Right firstly i have extremely limited knowledge on this, so if any of the below post is completely wrong, excuse my ignorance.
I have an A4 1.8 20v Turbo (n Reg '96) and am wanting to fit a dump valve, or not as the case may be. i know dump valve dump to atmosphere as the clutch is pressed and thats what makes the 'PSSCCHHH' sound, but another A4 from round my way makes a more of a PSSCCHH-CH-CH-CH sound. i have been told tat this noise is made by taking off/bypassing the wastegate?
how correct is this or is this making no sense to anyone
Any help greatly appreciated
atmospheric dump of intake charge on a 1.8t 20v is a bad idea, messes up the MAF reading and ultimately your fuelling. you need a recirculating one. you still get some noise, especially with a change of intake and filter.
The impreza crown like the over blown sound of venting air, personally i think it sounds pants.
Not sure what your "sound" is desribing, could just be a different make of atmos venting dump valve, highly unlikely that it is anything to do with a wastegate (different valev buried deep inside the exhaust housing of your turbo that makes sure you don't blow up.
Some WRC turbo cars make a distict chattering and squeaking....don't go there...you will have a five page blog on wastegate chatter and turbo stall and lots of ******.
Ask yourself why you want it to make this noise? Is it going to help the engine:
a) go faster
b) use less petrol
c) get you laid more often
If the answer is no to all of them...why bother?
I fitted one to my 944 turbo and it wouldnt tick over properly and kept stalling ,i have got round this by fitting a twin piston dv rather that the single piston one i had. My bailey valve is the same as the one supplied for the 1.8t audi but i wouldnt bother unless you are going to tune the rest of the engine !!!
no problems thanks guys