I replaced all 3 cats today with H&S soild up pipe, Scooby sport downpipe and centre. The car goes like stink, and stinks due to the zorst wrap , but i am getting a very odd noise when the turbo kicks in. It very hard to describe, almost like an induction/sucking noise, but almost like a very high frequency rattle or a whirring noise. I have put a bolt in the up pipe EGT sensor hole to block it off as i don't want this to break up and go into the turbo, it maybe coming from there. I decatted my last wrx from turbo back (left in up pipe), so i know what that sounds like but didn't expect this, is it just because i can here the turbo more, or is it a leak/blow/rattle??

Anyone??

 

Could it be the wastegate??? Mines kinda rattles like that, scared me half to death at first… not any more though!!!

 

Maybe, did yours only start doing it after you decated?? Have you got a full decat??

 

i think i got the same noise i decatted mine last weekend and got like a rotational rattle noise

 

Arh yes, that a good description, do you only get it on hard acceleration (when turbo is giving it some )

 

austen,
To check for leaks start the car and get a mate to put some thing over the end of the exhaust temporary to create back pressure and get under the car and check the joints you will soon see if you have a leak,when I decatted mine I noticed more wastgate chatter.

 

I'm Sure it’s the wastegate, the ecu send s a very quick pulsing action to open it once you reach full boost,, so it tends to rattle, especially seeing as you’ve done away will all the sound deadening on the exhaust……ignore and enjoy….. are you gonna get it mapped to suit the decat??

 

I had a blow on the bottom of the up pipe to sart with, tightened the bolts up which didn't get rid of it so eneded up wrapping the joint in exhaust putty and wrap.

Do you get the chatter during hard acceleration?? its almost like some has fitted spokey dokeys (remember them ) to the turbo!!

 

Yes that sounds like it as it only seems to happen on full boost, i need to get my boost gauge connected to double check!!

Booking it in for remap in march some time

 

It is the lack of sound deadening and also the resonating of the stainless downpipe (Stainless can 'ring' alot more then mild steel).

If you wrap it in heat wrap it will get rid of most of the noises.

Although mine has started doing it again, after 12 months. But it's only noticable when the exhaust is fairly cold. Once it warms through it's quiet again.

I've put this down to the heatwrap going a bit hard at the top of the DP, due to the excesive heat near the turbo. The wrap is alot softer at the bottom of the DP where it's cooler.