Hello all,

I was wondering if 3" cat-back exhaust would hurt/help performance on an NA s2000.I would be running this off of a 63mm test pipe. I am building another FI motor to be installed late winter. I will be running a full 3in exhuast for that so i was wondering if this would be a good start. The car is being driven now and don't want to do anything to effect that. I wanted to know if there is the proper amount of back pressure with a 63mm test pipe and 76mm exhaust. i have read that 70mm exhaust is great for an NA, so does 76mm work as well?

thanks
matt

 

hmm... i only found one other thread that adresses this and i'm gathering that 70mm is as big as i should go on a NA application....

just didn't know if the stock header to test pipe to 3 inch would work. i'm guessing no.

 

3" is going to be too big for a mostly stock na motor. that's really intended for FI.

 

yeah thats what i'm gathering. I'm just getting all my extra turbo parts together. Just thought if i could use this then more modivation to get it now.... I guess i'll just wait and have it made when the turbo is on.

 

I had a 3" single on my NA without knowing it. (seller said it was 2.5") My first impressions was that I lost power up top but gained better throttle response.

 

i think you lose power because you lose back pressure... thats my understanding

 

What I've always heard was that 63 gives more lower end power while 70mm gives higher end power. Being confused that I was, I started a myth busting thread. In the end, someone showed dyno graph of 63mm and 70mm back to back from AJR, and 70mm gained more power than 63mm at all powerband.

https://www.s2ki.com/forums/index.ph...ic=563243&st=0

Have a read if you're interested.

 

good stuff vik

 

Just put it on now - you probably won't notice a difference worth mentioning and there's no sense in doing it now and again after you go turbo.