Tom Wilson
December 21, 2010

Photo Gallery

View Photo Gallery

On The Dyno

We tagged along as Ken Christley labored on his development work with the KB manual-transmission test car. This was a major pain as the computer kept closing the throttle (something the automatic test mule never did, interestingly), but we were able to obtain good baseline 8- and 10-psi numbers.

We must explain that the baseline figure was set in totally stock configuration, with the ignition timing advancing as far as Ford has it tuned: 26 degrees total advance. The 8-pound number was set as KB normally sells its kits, with the ignition timing capped at 22 degrees-the practical limit with 91-octane fuel. If 94-octane fuel is available, then a smaller blower drive pulley can be installed and the ignition timing (electronic tuning) can be left alone.

However, if race gas is available (KB tests using 109 research octane unleaded for these conditions), then the 10-pound pulley can be run with 26 degrees of timing. Due to the difficulties in sorting the new Ford software, this was the only 10-psi run we obtained by press time, so we're showing that result and estimating what the 10-pound pulley would make with the timing at 22 degrees. Thanks to all variables being controlled and the linear response of the Twin Screw blower, such guestimates have proven surprisingly accurate with KB blowers.

Of course, it can't escape your attention that the entry-level 8-pound Kenne Bell kit made a staggering 177 hp and 136 lb-ft of torque over stock. This is outstanding performance, so good compared to other reported dyno results (even elsewhere in this magazine) that a reasonable person would want an explanation.

First, remember that besides differences in superchargers and electronic tuning, all dynos do not read equally (sometimes by 40-plus horsepower), and also remember the Kenne Bell is using a huge inlet breathing outside the engine compartment while others suck through smaller tubes inside the engine compartment. In addition, the manual transmission KB test car was wearing a Pypes muffler and tailpipe kit.

PulleyBoostTimingHPTQRemarks
dia., inlbsdegreesSAElb-ft
Stockn/a26375362100-percent stock
4.12582254746391-octane limit
3.8751022583 est.486 est.94-octane limit
3.8751026604504109-octane unleaded
4.125822522425Automatic transmission
Baseline KB, 8 PSI Baseline Vs. 8 Psi
RPM HP TQ HP TQ HP TQ
2,500142.08298.48181.15380.5739.0782.09
3,000178.10311.80242.35424.2864.25112.48
3,500220.59331.01293.26440.0672.67109.05
4,000261.40343.22342.24449.3780.84106.15
4,500307.21358.56388.70453.6781.49 95.11
5,000329.65346.27436.23458.23106.58111.96
5,500355.26339.25469.59448.43114.33109.18
6,000362.46317.28503.51440.75141.05123.47
6,500374.32302.45529.74428.04155.42125.59
6,800370.59286.23547.61422.95177.02136.72
KB, 10 PSI8 PSI VS. 10 PSI
RPMHPTQHPTQ
2,500201.01422.3019.8641.73
3,000268.80470.5826.4546.30
3,500324.02486.2230.7646.16
4,000378.97497.6036.7348.23
4,500428.36499.9539.6646.28
5,000469.40493.0733.1734.84
5,500513.01489.8943.4241.46
6,000547.25479.0343.7438.28
6,500585.32472.9555.5844.91
6,800604.87467.1857.2644.23