Boyesen Rad Valves for the Polaris CFI2 800 Boyesen marketing manager Joe Nocentino brought a new 2014 Polaris Indy 800 to DynoTech Research to have us assess their new Rad Valves developed for this engine. Just the day before we had dyno tested our first 2014 Polaris 800, the Fun Unlimited AmSnow Shootout Indy 800 that would be run at Woodgate, NY on December 13. We saw that the stock WOT fuel map was richer than 2011-13 in the midrange—then as revs climbed to the HP peak and beyond it leaned out to max HP A/F ratio and even leaner! If the Rad Valves added significant airflow at peak HP RPM, a Boondocker or PCV tuner would surely be needed to add fuel there. Here’s a graph of two tests of 2014 fuel flow compared to an earlier 2013 ECU installed on the same engine. Note that this data is created by the dyno measuring fuel flow from the pump to the fuel rail (flowmeter A), then subtracting the fuel flow returning back to the tank (flowmeter B) (net flow is Fuel A-B) (A_B in the test data) so there is some jerkiness in the fuel curves. But stacking two of each lets us see approximately what is happening this year compared to earlier years’s calibration:

Here’s a graph of the 2014 ECU calibration with drastically reduced top end fuel flow creating much higher pipe center section temperature, causing peak HP to shift to higher RPM. Compare that to the still-powerful 12.5/1 that the earlier calibration created:

Now that we have an understanding of what’s happening with the 2014 800 CFI2 fuel curve compared to earlier fuel curves, we can appreciate the fact that when we removed the stock reeds and installed the Boyesen Rad Valves peak RPM airflow and HP was identical to stock. Had the Rad Valves created higher airflow at peak RPM, horsepower very likely would have dropped, requiring a fuel tuner to add enough fuel to bring A/F ratio back to 13/1 or richer. But what we saw with the Boyesen Rad Valves was a great increase in midrange airflow that added 3-4 HP there, making use of the safer midrange A/F ratio in the early calibration ECU’s and even safer midrange of the 2014 calibration. Trail riders typically enjoy midrange torque and HP as much as peak HP—on-off-on throttle performance is improved by the added midrange torque and HP of the Boyesen Rad Valves as the following graph made with the early ECU (two tests with stock reeds and two tests with Rad Valves) indicates:

Here are the same four tests, with data from two tests with each reed set averaged. This shows identical top end airflow and HP, and vastly improved midrange torque and HP, making use of the extra fuel delivered there—especially with the fat 2014 midrange calibration:

STOCK REEDS: EngSpd STPPwr STPTrq BSFA_B FulA_B AFRA_B ElpsTm FulPrA RPM CHp Clb‐ft lb/hph lbs/hr Ratio Secnds psig

6050 89.5 77.7 0.563 49.9 14.78 0.05 66.96150 90.5 77.3 0.578 51.8 14.41 0.57 66.96250 92.3 77.6 0.575 52.5 14.41 0.83 66.96350 94.7 78.3 0.565 53.0 14.53 1.10 66.96450 96.8 78.8 0.542 52.0 15.04 1.38 66.96550 98.8 79.2 0.538 52.6 15.15 1.62 66.86650 100.9 79.7 0.552 55.1 14.78 1.91 66.76750 103.7 80.7 0.574 58.9 14.12 2.10 66.66850 108.7 83.3 0.614 66.1 13.04 2.27 66.46950 113.4 85.7 0.629 70.6 12.58 2.59 66.27050 117.5 87.5 0.624 72.6 12.53 2.89 66.27150 121.2 89.0 0.607 72.8 12.74 3.06 66.17250 125.8 91.2 0.592 73.7 12.85 3.22 66.17350 131.0 93.6 0.582 75.5 12.82 3.53 66.07450 136.6 96.3 0.579 78.3 12.59 3.92 66.07550 139.9 97.3 0.581 80.5 12.43 4.18 65.97650 141.8 97.3 0.576 80.8 12.48 4.41 65.97750 143.5 97.2 0.568 80.7 12.59 4.68 65.9

7850 144.5 96.7 0.564 80.7 12.65 4.97 65.97950 144.9 95.7 0.563 80.8 12.65 5.22 65.98050 144.4 94.2 0.565 80.8 12.65 5.53 65.98150 142.2 91.7 0.570 80.2 12.71 5.80 65.98250 136.8 87.1 0.588 79.7 12.69 6.09 65.9

…………………………………………………………………………………………… BOYESEN RAD VALVES EngSpd STPPwr STPTrq BSFA_B FulA_B AFRA_B ElpsTm FulPrA RPM CHp Clb‐ft lb/hph lbs/hr Ratio Secnds psig

6050 88.9 77.2 0.557 48.5 14.50 0.62 66.66150 90.1 76.9 0.554 48.9 14.61 0.87 66.66250 91.8 77.1 0.555 49.8 14.56 1.13 66.66350 93.8 77.6 0.557 51.1 14.44 1.35 66.66450 96.1 78.2 0.551 51.8 14.51 1.57 66.56550 98.5 79.0 0.551 53.1 14.46 1.84 66.56650 101.5 80.1 0.571 56.6 13.93 2.07 66.46750 104.7 81.5 0.593 60.7 13.34 2.21 66.36850 109.8 84.2 0.615 66.0 12.68 2.52 66.16950 116.3 87.9 0.622 70.8 12.28 2.82 65.97050 121.6 90.6 0.616 73.3 12.19 3.10 65.87150 125.1 91.9 0.615 75.3 12.12 3.33 65.77250 128.8 93.3 0.614 77.3 12.04 3.58 65.77350 133.2 95.2 0.606 79.0 12.06 3.88 65.67450 137.1 96.6 0.595 79.7 12.14 4.13 65.67550 140.0 97.4 0.586 80.3 12.18 4.38 65.57650 142.0 97.5 0.578 80.3 12.27 4.67 65.57750 143.6 97.3 0.577 81.1 12.21 4.92 65.57850 144.6 96.7 0.572 80.9 12.28 5.29 65.57950 144.9 95.7 0.568 80.5 12.38 5.58 65.58050 144.3 94.2 0.565 79.8 12.48 5.80 65.58150 141.2 91.0 0.575 79.4 12.47 6.14 65.68250 135.0 86.0 0.599 79.0 12.41 6.50 65.68350 124.5 78.3 0.641 78.0 12.38 6.95 65.6

…………………………………………………………………………………………