Decayes

Not sure if I am right in sayings it's a problem, just want to make sure it's ok

I bought a blitz system ( back and centre ) awhile back and got it fitted to my standard downpipe. More recently I bought a japspeed decat downpipe, I've had this fitted, it now sounds like air is hissing out somewhere ? I've tried to put my head under the bonnet while hitting some revs and I can't hear any hiss noise, I put my head under the car with some revs and it sounds like air is hissing ?

Friend of mine said it might just be the turbo spooling ? I don't think so as surely I'd hear that more with head under bonnet ?

I've just been to a local garage and they've checked the bolts are tight, they are nice and tight. Any thoughts or is it suppose to sound like that ?

Thanks

jaygsi

iTrader: (46)

So the exhaust isn't blowing? Record it and upload to here.

Decayes

It's not blowing no, the exhaust sounds perfect in idle and if I keep the revs below 1500 it sounds brilliant, if I go above 1500 you can hear the hissing. Will get it recorded and uploaded tomorrow

Thanks

Decayes

Picture is abit dark but you can hear the air noise

mattpat

iTrader: (1)

to be honest mate it sounds perfectly ok to me

Decayes

Attachment 19348Attachment 19349Attachment 19347

Not sure how to upload pictures, sorry if this has gone wrong :-/

Lee225

iTrader: (1)

sounds ok to me.

Lee225

iTrader: (1)

I reckon it's just turbo noise you're hearing.

mattpat

iTrader: (1)

agreed probably just more audible as a result of the decat

Decayes

Not saying you guys are wrong but wouldn't I hear that noise if I put my head closer to the turbo under the bonnet ?

Thanks

Lee225

iTrader: (1)

I expect the turbo noise is travelling along the downpipe which causing you to hear it underneath. I maybe wrong but it sounds ok to me...

jaygsi

iTrader: (46)

That does sound weird. Doesn't sound normal to me, sounds like a dump valve leaking air, although i don't think thats the issues.

Is the decat new?

Decayes

Downpipe is brand new from scoobyparts, it's a japspeed.

Dump valve is a completely standard dump valve that comes with the car. If I pop the bonnet and hit some revs, everything under bonnet sounds fine, if I put my head under the car you can hear some " air leaking "



That picture isn't mine but that's how mine looks, except as you see the flange on that picture, it looks level either side, however in my decat pipe at the centre pipe connecting end like that picture my flange wasn't level ? Sitting very very wonky. I assumed it was normal ? I assume it still is however it is giving my concern now though

Decayes

That is mine, not sure if you can see it properly but it looks like the flange isn't straight, I was meant to take a proper picture of it with a tape measure either side but completely forgot when getting it fitted

Don Clark

not necessarily as the sound will be transmitted away with the exhaust gas

Decayes

Is there a way I can test for air leaks at the joints ? Or is there any other things I can try ? I would say I'm about 90% sure this noise isn't normal

1509joe

iTrader: (2)

Looks like a 3" to 2.5" pipe in which case you'll need a donut can't tell from the pictures whats what.


http://www.ebay.co.uk/itm/GENUINE-SU...-/351011041880


Better than above you may have the wrong downpipe. The new piece needs above but the older piece looks to be 3" in which case you need a gasket and a different downpipe/ or the correct cat back exhaust.

thunder8

iTrader: (1)

when under the car you should be able to see the donut on pipe I got mine from local motor factors at £7

Decayes

It is the correct downpipe for the exhaust as it was recommended by Tim himself from scoobyworld. It does also have a cone gasket onit as it took me afew round trips to find one that would actually fit

1509joe

iTrader: (2)

Proper picture of joint that ones is very dull.

hardcoreimpreza

If you can here that whistling noise in the car that would do my nut in. I'd send it back and buy a sports cat off here.

stamina_daddy

iTrader: (3)

I've just reached under the car and put My hand near and around the joint before.
You can definitely feel it if it is leaking.
The doughnut is quite a specific size for the subaru think it's 57.5mm or 63mm.
I searched high and low for a cheaper version to the subaru oe one but just ended up paying for the expensive one.

cookstar

iTrader: (6)

Did I read the word Japspeed?

Decayes

What's wrong with japspeed ? You'll find afew people on here recommended japspeed downpipe..

cookstar

iTrader: (6)

I know several people that have had issues with them, mostly shoddy welds and flanges that aren't flat, so mate poorly with a gasket.

I know one tuner that even refuses to fit them due to this.