Boost Going Crazy..

[erald01]

Well since i fixed all my boost leaks the car ran good but i noticed that on the 3rd, 4th and 5th gear my boost goes to 25 psi. Btw i have mine set at 20 psi (or 1.14 kpa). Anyways what i am trying to figure out is that there is no boost spike, and i know i have a bad coupler by the charge pipe, but still do you guys think that could be from a boost leak or just my turbo going bad (it does whine a lot more after i drove with a blown coupler a few weeks back). Btw i have a greddy MBC and i turned it off to see the difference but NO, as i accelerated the boost kept building beyound the stock boost setting on the evo3 which is 11 psi. I have placed an order for the new 90* coupler, but do you guys think its the boost leak or my turbo bearings have gone bad?

 

[erald01]

Anyone? Where is all my boost/turbo experts

 

[MrBoxx]

If the turbo were going bad, you wouldn't be boosting that high. Instead of turning the MBC down, try connecting a line directly from the J-pipe to the WGA on your turbo.

Did you port the turbo for boost creep? It sounds like that's what you're getting.

 

[blcknspo0ln]

I will agree with that, it sounds like boost creep. As boxx said, run a vacuum line directly to the wastegate (bypass your mbc) and see if it reacts the same way.

 

[erald01]

Well thats how the MBC is originally hooked up, at the j-pipe and the wastegate actuater.

 

[crensinivon]

How To Cure Boost Creep By Porting

http://www.dsmtuners.com/forums/art...oler/186525-how-cure-boost-creep-porting.html

Hope that helps. Worked for me.

 

[bojanglesracing]

The fact that you build boost it is unlikely you have a leak, For if you had a leak you car would not hold boost. Boost spike is when boost goes over you set boost then come back down. Say you boost is set at 11 spike would be going over 11 then coming back down. Boost creep is where it goes past 11 and stay. boost creep is cause by your waste gate not being able to keep up. The wasstegate is not able to dump presser so it spins faster causing more boost.

 

[MrBoxx]

Well thats how the MBC is originally hooked up, at the j-pipe and the wastegate actuater.

What I'm trying to tell you is to take the MBC out and simply run ONE vacuum line straight from the J-pipe to the WGA. This takes MBC function/malfunction out of the equation. If everything is working correctly, this setup should result in steady 11-12psi of boost. If it hits 11-12psi, then starts climbing upward from there, you have a boost creep problem.

 

[erald01]

Thanx guys im'm gona defenitly try hooking up a vacum line directly from the j-pipe to the actuater. BTW my turbo has not been ported nor has the 02 housing.

 

[crensinivon]

With that 3 inch exhaust hooking the line from the j-pipe to the wastegate isn't going to help. Get a carbide burr bit and start going to town.

 

[blcknspo0ln]

With that 3 inch exhaust hooking the line from the j-pipe to the wastegate isn't going to help. Get a carbide burr bit and start going to town.

The purpose of doing that is not meant to help the issue, but to determine the issue. Once we know that the turbo is creeping, then we can move on to solving the problem.