tipsyhemi

I got a buddy with a revo-ed 1.8t jetta and hes been complaining about a noise that my car is making. Every one around me thinks that im loosing PSI off the diverter valve.
Ive pulled on him plenty of times when were both non-revo-ed and he also didnt complain about a high pitch hissing noise either. Now its really hard to shake him off and then theres that noise. just wanted to know if any of have any ideas of what it could be and if you know where i could host a video of the noise. ALL HELP IS GREATLY APPRECIATED

NJ1.8

When do you hear the hissing noise? I'm thinking it may just be the turbo spooling. I'm sure it's nothing out of the ordinary, unless you actually feel that the car is losing power. And about you keeping up, remember there is a lot less drivetrain loss on the fwd cars as opposed to our awd cars plus our cars are a lot heavier than the Jetta's. Race him from a stop and see what happens

Oh and about the video, www.putfile.com

tipsyhemi

from a stop if i launch it (and im my auto that means torque braking) hes gone obviously, but if i dont he actually gains on me. Thing about this is when we were both stock i was comfortably ahead of him, now im loosing with both of us revo-ed. and specifcally about the hissing it comes in at around 5000-redline and it does become loud as hell, with windows down i hear it over my exhaust. Reason is, at the runs i got him UNTIL i hit 5k then he gets ahead. It just something that got me perplexed. I got buddies from dvag and their A3 DO NOT MAKE THAT HISSING NOISE. im starting to think its a diverter valve leakin boost.

PD Performance

I tried to do some testing on my A3 but have not come up with anything definitive so far. I went as far as driving around with no airbox at all just the open turbo inlet and you still get the little whistle at times. I even purchased the Forge blow off plate (most obnoxious thing you can do to these cars, finally took it off last night) to see if you could hear it better blowing off. WHile I could not hear it blowing of through the holes the whistle was gone and I have the whistle back as of last night. So I think that narrowed it down to the DV opening.

If you were to remove the DV (I've got a spare) and put power to it you will notice that both ways you put power to it pulls the DV open. That means that the only thing keeping it closed is the spring pressure which happens to be a very very weak spring.

I tried shimming it but that just limits how far it can open didn't really increase the spring pressure.

B7Audi

And it stopped leaking boost? Any CEL's with the BOV?

PD Performance

The point is that it changed the sound so I could not hear the whistle... there is nothing the Forge blow off plate can do to make it run any better.

tipsyhemi

there until revo.

not badmouthing revo, but theres something with the software at the higher rpms, i want to know if APR/GIAC/etc chipped 2.0ts are having this

btw im having my revo dealer look at it on monday/tuesday

PD Performance

You were not pushing enough boost to push the DV open stock. If it is infact what is happening then it would happen at that same boost level on any car no matter what company software they are running.

tipsyhemi

i wonder what is going on with the apr guys?

bhvrdr

You'll see in an upcoming dyno comparison that the revo drops off quite a bit at 5000rpm in horsepower. This is likely what you are feeling and normal. cheers! Mike