Subaru header question/confusion. Just rice?

[kujito]

So, from lurking a few Subie forums, it seems that UN-equal length headers are the way to go. Apparently it's good for a few extra hp, as well as to bring out the Subie Rumble exhaust note.

I can go along with the sound part, but how in the hell would it add power?

Maybe I'm way off, but I've seen way too much time and money spent on the design and engineering of EQUAL length set ups to have much faith in an UNEQUAL length set up.

Those guys don't like the $300 Borla headers, as they are prone to cracking at the welds. That's no surprise from Borla, but they mostly recommend the ebay Borla knock-offs for $150.

Is this just dumbass ricer noise, or is there some validity that I'm just not seeing?

 

[XJLI]

UELs 'supposedly' dont add power... if you want to make the most power you can, you need an equal length. imho.. unless youre building a racer get the UELs bc they sound badass.

i had a ebay UEL and ebay catback on mine and it was great. still works great on it, my buddy owns the car now.

what kinda subie btw?

this was almost 100% identical to the setup on my GC:

http://www.youtube.com/watch?v=HaCeufSecas

 

[kujito]

I picked up a '99 Legacy Limited 30th Anny. SUS. Basically the GT without the scoop hood (has spoiler), but with cold weather package.

2.5, 4EAT, heated leather, heated mirrors, heated wiper rests, fogs, sunroof, 6 disc changer & powered sub (needs re-coned). Made my hour long commute much more tolerable, and nearly doubled my mpgs from the heep.

Got tires and brakes done, but I'm not really looking to do much to it at the moment. The header thing has just been bugging me. The Subie kids swear it adds power, even tho some don't match it to an intake. Just headers and exhaust. :dunno:

 

[vt98xj]

It might add power to have unequal length in the suby world because of the way the boxer engine is layed out. I would have to see dyno results.

 

[el_roy1985]

Might be because of the turbo, to keep the exhaust pulses at optimal intervals for spooling. I think they still use a header with the turbo, because of how the engine is designed. Been a while since I brushed up on my boxer engine knowledge.

 

[XJLI]

I picked up a '99 Legacy Limited 30th Anny. SUS. Basically the GT without the scoop hood (has spoiler), but with cold weather package.

2.5, 4EAT, heated leather, heated mirrors, heated wiper rests, fogs, sunroof, 6 disc changer & powered sub (needs re-coned). Made my hour long commute much more tolerable, and nearly doubled my mpgs from the heep.

Got tires and brakes done, but I'm not really looking to do much to it at the moment. The header thing has just been bugging me. The Subie kids swear it adds power, even tho some don't match it to an intake. Just headers and exhaust. :dunno:

those are nice looking, congrats dude. it adds some power, more noise though. the cheap catback from ebay WILL get you noticed. if you want tone, headers and a STi catback will do you great. i got a few exhaust tickets with my setup... damn small college towns!

It might add power to have unequal length in the suby world because of the way the boxer engine is layed out. I would have to see dyno results.

not really. i dyno'd my 2.5RS 5spd (same motor as the OP) and got 130hp,130lb/ft to all 4 wheels... stock is rated 165 to the crank and stock 2.5RS's usually dyno ~100hp. I had an intake, headers, catback, and lightweight pulleys. i'd say the pulleys gave me more power than anything.. shaved a ton of weight off the belt drive.

oh and just to prove i'm not a keyboard cruiser-

Might be because of the turbo, to keep the exhaust pulses at optimal intervals for spooling. I think they still use a header with the turbo, because of how the engine is designed. Been a while since I brushed up on my boxer engine knowledge.

no turbo on this model... and they all have headers regardless... turbo models just add the up pipe and down pipe before and after the turbo.

 

[asp]

My best friend recently sold his 05 STi that was putting down ~350whp. He had equal length headers on and decided he didn't like the sound so he put unequal length back on. The only way I could fathom making more power with UEL is that there is room for bigger tubes vs equal length, other than that - IDFK.

Good luck with whatever you get.

 

[CherBear]

The only way i can see UEL headers making more power is if the exhaust pulses are timed out so that the exhaust has the maximum scavenging effect. No idea if thats true, but seems to be the only feasible way to be true.

 

[Boveevil]

Don't know about power. But my buddy had an 02 wrx and with the equal length header it gets really tinny Honda-ish sound.. not the deep baltty? subaru sound.

 

[kidarkitect]

congrats on the scubaaru- my dd is a n/a 08 forester sports edition, cant wait for the day i can start working on it...... my last scooby was a 91 legacy turbo that i played colin mcrae in one too many times (RIP)


unequal sounds way better. as far as brands, i'm outta the loop. i would've said cobb but doesn't look like they carry/make headers anymore.

have you been on nasioc? subaruforester.org? (sorry those are the only two I've lurked on) they might have some more help. legacy forums?

i agree with boveevil about the sound i've heard from n/a's and turbo scooby's. very civic/inline 4 sounding. and you're never going to get that much power out of your engine, so it might as well sound good

 

[kujito]

Thanks Fellas.

I'm not looking to anything to the car at this point; I was/am just having a hard time wrapping my mind around the UEL header thing. One of my coworkers says that the UELs can add a bit of low end, but take away from high rpm power to an NA motor.

Right now I'm just enjoying the quiet, comfy ride, and looking to the warmth this winter. I worked nights all last winter, and between the barely functioning heater and the leaky door/window seals, I froze my azz off on both legs of my hour long commute. It was -19* when I walked out of the building one morning. That was a tough drive home.

Cold weather package and AWD FTMFW! I still prefer 4WD, but the heated seats and stuff are awesome.

 

[blubullett]

Depending on cam timing and firing order it is quite possible that unequal length headers are better on Subi's because you try to build the header so the exhaust pulses don't reach the collector at the same time. But I do know that with Mustangs equal length headers will always be more powerful by a couple of horsepower. At the power levels you are at though I doubt it will make much of a difference. If everything else is the same and the only difference is equal and unequal length there is probably only a horse or two difference.

 

[2000workinprogress]

I have a hopped up 06 forester actually and I kept with an uel just for the sound. In my experience equal length gives you a little more power because it gives you better flow, but when you do that to a subi it starts pumping out that awful annoying sound that comes out of a honda that boveevil mentioned. I was happy with 415 so stuck with not wanting to be annoyed all day driving it hehe