3"exhaust amd extractors

QUIKXR · 29-10-2005, 01:36 PM

Hi guys im thiinking about putting a 3" exhaust system and performance extractors on my au2xr8.
has anyone heard another one and tell me if it sounds good and what peformance increases should i expect??

**Stav** · 29-10-2005, 01:44 PM

Stiddy has 3 inch exhaust only in his xr6 au hp.That car flies man. He does not have extractors or cam.I would say that car is equal in speed as a full dev 3 hl..

29-10-2005, 01:54 PM

Yeh, get a 3" cat back, then it'll be as fast as dev3 setups...

loxxr6 · 29-10-2005, 01:56 PM

Slightly off (the main) topic :

Is a 3" exhaust on a 6 cylinder effective or do you get probs with lack of back pressure(or whatever happens when your exhaust is too big).

I'll def need a bigger exhaust for when I whack the turbo on so if a 3" is ok for a 6, I'll prob consider changing.

29-10-2005, 01:58 PM

Quote:

Originally Posted by loxxr6

Slightly off (the main) topic :

Is a 3" exhaust on a 6 cylinder effective or do you get probs with lack of back pressure(or whatever happens when your exhaust is too big).

I'll def need a bigger exhaust for when I whack the turbo on so if a 3" is ok for a 6, I'll prob consider changing.

3" is wayy to big for a NA 6. Turbo, yes it's good, but not NA. For an 8 (original poster) it would be better to get a dual 2.5" out.

JC · 29-10-2005, 02:06 PM

I have single 3" with 4into1 headers on my AU1 XR8. I trade off a bit of low down torque for great mid to high range power/torque.

**Stav** · 29-10-2005, 02:12 PM

Quote:

Originally Posted by Bangers

Yeh, get a 3" cat back, then it'll be as fast as dev3 setups...

Stiddys is...he rocks and his car rocks...Manual dev 3hls crack 14.9 on the 1/4 in manual form.Stiddy has done a flat 15..I believe he will run into the 14 second bracket soon.

EFFalcon · 29-10-2005, 02:26 PM

Quote:

Originally Posted by QUIKXR

Hi guys im thiinking about putting a 3" exhaust system and performance extractors on my au2xr8.
has anyone heard another one and tell me if it sounds good and what peformance increases should i expect??

deffinately worth doing, should see a little increase in power and the sound should be much more prominant.

EFFalcon · 29-10-2005, 02:29 PM

Quote:

Originally Posted by loxxr6

Slightly off (the main) topic :

Is a 3" exhaust on a 6 cylinder effective or do you get probs with lack of back pressure(or whatever happens when your exhaust is too big).

I'll def need a bigger exhaust for when I whack the turbo on so if a 3" is ok for a 6, I'll prob consider changing.

you'll generally loose some low down torque, Rmyers had a 3" exhaust on his EA for a couple of weeks before the car had the supercharger bolted on and it stll went pretty good.
peak power may improve slightly.
i'd just get the 3" exhaust a few weeks before the turbo.

loxxr6 · 30-10-2005, 12:00 AM

Quote:

i'd just get the 3" exhaust a few weeks before the turbo.

Cool. It's not like its a major cost item to purchase.

stiddy · 30-10-2005, 01:20 AM

Thanks stav, your a top bloke man..

Why are people saying 3in is too big on an N/A 6 ?? its not.. ive proven its not.. my car is actually faster, the only thing done to my car is a high flow 3in cat, mandrel bent 3in exhaust with a small rear muffler.. and a 3in mandrel intake i fabbed up myself.. and yes its loud and sounds like a drag boat or something..

Admittedly it has lost a 'little' down low but picked up a fair bit uptop, and being a 5spd, its not an issue for me.. 4000rpm launches at the strip are my friend..

i pulled a 15.009 with 2x15in subs in a massive box in my boot, spare wheel, amps and everything else, straight off the street and onto the track..
and yes i know gtech isnt everyones mate, but with my car empty eg subs out spare out etc etc its run 1x 14.8, 3x 14.9's and 1x 15.0 and since then i havnet been back to the strip..

Banger unless you've got a N/A 6 with a 3in system.. dont preach what you dont know.. EEVERYONE says 3in system is too big for a n/a 6.. its not the case and most people saying this havent ever tried it..
and as stav and many others have seen, my car goes a DAMN lot harder then alot of stockish 6's.. im seriously worried about doing any mods to it in the future apart from headers and a chip because im scared it will go slower..

rant on/rant off.. just sick of the repetitive bulldung poeple say on these forums sometimes..

anyhow a single 3 would be fine on an 8, twin 2.5 would be better i would think..

HLC · 30-10-2005, 07:19 PM

Stids, what did your exhaust set you back?

stiddy · 30-10-2005, 07:51 PM

$580 for a cat back mandrel bent system, i supplied the 3in cat though.. and they added it in for no extra charge..

reece1 · 30-10-2005, 08:05 PM

Quote:

Originally Posted by stiddy

Thanks stav, your a top bloke man..

Why are people saying 3in is too big on an N/A 6 ?? its not.. ive proven its not.. my car is actually faster, the only thing done to my car is a high flow 3in cat, mandrel bent 3in exhaust with a small rear muffler.. and a 3in mandrel intake i fabbed up myself.. and yes its loud and sounds like a drag boat or something..

Admittedly it has lost a 'little' down low but picked up a fair bit uptop, and being a 5spd, its not an issue for me.. 4000rpm launches at the strip are my friend..

i pulled a 15.009 with 2x15in subs in a massive box in my boot, spare wheel, amps and everything else, straight off the street and onto the track..
and yes i know gtech isnt everyones mate, but with my car empty eg subs out spare out etc etc its run 1x 14.8, 3x 14.9's and 1x 15.0 and since then i havnet been back to the strip..

Banger unless you've got a N/A 6 with a 3in system.. dont preach what you dont know.. EEVERYONE says 3in system is too big for a n/a 6.. its not the case and most people saying this havent ever tried it..
and as stav and many others have seen, my car goes a DAMN lot harder then alot of stockish 6's.. im seriously worried about doing any mods to it in the future apart from headers and a chip because im scared it will go slower..

rant on/rant off.. just sick of the repetitive bulldung poeple say on these forums sometimes..

anyhow a single 3 would be fine on an 8, twin 2.5 would be better i would think..

did the subs really help that much i should get a set for mine!lol
jokes aside have you got any pics/info on your inlet/exhaust custom job. how did you go about it. email me if you want i would like to pick your brain on this as i am doing some extractors at the moment

Sox · 30-10-2005, 08:38 PM

I prefer twin systems on V8's, and on a 5L twin 2 1/4" is ideal.

Something to consider is not so much the pipe diameter, rather the muffler choice, as it's not the pipe which is the biggest restriction, it's the mufflers.

Dual 2 1/4" mufflers will always outflow a single 3" muffler, and you will have the benefits of small(ish) pipes for good air speed, etc.

Rick.

stiddy · 30-10-2005, 09:13 PM

reece1, pm sent...

**Stav** · 30-10-2005, 09:34 PM

Sox I would not mind meeting you at my private test track some time..with the dev5..

xr8ute · 30-10-2005, 09:57 PM

Back onto V8's for a second......

I've just fitted Pacemaker 4-1's (PH4006), 2.5" cats, and Lukey 3" single catback to my AU XR8. Only other significant mod being the Crane 2030 cam.

It feels noticably doughier at part throttle compared with the stock headers/cats w/3" catback.

The sound is good enough to pitch a tent in your pants every time you nail the throttle...lol

IMO, it is too big for my mild n/a setup. If I wasn't fitting the blower soon, I would have gone for Hurricane tri-y's with their small 1.5" primaries and dual 2.25" from cats back.

Sox · 30-10-2005, 10:07 PM

Quote:

Originally Posted by useless

Sox I would not mind meeting you at my private test track some time..with the dev5..

I don't own a DEV5 anymore.

Rick.