How do you find out at what RPM is your peak torque is at . Is there a graft or something i should be looking at.

 

Technically, you need a dyno graph to know that. You can also get really close by looking at your load/boost curve via EvoScan or Mitsulogger (if you are using the stock ECU).

 

Put the car on a good chassi dyno is the best way to find out where peak torque happens at.

If you want a good estimate, you can log a few 3rd gear pulls starting at 2000 rpm and see what RPM the highest Load occurs at. That should be a good estimate of where peak torque occurs.

 

It depends on what your mods and boost level are, as well as what gear and what road conditions are... and of course the tune...

For assumptions sake, if you have stock turbo, at stock-ish boost levels (20-21psi) and are talking about a 3rd gear flat road or dyno pull with a stock-ish or decent tune... it's going to be around 3500RPM.

The more boost you run, the longer it will take it hit peak torque.

You can use DataLogLab to analyze an EvoScan log from a 3rd gear pull from 2500 - 7500RPM to estimate HP and TQ powerbands.

If you have a dyno chart, obviously, peak torque is... well, the peak of the torque curve

 

Yeah, a dyno is best. It is tough to tell on EvoScan pulls. The earlier you start the 3rd gear pull, the earlier you will hit peak load. I can start a pull with the Evo Green at 3k and hit highest load at 4900rpm's. When I start the pull at 2500 it occurs at 4500rpms and when starting at 2000 it occurs from 3700-4000rpms.

A stock turbo should be between 3k and 4k though.