Originally Posted by AmericanSpeed

The calculation is not 115% x rwhp. When you have 15% drivetrain loss, you multiply (1-.15) or .85 by the crank horsepower to get RWHP. So .85 x CrankHP = RWHP. Rewrite the equation to solve for CrankHP; CrankHP= RWHP/.85 So to solve for crank using RWHP, you divide by .85 (assuming 15% drivetrain loss).

424rwhp/.85 = 498.8 crank HP

Originally Posted by zachcrosen

Looks like I missed that one. You are right.

Originally Posted by rm9792

Drove in and started with 385 RWHP and left with 424 RWHP in 102 degree heat. Definitely feels peppier and hopefully wont code anymore. Saw a set of Shelby mufflers (used) on the floor and had those put on to replace my flowmasters. Lot quieter in the car and the ^#%$^*%$#*^ drone is completely gone. Tuner said mufflers would only suck out 2-3 hp so preferred to eliminate the drone. Hope to have my first SCCA race Sunday and test it out. Edelbrock marketing appears to be full of crap. The Eforce ads say 5psi and 466 bhp out the box. I am pushing 8 psi after the intercooler and getting about 470 bhp after a day of tuning.

Originally Posted by breathegood

I may be picking at nits here, but using a percentage to calculate drivetrain loss doesn't make sense to me. The more power you make the more power you lose......I don't think it works that way. Transmission, gears, tires,... all else being equal, drivetrain loss should be the same at 600hp as it is at 300hp. If you lose 15% or 45 horses at 300 bhp, you will still only lose 45 horses (7.5%) at 600hp. This is why a baseline dyno is so important. I could be wrong, but I think the physics is in my favor.