for a while now i always wonder what is that sputter noise you get on turbo cars. its not the blow off valve noise, it sounds more of a sputter noise, i hope someone knows what i'm talking about, its very common, i watch a lot of the best motoring and a lot of the nissan has it.

 

it's called chatter, and it's bad!

 

I would'nt say its chatter. Its more of a blow off valve, or wastegate noise. Its commonly heard on sylvias. Those guys know exactly what they are doing, why would they drive a car with chatter?

 

maybe they reroute the air from the blowoffvalve back to the intake mani, after the throttle body. i know i would, once throttle is realeased fuel is cut, and with the extra air into the intake/cilinder/exhaust/turbo, the turbo would spool easily a quite bit longer.

that's what i can logically think of

 

but what exactly is causing the chatter noise?

 

If i am not mistaken. It is when the throtal plate closes and the bov dont release all the pressure it is building and get forced back into the turbo and slows or stops the turbine.

Correct me if i am wrong.

Or am i mixing that up with turbo surge.

 

Its compressor surge guys. Commonly from an improperly adjusted blow off valve and its very bad for your turbo. Premature bearing wear and such...

 

oh, i saw an episode of top gear and this top end car has that noise, they said its due to the wastegate, i was thinking how that would work but yeah. thats what i herd.

 

yea its compressor surge.

 

When I first got my Greddy turbo kit installed and fully tuned by greddy, the sound of the wastegate was more of a fluttering sound.

It's hard to say whether it's a safe wastegate flutter, or compressor surge.

 

wastegate shouldnt make any noise... It will let noise out (exhaust gas if setup atmospheric) Otherwise in closed loop, should make a sound, unless ***** squeakin when the valve moves, lol...