On the smaller frame chargers your not nescessarily going to pick up peak power, your more than likely to pick up more peak torque. The testing FPE has done with our custom S366 Billet Compressor vs Cast didnt yield alot more peak HP but made nearly 50 more peak Ft/lbs of torque. The biggest story that the graph told on the back to back runs was that the FPE Billet wheel made between 100-150 more ft/lbs of torque from 1500 RPM up to peak which was around 2250.
This biggest difference is drivability; if the truck drives better, which means its more responsive, which means it spools quicker, which means it makes torque sooner. That all equats to a smoother driving, more powerful truck.
In some B to B testing last year on the big S4's nearly 100RWHP was gained by running a Billet Compressor over a stock cast borg wheel.
Caleb