Randomjim
Registered User
I've heard lots of different things about wastegate chatter. If i had a external wastegate would i get chatter or is it a myth? Discuss
jcb said:sometimes the noise people hear on rally cars is misatken for the wastegate but is actually turbo stall.
A4Quattro said:Also, a rally car would absolutely not be lacking a dump valve unless it didn't have a forced induction system.
jcb said:they don't just open and then close after the exhaust gases have all gone.
they are popped open when the pressure reaches a certain point and as it opens the exhaust gas pressure drops enough for it to close again, pressure rises and it opens again, repeat steps 1 -4 ten times a second. = chatter.
jcb said:SOMETIMES the noise people hear on rally cars is misatken for the wastegate but is actually turbo stall.
jcb said:does that make sense?
A4Quattro said:If an engine was at high revs and the turbo was producing high boost (1.5bar +) and the throttle was shut without a BOV, the compressor would indeed stall, the only problem is the hot exhaust gas still hitting the turbine vanes would try and spin it, the result would be a broken common shaft, and that you would hear as well as see when a huge cloud of smoke wafted out of the exhaust.
Tallpaul said:and i really don't know why an external wastegate would 'chatter' anymore than an internal one.
jcb said:so I read in "maximum boost" by corky bell
A4Quattro said:If an engine was at high revs and the turbo was producing high boost (1.5bar +) and the throttle was shut without a BOV, the compressor would indeed stall, the only problem is the hot exhaust gas still hitting the turbine vanes would try and spin it, the result would be a broken common shaft, and that you would hear as well as see when a huge cloud of smoke wafted out of the exhaust.
My supra had an internal wastegate amd a piston type atmospheric BOV and that chattered when changing down a gear at high speed.