33-37PSI on a MBC??

1993-Talon-TSI · 09-11-2008, 01:57 PM

Very dumb question but i have not been able to figure out the proper way to hook up my mbc on my car to get over 30psi of boost accuratly.

Turbosmart MBC
Tial 44mm Gate- heaviest 2 springs installed
GT35r-T4

The car was set up with the mbc going to the no-spring side of the wastegate (sping side was open to the atmosphere) to help it open when it hits the desired boost. with that set up maxing out my MBC it would work well up to about 30psi.
I would like to run more than 30psi, and thats were the problem arises, i almost have to help the sping stay shut now?? This seems like such a simple thing but it has been driving me nuts. The car has AEM EMS which i could use the electonic boost control function, just have not got to that stage yet.

Any ideas or diagrams would be great, thanks guys!

snowborder714 · 09-11-2008, 02:18 PM

Not sure if you've seen this or if it'll help at all:
How to install a (Turbosmart/Tee-style) bleeder-style MBC

Also, where are you getting your boost source from?

1993-Talon-TSI · 09-12-2008, 06:11 AM

The source is coming from the Sheet metal intake manifold. I have saw that, didn't think i had to go to that extent to get the desired boost, there has to be an easier way with an external gate.

95GSXracer · 09-15-2008, 04:40 AM

I'm running a Halman MBC and a HKS gate with ~20 psi spring, I can easily get over 40 psi. I would see if your MBC spring is strong enough to get the boost you want, try hooking it up to an air compressor and use the regulator to increase pressure to see where it opens when it's turned all the way up.

99gst_racer · 09-15-2008, 09:23 AM

1993-Talon-TSI - If you're running the twin blue spring combo (1 small, 1 large) in your Tial, then that puts you at about 20 psi. You should be able to run around 40-45 psi with the help of a boost controller.

I would recommend re-plumbing your vacuum line set-up. Try sourcing your pressure line closer to the turbo, instead of the intake manifold. The compressor cover is a great source.

Otherwise, it sounds like it's hooked up properly. If re-plumbing doesn't work, then I would suspect a faulty MBC.

andy4g63 · 09-15-2008, 03:00 PM

Yep, the shorter the lines the better.