Car won't boost past 12 psi

[Michael Jones]

I have a new 16g turbo, I recently put a manual boost controller on the car but was not able to achieve a higher boost level, the car usually boosts to 12psi under hard throttle. I was stumped so I disconnected the vacuum line going to the waste gate actuator, it boosted to 12 psi again. I wired the waste gate shut thinking exhaust may be pushing it open, it did the same thing. I did a pressure test on bov, ic and all pipe. The bov was leaking so I put a hks sequential bov on it. It still will not boost past 12psi. I am beginning to think that the factory boost guage will not work past 12 but I have not hit fuel cut ever. I am out of ideas.

 

[imagine3163]

I am beginning to think that the factory boost guage will not work past 12 but I have not hit fuel cut ever. I am out of ideas.

Getting an aftermarket boost gauge should be the first thing you buy before you start to turn up the boost. The stock gauge is only an estimate and can not be relied on (especially when trying to boost past stock levels). When you turn up the boost, does it feel like it is pulling any harder? Is this setup being ran on your 94 n/t? If not, update your profile so we can better help you.

 

[Michael Jones]

I put a 90 Eagle Talon TSI engine,computer, wiring harness in it. It doesn't seem to be pulling any harder, but the power band does seem a little smoother since changing out the leaking blow off valve. What do these cars normally boost, the turbo I bought had a wastegate actuator that has an adjustable rod. I adjusted it to where it had a slight bit of tension on it upon install. It has stock exhaust with the exception of an aftermarket muffler. I removed the snorkel from the intake filter housing. Other than that it is a stock 90 Talon TSI engine.

 

[imagine3163]

What do these cars normally boost

Normally as in the stock boost setting? The stock setting is around 11psi (for the T-25). With your setup though, I wouldn't run more than 15 - unless you have supporting fuel mods you aren't mentioning. What kind of mbc is it (ball and spring/bleeder valve)? Like I said before, you really need to get an accurate boost gauge before you do anything else.