Nathan L

Tonight I changed the DP on my JDM twin scroll STi with APS cold air kit.

At first all seemed fine, it started well and I couldn't find any leaks on either the turbo or mid section. The drive home was interesting and spool up is now really, really quick.

After driving 25 miles home I parked the car on my drive and turned the stereo off. I suddenly noticed the constant sound of rushing air behind the dashboard.

I've checked the exhaust as best I can (being dark outside), and can find no leaks. I can't see i've knocked any hoses off and it's a bit of a mystery at the moment. I did fit an EGT bung and Defi sensor next to the lambda boss but can't find a leak on this either.

You cannot hear the air noise outside the car as the engine is too noisy, only inside the car.

Anyone with any ideas? Had a decat DP on my 01 WRX and never heard this type of noise.

Nathan..

Nathan L

Have now checked the exhaust in the daylight.

Still can't see any leaks on the DP or breather pipes etc, so now really

Can still hear the slight sound of gushing air in the cabin so maybe a feature of the DP before it cokes up?

Nathan..

TonyBurns

iTrader: (3)

I can hear quite abit of noise coming from the turbo in my Spec C, possably due to no sound proofing so you could be getting more resenance off your new downpipe??

Tony

drb5

iTrader: (4)

a s/s dp will always make the turbo sound noisier. is it THAT bad, or would you say this could be the cause?

Nathan L

Cheers for the replies.

This is at stationary with the car at idle, so the turbo is at vacuum.

My MY01 WRX with full decat had all the usual wastegate noises etc but never the sound of rushing air at idle.

Weird

Car still goes like the clappers so can't be too much wrong Agree with Tony, under acceleration the turbo really does whine like a bar-steward. Sounds fantastic with the APS CAIK

Nathan..

ScoobyTal

Mine does sound 'funny' on tick over nath but no rushing air noise...

A bit of a clicky / mechanical mechanism on very low rpm under load i.e. 1500rpm in 5th/6th

Go carefull with that right foot till its mapped.... Hmm not long now


Tal

Nathan L

Tal

Car still goes like the clappers on part throttle

I've started the car several times now from cold and have had a good feel all round the turbo, lambda bosses / EGT bung and I can't feel any leaks.

I'll let Bob have a look before he maps the car and see what he thinks.

cheers

Nathan..

ScoobyDuck

iTrader: (1)

Nathan,

only thing i can think this 'might' be is turbo noise. I've heard an aftermarket one that is noisy on idle, and that noise does travel down the DP - which will probably be more noticable inside the cabin.
without hearing it - its gona be hard !
Bob's not had the same problem tho ?

Steve

Nathan L

Not that I know of mate. I've emailed to ask.

Not overly concerned at all, it's probably just the DP bedding in as it's not coked up yet. Car is simply stunning even on part throttle now. It just hauls itself down the road, pick up is instant. Can't wait for the mapping.

Nathan..

ScoobyDuck

iTrader: (1)

YHPM

Bob Rawle

I can't say I have noticed that on my car however even if I did and it was "expected" then I wouldn't have registered it if you see what I mean, will suss it on Sunday but sounds like the normal sort of downpipe type amplification on a new pipe to me. As mentioned as exhausts get lined they change.

bob

Nathan L

Thanks once again Bob

Nathan L

Just been for a drive round getting the engine nice and hot and the noise is starting to disappear already.

As stated above, probably as the DP is now coking up on the inside which is dulling the sound slightly.

That will teach me not to be paranoid

Thanks for all the replies.

Nathan..