Wanttogofaster

Hi I have 2000 camaro with a single turbo kit and when ever i get over 2500rpms and let off the throttle it sounds like a big rig. Its so anoying and so loud, I dont know if maybe its my exhaust because I have a loud mouth or maybe theres something else that i can do to fix this problem. Someone said it might be the air pump but that was removed during the install. So if someone knows what the problem could be please let me know Thanks.

ALLBOTTLE

iTrader: (13)

is your Wastegate recirculated or vented to atmosphere?

it could be the wastegate venting.

TS6

iTrader: (41)

I'm gonna take a wild guess and say you bought this car the way it is, right?

Any chance its the BOV?

Wanttogofaster

The wastegate recirclates. Its a GMRspeed single turbo kit. And the sound started right after the kit was installed.

Grr

iTrader: (2)

where is the reference for the wastegate located? if its before the throttle body its opening wide open when you let off and is probably loud as hell. also have your tuner, or you if thats the case scale down your DFCO tables so it only activates under more severe circumstances. Try moving your wastegate reference to the intake mani if its the first case.
Gary

SonofaBish

iTrader: (5)

Edited:
I think you guys are a little confused on the what a wastegate does and what its purpose is....

I think what you are referring to is the BOV... The blow off valve will open as the throttle blade closes... vaccum will pull the BOV open and release the air pressurized air either to the atmostphere or recirculated....

on the other hand, the wastegate opens when you reach full boost and allows exhaust gases to bypass the exhaust turbine... therefore keeping the turbo of overspinning.... it will be dumped to the atmosphere or recirculated into the exhaust, after the turbo

Not saying this is what i think it is, but what i would be worried about is that your "jake brake" sound would be the BOV NOT opening, therefore sending air back through the turbo, which is very hard on the bearings... I've never heard this sound in person, but it is often discribed on the forum - but i'm not good at converting sounds into words

Grr

iTrader: (2)

What? Thanks for being an *******. havent you ever heard an atmospheric WG open? Its loud as all hell. Thats what im referring to. Not the BOV, im guessing he doesnt have a BOV and its surging like mad when he lets off
Gary

Twin76mmTA

iTrader: (1)

a bov will make a slight noise and then stop.

The wastegate will continue to vent off excess exhaust gasses depending on how the vaccum boost signal is plumbed... it's the wastgate

RooRnZ28

iTrader: (14)

never heard that one before..... whats a jake brake sound?

Spoolin

iTrader: (8)

What's with the attitude?
I guess your a genius and you know everything right? well I guess we're lucky to have you on this site! Keep it clean man.

Referring to the OP, sounds like you need to reroute your BOV and wastegate back to your exhaust. If what you describe is happening don't worry it's not bad but yes it can be annoying.


This is a BOV that is vented to atmospere and makes a lot of noise once the Throttle is closed.


And this is a wastegate that is vented to the atmosphere, makes alot of noise when spring is set on low boost and your in boost. Doesn't make any sound when throttle blade is closed only when in boost.

bumpin_records

iTrader: (19)

Sound like the BOV to me. He did say when he let off the throttle,right. When you get off the throttle the wastegate should be close and the BOV open up. He is right if the BOV dont open up the pressure that dont release will make a shutter sound. But i cant see a BOV sounding like a jake brake, Jake brakes are loud *** hell

SonofaBish

iTrader: (5)

I'm apologize, i didnt' mean to come off like the *******, i just couldnt believe that two people posted up that your wastegate will open when you close the throttle, without someone else chiming in yet.... Like i said, Spoolin said, the wastegate closes tight whenever you let off the throttle... it can be referenced at the manifold or at the compressor housing of the turbo, but will only open when you have reached full boost, in order to let exhaust gases bypass the turbine...

but i agree that it doesnt sound like the bov... they often make just one "whooosh" sound.... I would suggest seeing if someone on the board lives near you and can come help you out in person...
sorry again for the attitude... looking back at the post now it was kinda mean... i was in a horrible mood all day yesterday... original post has been edited

Zombie

iTrader: (2)

I'm guessing no one who has posted so far knows what a jake brake is and the sound they create.

http://en.wikipedia.org/wiki/Jake_brake

The sound comes from the exhaust due to compression braking.
I'm guessing DFCO is kicking in, that's when my car use to do it back when it was 6spd.

bumpin_records

iTrader: (19)

Yep thats a jake brake. some areas dont allow you to use em cause of how loud they are.

smoke20

iTrader: (2)

contrary to your belief , a wastegate will open and release press when the throttle is closed after a hard pull and press builds . on my STS kit it came with no BOV so when you let off the gas it releases back pressure through the wastegate . now i know your suppose to have a BOV but the STS kit for A4 did not come with one.

SonofaBish

iTrader: (5)

i'm asking a serious question here btw...
if this is the case, then what opens the wastegate? the wastegate is opened by positive pressure, not vaccum i thought....

what pressure are you speaking of? exhaust pressure, or pressure in the charge/intake piping?

Spoolin

iTrader: (8)

That's new info to me as well but I guess if you have bad enough compressor surge you might be able to blow open the wastegate. The way I was understand it is when your in boost at xpsi (doesn't really matter) and you close the throttle blade the pressure inside the cold side piping will raise to about 50psi around. (maybe someone can correct that number as I'm not 100% sure.) You can check to see what spring is in the BOV and that would also tell you what it's set to open at. In any case if your cold side is pressurized to 50 psi it's gonna move back to the turbo cause it to surge and exit out the exhaust but it might also find itself at the waste gate and physically push it open. WG's are set at what boost your wanting to attain which if it's 8 lbs then that's what she'll open at and 50 lbs will defiently do that.

Also not all BOV make the same sound. If you have too big of a spring it will sound like this this....
http://www.youtube.com/watch?v=Xw0FH5uKlgI

Notice the WG opening when in boost, and the BOV making the PFFt Pffft Pfft sounds when throttle get's closed.


A weaker spring will keep it from slamming shut all the time and make the Typical sound that you hear in Fast and the Furious, etc...

SonofaBish

iTrader: (5)

This is exactly what my Tial sounds like (see below), but i was under the impression that the one big whoosh, vs. the sound you described above was the differnce in model, not the spring pressure.. dunno sorta like how some ricer bov's have a real high spitched squeel

at the end of this video of my car, you will hear my BOV.... it flutters a bit as well - from what i hear, this is common of the tial bov
http://smg.photobucket.com/albums/v6...t=CIMG1493.flv

I have never heard of the wastegate being opened by pressure coming back through the turbo... that's because air coming back through the turbo from the compressor side never touches the exhaust or wastegate....this is the way i'm thinking about it (i might be wrong)... as the throttle blade closes, vaccum is created, therefore pulling the wastegate shut (since it is opened from the back side by the positive pressure from your reference point - vaccum closes it).. when the throttle blades shut, compressed air is trapped and needs somewhere to go... if a BOV is not present to vent the air, then the air has to go back through the compressor side of the turbo and out through the air filter - rapidly changing the direction of the compressor/exhaust turbine... the compressor side and exhaust side of the turbo do not have any sort of "air interaction"... the shaft runnign b/w the two turbines is the only connecting parts b/w the exhaust air and intake air - this is why i see your theory of that air going back through the turbo into the exhaust flawed...
Since the wastegate lead runs from right before the turbo on the exhaust side to the wastegate, then from the wastegate to behind the turbo on the exhaust side, any compressed air that is blocked off by the throttle blades never has an opportunity to pressure open the wastegate valve...

the only way i see this being possible is that when the shaft changes direction rapidly from the air rushing back through the compressor side of the turbo, the exhaust turbine creates pressure back into the header, which then colliding with exahust gases still coming out of the engine, might be able to open the wastegate with pressure...
HOWEVER, this really doesn't make any sense to me, and i have never heard of it.... but i could be wrong...

Hugger Z

iTrader: (4)

Just another viewpoint here, but it could just be the exhaust and the engine resonance. My car seems to have a sweet spot around 2,000 rpm's where the exhaust seems to hit a high volume and sounds kind of like a Jake Brake if I am engine braking. You do have the loudmouth and that would amplify this effect. It is normal if that is the case and all of your BOV and wastegate checks out fine.

smoke20

iTrader: (2)

that fluttering noise is what my car sounds like when i take my foot off the gas when im in boost, i dont have a BOV installed , its coming from the wastegate opening closing real fast .

i looking at getting a BOV.