Boost falls off.

[OneFastEclipse]

Right now I have the T25 set to 15psi with the Manual Boost controller. The turbo holds 15psi till about 5000rpms and then falls to 10psi. Is this normal? I heard that the t25 can't maintain it. Or could this be a boost leak? thanks!

 

[Defiant]

Do you get what "boost" is?

It's when you're forcing more air into the intake than the engine can admit to the chambers.

The T-25 doesn't put out high volumes of air. It puts out good volumes at low exhaust pressures -it boosts early in the rpm range- but it doesn't put out enough to "boost" at higher revs. It's meant for a street car that hardly ever sees 5000 rpm, but is usually driven around 3000. Where it kicks in pretty well.

It's not meant to put out 15psi. It can do it, and it can survive. Some run 16psi, thinking they have the ability to measure that accurately.... which they probably don't. You'll get a good amount of boost at 15, but it won't carry very far up into the rev range. The motor outruns the turbo.

You don't have a boost leak. If you want more pressure further up, you'll need more turbo. And, you'll be moving the engine's power range up from the 3000 rpm neighborhood, and will probably have less poke at lower revs.

 

[RuBiCaNT5X]

You can also spend an extra 100 bux and get a new wastegate actuator that FP sells. It will hold 17psi til about 6000rpms and then fall off to 15psi....

 

[nine5raptor]

Originally posted by RuBiCaNT5X
You can also spend an extra 100 bux and get a new wastegate actuator that FP sells. It will hold 17psi til about 6000rpms and then fall off to 15psi....

Why torture the poor turbo by going so far out of its efficiency range? I'll admit, I ran mine at 19 psi for over a year and had no trouble with it, but for 100 bux you can through a 14b on there.