Chirping Wastegate...

[spoons]

I've heard cars in the past with dump valves that make a pshhhht sort of sound when changing gear.

Its a matter of preference and personal taste, but I'd rather not have one as the repetition would wear me down.

I've heard rally cars with chirping wastegates as well, which I thought sounded a bit different and was always lead to believe that Vectra VXR's dont have either... as it recirculates the pressure (or whatever lol).

Anyways, since my Stage III upgrade.. when the car is all warmed up and racing to the red line, I've heard my wastegate make that chirping noise on gear changes..

Doesnt happen all the time, but its quite good

Never had that before

[bangty 1]

i love the sound of it ill hear it on sunday lol

[Marcosuk]

If i speed up in say 2nd then come off the power, i usually get turbo chatter if theres not enough pressure for the re-circ to dump... Sounds pretty good imo

[Caveman_nige]

i have it on mine in each gear, I am not sure i like it.. Its louder if you have a cone filter type induction system fitted..

[Ian-Highlander]

Yup same here, my 2.0T has always done it in every gear if I accelerate reasonably hard.

[john_k_sri]

I had the same in my old 2.0T. Don't hear it in my diesel though.....sort of miss it

[benny]

rallly cars have a seperate wastegate / actuator in the lower part of the system .. most road turbo's have a built in wastegate / actuator so your never gonna get the rally sound ...but with upped boost and a few tweeks agreat sound can be had ....




this is a rally car style waste gate ......a mother of a wastegate ....lol ...http://en.wikipedia.org/wiki/File:Turboexternalgate.jpg


normal road going diesel wastegate ......http://en.wikipedia.org/wiki/File:Internalgate_vf39.jpg

also vvt ones ......http://en.wikipedia.org/wiki/File:Va...tryTurbo_1.JPG

all really a variation on a theme ...plus you got actuator types and loads more ......

[Derek Mc]

The noise comes from venting the excess boost to atmosphere, and was a constant source of debate when I drove Saabs as the ones fitted with early emissions would accept an atmos dump valve but later cars, the ones using an OBD2 diagnostic system (so cars basically made from 98/99 on measure the air volume as well as the quality so when you vent the pressurised system out it loses air that it has calculated as combustible volume and throws teddy out the pram.

Now,,,, there is a dump valve from Forge I think that is a dual action so does domp back into the low pressure intake stream as well as a little to atmos via the trumpet, so gives a lovely blow by sound for those so inclined,,,,,,

[iainm9438]

when i had the 'chirping' on my sapphire cosworth (stage 3), i was told that it was the noise made by the turbo stalling whilst trying to vent the excess boost. apparently it isn't good for the turbo unless it is uprated with stronger bearings etc.
how true this is i don't know but as i said it was what i was told?

[Al 22 dti]

when i had the 'chirping' on my sapphire cosworth (stage 3), i was told that it was the noise made by the turbo stalling whilst trying to vent the excess boost. apparently it isn't good for the turbo unless it is uprated with stronger bearings etc.
how true this is i don't know but as i said it was what i was told?

thats true.. and its called turbo compressor surge.

when the turbo it at full boost and you come off the throttle, the compressed air has no where to go and it backs up and forces its way back passed the turbine blades and makes the chirp and that slows the turbo down very rapidly and yes its not good for the turbo at all as it makes it spin off its axis and puts a lot of access pressure on the bearings.

thats why they dump the pressure off.