3.1 lg5 question

[SwiftDrift]

how much boost does the 3.1 turbo get stock?

[Superdave]

~7PSI

[SwiftDrift]

without changing the turbo, or doing major porting, is there a way to bump up the psi a little?

[robertisaar]

you could run up to 14PSI if you wanted to, but the little T25 is making more heat than boost at that point.

you'll also run out of injector much beyond where you are now.

[SwiftDrift]

i dont know jack about turbo setups, how do you increase the boost?

[robertisaar]

tune. boost is entirely controlled by the ECM acting upon a wastegate solenoid. boost level goes too far above what the ECM is commanding and it will cut off all fuel.

[SwiftDrift]

ohh okay, cool. how stable would 10psi be on the LH0? and roughly how much more torque would it have?

[Superdave]

the Top Gun chip kicks it up to 10 PSI, lots of people run it that way. Not sure on power but 3 PSI typically would be 20-30 HP, results could be skewed by tons of other factors though.

[caffeine]

If you have an LG5 probably one of the best/easiest upgrades would be a GT28 as the GT25 is way too small for that motor. GT28 is still probably too small but it should bolt to the stock y-pipe.

[SwiftDrift]

small turbos spool up quicker though right? 10psi is the highest i would want to go on the motor, i hear the bottom end isnt the strongest

[caffeine]

If a turbo is too small it will choke the motor. A Gt30 might even be considered too small so think how small a GT25 is.. It's more like a 4-cylinder turbo and even then a lot of guys will upgrade from a stock GT25 to a GT28.

[SwiftDrift]

so even if its 10 psi, it would basically be alot of back pressure in the exhaust?

[caffeine]

It might spool instantly but then at higher rpm a small turbo will max out and will prevent you from making more power. Also if you try to run a lot of boost to compensate you will just end up creating a ton of heat in the intake.

[SwiftDrift]

...well that sucks :/, i was thinking of having a pontiac 6000 ste as a dd. all wheel with the 3.1 turbo, a little extra boost would have made me actually like getting groceries XD though stock those motors are pretty mean.

edit: stock lg5 that is

[TurboGTU]

I'd still do it. Not a STI but sure makes it fun to drive. This turbo was desighed around the low rpm 3.1. So you don't need to rev the piss out of it. It make a mean torque motor.