initialDRacer

iTrader: (9)

Hey guys, how can I get consistent boost? For some reason I am having problems keeping up boost at the high rpms. At 3000 rpms, the boost is consistent and reaches 4.7psi. But when it reaches 4000, that's where it starts to come down. or stays at 2.3psi. Is it because of my cheap @ss blow off valve that came with the RRM kit? Do I have to weld the headers to the turbo pipe as well as the downpipe to the turbo pipe to get a "no exhaust leak" setup? I went with copper gaskets on my whole setup. Even the Greddy exhaust I placed copper gaskets. How about the intake side? How can I check if there are leaks? I already disassembled and retightened everything. I'm sick of having inconsistent boost.

Danno

iTrader: (4)

If there is a leek on your intake side you will hear a whisteling sound (usually). If there is a leak on your exhaust side you will see carbon around the joint on the outside.

OZLancer1

iTrader: (3)

I had no patience and put my RRM stage 2 on with the stock exhaust manifold (I had a friend rework it for more flow though) and I have a few leaks. One where the up-pipe attaches to the exhaust manifold, and one around my 02 sensor threading hole. Even with those leaks I have no problem reaching full boost. In fact I reach full boost pretty quickly in my opinion. I never have problems losing boost or getting to full boost. When you're boosting, does your car jerk or hesitate when you lose boost? Or is it running fine but just not going past a certain psi? Could be your wastegate or BOV opening too soon.

initialDRacer

iTrader: (9)

My car does not jerk or hesitate when I lose boost, it just gradually goes from 4.7 psi to 2.3 psi @ 4500 rpms. My BOV is a stock bov that came with the RRM kit. It wasn't adjustable or anything. I'm still waiting to install the greddy bov. I followed the instructions when installing the Wastgate so I have no idea if it's the wastegate or not.

KillahB

iTrader: (7)

This is what you should do to test for boost leaks. Get some sort of boost leak tester (my buddy used some PVC which covered the inlet of the turbo, with a tyre pressure inflation tube in the other end) and just ran some air through the system. That gets the turbo spinning and you can hear if there are any leaks.

What turbo are you running btw? You turbo might be too small and ineffective in the upper RPMs, even tho for that low of a boost seems incredulous... also, what setup do you have? Do you have any kinks or bends in your pipes that would inhibit flow esp. at upper RPMs? WHat size are your IC pipes?

I remember someone who had a similar scenario with lower boost at WOT in the upper RPMs, but I cant remember who. I dont think it was a Mirager, but I will ask around and see.

HobieKopek

iTrader: (8)

An exhaust leak isn't the same as a boost leak. The symptoms are similar, but they're much easier to spot. As Danno mentioned, carbon builds up around an exhaust leak (and fast if you're running as rich as you should be).

Boost leaks are significantly harder to find. You can check your vacuum hoses, or better yet just replace them all and make sure they're routed correctly. Leaks in hard piping can be very difficult to spot, and any boost leak is hard to pin down with any accuracy because there are so many lines and pipes that carry pressure. If you don't want to replace your hoses a soapy water test could work, but it's not exactly the best method. Good luck. I'd recommend checking the injector seals, especially if you've touched the fuel rail/injectors/intake manifold in any way.

initialDRacer

iTrader: (9)

There was one kink or bend on the intercooler outlet pipes. I asked Rob and he said it shouldn't be a problem. I actually tightened the tube all the way so that it will cover the whole kinked tube. I got the RRM kit with a T28 garret turbine.

Can you tell me more about the pressure tester? Can I use my car's boost gauge to find out the pressure? Does the car need to be running for this to work or just put the ignition on II?

How about the same pressure gauge used to fill up the a/c? Can I do something similar to measure the pressure?

sjl6102

iTrader: (1)

i had boost leaks on my wrx and when we hit atmospheric pressure it felt like a rev limiter at 4k. it was because the couplers weren't tight enough for our front mount. the turbo inlet hose could cause it to run horribly if it is loose. as far as boost dropping off it could be the wastegate spring or actuator. check the line from the wastegate to the pressure side or the boost controller which should T off of that line.

Blacksheepdj

iTrader: (88)

The GReddy is an option. Translation - pay more for it. If you don't, they give you the stock Evo/2g Eclipse BOV.

initialDRacer

iTrader: (9)

I'm looking at a couple of boost leak testers and I'm not sure which is recommended. One is from Mach V

Here are other links:

http://www.team3s.com/~egross/3S/Maint/TT/IntPresTest/

http://www.stealth316.com/2-pressuretester.htm

Or maybe i can make something out from home depot parts... Any thoughts?

livelyjay

iTrader: (20)

You realize Mach V is like right down the street from you right? They are in Sterling, VA. I would call them up and see if they can test for the boost leak for you, so you don't have to buy the kit and mess with it yourself. They might also be able to diagnose the problem if it isn't a boost leak.

OZLancer1

iTrader: (3)

This is the downside of turbocharging. Everyone told me that when you go with boost, you can get more problems and they are tougher to troubleshoot cuz a lot of problems can give you the same symptoms. I think it's worth the trouble though. I had some problems with mine, but we figured things out quickly and now it runs fine. Sucks you're having so many problems narrowing it down. Hope ya get it figured out man. Good luck.

sjl6102

iTrader: (1)

modifying at all can bring more problems but once you get the kinks worked out, it is a beautiful thing. in the case of not modifying the wrx tranny and just kept going through stock ones it would be rediculous. we went with the good stuff once warranty was up.

initialDRacer

iTrader: (9)

What's up jay you still busy man? Well I'm not sure how much I'll pay for labor but I hope it's not that much to get a little diagnostics.

initialDRacer

iTrader: (9)

Ok, I'm planning on making my own pressure tester. I guess to do that I will just have to cover up the K&N CAI intake and put a pressure tester there eh? Do I have to seal the blow off valve? This is assuming I want to test it from the intake down to the intake manifold? Or do I have to just go from the turbo inlet?