jetblack

I just had a used turbo installed a few days ago,since I blew the one i had. Well the problem is I cant get boost past 12psi with my profec B on, 6.5psi w/off. I was running up to 17psi before it blew with profec B on and 12 w/off. We checked all the hoses and the profec ,yet we cant find the problem. We removed the pressure side of the wastegate and it still would not past 12psi.

Scott 89t2

this is a stock turbo?? they are no good past 10psi. if you want to run that high you need a full T04 setup. what other mods do you have to safely allow 17psi??

jetblack

I have a 5th injector, a fuel cut defencer,profec B and a 300zxtt fuel pump for fuel support. I dont have any fuel problem, my egt goes to 7.5 the most when I was running 17 psi. Everyone I know with a t2 run up to 15psi on stock turbo. Its just with this new turbo I cant it up to 15psi lioke I use to.

Scott 89t2

dam, what are you intake temps at 17psi?? they would be through the roof. I can't help you. everyone I know has problems running over 10-12, it just dosn't work on a stock turbo unless you have upgraded compresser wheel. and it is pointless on a stock turbo, you are probably making the same power at 12 then at 17. cause all you are doing is making heat.

jetblack

I have a jap engine and I have had that turbo over 2 years running at 15 psi. You will feel the difference at 15 compare to 12 psi. All my friends and my mechanic believe and have been doing this. I dont know if its only happens on jap engines, but thats what we are using.

BOOSTD 7

Hell, every T2 I've worked on had no problem boosting as high as I want it to. It sounds like your turbo is shot if it will only make 6.5 without the controller where you made 17 before. I assume you have an open exhaust. Any play in the shaft? Does it smoke at all when you hit the gas?

I think it's not true that stock turbos won't make power above 12psi. I think the limit is more like 15-16 psi. I know I ran 17 before on my stock turbo and it pulled like hell compared to 12 psi.

Maxthe7man

Well, a stock turbo will easily go to 15 psi, but runs out of voume past about 5000 rpm, and the boost will drop off, the thing to check is the gaskets between the turbo, and the gaskets between the block and the manifold, if you have an exhaust leak it that area it will cost you boost.. Also, you may be leaking past the wastegate, if it was overported or the seat/flap has erroded, you have checked for boost/vacuum leaks right? Max

swoop

I was just going to start a thread about this subject.

I have a 87 T2, with down pipe and stock IC I was running about 12 lbs without a boost controller. This weekend I put on my FMIC and boost shoots to 15-16 lbs at half throttle, so needless to say I haven't floored it yet. My A/F gauge is still in the green. What's the max boost the stock turbo can make???

jetblack

15 PSI SHOULD BE THE MAX CONSIDERING EVERYTHING IS STOCK. IF YOU UPGRADED THE BLOWOFF VALVE AND/OR THE WASTEGATE YOU COULD PLAY WITH IT A LITTLE. AS LONG AS YOU ARE NOT LEANING OUT YOU CAN INCREASE IT. IF THE TURBO CAN'T GET RID OF THE EXCESS BOOST IT WILL OVERBOOST AND/OR BLOW EVENTUALLY.

jetblack

WELL IF I GET ON IT HARD, IT WILL SMOKE A LITTLE AFTER. THERE WAS NO PLAY IN THE SHAFT BEFOR IT WAS INSTALLED. THE TURBO SEEMED TO BE IN GOOD CONDITION WHEN WE GOT IT.