Boost Help??

[REDBLUR]

Alrite I installed a boost controller recently (home made off the net) and have a few questions. I am running the stock exhaust with a fuel pump rewire. I adjusted the boost to 15 psi(aftermarket boost guage). When I hit 15psi it holds for a couple of seconds and then tapers off to 10-12psi as i move up in the RPM range. Is this normal??? Or do I have a boost leak somewhere???

I am going to be making a leak tester and checking anyway, just wondering if the boost is supposed to hit and hold at the specific PSI setting throughout the whole RPM range (3500-6300RPM).

Thanx

 

[CL MaNTis GST]

first off you need to specify which turbo you are running. Judging by the yr/model of your car im guessing the 14b. I'm not exactly sure about the 14b but i know that the T25 looses boost pressure after 5500rpm. I know the 14b is a bigger turbo than the T25 but it is not a big difference so that might be your problem.

at what RPM exactly does your psi start to drop?

that alone might answer your question.

...i could be wrong, but i hope this helps

g'luck

 

[REDBLUR]

I made an intake leak tester and tested for leaks. Right after the compressor housing there seems to be a leak where it connects to the exhaust side of the turbo (14b). Is this an easy fix??

Boost jumps to 15 psi and jumps down immediatly to 9-11psi on hard throttle above 3500 rpms. It is not a huge leak, dont lose pressure immediatly but does go down in about 1-2 min after being pumped up to 18psi.

 

[CL MaNTis GST]

hmm damn u are at WOT for 2 minutes? thats long...

 

[REDBLUR]

No thats when I pressurized the turbo using the intake leak tester!

 

[CL MaNTis GST]

oh got ya!

 

[pasths]

Well I also just installed a Hallman MBC and I'm having the same problem the boost drops back to stock level. I didnt have this problem when I didnt have the MBC. I had a UPIC pipe and 1 gen bov and the turbo was holding 15 psi without dropping (without MBC). The MBC so far has decreased my 1/4 mile time by half a second.

So my guess is its not leaking. Just need to crank more boost and live the spike.

I have the T25 though.

 

[CL MaNTis GST]

at what RPM does your boost drop?