Quote:
Originally Posted by new2subaru
In all honesty I think the power is a given. The lightest header is still a bit of a ? mark. It's been written that your average header will give you 85-90% of the more expensive headers. I want it all, power and weight reduction and limited noise. 
I may give the WRX/BRZ/FRS Willwood kit a shot though. I know the rotors are thinner but stock holds up fine. Only one way to find out! |
Maybe, Removing the cat nets at least 50% of the total potential gains. Pipe diameter, runner length, EL vs UEL, and merge collector design will also contribute to the remaining gains.. Quality of welds and flanges etc... may differ with cheaper vs more expensive too, just things too consider. But Weight would be the least of my concerns when swapping headers, cost, hp gains, sound would be my greatest concerns, At that point you can’t really care about a 1-2lbs difference with aftermarket headers. I’m sure almost all are 7-10lbs lighter with no cats or heat shield.
The WW 4R are thinner, and less mass, so will heat up quicker but should cooldown quicker as well. This is why i think brake ducts would pair well with it.