Hey whats up fellas i have a jdm gsr block i built for boost eagle rods,wiseco 8:9:1 pistons and all that good stuff...i had the car street tuned on 14psi and it ran great would spin very badly throu 2nd into 3rd..now for some reson the turbo spools slower than it used to..like in 1st it would start building boost the smack the revlimiter now it pulls but dosent break the tires loose and have near the power it felt like it used too..and i have a open loop dump tube and it used to be pretty loud once opend up but its not loud at all....im thinkin it the manual boost controller..its a tial 38mm with 8psi spring and turbosmart mbc but its about 5-8 years old...would i mbc play this roll causeing the wastegate to act alil funny..im hoping yall say yes because ive checked for leaks and cant find anything...ive ordered a new mbc..thanks for your help

 

wat

 

check the turbo piping. could be a loose clamp.

could be the wastegate but doubtfulll, but check the wastgate gasket

 

I'm thinking it's a MBC problem. They aren't really that great of a control solution, and aren't the most consistent devices either. A boost leak on the main piping or wastegate should be easy to spot and usually easy to hear, and you're having a problem building boost so it may be a problem with the wastegate control. That's why I would take a long look at the boost controller.

I guess my biggest question is have you actually looked at the boost response with a boost gauge, and is it having problems building boost or is it just low on power with a normal boost response?

 

Did you first get it tuned in cool weather? There will be a noticable difference in power between hot and cool ambient temps.

 

yea sorry let me reword this..it builds boost like 3500-4000 spools kinda quick but sometimes it goes to 8psi sometimes 14 sometimes 12..i ordered a joe p mbc will be here thurs.i took the wastegate apart and checked for anything out of the normal..al was good..i noticed my dump pipe is no where near as loud as it was..i thinking because before it built bost then opened when it got to the set point..now i think the mbc is playing tricks on the wastegate and its slowly bleedin...any yes it was tuned in cooler temps kinda muggy thou..i will be soon coming to u to get it tuned

 

i pretty much got it figured out...i heard a rattle when i was backing up..got under the car and beat on the cat..yea the guts are loose as shit..its coming out tomm and either getting gutted or sliding a peice of 3" in place of the cat

 

I recommend just removing it and going with a 3" straight pipe

 

yea thats what im going to do and im going to also install my oil catch/breather can