Ok, ever since I got my new single set up I've had problems with overboosting. My first problem was that the custom exhaust manifold was built wrong and the wastegate was welded coming off of only one of the two pipes. Meaning that the wastegate would open at 9psi coming off the one pipe, but the other pipe kept boost pressure and made me overboost. It would boost creep past 15psi around 4k RPM. I was running the turbo off the wastegate btw. So I took off the manifold and had it fixed (making the wastegate coming off of both pipes). Right after I got it fixed I took it for a test drive and it boosted right around 10psi, but I never took it past 5k RPM. So.... today I took it past 6k and the boost crept past 18psi. Some people tell me it might be my wastegate, but I got this wastegate off my buddy and it worked fine on his FD and it never overboosted. So what could be my problem (my manifold, my wastegate, my turbo?) Anyone else experience this after they went single. I do have a Profec B boost controller on the car but I'm not currently running it with the single set up. Should I use my boost controller? Do you think it would help my overboost problem? Sorry for the long post, I'm just so damn confused and frustrated.

 

What type of Wastegate is it?

Have you tried adjusting the spring on the wastegate?

too rich the car opens up slower to build boost
too lean revs real fast and can cause overboost

 

It's a turbonetics, and I haven't tried adjusting the spring on it.

 

What pound spring is in there?

 

It sounds like the wastegate is too small to handle the kind of Boost the Turbo is making, if your friend was running a smaller turgo he might not have the same problem you are having.

 

Yep if it is the deltagate which is 35mm that might to small, hmm even tho the HKS standered is also 35mm
it might have a better reaction time, since I've seen people with 60-1, HKS manifolds and wastegates and no overboosting

Try getting a stiffer spring for the deltagate

I have a RaceGate 42mm(stiffest spring on it) and it kept my boost under controll for the most part with a T-66. I had the wastegate tube coming out near the T4 flange in between the 2 primary runners

 

Can you show us a pic of the exhaust manifold and it's wastegate placement?

 

Im running a T72 with the HKS wastegate i believe its a 40mm and has a 10lb spring. I have zero creep problems, depending on how much boost your going to run you may need a larger gate.

mike

 

I am planning on running about 12psi for now until I get bigger injectors. Here are some pics of the manifold. Sorry for the quality, I tried my best snaping the pics with the little room I had. For better quality, add .orig.jpg to the pic's url.

 

Also, not meaning to get off topic but after my single set up we had to plug up this hole that comes from the intake manifold. I sounded like exhaust came out of there (exhaust leak sound) so we pluged it up with some epoxy. What's the point of this hole on the intake manifold. My boy told me that it was part of some emissions crap. Is that true?

 

Hmm, no pictures of it off the car? It's hard to tell how the WG plumbing comes off the main runners. Maybe it's just a issue of too small of a WG?

 

Who made the manifold Rey... Gato?
By the looks of it, It places the turbo real high
hmm looks alot like my old design except the placement of the wastegate runners

looks like by the 1st pic the wastegate runners come off the bottom of the primary runners

If placing the runners that low underneath they should be placed at a angle in the primary runners

or better by the Turbine inlet flange where most exhaust pulses collect..something like that

 

Fuego made my manifold Roger. The waste gate comes off right where the pipes bend up towards the turbo.

 

LoL Yep I thought so
He made mine
I see he perfected the welding a bit compared to mine

He placed the wastegate tube in between the 2 runners
compared to yours

Worked damm good after I had it rewelded
I also after this pic had it sand blasted and ceramic coated

 

Too rich will cause overboost because the unburnt fuel ignites in the manifold causing the turbine to spool faster.

 

could be I have my facts wrong
I know it was one of those conditions vice versa

 

I had Rolo tune my car up to 14psi, before it would spike, and it was just right. I don't think I'm running too rich or lean. So you guys think it's my wastegate? My flange is for a 35mm or 38mm. If I switch to a 38mm would it help my over boosting problem? Or should I redo my manifold once again and make it for a 40mm wastegate? Or should I just buy a new manifold and new 40mm wastegate? I don't want to go with that last choice because I don't have the money.

 

Well I did have a deltagate
and Once I took a look at the turbo I was about to use
I said hell no thats too small
sold it on ebay and got a RaceGate 42mm on Ebay

Tial wastegates share the same flanges

 

So should I get the Tial 38mm wastegate with a .7 bar spring (10psi)? You think this would fix my problem?

 

my friend has a brand new turbonetics racegate for 300 dollars with flange.

 

Just tune it for more boost.

 

Thats what I was thinking.,.....whats the problem....just add fuel haha

 

I'm adding fuel pretty soon, but I don't want it to boost over 20 psi. Besides I need a bigger intercooler.