ive (new) purchased a HKS down pipe im wondering since my car is almost stock other than B.O.V. and wires is this 3 inch down pipe to big ive never seen the factory one and dont know how big it is but this look really big to me.....well i was gonna put a pic on but it seems to be to big mail me if you want to see it to better your answer and its shappped funny not like a purfect pipe all the way down right where it bolts ti the turbo i think its kinda oval shaped:friut:

 

3" is what most, if not all downpipes for these cars are. Its shaped to match the bends of the precat so that it fits correctly. If there were no bends then there would be no way to install it. Lastly, I know my grammar isn't perfect, but could you please try to use punctuation next time?

 

3" is good

 

You should be alright with 3in.
Most of us has 3in. downpipe

 

3" is 75mm, most ppl use it. Some brand have 80mm, but I don't it will help more or not.

 

3'' is it...should be installing my RVM next week!

 

The HKS down pipe has got to be the ugliest down pipe ever made. Why it's so ugly it could almost pass as a precat. However it has also to be the best flowing dp. At the top it is cast iron and widens out further then you could with a SS 3" pipe for that hard 90 degree turn down. Then it has a gentle curve instead of a bend. Awe hell I'll just post a pic.

 

I've got one of those too, and it really is ugly as hell!
But.. Is it really that fast-flowing? I always suspected it wasn't.. It seems a bit narrow at the turbo-end..
But then again, what do I know..
Anyway, can't be worse than the pre-cat!

 

3" is fine, thats what everyone else has and no one has complained.

 

The HKS is narrower at the top, the only reason it is shaped like that is because it is a JDM part. It is designed to clear the right hand steering.

 

You're a boner.