Just installed Defi boost gauge (only mod) today on my '03 with 17k miles. I bought the EVO used with 12K on it. My boost peaks and stays at 11-12psi!! We have sprayed carb cleaner on all the hoses and cannot find a leak. All of the hoses are tight and connected properly. My vacuum is sitting at 15 at idle. My friend says that is not right either. I found out the stock turbo was replaced under warranty after i bought the car. I am really freakin out, so any suggestions would be greatly appreciated. The car is all stock, and from what i have read on this site, should be pushing 19-20psi peak, right? If i take to the dealer, should i leave my guage installed? Please help, b/c this car already seemed fast to me, but if im only boosting 11psi....i cant imagine 20psi! I really want to get this fixed ASAP, so again, thanks in advance for any suggestions.

 

When you hit full boost, does it take longer than normal to hit 11 psi?

 

Sounds like boost control is malfunctioning for some reason and you're only getting spring pressure of 11-13 psi. That will certainly make for an underwhelming experience.

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FWIW that's how much boost I see when my boost controller is closed.

 

If the turbo was replaced before.

Check the wastegate actuator. Maybe the rod is bent or not properly adjusted.

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Have you ever ridden in an evo pushing 19-20 psi and an evo pushing 11-12? You can feel the difference.

Is the reason you got the gauge because you thought it wasn't pulling hard enough? If you think it feels fast, have you considered that you may have a bad boost gauge? I have a Defi D gauge, and mine is good, but I've heard horror stories of Defi D gauges reading incorrectly.

 

are you still running the stock BOV? they seem to have a tendency to leak especially if you decide on upping the boost a bit.

 

bet your boost gauge is screwed up. I had the same problem, replaced gauge and it really was boosting 20. I had an autometer. I have heard of Defi gauges going bad. 15 vacuum is waaaay too low also, your car would be running like crap.

 

We need to know.

 

Seen this a bunch of times... you need to check your vaccum hoses that go from the compressor outlet and wastegate to the boost solonoid. This hose should have a small restrictor inside them that limits the amount of air through them. If this restrictor is removed you will not get more than 11-12psi.

 

This is what my friend said after checking everything. I know he didnt check that. Is it hard to get to? I will ask him if he could check that. I dont know about turbos....he is very good with them. We will try a new gauge tomorrow. He said he has a "boost meter" that would be hard to hook up. I will call him now. I am getting alot of answers here, thanks alot for all the quick responses. Hopefully we can figure this thing out. Im going crazy thinking about it. My friend with a modded srt-4 says he thought it pulled pretty good, but imagined an evo would be much faster. Keep the ideas coming...i will answer everything...really appreciate it.

 

NO., it jumps to 11psi almost immediately at WOT and stays there perfectly. Actually it hits max boost at 11psi at half-throttle.

 

Thats interesting...i will mention that definately to my friend. As far as i know, a boost controller is not installed. I am pretty sure he checked for one. So, considering your situation, i wonder if i got a mbc would that get going? I shouldnt have to though i would think

 

maybe the hose that is connected to your gauge is pinched. my guess is your car is fine and its the gauge. a good way to find out would be to drive an evo that you know is making 20psi. if there is a big difference in power, you will know somethings up with your car...

 

+1 check your lines make sure their not pinched