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Equal and Unequal Headers

Posted:
Sun Jun 03, 2012 7:43 pm
by LBR37Y
Hey guys this might be a stupid question to some, but is the difference (power gain or loss wise) with these two styles of headers
and to confirm what i think i know, Equal length headers is the length in reference to the stock length header??
Re: Equal and Unequal Headers

Posted:
Sun Jun 03, 2012 7:49 pm
by yipming
Equal length in theory will be more efficient and give power gain. You may lose the "boxer rumble" but that's about it.
Usually unless going for Time Attack glory it's not worthwhile to have ELH.
The twin scroll turbo uses ELH while the ones in the 2.5 have unequal ones. The length measures from the exhaust port to the turbo.
Re: Equal and Unequal Headers

Posted:
Sun Jun 03, 2012 7:52 pm
by LBR37Y
so from a 2008 GTB point of view who WANTS the boxer rumble these would be suitable??
http://www.celticmotorsport.com/catalog ... ts_id=2857
Re: Equal and Unequal Headers

Posted:
Sun Jun 03, 2012 7:58 pm
by Kekotic
Your car already has Unequal length headers because it's a post facelift with the 2.5 Turbo engine.
Re: Equal and Unequal Headers

Posted:
Sun Jun 03, 2012 8:03 pm
by LBR37Y
as my car is completely stock and I'm in the market for some exhaust mods.. Thats what i meant by suitable sorry should of specified in the beginning
Re: Equal and Unequal Headers

Posted:
Sun Jun 03, 2012 8:19 pm
by Kekotic
Why would you want to change the headers in the first place?
Just change Dump pipe centre and mufflers?
Re: Equal and Unequal Headers

Posted:
Sun Jun 03, 2012 8:24 pm
by Mat04
So do all the 2.5 engine variants come with the uels or just the turbo engines?
Re: Equal and Unequal Headers

Posted:
Sun Jun 03, 2012 8:31 pm
by LBR37Y
chaotic2050 wrote:Why would you want to change the headers in the first place?
Just change Dump pipe centre and mufflers?
i plan to do both
iv been told of several people that a lot of stock parts on subarus are very restrictive, so providing that is true why wouldn't i want to un-restrict my engine??
Re: Equal and Unequal Headers

Posted:
Sun Jun 03, 2012 9:22 pm
by dr20t
Summary:
- 2.0litre turbo Gt has equal length twin scroll headers /manifold
- 2.5 litre turbo Gt has unequal length headers
Boxer rumble can only be achieved with unequal length headers
Cheapest way to do this is change the mufflers on a 2.5 turbo motor
If you want a more pronounced rumble you need a full turbo back or cat back exhaust
In terms of power - the stock headers are good for up to 240 - 250 awkw. Until then there's no real point changing them
That's both the Uel and el ones
Save your money and do other mods instead of spending 600 plus dollars on shiny new headers
Mick
Re: Equal and Unequal Headers

Posted:
Tue Jun 05, 2012 12:29 am
by sbv
Driveability is a different story though. When I went to EL headers, I noticed an immediate difference in how the car drove. It felt like the car basically came onto boost immediately and held out through the rev range. It was VERY smooth and probably the most noticable improvement in how the car felt as far as I was concerned. Gambit actually described it very well in his build thread (fairly early on in the build).
I didnt get a back-to-back dyno tune with/without the headers, so I cant say it gave any additional KWs, but it definitely felt a lot nicer to drive!
You will loose the burble though, but I found it also made the car a little more quiet.
It would be interesting to hear from others who have have done aftermarket EL and UEL headers...