Boost issues..

[Swifty1638]

I had not had a mbc on the car, as the one before it seemed to be screwed up. So, Iwas boosting at 10 psi. Today, I got a mini butterfly valve deal from kory, that he had used before. I put it on, and boosted to 18 psi. However, I am not building past like 8 psi in first gear, and it seems as if I had to really step on it to get to the other upper half of psi..not only that, but it would boost up to 10 psi, then pause a bit, then go up towards 15 and lil past. Also, sometimes, when I drive, the turbo spools, but i don't feel that kick in the ass on power. What could be the issue?

-A. Swift

[Swifty1638]

And, as far as the not feeling the kick in the ass, even though the turbo spools..That's always happened. I'll not feel any boost when i leave my house, but when I get towards cnty rd. 81, i then start to feel that kick. And, I have a remote start, so I do warm the car up every morning.

-A. Swift

[Jakey]

I had not had a mbc on the car, as the one before it seemed to be screwed up. So, Iwas boosting at 10 psi. Today, I got a mini butterfly valve deal from kory, that he had used before. I put it on, and boosted to 18 psi. However, I am not building past like 8 psi in first gear, and it seems as if I had to really step on it to get to the other upper half of psi..not only that, but it would boost up to 10 psi, then pause a bit, then go up towards 15 and lil past. Also, sometimes, when I drive, the turbo spools, but i don't feel that kick in the ass on power. What could be the issue?

-A. Swift

Please list the year of car, drivetrain type, ..... Also list any relevant mod's to the car and anything that you have already checked.

....

[A//// Guy]

Why not get a real MBC and see if that "valve" you are using is the problem? Also maybe your AF ratio is terible if you are switching boost up and down 8-10PSI...

[Swifty1638]

Well, I am running boostingsx's car. ( 92 gsx, awd, built motor by mike, etc etc). I bought it from him. I don't have another mbc to use, but kory seemed to have no problems with it at all. I really don't know what it could be.

[JiggahMan]

Sounds like you're getting knock..

[GODspeed1320]

Sounds like you're getting knock..

I'd have to agree with JiggahMan on that one.

[JET]

Well, the 2 newbies seem to agree.

I would do a boost leak test. You could have a massive boost leak causing it to run rich and that will also limit your boost.

[Swifty1638]

Well, It does run rich. I am waiting on mike to make me a new pipe to move the maft towards the intake. how can I perform a leakdown test? Just spray the shit with a soapy mist of water, and find the bubbles? I got on it today, and when i hit about 17 psi, the car felt and sounded as if i had hit the rev limiter. I was pretty sure i didn't though. I turned it down to 15 psi or so. I know that I want 20 or so, so what can a big 16g take? The motor is built by mike, and I am trusting this guy's work. I hope to take the car back to him, in hopes he can drill, tap, and place my egt probe for me. I am also waiting on that fuel rail from him( kory dropped off the sending unit for my gauge). Anyone have any other ideas? Those 3-4 vacuum "ports" on the top of the intake, right behind the biss screw (idler screw) are all plugged of. Basically, a hose, routed from one port, and 180'd into the next. Something tells me that that's not a good idea. I also thought the boost gauge was supposed to be tapped from there.

-A. Swift

[JET]

Those ports up there are just the EGR stuff. One is a pressure port though. Here is the boost leak tester.

http://www.vfaq.com/mods/ICtester.html