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View Full Version : Won't build boost?


Solidus311
07-16-2008, 06:12 PM
My rb25 won't build boost. My gauge reads vacuum then goes to 0 and no further. I bought a used OEM wastegate but I am being told that it could be the turbo itself. I checked all my piping and I don't think there are any leaks. I have yet to do a boost leak test though.

Prior to losing boost I was doing a little clutch kicking. :ugh:

I have an SAFC with fuel turned down 10-22 percent, and a manual boost controller set to about 12 LBs. Car has trouble running at all, much less with boost. Seems to be running super rich, it bogs down and can hardly make it to 4k RPM's.

What about the ECU wiring? I had someone with me at the time and maybe he kicked the kick panel and fucked up my ECU.

kevtrinh
07-16-2008, 07:02 PM
sounds like boost leak

Solidus311
07-16-2008, 09:24 PM
sounds like boost leak

Alright, I guess I'll rig up something to test for a leak before I drop the money for a turbo.

fliprayzin240sx
07-17-2008, 01:39 AM
Check the tubo too, not that hard to check it. Take the inlet off and spin the compressor by hand.

Solidus311
07-17-2008, 02:11 AM
Check the tubo too, not that hard to check it. Take the inlet off and spin the compressor by hand.

Compressor side seems fine, spins freely and not a lot of play. I haven't checked the exhaust side.

awesomenick
07-17-2008, 02:28 AM
Both wheels on the turbo are connected on a solid shaft. Normally a problem with the turbo would be in the center section, so you probably don't need to check the exhaust side too. If it spins and doesn't have excessive shaft play through the intake side, it's probably not causing your issues. It sounds a lot like a boost leak, maybe one of your couplers popped off, or has a tear in it. You should build a boost leak tester, and also use some soapy water on all connections to make sure it's perfect.

When you have a boost leak, you're leaking out metered air. This would cause the MAFS readings to be totally incorrect, and that could be why your car hardly runs.

Solidus311
07-18-2008, 02:40 AM
Both wheels on the turbo are connected on a solid shaft. Normally a problem with the turbo would be in the center section, so you probably don't need to check the exhaust side too. If it spins and doesn't have excessive shaft play through the intake side, it's probably not causing your issues. It sounds a lot like a boost leak, maybe one of your couplers popped off, or has a tear in it. You should build a boost leak tester, and also use some soapy water on all connections to make sure it's perfect.

When you have a boost leak, you're leaking out metered air. This would cause the MAFS readings to be totally incorrect, and that could be why your car hardly runs.

Man I hope you're right. Fixing a boost leak is far cheaper than a used/new turbo.