Compressor surge?

[Jaychen]

Guys, searched but didn't find the answer I was looking for.

I get a psh psh psh psh sound when letting of the throttle when my car is making boost. I am stock with 3'' catback exhaust, my boost gauge reads 11psi at full boost.

My questions are 1. is compressor surge bad and 2. how do I fix it if it is?

I am assuming upgrading my bov would be the first thing I should look at.

 

[mkiii 4 life]

are you running the stock bov? if so try to blow through it and if you can it is bad.

 

[figgie]

My questions are 1. is compressor surge bad and 2. how do I fix it if it is?

1. Well think about it this way. If the turbo can fill all the intake with PRESSURIZED air and not skip a beat and now that pressurized air has no where to go but back against the turbo..........

2. You need a working BOV. If your is stock it is more than likely not working.

 

[Doward]

Check the BOV

 

[black89t]

so you guys with a good working stock bov is it silent or what? now i'm thinking mine is fucked up. but what i noticed when i got my first supra all i had was a intake and dp. before those modes i didn't hear anything. then the moment i install the intake i hear it. i'm thinking that the stock intake baffles the sound compared to a aftermarket. i don't think even a working stock bov (bpv) is silent. it seems unclear for a lot of people what it SHOULD sound like.

 

[figgie]

so you guys with a good working stock bov is it silent or what? now i'm thinking mine is fucked up. but what i noticed when i got my first supra all i had was a intake and dp. before those modes i didn't hear anything. then the moment i install the intake i hear it. i'm thinking that the stock intake baffles the sound compared to a aftermarket. i don't think even a working stock bov (bpv) is silent. it seems unclear for a lot of people what it SHOULD sound like.

The stock intake does absorb most of the high pitched sounds (due to the rubber matterial and the "baffling" that is used to deflect sound even more).

 

[blk92suprat]

Many years ago when my only mod was a Blitz SUS Power Intake....Right after installing it the stock bypass valve was very audible and after I left off the throttle it would go pshh pshh pshh....

Before installing the intake I could not hear the bypass valve.

I have an HKS SSQV now and it still does the same thing.

In my case I know its the Blitz intake making that noise.

 

[dumbo]

yah i got a hks ssqv and i get some flutter under light to moderate throttle apps, but if i giver i only get the EXTREMELY lound pshh, my friend gets the same thing on his skyline, i guess a little flutter aint too bad. or its a pos bov

 

[tekdeus]

I think at light throttle, a lot of BOV's flutter. I've tried a Bosch and a GFB brand BOV, and they both did this. At full boost, my BOV does not flutter, and that seems to be the most important.

 

[Rennat]

I think at light throttle, a lot of BOV's flutter. I've tried a Bosch and a GFB brand BOV, and they both did this. At full boost, my BOV does not flutter, and that seems to be the most important.

same here... i hear it flutter 4 times to be exact... chug chug chug chug... and by then its died out... WOT though, its just a giant PSHHHHH of air...

i would just make sure you have a nice big, and clear vacuum line dedicated to the BOV.

 

[grimreaper]

only single psssshhhhh from mine, bavarian brand. Low hg, (vac) barely any sound but with a few hg or a few psi a single pssshh.

 

[Keros]

The vacuum control line for the BOV may be clogged if you think the Stocker isn't working... that's the cheapest and easiest thing to look at first.

 

[supradjza80]

The vacuum control line for the BOV may be clogged if you think the Stocker isn't working... that's the cheapest and easiest thing to look at first.

^^^ yeap thats what happened with my car.

With the stock intake the turbo and blow off were almost in-audible. Once I put the Apex intake on I could easily hear the BPV and the turbo, however I was always getting the flutter noise (which while it is not ideal, flutter when letting off the throttle is much less damaging to the turbo then surge while under power). Anyway, when I put plugs and wires in the car I accidentaly snapped the rubber vac hose to the BPV and when I replaced it my car magically no longer fluttered and now just makes just one Pshhhhh sound except under low throttle/low vac to ~1 lb of boost.

So in the end, if the BPV is operating properly I would definitely check the vac lines to get rid of the constant flutter.

 

[Grimsta]

My Bosch BOV flutters as well.

 

[IJ.]

Dual Turbosmart type3's/T04z auto I get a surge if I don't fully lift off (say back off into a corner where you hold a small throttle %)

 

[empera]

im gettin surge with the phr stage 1 and a tial bov....not as much as before but still some.

 

[supradjza80]

http://videos.streetfire.net/video/Real-Compressor-Surge_163406.htm

heres a good video for anyone that is unsure of the difference between BOV 'flutter' and compressor surge under power. As IJ said it normally would occur at part throttle/high load situations if it occurs at all.

 

[zambini]

ive never heard anything while under load, full boost like that, but i do get a consistent flutter when i shift. is this just because its recirculated and its unavoidable or what?

im on the stock bov by the way. all hoses running to it are brand new

 

[johnathan1]

My BOV has always made one solid pshh when letting off the throttle. Then when I installed my 57trim CT26, it started to flutter every time. Switched back to the stock BPV, and made sure the vac lines were all new, and that the hardlines are clean, and my vac at idle is a solid 20. It still flutters, and I have no idea what the problem could be lol. It doesn't seem to be getting any worse, and everything seems fine, so I have just left it alone.

 

[Rennat]

by BOV... do you mean the stock one? what did you have before?

if so... i dont think the stock bov can handle the amount of air that needs to be bypassed for the 57trim...

mines surges only below 4psi... and only when its light throttle boosting and then i let off...