR the situation is

no different. Back in 2011,

NASCAR felt that speeds in Sprint

Cup races on super speedways

had gone too high, with the

so-called two-car tango drafting

style. So it decided to make some

changes to the car to prevent it.

The cooling duct on the nose was

shrunk in such a way that if drivers

attempted this style, the trailing

car would lose all of its cooling.

‘NASCAR must have forgotten

that we are racers, and we will

continue to try to find ways to go

faster,’ said Lake Speed, a certified

lubrication specialist at Joe Gibbs

Racing who was tasked with

finding away around this problem.

In the two-car tango, only

the trailing car ran a high

temperature, and the leading

car ran as normal. But in a Sprint

Cup race, any car could be leader

or trailer, meaning that the oil

had to be able to cope with both

types of running conditions.

‘It was common to see oil

temperatures above 135degC

during the race,’ said Speed.

‘Previously, 105degC was normal

and 115degC was cause for alarm.

Of course, the “cold” temperatures

of 105degC allowed us to use

very thin oils – 0W-10. Now, with

temperatures reaching 140degC or

more, we increased the viscosity

of the oil to 0W-20. That was a

step in the right direction, but

pack racing led to sustained high

temperatures. We could have gone

to a much heavier oil – that would

have raised oil pressure. However,

these actually generate more oil

temperature, so we did not want

to do something that contributed

to higher temperatures.

‘Chevron Phillips has recently

pioneered synthetic base oils that

provides greater thermal stability.

Developed for wind turbine

gearboxes, these new synthetic

base oils provide a much higher

viscosity Index. The higher this is,

the less the oil thins out at higher

temperatures. Using these new

oils, we created a new 0W-10 oil

that would not thin out too much

at high temperature.’

The experience and expertise

these teams are gathering has

started to filter down to other

parts of the sport. The Joe Gibbs

products, for example, are made

available to rival teams as well

as smaller outfits as part of the

‘driven’ range of products.

How lube specialists came up with an oil-based solution to the two-car tango problem

The high temperature high shear (HTHS) viscosity of an engine oil is a critical property related to engine durability and fuel economy. It is essential to have a ‘thick’ enough HTHS viscosity to maintain a protective oil film between moving parts, but you also want the right balance of protection and ease of movement. The oil has to be thick enough to maintain separation of the critical moving parts, but thin enough to allow for fuel efficient operation.

New fuel economy regulations implemented by the US Environmental Protection Agency (EPA) seek to improve fuel economy in the years ahead. In Europe, the reduction of greenhouse gases through improved fuel economy marches forward, and lowering HTHS enables these fuel economy targets to be met, but lower HTHS requires careful balancing. Lower HTHS viscosity tends to improve fuel economy, but higher HTHS viscosity affords better wear protection. The right balance

must be struck between durability and fuel economy, and this must be maintained throughout the oil life.

SAE International recently approved the new ‘16’ viscosity grade that will allow car companies to specify lower HTHS oils such as 0W-16 and 5W-16. These new oils will be offered for specifically designed engines. Engine manufacturers are currently evaluating older engines to see if engine durability is an issue with low HTHS viscosity oils. If durability does prove to be an issue, manufacturers may have to redesign their engines to take advantage of the potential fuel savings. No engine tests in the current diesel engine oil category, API CJ-4, address adhesive wear, which often occurs during running-in, and the use of low HTHS oils could lead to excessive premature wear if misapplied, especially during running-in.

This is of particular interest to performance auto enthusiasts, as many use diesel engine oils for running-in and use low viscosity road car oils in their racecars. As fuel economy regulations continue to force change in motor oil formulations, auto enthusiasts need to be aware of the possible consequences of these changes on their high performance or vintage engine, especially in regards to bearing life

New mPAO synthetic base oils are now available that improve HTHS performance. The new mPAO base oil used by leading companies in its synthetic oils boosts HTHS while maintaining viscosity grade.

THE HTHS BALANCING ACT


STOCKCAR PRODUCTS

A modern alternative to the Ford Type E transmission from Quaife

Replacing the Rocket

For many years the

venerable Ford Type E

‘Rocket’ transmission

has been standard

equipment on

European circle track cars such

as NHRPA National Hot Rods.

The four-speed single rail

gearbox, was fitted to many

European Ford sedans such

as the Mk2 Escort and Sierra

models, and for years examples

were abundant. But things have

changed and one family-run

English engineering firm has

decided to bring the European

oval track market up-to-date.

‘The original Rocket is 40-50

years old, so parts supply is

limited,’ explains Michael Quaife,

director of RT Quaife Engineering.

‘But it’s a very successful

transmission and it will never

die, so there’s a large demand for

different ratios to suit different

forms of motorsport. But the

problem is that ratio availability

is limited and users are fed up

with having to carry alternative

crown wheel and pinion ratios.

This is why we’ve designed

QBM1M, to provide a modern

alternative, which offers a wide

range of gearing options with

its drop gear system and all-new

gear-change mechanism.’

Quaife used its in-house CAD

and analysis capability to design

the new transmission in such a

way that the required versatility

was included, while the shape of

the new box allowed it to be a

straight swap for the Rocket. ‘Oval

racing is the reason the design of

QBM1M evolved as it has,’ says

Quaife. ‘Firstly, it’s four-speed, it’s

as light as the standard Rocket box,

it uses the same stud pattern, plus

it’ll take roughly the same level of

overall power as the original. But

it’s much, much more compact and

users can position the gearbox and

gear lever where they want to in

the car, whereas with the original

Rocket you’re limited because of

the long tailcase.’

Despite its versatility, Quaife

expects that it will take some

time for the new transmission

to gain in popularity in the UK

circle track market, but it will

likely find applications in other

areas. ‘I think it will take some

time to penetrate the market,

and I’m not looking to flood the

market anyway,’ says Quaife.

‘There would be no difference to

the design if it was to be used on

road courses. There is such a large

selection of drop gears that you

can simply drop the propshaft,

change the drop gears and you’ve

altered the overall gearing. It’s

easy to change between ratios

that would suit Lydden Hill or

Spa,’ he explains.

The transmission could find

markets further afield and will

be available for sale in the first

quarter of 2013. ‘We’re looking at

it costing around $5,000 excluding

taxes,’ says Quaife. ‘It will be on

sale worldwide – there is still quite

a lot of demand in United States

for Rocket transmission parts.’


STOCKCAR PRODUCTS

In 2013, some NASCAR

Sprint Cup teams will

be using a technology

developed by the British

atomic energy industry

which was originally designed to

be used in Formula 1. ‘Zircotec

is constantly asked by our

automotive customer base for

lighter solutions to protect

against heat problems,’ says

Terry Graham, the company’s

managing director.

Zircotec’s ceramic coatings

are renowned in European

motorsport. Supplying 11 of

the 12 Formula 1 teams last

year, and half the BTCC grid, its

products are trusted to manage

heat effectively. The firm’s

ceramic thermal barrier coatings

offer surface temperature

reductions of over 125degC, and

is almost universally used on F1

cars in areas such as airboxes and

brake ducts. However, in some

specific applications the teams

were using ‘gold’ in addition to

reflect heat away. ‘Engineers

would sometimes attempt to

apply “gold” over our coating,

but it was time-consuming,

expensive to use, and required

complex adhesives,’ added

Graham. He smiles when saying

‘gold’, as analysis discovered that

several were in fact copper. ‘While

there are already a significant

number of “gold” heat reflective

products on the market, these

are generally not real gold.

They offer no real performance

benefit, but to the untrained eye

they can appear similar to gold,’

claims Graham. ‘Gold leaf is very

difficult to handle and apply,

while metal foil (normally copper)

that has been electroplated with

gold is too rigid, also carries a

weight penalty and deteriorates

quickly at high temperature

due to oxidation of the copper

substrate.’ But Graham’s firm

had to react to the demand

of the teams, especially as

temperature control will increase

in importance substantially with

the introduction of Formula

1’s new powertrains in 2014.

Its solution, the ZircoFlex Gold

heatshield, is just 0.17mm thin

and at 225g/m² is half the weight

of the current ZircoFlex product.

Combining superlight weight

with its ability to be cut and

folded, it’s attractive for weight

sensitive or package restricted

applications. Supplied as a flat

sheet, it can be used to protect

ancillaries such as batteries as

well as bulkheads, composite

parts and fuel tanks and crucially

is something the teams can

carry and apply as necessary

‘in the field’. ‘We expected after

Autosport Show that F1 would

be the key market for this, but in

fact we have received significant

orders for ZircoFlex Gold from

NASCAR teams,’ says Graham.

A versatile, superlight new coating that offers real gold and real benefits

Canned heat

“Gold heat reflective products are generally not real gold, and carry a weight penalty”

The new ZircoFlex Gold is half the weight of the previous ZircoFlex product


STOCKCAR PRODUCTS

In a world where everything

is defined by speed,

the motto is simply ‘be

faster’. Stockcar racing

is a sport where fractions

of inches can separate the

winners from the losers.

More and more this world

is looking for innovative

technologies, and one area many

teams has started to investigate

is 3D printing, especially

additive manufacturing.

In addition, the teams require

functional parts to be available

with very short lead times, so

the materials used in the

printing process have to have

the right mechanical properties.

This has led some in the cup

garage to look beyond the the

shores of the USA to the world

of Formula 1, where the practice

is more commonplace. Leading

the market there are the

Windform family of materials

developed by CRP Technology, an

Italian-based company.

The additive manufacturing

procedures used by the firm

allow a finished and fully

functional mock-ups to be

obtained in a short amount of

time. This is especially important

in aerodynamic programmes,

where teams work between the

templates to find that extra edge.

The Windform materials have

been specifically developed for

motorsports applications, can

withstand high temperatures

and have material properties

previously unheard of for

selective laser sintered (SLS)

materials. It has opened up a new

world of possibilities for the top

designers in NASCAR. Functional

parts and small volume

production runs are possible in a

few days, instead of the weeks

that they would have taken in

the past. Driver compartment

accessories, custom ducting and

packaging optimisation are just

a few areas where engineers are

designing custom solutions using

SLS material technology for on-

track production parts.

Scale model and rolling road

wind tunnel programmes are as

common and available in NASCAR

today as they are in F1. Anywhere

there is a high demand for rapid

development cycles of highly

complex geometries, programmes

can benefit from CRP’s additive

manufacturing knowledge and

F1-derived experience.

Indeed the demand has

been such that the Italian

firm has set up its own North

American subsidary CRP USA

based of course in Mooresville,

NC. It has already completed

many projects for Cup teams

such as Earnhardt-Childress

Racing for the manufacturing of

an alternator shroud.

Alternators are one of the

most problem-prone parts on

NASCAR race engines. The

combination of high under-hood

temperatures (up to 350degF),

high vibration (up to 600g), and

high electrical current demand (up

to 140A) present unprecedented

design challenges. Initial attempts

at implementing a duct involved

fitting a secondary rear cover to

the alternator with an integral

hose attachment. Packaging was

tight and cooling efficiency of the

cover was sacrificed by retaining

the original OEM rear cover.

ECR designed a replacement rear

cover for a standard NASCAR-spec

Bosch alternator that fitted well

and provided maximum cooling

The irrepressible rise of additive manufacturing to create functional parts, fast

3D printing and new materials, the secret of stockcar racing

ECR designed a replacement rear cover for a standard NASCAR-spec Bosch alternator using 3D printing


STOCKCAR PRODUCTS

3D printing is enabling firms to prepare and release

prototypes for testing at a much faster rate

efficiency. Once this potential

solution was found, the next step

was one of how to manufacture

the parts needed using a

reliable material in a short lead

time. Traditional machining and

moulding offer reliable materials,

but once the cost of tooling is

included and the time penalty

incurred, neither approach was

really adequate. 3D printing was

really the only way forward.

Windform LX 2.0 was chosen

as the material to use, as it has

the right strength and thermal

resistance properties. This

improved version of the material,

has increased performance in

both mechanical and thermal

properties. It is non-conductive,

and in the case of the alternator

cover, it is critical that the

material does not interfere

with the electrical operation

of the device. Six alternator

cooling covers were produced

in a very short time, much to

the satisfaction of ECR Engine

technical director Dr Andrew

Randolph: ‘The Windform

alternator covers from CRP fit

perfectly from the onset and

we have not a single alternator

failure since instituting them on

all ECR’s NASCAR Cup engines.’

Many other applications

have been carried out with 3D

printing and Windform materials

in NASCAR, though most are

still confidential. One though has

seen two companies relatively

new to stockcar racing work

together to create a new product.

CRP USA have designed and built

a part for DC Electronics, one of

the leading manufacturers of

custom-built electrical systems

which has its North American

office sited next door to CRP

USA. DCE made its entrance into

stockcar racing by producing

wiring harnesses for the Sprint

Cup Fuel Injection systems. The

company is also expanding its

product range and required an

enclosure for a new electronic

circuit it had designed. Several

iterations of enclosures were

developed with a final version

produced in Windform LX 2.0. In

comparing the cost and weight,

the Windform enclosure came out

on top compared to the traditional

carbon fibre mould and layup that

DCE would normally use.

‘As we went through the

design process, it was evident

that the enclosure size and shape

would continue to evolve until

testing was complete,’ enthuses

David Cunliffe, founder of DCE

Electronics. ‘By using 3D printing

from CRP, we managed to greatly

reduce the cost and cut the lead

time dramatically, allowing us to

release the prototypes for testing

at a much faster rate.’ While this

part is pending approval for racing,

the enclosures have performed

extremely well in all testing, and

will be ready at a moment’s notice

for full production.

Thanks to 3D printing and

the performance of Windform

materials, the time from concept

to production has been reduced

from weeks to a matter of days,

enabling the NASCAR teams to

find the right solution, in a near

instant timescale.

“The Windform enclosure came out on top compared to the

traditional carbon fibre mould”


STOCKCAR PRODUCTS

When tablet

computing first

appeared, few

thought that

it would have

a role in the motorsport world

beyond sending a few emails

from the hauler and reading

publications like this one. With

Apple leading the market for

these devices with its iPad, it did

not seem plausible that teams

would find real-world applications

for them beyond using them as

a tray to carry coffee back to

the hauler on. Very few serious

engineering software packages

are able to run on the OSX

operating system, but when

tablets running Windows came

on the market, everything

changed – and some big players

started to get involved.

Just ahead of the 2013

Daytona 500 Toyota announced

that it had been working

with Microsoft to develop a

touchscreen app for Windows 8-

equipped tablets. Unlike many

of the apps announced for

motorsport applications, this

one has a real-world purpose,

and forms the centrepiece of

a new strategy to improve the

performance of the Toyota

teams competing in NASCAR.

When drivers, crew chiefs and

team engineers expressed

the need for a more mobile

computing platform to monitor

real-time performance data,

TRD (Toyota’s North American

motorsport subsidiary) developed

the app and named it Trackside.

During practice, drivers

and crew chiefs previously

had to record racing performance

data with software on a

laptop, or even with pencil

and paper, requiring drivers

to get out of their racecars

to view information about

the car’s performance, as well

as to explain what was

happening on the track.

With the new app, race teams

can capture performance data

and share it with the crew in

real-time, enabling mechanics

to immediately get to work

fine-tuning the car. It also offers

real time data that gives the

crew chief and driver insight and

analysis on timing and scoring

data versus competitors, allowing

a team to determine if the right

adjustments have been made to

the car, or what adjustments may

need to be made.

‘Trackside running on Surface

Pro means more time is spent on

the track and less time is spent

talking, said Steve Wickham,

TRD’s vice president of chassis

operations. ‘Teams are back on

the track faster, allowing them

more time to determine the

optimum setup for the racecar.’

When it came to choosing

a device, TRD wanted a high-

performance, lightweight, touch-

enabled computer to complement

the fast-paced environment at

the race track. Several tablets

were tested during the pilot

phase, but the Surface Pro was

ultimately chosen because

it delivered the power and

performance of a laptop PC in a

tablet package, as well as being

able to withstand the harsh

environment of the garage.

Far removed from web surfing, email and Angry Birds, tablet technology is becoming increasingly invaluable in motorsport through applications such as TRD’s Trackside

Software upgrade

Complex data is compiled quickly, giving the crew chief and driver insight and analysis on timing and scoring data

With Trackside, race teams can capture performance data and share it with the crew in real-time


TECHNOLOGY CONSULTANT

We don’t know for sure if this

Dirt-style Modified is behaving

like this on its own, or if the driver

is ‘driving a tight car loose’

T he image below

shows a Dirt-style

Modified, cornering in

a powerslide, with the

left front wheel high in the air,

a large roll angle, and the rear

wheels visibly aimed to the right.

I can tell that the car had

maintained the attitude for

some time when the picture was

taken – the left front wheel has

stopped turning.

To address one part of what’s

happening dynamically, the right

rear tyre is probably the most

heavily loaded on the car, but it

is not more heavily loaded than

it would be if the car were set up

to corner on four wheels. On the

contrary, it’s as lightly loaded as

it can be, at that lateral force. The

left rear is as heavily loaded as it

can be on that car, at that lateral

force. The front load transfer is

100 per cent, and the rear load

transfer is whatever remainder

is needed to keep the car

from tipping over, which is the

smallest value it can have.

This means the rear tyres are

as equally loaded as possible

under those conditions, and

consequently the car should be

tight. The exaggerated rear steer

is needed to counter this effect.

Really, we can’t tell from the

picture whether the car is tight

or not. It’s in a state of obvious

oversteer. The rear slip angles are

greater than the front, even after

allowing for the roll oversteer.

Without talking to the driver we

don’t know if the car does this on

its own, or if the driver is ‘driving

a tight car loose’. Many times

I’ve seen vehicles on dirt tracks

corner outrageously sideways,

more so than their competition,

and had the drivers tell me their

vehicles had a push. What’s

happening in such cases is that

the driver is pitching the car on

entry, and then horsing the tail

out with the throttle, simply

because if driven any other way

the car won’t rotate at all.

LATE ARRIVALThe car is exhibiting a design and

setup strategy that first became

popular in dirt Late Models, and

has since become fairly common

in the lower-cost IMCA-style

Modifieds as well. Part of the

strategy has even been in the

news lately in relation to upper-

division Nascar pavement cars.

There are basically two

elements to the strategy. The

first is to aim the rear wheels

out of the turn, either statically

or dynamically, or both. Doing

this statically is what has been

recently tried on Cup cars, and

has now been limited by Nascar

in a mid-season rule change. The

second element, mainly on dirt

cars, is to make the car ‘hike’.

That is, make the left rear jack

dramatically, typically in response

to both lateral and longitudinal

force. The rear suspension is set

up with large amounts of thrust

anti-squat, especially on the

left, and with a beam axle this

concomitantly produces a lot of

roll oversteer. Most commonly

there are two trailing links per

side, attached to the axle with

rotating brackets called birdcages.

The links are not extremely long.

The axle ends move in a path

that is both sloped and curved.

The wheels move rearward,

at a decreasing rate, as the

suspension compresses, and they

move forward at an increasing

rate as it extends.

Typically, there is also a short,

steeply raked Panhard bar on the

left side of the car, which jacks

the left rear up in response to

lateral force. The result is that

even on a dry slick track, the

car will jack the left rear up so

much that the left front tyre will

come off the ground. This would

normally make the car push like

Mark Ortiz Automotive is a

chassis consultancy service

primarily serving oval track and

road racers. Here Mark answers

your chassis setup and handling

queries. If you have a question

for him, get in touch.

E: markortizauto

@windstream.net

T: +1 704-933-8876

A: Mark Ortiz,

155 Wankel Drive, Kannapolis

NC 28083-8200, USA

Rear steer and hiking Deciphering unusual behaviour on a Dirt-style Modified

Q Below is a photo of a northeastern modified in a turn at Fonda speedway in NY by my son. He has chosen artistic

expression with a camera as his life’s passion over his father’s preoccupation with physics and chassis dynamics in particular and racecar engineering in general. Most days I think he is the smart one.

Could you please look at the image and give me an assessment as to what’s occurring

dynamically with this car at this instant in time? I will withhold my thinking at this time as to not muddy up the water.

The only bit I’ll add is that this chassis attitude, on this car, in this location of the track is the same almost every week and it carries this mode over a considerable distance along the corner – ie this is not a quick snapshot of the phenomenon; the car maintains this attitude over a certain length of time.


TECHNOLOGY CONSULTANT

October 2008 • www.racecar-engineering.com/stockcar SE7

down to what is the most economical design we can achieve for anything from the local short tracks to the Sports Car Club of America to drag racers and just about anybody else in between.’

Using an abstract from the overall experience at AeroDyn, where the air blows at between 125 and 130mph, the new, smaller tunnel was built with an NHRA Funny Car as the standard for size at the upper end. If these relatively large, muscle-bound cars that generate huge horsepower numbers could use A2, it would be a success in terms of accomodating a relatively wide variety of smaller vehicles. This idea rested on the assumption that vehicles smaller than these fuel burners would fi nd the tunnel useful as well.

RACING BICYCLESThat’s when a big time surprise hit. Racing bicycles of the Tour de France variety, it seems, were a natural cus-tomer for A2’s smaller scale and budgets. Motorcycles, yes. Karts, yes. But bicycles? This came about through one of the employees of a nearby bike shop called Cool Breeze Cyclery. ‘One of the people we hired as a fabricator and technician during the con-struction of the tunnel, Mike

Giraud, happened to work for a bicycle racing organisation,’ explained Eaker. ‘That’s not why we hired him, bicycles were not on our horizon, but when Mike suggested it, we said, “Sure”. With his con-nections, it turned out to be serendipity. He knew of our capabilities and with some specifi c modifi cations for bicycles, A2 is on the verge of being a very high use facility for bicycles.’

The far larger and more

expensive AeroDyn is an open return tunnel with walls that can be ‘tuned’ (adjusted by jack screws) to match the streamlines coming off Sprint Cup cars and scales that enable the wheels to spin during the tests.

To accomodate a wider variety of vehicles and budgets, Eaker needed to take a different, less complex approach to A2. ‘I sometimes refer to it as our science fair project,’ he laughed. ‘By most

industry standards, this is too simple, too small to be really effective, but that was the real challenge to us.’

TUNED CEILINGIn the end Eaker decided to use an application that has been used previously based on a concept long since proven in supersonic aircraft. He installed a ceiling that can be ‘tuned’ ie raised and lowered. The analogy would be to an aircraft’s relationship between the wings and fuselage – as the wings grow wider, the body of the aircraft grows slimmer.

‘If you look at the B1 bomber with the wasp waist,’ he continued, ‘as the area of the wings grew, the cross-sectional area of the body was diminished. I’m not drawing a direct parallel with it, just using that as an example. The cross section of the wing was out there and the cross section of the body was over here. But they were still talking to each other.’

With his feet fi rmly on the ground, the former pragmatic racer chose his compromise. ‘The purist would say you

Gary Eaker was introduced to NASCAR while employed by GM Racing. He jumped into Stock Car racing in a big way when he signed up as aerodynamicist for Hendrick Motorsports.Then, in 2003, he went out on his own, opening his own wind tunnel in sleepy Mooresville, North Carolina. His ingenious tunnel, which is known as Aerodyn or sometimes just as ‘Eaker’s place’, is a one-of-a-kind tunnel that has changed the modus operandi of NASCAR Cup teams, not to mention the bodywork from top to bottom of many a Stock Car

match the streamlines coming industry standards, this is too

BUDGET BLOWA2’s cost strategy allows competitors in lower-level series to get valuable wind tunnel time

GARY EAKER

6_SE1N2_Aerodyn-MPS.indd 7 22/8/08 17:04:51

a pig, but the exaggerated roll

oversteer at the rear is used to

kill the push.

It’s not uncommon for the

hiking effect to use up all or

most of the suspension travel

at the rear, in compression at

the right rear and extension

at the left rear. This leaves the

suspension with little ability

to absorb bumps.

TWISTING LOGICDoes this make sense? From

the standpoint of tyre and

suspension dynamics, it doesn’t.

It makes more sense to have

only as much dynamic wedge

as it takes to balance the

handling, with the tyres and car

construction the rules permit.

Hopefully, we will still have some

travel left in the suspension to

absorb bumps, and some ability

to vary the amount of dynamic

wedge to control the car’s

balance. The left front tyre will

probably still be the most lightly

loaded of the four in many cases,

and will contribute the least to

the total cornering force, but

what’s the sense in throwing that

away and turning the car into a

tricycle unnecessarily?

Yet there is a long history of

popularity for this approach, and

cars using it have won a lot of

races. What might be the reason?

It could have to do with

aerodynamics. In the case of

the Cup cars with the axle

snouts aimed to the right, that’s

undoubtedly the case. It used to

be standard practice on all but

the fastest tracks to work the

body rules by moving the tail to

the right, relative to the rest of

the body. This got more air to

the rear deck and spoiler when

running at some leftward yaw

through a left turn. But in recent

years this has been prohibited, or

severely limited. A similar effect

can be had by simply yawing

the whole car by aiming the rear

wheels rightward.

Not only does more

aerodynamic yaw get more air to

the rear deck and spoiler, thereby

generating more downforce, but

it also generates an aerodynamic

lateral force. This is maximised

when the car has extremely

slab-sided bodywork. Hiking the

left rear also lifts the spoiler

higher. It would be possible to

just have it higher statically,

but the rules restrict that.

Rather similarly, it would be

possible to statically lead the

left rear a lot, but the classes

we’re talking about have rules

limiting wheelbase inequality on

the two sides of the car. It might

be possible to get around this

by moving the left front wheel

ahead of the right front. However,

the engine setback rules often

(though not always) specify how

far the nearest spark plug can be

from the left front upper ball joint.

When this is so, we can’t move

the left front wheel forward; we

can only move the right front

back. The only way to aim the

rear wheels to the right without

losing engine setback is to make

them steer that way dynamically.

UNKNOWN QUANTITYHaving the car rolled a lot also

should get us some downforce

from the lateral component of

the airflow. On the other hand,

especially in a Late Model with

a full-width front end, having

the left front corner high costs

us downforce by letting more

air in under the left front.

Whether there is a net gain in

downforce, or exactly when there

is or isn’t, is not known.

Why? Because it’s not easy

to test this in existing wind

tunnels. Most teams involved

in dirt racing don’t have

the budget for wind tunnel

testing anyway, but even if

they did, most tunnels will

not accommodate the yaw

angles required. The belts or

wheel support rollers won’t

accommodate the required wheel

positions. Most tunnels aren’t

big enough to accommodate the

aerodynamic front-view width of

the car when yawed dramatically.

Blockage effects would result

which would compromise the

accuracy of the testing.

It might be possible to try to

model and mesh a dirt Late Model

and apply computational fluid

dynamics (CFD) to the problem.

But that’s not cheap either at the

level that would be required.

One possibility might be to

instrument a Late Model, and

adjust the suspension so it

would run in various hiked and

yawed positions when running

straight on smooth pavement,

and measure the suspension

displacements with various

setups. Aerodynamic forces

might then be inferred from that.

A Late Model in the wind tunnel – something few teams can afford – where the hiking affect can be examined and assessed


STRAIGHT TALK RICARDO DIVILA

Bending the rules

Interpreting the regulations

governing the technical

aspects of motor racing is

like playing the bagpipes

– no one can judge if it is

good or bad.

The NASCAR garage has an

expression: ‘if you ain’t cheatin’,

you ain’t tryin’. Junior Johnson had

this to say: ‘I’d have four of five

new things on a car that might

raise a question. But I’d always

leave something that was outside

of the regulations in a place where

the inspectors could easily find it.’

Another colourful character was

Smokey Yunick, whose antics could

fill a book, and did – his memoir

Best Damn Garage in Town is

required reading.

His notorious 68 Chevelle,

reputed to be a 7/8-scale version

of the homologated car, led

NASCAR to create the infamous

templates they use on all cars

today. Legend has it that when it

picked up its 16th violation during

tech, he got in the car and drove

it back to his garage in Daytona

with the fuel tank still sitting

in the inspection area, with the

parting shot of ‘make it 17’.

As Karen Van Allen once wrote:

‘Cheating has been around since

the inception of stockcar racing.

1966 produced two of the most

notorious violations of rules quite

possibly witnessed in the sport of

NASCAR – and both cars passed

inspection prior to the Dixie 500

at Atlanta. Junior Johnson’s ‘Yellow

Banana’ Ford Galaxy and Henry

‘Smokey’ Yunick’s “little” #13

1967 Chevy Chevelle, complete

with an offset chassis, raised floor,

roof spoiler, balloon in gas tank

and a host of other “brilliant” rules

book interpretations. NASCAR

finally disqualified Yunick’s

creation in 1968 when it was

found to be some 200 pounds

underweight.’ The use of water-

filled tyres to be fitted after the

qualifying run before tech could

have something to do with it.

After the templates closed

the stable-door, Smokey is

deemed to have pulled another

one. Templates were cut to

the production drawings of the

manufacturer. When Smokey’s

new car didn’t fit the templates

at tech, he loudly protested his

innocence, maintaining they

‘musta’ve got templates wrong’,

challenging them to check on any

car of the model they could find.

Upon going to the track’s

parking lot, those templates

wouldn’t fit any of the few cars

they found, just like they wouldn’t

fit Smokey’s. As the new racing

car was one of the first from

the assembly line, Smokey had

munificently provided several

examples, coincidentally modified

as the racecar, and scattered them

around. Game, set and match.

Again, an environment-

generated mindset, where the

antecedents of the bootlegging

good old boys racing led to the

ideal of not getting caught by

the law. The concept of unfair

advantage is quintessentially

American, even if the word

‘unfair’ is the vestigial appendix

of sporting ethos from the

playing fields of Eton.

Eton also came up with

‘gamesmanship’, detailed in

Stephen Potter’s The Theory and

Practice of Gamesmanship, or the

Art of Winning Games without

Actually Cheating, which describes

‘the use of dubious methods to

win or gain a serious advantage

in a game or sport.’ Or ‘pushing

the rules to the limit without

getting caught, using whatever

dubious methods possible to

achieve the desired end.’

‘It may be inferred,’ Potter

writes, ‘that the term derives

from the idea of playing for the

game (ie to win at any cost) as

opposed to sportsmanship, which

derives from the idea of playing

for sport.’ Or bagpipes again.

In the first case, legality is a

binary condition, like pregnancy.

You either are or are not

pregnant, but in other regards

you are NOT either legal or illegal.

There is a spectrum of legality,

and where you reside relies on

the intention, definition and the

policing of these rules.

Racing is littered with

examples of tricky interpretations

of the rules. At Le Mans there

was a rule that tyres could not

be heated in the garages, but

it didn’t mention about tyres

heated ‘behind the garages’.

And when cars were supposed

to be road useable, there was a

rule specifying the size of the

compartment where baggage

could be carried, but no definition

of what the baggage was.

Making up new rules is every

bit as tricky as interpreting them,

but nowhere near as fun.

NASCAR has seen some of motorsport’s most ingenious regulation dodges

“Yunick’s ’68 Chevelle was 200lbs underweight. Possibly due to it having water-filled tyres”

Take cutting-edge wind tunnel technology. Add a 180 mph rolling road.

And build in the best in precision data acquisition capabilities. When we

created the world’s first and finest commercially available full-scale testing

environment of its kind, we did much more than create a new wind tunnel.

We created a new standard in aerodynamics.

1 8 0 m p h w i t h o u t m o v i n g a n i n c h

704 -788 -9463 info@windshear inc .com w indshear inc .com

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