i was wondering what kind of numbers are you guys putting down with the greddy turbo kit and the stock exhuast, I've searched n there were a few running this setup but never posted any numbers. and are you running the oem cat/testpipe/hfc?

my other option is that I have a 70mm hfc and 70mm t1r dual and was wondering how much power would I be losing over running the stock exhaust, I don't want to run the t1r because ok getting tired of it being too loud.

also if I run a 70mm hfc on a stock exhaust would that be bottlenecking it or anything or should I really pick up a 63mm hfc? Thanks

 

70mm will make much more power with a 70mm hfc and this kit over stock. I would say you will give up around 15hp.

 

my greddy tic single with the silencer in was extremely quiet with the greddy kit. It was like stealth boost

i miss my car being so quiet...

 

I'm trying to retain a stock look and sound while going boost, anyone have any idea what the outcome would be if I run a 70mm hfc on the stock 63mm exhaust? Would I be worse off than with a 63mm hfc?

 

if you keep the stock exhaust or any 63mm exhaust get a test pipe

 

Try this:

https://www.s2ki.com/forums/index.php?showtopic=794079

 

i dont want the test pipe due to the smell, i have an 70mm hfc already and was wondering if anyone know how this would pair up with the stock exhaust? or would i just be better off picking up a 63mm hfc?

 

Here's my 2 cents based upon my recent experience and feedback from a quality tuner

I doubt the 70mm HFC would marry up with the stock 63mm exhaust - that doesn't sound like a great idea in general. My original GReddy kit setup was boosted to about 8 lbs and made 265whp - about the limit with stock cat and exhaust. When I went to the 63mm Berk HFC the boost could be dialed up to 11-12 lbs and I hit 300 whp, but started to run out of gas with the 550cc injectors. I had the tuner dial things back to about 9lbs of boost and am running around at about 285whp. The MAP sensor is needed as you get higher levels of boost, since the OEM one is designed for NA conditions and is generally a lower qual prod. I didn't need it for the lower boost, but as you start to play around you want the MAP to be right on, so I upgraded. If you hit 10lbs of boost, you absolutely need it. Replacing the HFC is really the best bang for the buck in terms of improving flow. If I had 675cc injectors I would probably be at the limits of the GReddy kit running 11-12lbs of boost and 320whp, all with the stock exhaust, nice & quiet, no stink from a TP, and very stealthy Later, if you change out the exhaust for looks/sound reasons, you may pick up another 5whp, but that seems like a lot of $ for 5whp. Sorry for the long answer, but I would buy the 63mm HFC, sell the 70mm to someone on these boards with a 70mm exhaust, upgrade the MAP, and get to a quality tuner. Enjoy!

 

^ thanks for all the help mezzfin, is anyone else out there running a simliar setup?

 

I've got exactly what mezzfin suggested: 63.5mm Berk HFC and Fujitsubo exhaust. Overall the car is a lot quieter than stock because the turbo and intercooler smother the normal intake noise. It's dead silent at idle - sometimes I actually wonder if the car's on. In normal driving the exhaust is sometimes audible; sometimes not; but always very quiet.

There's never any drone on the highway. I have to listen for the exhaust to be sure I hear it, and I can hear the radio and passengers better than I could stock. When you run it there's a nice rumble, but it never gets that loud.

I think this is the best exhaust combo available for an S2000, turbo or not. Also I bought my Fuji used, so it was cheap.