Why is that boost different in lower gears vs higher gears?, Gen4 3sgte. Turbo noob Options

[ILoveMySilly97]

Just swapped in a 3sgte gen4 into my 97 GT. I was looking around to find the stock boost. I read we get peak boost at 14 psi in 3rd gear and up. But 7-8 psi in the 1st and 2nd gear.

Also why's it that it's different boost in the gears? What controls it or is it safe to make a mod to get even boost through the gears? I'm guessing that's what a boost controller is for?

Sorry for the rookie questions.

This post has been edited by ILoveMySilly97: Apr 29, 2016 - 12:49 PM

[98celi]

Just swapped in a 3sgte gen4 into my 97 GT. I was looking around to find the stock boost. I read we get peak boost at 14 psi in 3rd gear and up. But 7-8 psi in the 1st and 2nd gear.

Also why's it that it's different boost in the gears? What controls it or is it safe to make a mod to get even boost through the gears? I'm guessing that's what a boost controller is for?

Sorry for the rookie questions.

Trying to create even boost in all gears will destroy traction. Even with a dual clutch or in newer cases, a CVT still don't get consistent boost pressures. There's also external load contributors like road angle and wind resistance that you can only do so much about. Building on richees response. Turbo boost is based on the engines power band. The turbo won't spool up near as much in first because the duration is so short. 3rd gear is usually the best spool gear because the power band is long enough to feel full boost but short enough to feel the transmission torque. 4th gear output runs 1to1 with the engine (usually) so the transmission is less aggressive and the boost won't spool as fast.