I am considering purchasing one of these. Does anyone have any feedback? Will I need to get an aux switch if I run these to the stock cat to a catback or will there be enough back pressure to actuate it. Will the power gained be noticeable on an s4?

 

pic?

 

These are a relatively new product and I've not heard of anyone using them yet, at least not anyone on here, so you may not get any responses on that. You should have sufficient back pressure though with everything post header being stock.

 

if you look on their website they have dyno charts of the improovments that it made.. i think it was 13.8 hp at most... let me see if i can find it.

 

That was for an s5, I wonder how the gains compare to the s4

 

i dont see why they wouldnt be somewhat close to that... tell you what, when i get back to Oregon with my s4 i will drive up to Corksport and pick one up and do the dyno myself. I got a friend who lets me take a few pulls. It will be mid May tho,

 

I want more on this i haven't seen it. Pics?

 

stainless.. loud .. needs to be wrapped.. comparable gains to Rb header.. both feel about the same.. super loud with a n1 dual..

 

Save your money and go turbo, or NA-T.