Restriction In The Exhaust

[rondofj]

Aggroman, u got a GTT, what cat, mid muffler n rear muffler u got?

[LaurelPWR]

May be of some help.....

http://www.ebay.com.au/itm/191089200535?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

[XKLABA]

Mick how does your system go for noise suppression?

It would have plenty of flow capacity, be good to see pics for how it looks and fits.

It's a lot quieter then the 80mm jap exhaust I took off, it's not that loud until you get on the loud pedal then it gets up there, but idleing it has a nice tough murmur, Paul heard it tonight maybe he can comment on it

I have GT-RSs on the car so I needed as much flow as I could fit under the car

[discopotato03]

How about this , where your oxygen probe goes get a plug and drill/tap/braze whatever a take off into it and measure the pressure in the exhaust behind the turbocharger .

Compare it to boost pressure and note the difference .

It may not be a bad idea to pull the cat out and see if its blocked or collapsed as well . Changing that mid muffler shouldn't be a biggie surely .

A .

[Piggaz]

It's a lot quieter then the 80mm jap exhaust I took off, it's not that loud until you get on the loud pedal then it gets up there, but idleing it has a nice tough murmur, Paul heard it tonight maybe he can comment on it

I have GT-RSs on the car so I needed as much flow as I could fit under the car

Couldn't hear it. All I heard what that farken pump. BBBBBZZZZZZZZZZZZZZZBBBZZZBBZBZZZZZBZBBZBZZZZZX

[GTSBoy]

Compare it to boost pressure and note the difference .

That's not really the ratio you're supposed to look at against boost pressure though. Ex manifold pressure against boost - yeah, fine. But not really dump pressure. Realistically, if you have more than a couple of psi of back pressure in the exhaust you're looking at a substantial restriction. So measuring the pressure there is a fine idea, but you're really just looking for the absolute amount of backpressure.

It would also pay to measure after the cat too, just to see if the cat is the problem or if the mid muffler is the problem.

But, my 2c on that issue is (which coincides with a lot of opinions above)

1) Why not just drop the exhaust behind the dump and take it for a quick drive, see if it changes behaviour?

2) Unless there is a massive step down in the muffler(s) it should still handle quite a bit of gas flow without killing the power. So you have to wonder about tthe cat more than any other part.

[XKLABA]

Couldn't hear it. All I heard what that farken pump. BBBBBZZZZZZZZZZZZZZZBBBZZZBBZBZZZZZBZBBZBZZZZZX

Who ever thought someone sporting two 044s would complain about pump noise

It's character building lol

[discopotato03]

Well this thread is about exhaust restriction and anything significantly positive behind the turbocharger under load tells a story . I just picked on the sensor location because it's an easy place to tap from . If that exhaust is restrictive and gets fixed the dump pressure should fall and so should the exhaust manifold pressure . Boost and power characteristics should change as well .

A .

[rondofj]

What do you guys think of this - ok or a pile of junk? The cat is a gutted catco item (what I was suggested with a bit of reluctance), the mid-muffler looks 3" in/out (no necking like mine), the rear muffler is a crappy jasma cannon but free-flow from the look of things.

System is off a 33GTST goin for cheap ( I know 34 is slightly shorter) and the I'm thinkin of buying it..

Edited March 26, 2014 by rondofj

[gtr jet]

Looks just like mine which is loud as shit.

[rondofj]

lol...what system have you?

[Piggaz]

How much are you gonna pay for it?

[rondofj]

100 bux, I ain't using that cannon though, will look for another nice quiet oval without the small outlet like mine

Edited March 26, 2014 by rondofj

[gtr jet]

Mine was just some jap one that came on the car with no center muffler so I slapped one in just like the one in the pics. It's still bloody loud though.

[hy_rpm]

Doesn't seem too bad for $100

Has a gutted cat already and a 3inch in and out same side mid muffler so that shouldn't be a problem

Just sack that rear cannon as most jasma approved mufflers have a smaller inner pipe which the oval muffler should fix

Worth it for $100 imagine how much it will be for a new custom 3inch catback atleast $500

[rondofj]

Yeh was thinking so, waiting for sellers reply, how do i tell the mid mufflers not stepped down inside?

[zebra]

You can't without chopping it off and looking

[rondofj]

That's a bit farked then aye.. So most peeps just slap one on as long as its 3'' in/out...

[hy_rpm]

The step down pipe is rarely in the mid muffler

Is almost always in the rear muffler or cannon

If the mid muffler is stepped down it's usually on the inlet or outlet and not internal as that muffler isn't offset so will be straight pipe thru just perforated and packing around it

[KiwiRS4T]

That's a bit farked then aye.. So most peeps just slap one on as long as its 3'' in/out...

No I look inside each component before its welded up.