What size exhaust for 2.6 na

[81pw]

Just wondering what size exhaust should I do for a mate 2.6 na. 2 1/4 or 2 1/2 For best performance?

[ISKA8]

hmm i dont know whats the best for a 2.6 but i had a 2 1/2 on my sig with genie headers,worked out good..even when i turbo charged it,i made a dumpie and left it the same with good results..not losing any power.good size i reckon

[GLANT]

I am with ISKA8..2.5 inch all the way

[Rally_2.6LC]

depends what you want to tune it for....hp or torque.
I had a mate who had 2.5" from extractors through the mufflers and then had 2" after the rear muffler over the diff, this gave him more power.
Best way to get most power is for tuned length exhaust...but that is mega $$$ and not worth it for most people.


Cheers Matt

[81pw]

Cheers boys I'll go with the 2 1/2 all the way through

[Scorpma82]

I originally went for a set of OTS Lukey extractors (4-2-1) fitted to a 2 1/4 system.......had a great note...but i went crazy with being unique so i sliced off the last section of the extractors and kept it as a 4-2 setup.....with a 2" pipe running down either side of the car, then bolting on a pair of twin 3" chrome dump tip on either side!!!


From the back of the car it looked a bit radical.....coz i had (well still have) 235/60/R15 wrapped around the pepperpots, a Ford 9" diff sitting in the centre and a pair of twin 3" chrome tips poking on eithe side of the car......in terms of gaining HP....probably didn't really do a greaat job since a lost alot of back pressure with the new system.....but since the motor was dieing and i wasnt interested in going fast....i didnt care about gaining an extra 3 HP from a "racing" exhaust system....



If your on a tighter budget (like me)...i found using mild steel (as opposed to stainless steel) and have the exaust system press bent instead of mandrel. That's what i'm doing for the next car..and for the extractors (for a street car i mean), I found a better Bang for your Buck in using OTS headers coated in heat treated header paint (and in my case) as well as wrapping the headers in black "header wrap" (again, as opposed to stainless steel or "racing" headers).......Like i said, this is just from personal experience, but i found that you won't "MAKE" as much HP as against to a far more expensive and more sofisticated system.....but you will "RETAIN" or "LOSE LESS" HP through things like heat soak in the engine bay......plus..depending on your engine bay...the black wrap may give the engine a bit more of an agrressive look (my entire engine will be painted in wrinkle finish black.....much the rocker covers on the turbo sigmas).

[C_Fernance]

That sounds kinda like one of my old Scorps. Had a set of old 4-2-1 extractors, and I wanted a sports exhaust. I couldn't afford one, but did have a few old standard systems. The extractors went into a short section on 2 1/4" that I then split back into 2 which were the the standard 1 3/4". Had one of theses going out each side with some chrome tips to make it look 'good'. Was as loud as hell as it was basically a straight though exhaust about 3 feet long. Best part was downshifting and making it shoot flames out both sides of the car!!! Had a set of 225 or 235 (can't remember) on the back with gold meshies, and 185's on the front.

Added to this the front had a massive spoiler, and was lowered a heap, while the rear end was basically standard height, and was yellow with heaps of patches. It soon ended up being nicknamed "The Bulldozer" by the guys at work.

[webby]

Basic rule of thumb:
<1.5L NA: 1.75"
1.6-2.0L NA: 2"
2.0-2.5L NA: 2.25"
>2.5L NA: 2.5"
Turbo: 3"
This is what I've been told anyway.

I got the best results from the L24E in my old R30 Skyline with a set of equal-length 6-2-1 extractors, 2.5" with a single Lukey muffler back to a 2.25" under-diff tailpipe. Was loud as hell, but it sounded freaking awesome and made just over 150rwhp, as compared to 144rwhp with a full 2.5" system.
It had a stage 3 cam, ported head and L28ET valves, Megasquirt II ECU and 20v 4AGE throttles as well.

[cheaterparts]

if its any help we did a few dyno runs some time back about 9 years ago ( and dont ask me for the sheets who knows where they are now )
for my 2.6 I made my own headers with mandrel bends and tig welded them up using 1 3/4 tube and they where 4 into 1
I think the primary tube lenth was 29 " its a while back so the memory is failing a bit

however we did use a 2 1/2" system and one straight though turbo mufler after the diff
anything like a hotdog or mufler in front of the diff reduced power
at one stage we tried a short side pipe with a mufler closer to the engine , we found that the jetting had to be leaned as this set up made to much back presure - choking the engine and it also droped 9 Kw atw

so with all our testing the best power was made with the 2 1/2 system going from the headers and over the diff with out any restrition then fitting the mufler right near the end

I was going to make up a set of 4 into 1 headers using 1 7/8" tube but never got around to it

hope that is some help
cheater

[mstrrab1992]

i think my 2.6astron in my lancer has a 3" all the way sounds weird

[SIKMA]

How do the headers on ebay for our sigmas fair? Anyone tried them out?

I might be buying another sigma soon so might be looking at getting an exhaust system made up. Ive already scored myself a Magnaflow stainless muffler on ebay but its a 3" one. Oh well lol, will just flare the pipe and weld it.

[amgis_obrut]

Basic rule of thumb:
<1.5L NA: 1.75"
1.6-2.0L NA: 2"
2.0-2.5L NA: 2.25"
>2.5L NA: 2.5"
Turbo: 3"
This is what I've been told anyway.

I got the best results from the L24E in my old R30 Skyline with a set of equal-length 6-2-1 extractors, 2.5" with a single Lukey muffler back to a 2.25" under-diff tailpipe. Was loud as hell, but it sounded freaking awesome and made just over 150rwhp, as compared to 144rwhp with a full 2.5" system.
It had a stage 3 cam, ported head and L28ET valves, Megasquirt II ECU and 20v 4AGE throttles as well.

sweet ima getting a 5" on my siggy now and a 8.5" on the transit van