turbo problem, or boost loss???

[Renagade]

ok heres the deal...
@ 2,300 rpm i get into boost, spiking @ 19-20psi
from 2600-5200 rpm i hold 17psi
after 5200 rpm on into the redline i drop off to 9 psi

all this is at WOT... so whats going on?

 

[Coldandafraid]

stock turbo?

 

[Renagade]

yup, stock turbo, stock piping, stock intake

 

[Enigma_Man]

If you're wondering why the boost is dropping off, that's normal for a T-25 (stock 2G turbo).

It's a bit too small for the car, and can't keep up with the demands of the engine.

-Jesse

 

[Renagade]

but heres the weird thing... it just now started doing this... it used to hold 17 psi... all the way through

 

[Enigma_Man]

Well either you have a boost leak (see my sig) or you have a dying turbo.

To check for dying turbo, pull off rubber accordion intake to the turbo inlet. Reach fingers in (car off of course, and preferably cooled down, can be hot hot hot) grab shaft. If it can wiggle side-to-side only a little, that is okay. If it can wiggle in-out at all, that is bad. If it can wiggle side-side a lot that is bad.

-Jesse

 

[JessesTalon]

My bet is your ECU is seeing too much knock, and drops boost down to 9psi when it gets to a certain level, check knock levels on a datalogger.

Do you have a MBC? if so get rid of your stock boost solenoid, that seemed to fix that problem with my 1g...

 

[2GeNTSi]

Originally posted by Enigma_Man
Well either you have a boost leak (see my sig) or you have a dying turbo.

To check for dying turbo, pull off rubber accordion intake to the turbo inlet. Reach fingers in (car off of course, and preferably cooled down, can be hot hot hot) grab shaft. If it can wiggle side-to-side only a little, that is okay. If it can wiggle in-out at all, that is bad. If it can wiggle side-side a lot that is bad.

-Jesse

Oh god I think my turbo is dying...maybe that's why I lost to my friends almost stock 1g GSX. After I raced him, I saw A LOT of smoke coming from my side of the car, I thought it was clutch smoke but it didn't appear to be because there was no smoke seeping between the tranny and the block. We ran three times and without thinking, didn't bother keeping and eye on my gauge so the whole time I was probably boosting at 16psi because it would creep, hence the smoke probably.

Anyways for the last week or so I've been noticing this weird whining noise from 1st gear, it would only happen for a sec. I read that it might be a sign of your turbo dying out but I didn't it was because it only occured in 1st gear from a stop only for a second. I just got home from work and I got on it a little bit and I took a glance at my boost gauge and it went straight to 20psi so I immediately let off the throttle and drove normally until I got to the entrance of my neighborhood. I stop at a stop sign and I start going and again I hear this whining noise but now it's not going away.

So I pieced everything together while the turbo timer was letting it cool down and everything seems to point towards a dying turbo:

Whining noise
Smoke after racing
Boost creep/spike

I'm pretty sure that's what it is, tomorrow I'm going to check for shaft play if it's bad then I'll see if I can get my friends 14B for cheap because I don't have money to go and buy a new turbo.