exhaust questions

[L-VrCalais]

Hi guys

I want to put a sports exhaust on my 3.8 litre calais but I not sure wat size to go for 2" 2.5" or 3" and is red back a good brand? But there is one thing that confuses me with my calais after the cat it breaks into 2 pipes and has a muffler box on each then it joins back up into one so would the sports exhaust be the same or would it just bypass into one pipe? and follow through any advice would be be great guys.

cheers

[moff_man]

sounds like you have twin cats. you would just need the pipe after that and i wouldn't go any bigger than a 2.5inch unless its supercharged or a v8

[L-VrCalais]

No i doesnt have twin cats its after the cat it breaks into 2 mufflers

[MADDNE33]

dont go a 3' it will be over breathing, 2.5inch is best for v6 or ive heard of some people going 2 1/4 twin system. Go and see and exhaust shop and get some advice. gd luck mate

[L-VrCalais]

yea ill do some research first but i think ill go 2.5 probs

[Trikky]

All I can say is make sure you get one with the resonator, I have a redback 2.5 cat back system and got the one with the straight thru tail pipe - droned like crap ended up getting the new tail pipe and all is good now, still a bit louder than stock but still a big diference in get up and go compared to the stock system

[nathanVY]

I'm running twin 2.25" with twin cats on my v6. Pacemaker headers too, the lack of drone is incredible, i think it may be the headers and general flow through the whole system that fix that up.

[dynoryder]

wtf is over breathing how can an engine over breath with an exaust

breathing is from air fillter to exaust tip

exausts just sound good and bearley that on v6's

[jokerflingo]

All I can say is make sure you get one with the resonator, I have a redback 2.5 cat back system and got the one with the straight thru tail pipe - droned like crap ended up getting the new tail pipe and all is good now, still a bit louder than stock but still a big diference in get up and go compared to the stock system

Can vouch for this, definitely get a resonator, or else drone is terrible.

[L-VrCalais]

yea i got the paced maker extractors on it they came with the car, but the calais exhaust breaks into 2 mufflers after the cat so I'm not sure if the new exhaust will bypass them into one and also the resonator I will ask the guys on ebay as thats where I'm gettin it from thanks for the advice guys...

[L-VrCalais]

If the exhuast is too big the the car loses back pressure so that slows it down dont it?

[mitchy_vn]

hrm for my vs calais i was thinking getting one of ebay (red back) 2.5inch for like $160 buh it dont come not with a resonator.. does a resonator make a big differnce on how the exhust will sound?

[jokerflingo]

hrm for my vs calais i was thinking getting one of ebay (red back) 2.5inch for like $160 buh it dont come not with a resonator.. does a resonator make a big differnce on how the exhust will sound?

You want drone or not?

[mitchy_vn]

You want drone or not?

lol dis iz a stupid question whats drone??

[Andrew426]

If the exhuast is too big the the car loses back pressure so that slows it down dont it?

Its more about helmholtz resonance and air velocity than back pressure.

Anyone who tells you that you need back pressure in your exhaust needs to take a break from the internet and go learn some physics.

[jokerflingo]

lol dis iz a stupid question whats drone??

Exactly as it sounds, that noise at a certain revs that just does your head in especially if your going up a long hill, usually around the 2000-3000rpm range.

[smitheyes]

Exhaust Theory

great article on exhaust theory for anyone interested as opposed to taking a break from the internet and going to uni (no hacking on andrew426 intended, i totally agree with his comments)

[Andrew426]

Exhaust Theory

great article on exhaust theory for anyone interested as opposed to taking a break from the internet and going to uni (no hacking on andrew426 intended, i totally agree with his comments)

Ha ha yeah. I think its like 6th form physics, but its all the same really. You keep the gas velocity up and it scavenges your exhaust gasses.

I just dont agree with people saying backpressure is good. Backpressure is not good, if it was we would be seeing gains from blocked cats, potatoes stuffed in exhaust tips etc.

[L-VrCalais]

people are on here asking for advice not asking to be mocked you wanna be nice and give advice then do it if you want to be a dick about it then go onto someone elses post and do it...

[DevilDRake]

lol dis iz a stupid question whats drone??

Simply said, go in a car with an exhaust done, and do 60kph in 4th gear then flat foot your accelerator, if you get a headache quickly then you'll understand.

[DevilDRake]

people are on here asking for advice not asking to be mocked you wanna be nice and give advice then do it if you want to be a dick about it then go onto someone elses post and do it...

Re-read what he said mate, he said "any one that tells you"

You've just started a no-reason flame war.

[L-VrCalais]

I get what you mean Ive heard it before

[Andrew426]

people are on here asking for advice not asking to be mocked you wanna be nice and give advice then do it if you want to be a dick about it then go onto someone elses post and do it...

Uh?

Sorry bro, didnt mean to offend anyone with that. Just correcting the common myth of backpressure being good.

[mitchy_vn]

ohkk i understand drone noise now.. my mate had it wen he jst did a str8 pipe... on his vr.. what i didnt like about it .. low revs was loud buh wen he put his foot down sounded like shit at high revs.. . he got the exhust noise wen he didnt need it .. n wen he put his foot down sounded werid

[L-VrCalais]

Na sorry guys didnt mean to bite just had a bad day grr!!!