Tom Wilson
March 1, 2013

On The Dyno

NA Snow Nitrous NA vs. Snow
RPM Power Air/Fuel Power Air/Fuel Power Air/Fuel Power Air/Fuel
2,750 161.82 14.14 165.72 14.34 160.95 14.64 -0.87 0.50
3,000 176.53 13.36 179.69 12.94 175.96 13.33 -0.57 -0.03
3,250 195.10 13.01 198.12 12.62 193.58 12.67 -1.52 -0.34
3,500 209.82 12.95 213.36 12.56 207.89 12.42 -1.93 -0.53
3,750 228.75 13.03 232.29 12.64 226.19 12.60 -2.56 -0.43
4,000 248.00 13.13 251.08 12.84 244.55 12.73 -3.45 -0.40
4,250 270.00 13.18 272.51 12.88 265.47 12.73 -4.53 -0.45
4,500 288.92 13.25 292.99 12.88 295.46 12.71 6.54 -0.54
4,750 306.26 13.21 309.50 12.62 340.11 12.92 33.85 -0.29
5,000 321.72 13.15 325.11 12.50 355.31 12.80 33.59 -0.35
5,250 338.57 13.14 345.74 12.66 379.02 12.80 40.45 -0.34
5,500 356.07 13.21 360.72 12.77 395.72 12.87 39.65 -0.34
5,750 362.36 13.30 368.47 12.93 405.22 13.04 42.86 -0.26
6,000 367.39 13.39 376.47 13.06 410.48 13.06 43.09 -0.33
6,250 374.71 13.32 382.20 13.08 419.87 13.07 45.16 -0.25
6,500 377.20 13.36 385.44 13.07 423.98 13.17 46.78 -0.19
6,750 377.95 13.34 385.66 13.09 424.20 13.08 46.25 -0.26
7,000 371.25 13.31 381.71 13.18 423.77 13.05 52.52 -0.26
7,250 368.42 13.30 379.41 13.19 427.30 13.16 58.88 -0.14

Snow Performance's test vehicle was a 2012 Boss 302 Laguna Seca set up for NASA High Performance Driving Events (open tracking). Modifications included Hoosier racing slicks, adjustable shocks set firm, a Snow Performance Stage-3 Boost Cooler water/methanol injection system, along with a 50hp dry nitrous system.

Additionally, Snow Performance dyno tested the Boss' standard and TracKey tunes; there was the most minimal changes in power so we aren't bothering with those results here and are using the TracKey tune as the baseline. In other words, this was a typical open track car in that the engine was not supercharged nor even highly tuned.

Snow Performance's first test was to document how much reduction in intake air temperature occurred with water injection. This test was done on the road, with the engine temperature verified at 210, then accelerated in second gear between 2,000 and 7,500 rpm.

Measuring the intake air temp before and after the water injection took a little doing. The incoming air temperature information was captured from the car's stock IAT sensor using a DiabloSport handheld device. The IAT sensor is mounted before the throttle body and water injection nozzle, so it essentially reads ambient air temperature.

To measure the air temperature downstream of the throttle body and after the water injection nozzle Snow thought they could use Ford's second air temperature sensor on the RoadRunner engine. It's appropriately placed in the intake manifold, but Snow found that accessing its data with the Predator meant running afoul of the engine's stock tune. Therefore Snow added its own thermometer, a laboratory-type Omega thermometer fitted with a K-type temperature probe. The intake manifold was drilled and tapped to accept the probe's ¼-inch NPT temperature probe, which protruded into the air stream. It's believed this helped speed the temperature probe response time, rather than relying on the stock probe which is buried in the intake manifold casting.

Still, Snow Performance found a slight delay, or possibly a lingering cooling affect, as the charge air continued to drop after the water flow had been shut off. This could be continued quenching as it can take a little time for all the water to change state from liquid to vapor, which is when the cooling takes place.

And there's plenty of cooling affect, as shown by the results.