What is involved in changing the rear gears

[Ace23]

Originally Posted by joyridin'

17% drivetrain loss is usually what they use for the calculation with an IRS rearend.

I wouldn't bet on the 10% difference between the DynoJet and Mustang. Way too many variables to use that number. You are not even sure when the last time the dyno was calibrated. I called a shop to have my car done a few months ago and the guy said to me "It needs to be calibrated?" I guess that meant his 8 year old dyno had never been done. 491 rwhp is probably a pretty accurate number.

Point taken and a good way of looking at it. I don't ever want to come across as not being open to others opinions on here. This forum is the place I like to come and conjure up about what is next for the car. I have a local shop about 5 miles away that has a dynojet. I'm going to make it a point to go by in the next few weeks and have them make a pull just as a comparison.......this would be good idea since after we changed up the fuel system and changes the RPM limiter. This will give me more to go off of.