Steve Turner
Former Editor, 5.0 Mustang & Super Fords
December 17, 2010
Photos By: Courtesy Of VMP Tuning

On The Dyno

StockRoushcharger85MM Pulley
RPMHPTQHPTQBoostHPTQBoost
2,00090.35237.24146.09383.554.83152.62400.725.69
2,500136.15285.98198.98417.955.09209.95441.006.38
3,000170.07297.69257.84451.345.89271.57475.336.54
3,500214.68322.08308.13462.295.23328.82493.326.70
4,000252.91331.99354.17464.956.39382.51502.126.61
4,500297.46347.08398.84465.407.13429.19500.776.95
5,000311.11326.68441.60463.756.65473.43497.128.02
5,500340.60325.13470.82449.468.27494.56472.067.05
6,000348.01304.49506.89443.544.93522.69457.317.28
6,500354.55286.32518.82419.036.95546.45441.286.61
CJ TBDifference
RPMHPTQBoostHPTQ
2,000n/an/an/an/an/a
2,500208.93438.846.6072.78152.86
3,000271.94475.996.67101.87178.30
3,500331.65497.566.37116.97175.48
4,000384.56504.806.75131.65172.81
4,500432.69504.857.18135.23157.77
5,000469.05492.527.15157.94165.84
5,500496.22473.657.94155.62148.52
6,000522.40457.057.53174.39152.56
6,500548.31442.788.28193.76156.46

How's that for a gain from a single bolt-on? Adding the Roushcharger boosted Rebecca's otherwise-stock '11 5.0 by about 170 hp and nearly 140 lb-ft of torque. Better yet, the supercharger looks like it was factory installed, and Rebecca reports that the car drives better than stock.

Justin, of course, couldn't leave the car in as delivered form. He first tried a pulley 5mm smaller than the standard Roush pulley; then he bolted on an FRPP CJ throttle body. Both provided a small boost under of the curve, but only the CJ picked up the peak power by a handful. Justin firmly believes the stock airbox is the big restriction at this point, but he wanted to get the car into the 10s with a CARB-legal airbox, and Rebecca did just that.

We'll be following this car as Justin opens up the inlet and exhaust to see how much more the Roushcharger combination has on tap, so stay tuned.