Compressor Surge/low boost-14b

[jrh8tc]

I am getting bad compressor surge and I can't figure out why. I have a stock 14b setup with hard intercooler piping, 3" gm maf sensor, a knock off MBC and a knock off bov. I am able to only push about 9 pounds of boost even with the MBC shut. The turbo is spooling really slow and boost levels are low. At first I thought it was the BOV fluttering but after a closer look it is definitely compressor surge, even after loosening the spring in the BOV all the way I can't get the BOV to open. I have ran boost leak tests and can't find anything. There is no shaftplay in the turbo and it spins easily. The car only has 102000 miles on it. I do think there may be an extremely small exhaust leak. Any suggestions on how to mitigate the compressor surge and what could causing low boost levels??? How detrimental can an exhaust leak be??

 

[stefanOst]

Have you tried switching the BOV over to a known working one?

 

[Dsmj89]

Loosen up the adjustment screw on the bov, it's most likely tight and not opening, and then report back.

 

[jrh8tc]

I am trying to track down a working BOV to test that, I have loosened the BOV screw all the way and still it wont open. I can open the BOV with my fingers but I am not sure exactly how stiff it is when it is working. Even if the BOV is not opening, that would not be attributing to the low boost in the first place. Correct me if I am wrong but the BOV only opens when there is a drastic change in pressure which I am not getting with low, slow building boost.

 

[sschambers]

Depends on how bad the exhaust leak is. If it's before the turbo, it could possibly hinder performance. If it's after (like a bad downpipe for instance), it wouldn't hurt performance. Either way exhaust leaks sound terrible (depending on how bad they are).

As for your compressor surge...Get a reputable BOV, not a knock off. Trust me, real ones that have good reviews are worth the extra money, and not just because of the noises they make.

If you're venting this BOV, your performance problem could be because the BOV is leaking out the boost, if the spring is too loose. But wouldn't exactly explain the compressor surge...

Double check for a boost leak, and also check all vac lines.

Make sure the vac line for the BOV is properly connected. Not only does the boost that the turbo creates help open BOV, but the sudden pressure change (boost to vac) pulls that valve open also.

What's your vac like at idle? "Normal" is anywhere from 17-21 I believe.

Either way, quit boosting and making compressor surge. Find the problem and fix it ASAP unless you want a blown turbo.

 

[96turbospyder]

adjust your bov the adjuster is ###### to tight.

 

[jrh8tc]

Thanks for the response sschambers, vacuum appears to be fine at about 18 at idle. I figured that an exhaust leak would be pretty apparent due to the sound but I was not sure. I have been thinking maybe my turbine housing is cracked leading to a lack of boost but I would think that might make a decent amount of noise also.

As for everyone else, please stop telling me to loosen the spring in the BOV, it is out all the way!!! read all the post.