Still having trouble building boost!?

[V7X]

Okay so I posted a long time ago that I was having trouble building boost in my 1g Laser. Here is the update....I did yet another boost leak test and found 1 very small leak. It's the Gasket for the J-pipe. An easy fix, but not the only problem apparently. I disconnected the Boost controller from the wastegate in an attempt to reach something above 12 psi. During the boost leak test I had to turn the Compressor up to almost 30 psi in order to get 18 psi charged into the system.....I took the car for a drive with technically no wastegate control and couldn't get over 10 psi in any gear. Theoretically I should have maxed out the turbo, correct? Why is it that the turbo is having such a hard time building boost?...The boost leak isn't that big.....It took a long while for the pressure to drop during the test. One friend suggested that the cat may be so clogged that the turbo is too restricted. And another also suggested that the flapper may not be closing all the the way.

Almost forgot, with the Joe-p turned in all the way I could hit 13psi in 3rd gear, but I could hit full boost until about 4900 rpm.....?

Ideas?

Thanks!!!!

 

[ddavisaf]

If the cat was that clogged, you would but stumbling every time you tried to accelerate. If all of the leaks have been fixed meaning you can hold 20 psi in your system for 30 seconds or more then the wastegate would be the next area to look at.
Since you've already ran the unhooked wastegate test... one could assume that your MBC is fine. You'll want to take off your O2 Housing and see if the flapper is sealing shut, or if the turbine housing is so badly cracked that you cannot possibly seal shut.
If you're simply not sealing and your have a non-adjustable wastegate arm. Try reinstalling the wastegate actuator with washers. This will push it back more and allow it to seal properly without bending the arm.
If it's cracked to the point where it's not sealing anymore you can try having it machined, but I'd recommend replacing the turbine housing.

 

[Ultimatedsm]

Turbo lag is caused by a few things. Anyway, you said you did a boost leak test and you fixed all the leaks. Have you checked for a crack exhaust manifold? Its a common problem for 1g's. A big exhaust leak will cause a slow spooling engine. You said it took 30 PSI of pressure to hold 18 psi in your intake tract, how long did this 18 psi last? Re-due a boost leak test and hold 18 or 20 psi for 30 seconds.

 

[V7X]

Thanks for the info.....I'll definately will check the turbo...And it held the 18psi for over 30 seconds, even with the small leak... I will of course do another boost leak test after replacing the gasket. But I think that you guys are more on the right track as far as the turbo goes.....I guess I'll find out this Wensday. Is it exspensive to fix the exhaust side of the turbo or should I just start looking for a new one if thats the problem? I was thinking of just getting a 16g and upgrading...Thanks agian for the Help!!!!!

Ryan

 

[blah blah dsm]

im gonna go with the flapper on the exhaust sid eof ht eturbo not closing all the way.

 

[91gsxboosted]

Okay so I posted a long time ago that I was having trouble building boost in my 1g Laser. Here is the update....I did yet another boost leak test and found 1 very small leak. It's the Gasket for the J-pipe. An easy fix, but not the only problem apparently. I disconnected the Boost controller from the wastegate in an attempt to reach something above 12 psi. During the boost leak test I had to turn the Compressor up to almost 30 psi in order to get 18 psi charged into the system.....I took the car for a drive with technically no wastegate control and couldn't get over 10 psi in any gear. Theoretically I should have maxed out the turbo, correct? Why is it that the turbo is having such a hard time building boost?...The boost leak isn't that big.....It took a long while for the pressure to drop during the test. One friend suggested that the cat may be so clogged that the turbo is too restricted. And another also suggested that the flapper may not be closing all the the way.

Almost forgot, with the Joe-p turned in all the way I could hit 13psi in 3rd gear, but I could hit full boost until about 4900 rpm.....?

Ideas?

Thanks!!!!

I would check to make sure the exhaust manifold had no leaks, and check the wastegate flapper. I would also keep doing the the pressure check, and hold it. If the cat is clogged, you probably wouldn't even hit 10 psi of boost.

 

[V7X]

SO I got my turbo off today and you wouldn't believe how cracked the housing was on the inside. There was so much materiel missing from the wastegate side that it looked like the flapper was off center! So my question is do I go looking for an exhaust house( I found one actually) or do I just spend the money and get the Evo III 16g? I don't even have an exhaust yet! I was think that my 14b would last at least long enough to at least get my exhaust.....

Thanks!

Ryan