Most side by side dyno comparos have them about equal.
Some will claim that the equal length have better spool up, but from everything I have seen, it is marginal at best.
But max power / torque gains look to be the same.
For the 02-14 WRX / STi / FXT / 2.5 GT etc. equal length headers are at least 2-4 times the price.
If I like the sound of unequal length headers better then they're better to me. Modification is all about personal preference. I've learned over the years that sound is a VERY important part of my love for automobiles.
Odd? Sure. But that's why we mod: to make a vehicle closer to what WE want, not the bean counters that run all major automotive companies these days.
Get used to it guys. All of the modern turbo Suby engines are gonna be equal length or very close. It started with the turbo diesel turbo placement down low, front and off center. Then the LGT adopted close to the same fitment. Then the Foz and now the WRX/STi all having the turbine about dead center. They should all be twin scroll or very similar because each two runners will be feeding into the top/bottom of the turbine. The only real diffeence between the gas and diesels is that the oil burners have a ginormous cat after the turbine where the gas has a normal-ish sized cat.
I think we are witnessing the death of the boxer rumble that we have all come to know and love in our Suby's.
Sabre (Julian) 92.5% Stock 04 STI
Good choice putting $4,000 rims on your 1990 Honda Civic. That's like Betty White going out and getting her tits done.
It will be different but not gone. You can't really remove the rumble. It's attributed to the flat 4 layout as much as to the exhaust.
The Porsche flat 6 has a distinct rumble and tone that isn't suppressed by equal length exhaust.
Yerp. Sad pandas and bananas all around. I do believe that the 2015 STi will still have the EJ25 in it from the looks of the engine bay/intake mani, but from there forward I can't say what will happen.
Sabre (Julian) 92.5% Stock 04 STI
Good choice putting $4,000 rims on your 1990 Honda Civic. That's like Betty White going out and getting her tits done.
It might not be the secks on wheels in the looks department, but these guys seemed to be smiling pretty damned hard after their introduction. http://www.youtube.com/watch?v=KneJiOUG9c0[/video]
Would really have liked to have been there to hear the design philosophy (in Japanese of course), and to see it all taken down to pieces.
Patience is the ability to idle your motor when you feel like stripping your gears