Supra ST Myster Posted July 7, 2007 Share Posted July 7, 2007 We all love that sound (well most of us do) but is it a proven fact that it does damage the Turbo, has somebodys turbo been damaged and proved it was down to compression surge? you can hear it on here if you turn it up Link to comment Share on other sites More sharing options...
Steve Posted July 7, 2007 Share Posted July 7, 2007 Is this like the Anti Lag thing that Jamiep had on his car,which did kill the turbo. Link to comment Share on other sites More sharing options...
Supra ST Myster Posted July 7, 2007 Author Share Posted July 7, 2007 no, its the bit that goes do do do do do do lol, when you lift off, hear it alot on the singles, my understanding is that if the BOV doesnt let all the air out then that air goes back and hits the turbo which apparently tries to stall the turbo but it then goes out the air filter making that noise, just i get it alot and i cant hear my BOV at all since ive gone single and i thinks its because of that, that i get this noise, dont get me wrong i love the noise, but people say its bad, but is it proven?? i can see it myself as belive it exits via the air filter quick enough to do damage, if it didnt go anywhere then yes i can see the problem. Link to comment Share on other sites More sharing options...
Steve Posted July 7, 2007 Share Posted July 7, 2007 I thought it was the external wastegate that made that noise? PS like the do do do do do do do description Link to comment Share on other sites More sharing options...
Supra ST Myster Posted July 7, 2007 Author Share Posted July 7, 2007 apparently its not, its the air comming back out the air filter, i have proved this also as when i first did my test with a quick blast down the road i just had some mesh infront of the turbo and then when i stuck the filter on the noise was a lot deeper sounding as it was booming in the air filter.. couldnt explain the nosie any other way lol i belive the wastgate does also make a bit of sound though? Link to comment Share on other sites More sharing options...
Homer Posted July 7, 2007 Share Posted July 7, 2007 The noise you're talking about is compressor stall. It's cause by the BOV not releasing the pressured air from the intake system after the throttle is closed, thus causing the compressed air back through the turbo compressor causing it to stall. The noise itself is coming from the air being pushed back out of the air filter. It has nothing to do with the wastegate (a common misconception). I'm suffering from this in a big way (though it DOES sound great ). From what I can ascertain, BOV likes the HKS SSQV are not really suitable for big turbo installations, in fact the only cars I know that don't suffer from it have the cheap XS Power BOV installed. Some people have added an additional BOV to reduce the effect. Link to comment Share on other sites More sharing options...
Jake Posted July 7, 2007 Share Posted July 7, 2007 Yeah, my car does it too. Not as much as the smaller PHR1 turbo I used to have though. I've wondered in the past if this stalling could have been the/a cause why the bearings in that turbo failed. As far as I'm aware my BOV doesn't work at all. OTOH I think CW said compressor stall isn't a bad thing and doesn't kill turbos. Link to comment Share on other sites More sharing options...
Supra ST Myster Posted July 7, 2007 Author Share Posted July 7, 2007 so the fact that i cant hear the bov is a sign that its either not working or its crap? which is why there is soo much noise when i lift off from the air filter, like i say, id rather have this noise than the bov noise, but is there any actual proof that it causes the turbo to fail, how? what sort of failure does it cause? blade or shaft damage maybe? Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 7, 2007 Share Posted July 7, 2007 It may cause damage in the long run if you didn't have a BOV, most turbo cars have a BOV for this reason, and most of the time you get compressor stall as well to a small degree, i have never heard of it causing damage, if you get this a lot on big singles you can just add another BOV. Link to comment Share on other sites More sharing options...
b_have Posted July 7, 2007 Share Posted July 7, 2007 Don't think it harms the turbo, mine has done it (T61) for 5 years on an inadaquate SSQV with no problems. I got fed up with the noise and just fitted a huge HKS racing type BOV, no more stall (just a big sigh on gearshifts ) Link to comment Share on other sites More sharing options...
Class One Posted July 7, 2007 Share Posted July 7, 2007 I get compressor stall on low boost on mine. I have an aftermarket HKS SSQV welded onto my metal no5 air hose andhave the stock recirc system capped off, so occasionally hear it through my intake. Link to comment Share on other sites More sharing options...
RedM Posted July 7, 2007 Share Posted July 7, 2007 I can (but not often) get mine to do this and I'm only stock everything. Link to comment Share on other sites More sharing options...
JustGav Posted July 7, 2007 Share Posted July 7, 2007 I remember having a conversation with Terry S regarding this, and he reckons that some installations require multiple BOV's to cope with the amount of air that these turbos push. I seem to remember the purple monster had two of the units. One on the throttle body side and one close to the turbo (I believe, this might not be the case though). Link to comment Share on other sites More sharing options...
Homer Posted July 7, 2007 Share Posted July 7, 2007 I get compressor stall on low boost on mine. I have an aftermarket HKS SSQV welded onto my metal no5 air hose andhave the stock recirc system capped off, so occasionally hear it through my intake. Most TT's do this (certainly those with the HKS), it's caused by the BOV not opening under low boost pressures. On quite a few of the singles (mine and Emin's included) it's happening under high boost conditions. Thinking about it, it must be down to the BOV not being capable of removing the pressured air quickly enough. Link to comment Share on other sites More sharing options...
Supra ST Myster Posted July 8, 2007 Author Share Posted July 8, 2007 Most TT's do this (certainly those with the HKS), it's caused by the BOV not opening under low boost pressures. On quite a few of the singles (mine and Emin's included) it's happening under high boost conditions. Thinking about it, it must be down to the BOV not being capable of removing the pressured air quickly enough. yeah i agree with that, i think my BOV isnt up to the job, its an unknow brand you can see it moving and that but i dont think its doing anywhere neat enough to release all the air, going to try and change it for a decent one, Link to comment Share on other sites More sharing options...
suprafan72 Posted July 8, 2007 Share Posted July 8, 2007 Most TT's do this (certainly those with the HKS), it's caused by the BOV not opening under low boost pressures. On quite a few of the singles (mine and Emin's included) it's happening under high boost conditions. Thinking about it, it must be down to the BOV not being capable of removing the pressured air quickly enough. I have this issue too..this seems to happen after 1.1 bar.... sounds great and very noisey but it does concern me as i don't want to reck my turbo. Link to comment Share on other sites More sharing options...
mikeyb10supra Posted July 8, 2007 Share Posted July 8, 2007 Guys get another BOV in there somewhere, if your not dumping enough pressure all your doing is slowing up the spool charecteristics of your given turbo as the compressor is fighting against air trying to turn the blades the other way. I would personally run two on mine, one on one side of the intercooler and one on the other Link to comment Share on other sites More sharing options...
Wez Posted July 8, 2007 Share Posted July 8, 2007 Compressor stall not surge and not the wastegate, as mentioned above alot of singles do this when driven on low boost. FYI i have one adjustable HKS BOV fitted near the throttle with PHR Stage 1. With singles the airflow is that much greater that you require the BOV to be setup/adjusted stronger so they are not blown open and become a boost leak, the downside is on the lower scale that they dont always open low down, therefore you get a small amount of pressure surge. One of my previous cars had a really chavy dump valve/bov which I hated, so to resolve this I simply fitted a one way valve to the BOV which stopped it from opening, the compressor noise was not as bad and I ran like that for a couple of years and the turbo was fine, this said I am sure stalling the turbo will reduce its life but by how much I have no idea. Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 8, 2007 Share Posted July 8, 2007 Skyline GTRs have two BOVs as std so it seems TT 6 pot designs push enough air to warrant this. Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now