For some reason or another I'm haveing this boost problem in fourth gear. every now and then mainly under WOT in 4th I hit anywhere between 18 and 20 psi, I've had the gauge checked and it seemes to be accurate. Sometimes it spikes that high and sometimes it holds it there. Does'nt trip any codes for the engine light either. I have not Idea what the problem is. Maybe I need a boost controller and good wastegate? If anyone else has had this problem please let me know what you did about it.

 

what are you mods? i'm not understanding why this is a problem.....please explain a little more about the car and situation.....

 

I agree, Psi. Where/Whats the prob?

 

I dont have many mods, CAI, Exhaust, BOV, Springs and sway bars, the reason i'm concerned is because A: the boost usaully drops at 5000 rpm to 11ish right......this doesnt..and B: 5 psi extra is a hell of a spike.

 

is this happening when you're just crusing in 4th and then go wot, or on a full run?

 

I agree - it sounds like a little big of a spike on a stock ecu.

Have you put atogether a boost leak tester? Definitely a good idea, it sounds like you have a small leak, to me. The turbo might be compensating.

You can make one easily with a valve stem a 2.5-3" pvc cap and a rubber plumbing elbow and 2 band clamps. Once you hook it up to the turbo and pressurize it to 20 psi, listen; I bet you'll find the problem. Maybe intercooler piping, maybe the one at the bottom of the turbo, maybe lines, but listen for the hiss as it depressurises.

Alternatively, some are hooking it up, via 3" rubber hose to the mid-section of your cai, But I like to hook it directly to the turbo, myself.

Good luck.


Edit - unless - like psi chick, said, you're hitting full boost in low rpm's and lugging it, like psi chick said. Then, it is pretty normal. But it doesn't sound like that is the situation.

 

if this is happening from a low rpm going to wot in 4th it's not that odd. it's the ecu trying to produce power requested, and plus in the heat that's been going on you're going to see higher psi levels.

 

Sweet, I'll give that a try and get back to you......I found that if i'm setting up for drag run (WOT through evey gear) its stable but every now and then say I'm on the highway somewhere around 3300rpm give or take a litle and plant it thats when it will spike. I have to do a litle more playing around through out the rpm range to find out exactly. I also read that the stock turbo can't handle much more then 16 psi without running the risk of turbo lock or sesuire.? What are your thoughts?

 

when i was s2 i was spiking 21 and holding 19, turbo was fine. i wouldn't go much past 17 without addressing fuel delivery though.

 

S2 meaning stage 2 I assume. you were holding 19 ...... was that through evey gear?