I've got a quick question. I've tried to do my homework around town, but no one has much experience around here and unfortunately I do not have any Supras to compare with in my area. Whenever I boost and then let off - I get a fluttering sound. More boost = louder fluttering. I have a Greddy T-06 and the factory bov (which is suggested for the turbo kit). Are there any tell tale signs as to whether this is compressions surge or typicall wastegate chatter? Thanks for the help.
Wastegate Chatter or Compressor Surge?
- Thread starter 89MkIII
- Start date
my car came with a TurboXS BOV and it flutters like that also (factory turbo) I even took out out the spring tensioners and it still does it, wtf, could having a vacuum leak do this?
If your BOV is fluttering - ie. you have a bov that you should be able to hear and it sounds like it should, but is just fluttering you usually need to tighten up the spring, not remove or release tension.
If you are getting compressor surge you will hear a lower, deeper flutter, and you will most likely feel it in the car. Then you would need to release the bov spring tension, get a bigger bov, or make sure it is getting proper vacuum.
If you are getting compressor surge you will hear a lower, deeper flutter, and you will most likely feel it in the car. Then you would need to release the bov spring tension, get a bigger bov, or make sure it is getting proper vacuum.
I definitely am getting compressor surge, but it only happens at low RPMs and low boost, if I rev it out at max boost the BOV screams the way it should, but at low RPMs and low boost I get nothing but compressor surge...
BOVs sound different at different Rpms. Maybe your just hearing it blow off lightly, like it should at lower Rpms and low boost. Just my 2 cents, I don't have the car in front of me.
TurboSupra7 said:
Yes, lowering the tension lets lesser pressure open the valve.
You need to make sure you are getting proper vacuum on the bov - try running a new silicon line from the tap on the intake manifold. Get rid of any of the plastic filters or reducers that may be in the way. Then you just adjust the spring tension so the valve opens at a low enough pressure to avoid that low pressure surge and also does not flutter at full pressure
This is the factory blow off valve and stock wastegate. Does anyone else run this setup w/ an upgraded turbo? Can a flutter or chatter be expected? As for feeling the flutter in the car - not at all. If the radios up, I don't feel any changes. Man - now I'm getting worried.
i remember someone writing a post that said that his upgraded ct was destroyed because he was using a bov that used the stock 1" passages for the bov... upgrade that bia
Well it sounds like I definitely need to get a new BOV regardless. Is there a chance this is wastegate chatter though? Does anyone get wastegate chatter? Shouldn't my turbo be fried after a year of this if it is compressor surges? Thanks for the advice everyone!
The stock bypass valve is pretty worthless. I wouldn't bother with the bosch either. If you want to save some bucks and still have a good valve, look into a 1G DSM valve.
I've never heard of wastegate chatter(?). It just sounds like you are getting low boost surge so it won't do nearly as much damage as full boost surging.
I've never heard of wastegate chatter(?). It just sounds like you are getting low boost surge so it won't do nearly as much damage as full boost surging.
LOL....I have heard of WG chatter back in the day....it was really the "warble of exhaust gases being despensed from the external wg itself...of couse.
I have the BOV chatter SOMETIMES.....its weird. Depends on the weather heheheh
I have a PROF sheepdog BOV...sounds awsome...and I love the chatter...
heck, my buddy runs a upgraded turbo on his GN and does not have a BOV....he "snorkles" it all the time on purpose becuase it sounds soo cool..
I really dont thing that Compressor surge hurts the turbine blades as much as we really think.....Of couse, if it happend over a 40,000 mile period of time something is going to come loose...but on a stock turbo, running stock boost...i doubt anything will come of it in the NEAR future.
just tighten your BOV ( as garrotrowe stated) and have no more chatter.
-Jonathan
I have the BOV chatter SOMETIMES.....its weird. Depends on the weather heheheh
I have a PROF sheepdog BOV...sounds awsome...and I love the chatter...
heck, my buddy runs a upgraded turbo on his GN and does not have a BOV....he "snorkles" it all the time on purpose becuase it sounds soo cool..
I really dont thing that Compressor surge hurts the turbine blades as much as we really think.....Of couse, if it happend over a 40,000 mile period of time something is going to come loose...but on a stock turbo, running stock boost...i doubt anything will come of it in the NEAR future.
just tighten your BOV ( as garrotrowe stated) and have no more chatter.
-Jonathan
lagged said:
you and me both....
siman said:
actually, compressor surge hurts the COMPRESSOR....not the turbine. compressor = cold, turbine = hot.
siman said:
eh, it's an entirely different story for auto tranmissioned cars. they really don't need a BOV as the throttle plate rarely closes under + pressure. yes, lower boost does mean less air mass to back up on the compressor, but it's still wear on the compressor...
as for WG chatter, never heard of it. w/an EBC you can have some pretty crazy WG noise as it cycles the valve/open closed.....doubtful that's what's being referred to.
siman said:
3 months on a stock ct @ 10psi with no bov took a tight turbo to lots of radial slop and oil leaking into the turbine housing. No damage my ass. :hsugh: