twin 2.5" or 3" exhaust for worked ls1?

[Victimiza]

Is there power to be gained in going from a 2.5" to the 3" exhaust system at 250rwkw+?

I'm fairly happy with my exhaust note as it is, plus wouldnt mind avoiding spending a grand on another system, but if the 3" is going to give a significant power gain í'd consider it.

cheers.

[saundyvx]

has it got extractors, 2 mufflers and a cat? i'd look at that before the pipe diameter. But i'm pretty sure with a v8 you would be right to put on a 3"

[Cobez]

If you are gonna be doing more mods in the future, a twin 3" system will be fine too. I run a single 3" on my 5 litre, that works well, for a 250kw LS1, i'd go twin 3" to accomodate future mods. Would be fine as it is now too.

[johnvtls1]

2.5" is plenty mate. if your gonna spend a grand on power theres better places to spend it. twin three inch sounds awesome though, especially on a cammed ls1.

[mrbeef]

im just curious, what is the difference between a twin and say a non-twin.
my exhaust comes off the manifold for each side then comes into two mufflers then goes into 1 to another muffler/resonator then to tip. is this a non-twin? i think its about 2.5" dunno havent got the ruler out, its loud tho

[Cobez]

2.5" is plenty mate. if your gonna spend a grand on power theres better places to spend it. twin three inch sounds awesome though, especially on a cammed ls1.

Hell yeah, but i just re read the original post, probably wouldn't get a twin 3" fitted for under a grand.

im just curious, what is the difference between a twin and say a non-twin.
my exhaust comes off the manifold for each side then comes into two mufflers then goes into 1 to another muffler/resonator then to tip. is this a non-twin? i think its about 2.5" dunno havent got the ruler out, its loud tho

Twin system basically one pipe for each header to put it very simply. Twin cats then usually both pipes merge into a twin in twin out resi or whatever at the back. On later model Commo's, one pipe comes out each side of the rear bar.

Depends on the car and what the person wants really.

[Not_An_Abba_Fan]

Twin 2 1/2" would be fine. You would gain nothing by going to a twin 3" unless there was a considerable amount of work done.

[GMMAD]

Hell yeah, but i just re read the original post, probably wouldn't get a twin 3" fitted for under a grand.



.

twin 3" X force are around $500 on ebay

[Victimiza]

decided to go a sureflow 3.5" with ballistic cats.

was going to go with the twin 3" from NAAF but apparently the 3.5" sounds better and funds are short, the single pipe is 2/3 of the price.

[GMMAD]

decided to go a sureflow 3.5" with ballistic cats.

was going to go with the twin 3" from NAAF but apparently the 3.5" sounds better and funds are short, the single pipe is 2/3 of the price.

nope twin 3" sounds better
I have had a 3.5 a changed to twin 3" and it does sound better
and they are cheaper at around $500-600

[Not_An_Abba_Fan]

My opinion is that twin sounds way better than single too. I hope you're not disappointed with the sound of the single.

[Vt_vic]

if your going over 300rwkw go with the 3 inch otherwise stay with the 2.5

[Joey_21]

would u loose back pressure ud think 3" would sound better if theres no gains or loss's y wouldnt u go 3" over 2.5" people always say go 2.5" no1 actually says y care to explain any1 I need this info before i do mine

[Not_An_Abba_Fan]

Back pressure is a bad thing. Ideally you want zero back pressure. It is exhaust velocity that is your friend. A system that is too big can have more back pressure than one that is too small. Once you get the exhaust flowing out of the engine, then the size of the exhaust needs to be matched to it so you keep exhaust velocity to a maximum.

[Joey_21]

so ur saying basically if you get a cat back with a bigger exhaust width and u have stock extractors its just the same as having aftermarket extractors with say a 3" without mods? if that makes sense lol

[Joey_21]

what happens if u get a lot or even a little bit of backpressure do u loose horses? or Kw

[M01ST]

Twin 2 1/2 inch FTW.

[GMMAD]

what happens if u get a lot or even a little bit of backpressure do u loose horses? or Kw

on a stock car you will loose power with a twin 3"
if you plan on getting a cam or better
go twin 3"

[Victimiza]

on a stock car you will loose power with a twin 3"
if you plan on getting a cam or better
go twin 3"

post up a clip of your twin 3", I've yet to hear a good one

[kiwiss5L]

yeah put some clips up, looking at upgrading mine so would be good to have a listen.

[GR3GA]

4-1 extractors and xforce twin 3" i LOVE IT!!!!!!

touch the loud pedal and it gets pretty loud


vt :: 100_3476.flv video by Grega_vs - Photobucket

vt :: GR3GACAM3.flv video by Grega_vs - Photobucket