hey guys,

I just replaced one of my turbos with a brand new one.
My tune is set to 12psi but it's hitting 20. Any ideas? I'm running unichip.
Also, when I go over 12psi at high rpm, I have a symptom of the clutch slipping.
My clutch is new, stage 2 clutch that hold 530 wtq.

 

Kaboom.... you need a boost controller or a need spring. The new turbo is set at 20 psi. You need to dial it down. Possibly retune.

 

I'm leaning towards the retune. I've never had boost controller installed and happy with a fixed psi. Also, the engine's rebuilt with forged internals.

 

It can still blow.

 

also want to add that AF is normal.

 

won't hurt to add a boost controller. can only help

 

Sounds like either wastegate is stuck, or needs a lighter spring. Which boost controller will not help in either case. A boost controller will not get any lower than what the wastegate spring is set at.

 

more info on the turbo?
Internally wastegated? Would seem so.
All vac lines re hooked up?

 

Why only replace 1 turbo? I would think if 1 went bad the second ones is not far behind.

 

per jdm and cux> check wastegate lines!

 

thanks for chiming in guys.
yes, it's an internal wastegate. aps twin turbo.
jdm, what do you mean by wastegate being stuck? can this happen on an external one?
I've visually and half checked the hosing and didn't see anything obvious. I think I may need to take it back to the shop. I'm thinking that they improperly assemble the hose or 2.

 

The internal wastegate spring may be et for 20psi.

Externals can fail as well.

Should only be one vacuum connection on those turbos for the wastegate.

 

Yes wastegates can fail. Both internal and external.The spring can bind causing wrong pressures, or it can get a lot of exhaust buildup and not function properly. Seals can also leak. If the vacuum line is hooked up properly with no kinks, then it's probably one of the problems i've mentioned.

 

Ah yea I see boost controller for quicker spool but won't regulate..

 

Boost controller doesnt help spool either. All it is, is a controlled valve that does not allow manifold pressure to reach the wastegate until it reached the desired psi you set it for to allow you to achieve higher boost.

example: you have a wastegate with a 7si spring but want 15psi. set boost controller to 15psi and it will not allow pressure to actuate the wastegate until it reaches that 15psi.

 

I have been told by multiple ppl that boost controllers totally help with spool and lag IE reaching target PSI sooner than when just running on a wastegate spring.

From another forum:
A PROPERLY working and programmed electronic controller will delay the opening of the wastegate untill the last moment possible. This speeds spool time.

 

On my 2jz with a BW s362 FMW running on wastegate only i was told that a boost controller would speed up spool:


What a boost controller does is bypass the wastegate in one way or another. By lowering the amount of pressure the wastegate sees you can "fool" the turbocharger into spooling faster and creating more boost. By disconnecting the wastegate before the maximum boost is reached with certain types of boost controllers you can also increase the spool rate of a turbo because no exhaust is being leaked out. There are two primary ways that boost controllers work and these are separated into manual boost controllers and electronic boost controllers.

 

it does help a little as far as not allowing any leakage but that is not its primary purpose. also if you have leakage the proper way to fix it would not only be a boost controller but higher psi spring. I have owned both manual(turboxs) and electronic(greddy profec B).

maybe the increase is more significant with a bigger turbo but I don't have any first hand experience with that.

 

Yeah I think a bigger is where this particular topic becomes more significant. I'm still learning about boost myself.. good chat

 

Yup! but either way, this wont solve the OP's problem lol. but more than likely a wastegate issue.