Need to fix low boost by tomorrow.

[theamsoilguy]

Hi all. I am green when it comes to this stuff. 90 Eclipse GSX stock but built for the chumpcar race series. Blew the turbo last year and had another rebuilt. Now the aftermarket guage shows 7psi. I ran 17.5 in the quarter mile today with a soft launch and not pushing redline. This is a road race car but what was a fast car is now slow.

Being the car is not street legal I have a chance Friday to go to the drags to troubleshoot\test. My 24 hour road race is coming up fast and I have few opportunities left to sort this out, hence the post of questions that have probably been answered. Don't worry I am looking for answers but I was hoping for help also.

I will be trying to do a leak test tomorrow, read up on that and I have a friend who has made the tool to pressurize the system. That's one item for tomorrow.

The wastegate...The arm is a real bear to move by hand so the spring seems good. If I take the arm off and then line it up with the pin it looks like the flapper isn't closed, there might be 1 or 2 Millimeter. It probably could use a longer arm to push the flapper closed with more force. There are no threads on it so I am wondering if it is adjustable.

Rules don't let me run a boost controller but I have one. I might experiment to see if I can raise the boost or not.

I have no idea how or what to test. Especially on a car that is parked in my garage. Once I think I have a solution I can go out and test.

Could it be the turbo? It was rebuilt by a professional shop that only does turbos but it was a unknown core.

Advice would be great so I can try something tomorrow.
Thanks
Al

 

[Dsmkauai]

Have you done a boost leak test? Seems like your issue since you just changed things and now have a hard time making boost. Also what bov are you using?

 

[keltalon]

Yeah a boost leak test is the first thing I do when I am having any kind of boosting issues. I recently had a boosting issue during the ga 1/2 mile event and found out after I boost leaked the car that I had a cracked intake manifold.

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[keltalon]

Sent it back to jmf and they fixed it no charge

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[theamsoilguy]

Found a bad leak on the throttle body gasket, which led to finding that the intake has some stripped threads. Should be easy fix but I have to take the throttle body off and borrow the right size tap and die and grab a larger bolt. The flapper also wasn't pushed all the way shut and that was fixed with some bending of the wastegate arm. That probably solves my problem but I wont make the track tonight to test.

 

[keltalon]

Found a bad leak on the throttle body gasket, which led to finding that the intake has some stripped threads. Should be easy fix but I have to take the throttle body off and borrow the right size tap and die and grab a larger bolt. The flapper also wasn't pushed all the way shut and that was fixed with some bending of the wastegate arm. That probably solves my problem but I wont make the track tonight to test.

Glad you found it!