Look At This Exhaust...

[R338OY]

I took these pics of my exhaust system. It came like this from Japan. First is the cat, and i'm not sure what it is but i'm guessing its a high-flow (or at least better than stock), and following it is this ugly muffler, before getting to the stainless canon at the end.

My questions are:

Does the exhaust look 3-inch?

Is that cat high flow?

Should i turf the muffler and get a straight pipe?

Lastly, from cat to turbo is stock piping...is it urgent to chuck that for a 3 inch dump+front pipe setup, on a stock turbo?

Thanks for the advice.

[R31Nismoid]

Dump pipe - gives good gains. So its an idea to upgrade it as a thing to do.

CAT, doesnt look the same size as the rest of the piping.

And i wouldnt remove the muffler in the middle, if dont want a loud drone-bug exhaust keep the middle muffler.

[R338OY]

Dump pipe - gives good gains. So its an idea to upgrade it as a thing to do.

CAT, doesnt look the same size as the rest of the piping.

And i wouldnt remove the muffler in the middle, if dont want a loud drone-bug exhaust keep the middle muffler.

Oh thanks. Yeh i'll definitely go the dump. I thought of keeping the muffler though i was told it causes restriction, and reduces (only a little) power.

[GunmetaL]

Anything other than a straight through pipe will have power robbing restrictions to the system

However you have to consider the legalities (cat convertor) and noise level (mufflers).

If they are call 3 inch and 'hi flow' items they will be as unrestrictive as possible while still doing their job

[R31Nismoid]

Anything other than a straight through pipe will have power robbing restrictions to the system

Crap.

I currently have a 3.5" Exhaust, that not only passes noise tests, but will also easily flow 350rwkw, if not 400rwkw.

Mufflers correctly designed and piping correctly made, will NOT impede flow

[The Mafia]

lol at "does it look 3 inch"

Ever heard of a tape measure?

[murrayis]

Well i would turf the rear mufler, change the cat to a 3inch highflow as that one looks 2.5" and yes as everyone has said definetly a dump pipe and maybe new front pipe.

But yes always with doing Exhaust mods be very weary of the noise level it puts out.

[Munkyb0y]

why is the cat earthed? it looks like a compliance type cat, 2.5inch

a straight through muffler, ie a resonator, wont rob you of power. your's may well be straight through.

as mafia said, measure it side to side to find if its 3 inch. lol.

[R338OY]

lol at "does it look 3 inch"

Ever heard of a tape measure?

OK so my first exhaust mod is buying a tape measure

I guess i'll take it somewhere to see if that's a resonator or muffler. The cat...well u guys said change it for a 3-inch so maybe it'll have to go when i chuck on a dump???

And i have no idea why it's earthed.

I read another thread saying a fat exhaust can give boost creep issues on a stock turbo that has aftermarket boost control (like mine, 11psi)...will i have boosting issues after a full exhaust system is in place?

[murrayis]

A larger exhaust, mainly the dump pipe and front pipe will flow alot more efficiently, so you might gain 1 - 3 psi because there not as much load on the exhaust side of the turbo.

On your boost controller you will just have to wind it back or change the duty cycle if this does occur

Edited September 11, 2007 by murrayis

[aphid]

the laws of physics suggest otherwise.. A correctly designed and made muffler will have very little impedance on flow, but a pipe going straight through is always going to flow better

Crap.

I currently have a 3.5" Exhaust, that not only passes noise tests, but will also easily flow 350rwkw, if not 400rwkw.

Mufflers correctly designed and piping correctly made, will NOT impede flow

[R338OY]

Well i'll find out if its a resonator or muffler. Can't tell myself.

Yeh I'll get a dump+front soon...its a good early mod from what everyone says ...and you guys say a lot!

Is installing the piping from the turbo to the cat a hard job for someone with decent mechanical ability? Seems like a great way to waste my afternoon

[BAMR33]

A couple of nuts and bolts are hard to get at with out a hoist, but can still be done relatively easy. Anyone with a set sockets could do it.

The input diameter of the cat looks smaller than that of the dump pipe, I'd be thinking of upgrading that to while your at it .

Edited September 11, 2007 by BAMR33

[R338OY]

Ohh good point. I might as well go for a high flow yeh. Don't even know what the hell that one is anyways.

Damn i'm gonna need to skip insurance to pay for these upgrades

[BAMR33]

Bad idea, you don't 'need' performance mods but you do need insurance.

[TTT]

1.) insurance is more important than a dump pipe.

2.) resonator and muffler are same things

[Munkyb0y]

but straight thru muffler, and normal (commodore eg) muffler are very different things.

[Beer Baron]

buy a $2 set of vernier calipers and you can tell us if the exhaust is 3 inch or not. for moderate power it looks fine. upgrade dump and front and get a better (larger) cat and you will be fine. from the style of muffler it looks like a trust system to me. I would say it's 80mm which is just over 3 inch.

[R338OY]

OK i already have comprehensive insurance...

lighten up guys...