I just had one installed not too long ago, can hear the turbo spool up, and the signature flat4 rumble, but I'm not sure if I'm any faster or not?

I think I gained more in the top end (80-100+), but I can't really tell. might be all in the head.

the reason I'm wondering if it helps at all is because the exhaust gasses are going from unrestricted back to restricted again correct?(i'm running stock cat-back)

would i need to get a cat-back exhaust to see gains?

 

yea

 

YEAH I have one of those and I didnt really notice much if anything with it either. Im going to a Turbo XS or Helix DP. Laters

 

Get rid of the hks down pipe, it doesnt do anything at all, i just sold mine, i am going with Helix.

 

i have the hks downpie. i actually love it i have the cobb stage 2 and i use the hks downpipe and i run consitant 13.4 13.5 and thats with the stock uppipe on. so i would say thats pretty darn good. so just get the full turbo back and you will see a HUGE differance.

 

i am pretty sure the hks does something because now i can beat stock wrx's by quite a bit. now im just looking for a decently quiet catback to slap on.

 

get helix up and down pipes and a catback
i love it
with cobb stage 2 until i get a utec and upgraded turbo/brakes

 

i have pde uppipe, hks downpipe, with stock cat-back on cobb stage 2 ecu and 2nd gear pulls like a mother F*r...i love it

 

Well I have the HKS I done t feel much but Im sure it does something because of the added air flow. But the other down pipes have the bell mouth opening for better flow. Laters Mikal

 

I was wondering, Will the HKS downpipe throw a CEL?

 

Well I did all my mods at the same time so its hard to tell wich one caused the Engine light to come on. But I think as soon as you remove a cat or change the air flow even air temp, the computer thinks theres something wrong and sets off the light. laters Mikal

 

The HKS doesnt have a divorced waste gate or a bell mouth design, its the same design as stock so it doesn't help as much as downpipes like the Helix or Perrin or Cusco.

I would suggest selling it and getting one of those, the Helix is probably the best value.

-Zoeb

 

hks does get rid of the two cats and it will give you some power difference but not as much as other dp's with bellmouths and the others other members has stated already.

 

yes it will. on my 04, it didnt throw a cel until after 300 miles.