357MAGNOLE

Tax return is pretty nice this year. I haven't done anything to my new to me S yet. I am thinking K&N CAI, Berk 70mm HFC, HKS Hi-Power single exhaust and then the single exhaust exit rear bumper cap. Looking to squeeze a few extra horses out of the ole girl and just make some changes in general. Any changes I should make before I make the purchases or sound good?

357MAGNOLE

No opinions? So this is a good first step in the N/A world?

Chuck S

You lose exhaust velocity and add turbulence by opening the system up to 70mm right after the 57mm exhaust header. The HKS is even bigger at 75mm. From what I've been reading keeping the exhaust velocity up helps the flow and mid range torque. Convincing enough that I have the 63.5mm Berk High Flow Cat and the Tanabe Medalion Touring dual exhaust (60mm). 221 bhp at the wheels on a conservative Mustang dyno (some say these are 10% low).

No personal dyno tests, just very happy with the results in power and driveability without unnecessary noise and drone.

The HKS single is reputed to supply at least as much power but my car's styling demands a dual exhaust.

My '06 is Gernby tuned which, I'm sure, helps it achieve the results.

-- Chuck

357MAGNOLE

Yeah, I dont have the option of flashing the ECU. Not ready for a stand alone yet either.

So you are saying that the more open exhaust will cause me to loose some torque?

I will eventually end up putting a S/C on the car. It might take a few years, I will have the engine rebuilt first for sure but I want the exhaust to be squared away and done. I was thinking the 70mm high flow to the 75mm single exhaust would be adequate.

Thanks for the reply by the way.

Chuck S

Open exhaust tends to benefit high RPMs at the expense of mid range. Exhaust physicists can demonstrate how exhaust flow and back pressure pulses affect exhaust scavenging and big pipes slow gas velocity. Only way to tell on your car is to get a dyno number before (something I wasn't able to do) and after. And then look at the torque curves. That and some quarter mile times. These cars benefit greatly from tuning, especially the VTEC engagement point. It's 3,600 rpm on my car now which gives me 5,000 rpm of VTEC power under WOT.

Every exhaust claims to add power and the OEM exhaust is not all that restrictive and quite good albeit heavy. I noted the Speed Academy ASS2000 track car build uses the Tanabe Medalion Touring to enable the car to be streetable too. Their FRS rally car used the HKS single behind the Subie engine.

Supercharger will make serious power of course.

-- Chuck

357MAGNOLE

I would love to find a cheap and easy way to adjust the vtech engagement other than spending $800+ for a stand alone system requiring a full tune. At this stage for the car, its just not worth it for me to have a stand alone EMS.

But essentially what you are getting at is, with the exhaust setup I am going for I will sacrifice some mid range power and pick up some on the top end. Are you suggesting I should stick with a smaller HFC and smaller diameter exhaust?

I appreciate the help, new to the S2K world. Been doing lots of reading, but just when I think I have things figured out I find differing info.


***EDIT***

Did some more research. So basically it seems not much is to be gained without a tune to begin with. But I now understand the turbulence/resonating issues when having different sized TP/HFC and exhaust setup. But from what I gathered, there should not be much of an issue going from stock header>70mm HFC>75mm Single exhaust because it is stepping up on the way out. If it was stepping down somewhere in that link I would be causing myself issues. That makes sense.

I am hoping this is a good combo, at least something that will keep me content. I was going to go with the Q300 but seeing people with fitment issues (having problems with the exhaust lining up evenly) that bothered me. I am too OCD to have one pipe hanging lower or sticking out further than the other. Would drive me insane.

Plus the weight savings and small gains of the single seem intriguing. I just hope I am happy with this HKS. Someone local to me has a buddy club spec 3 they are selling for $450 that looks good, but I dont know much about them.

s2000Junky

TP, Apexi Neo, Wideband. Most bang for the buck. After that your % of performance value goes down quite a bit.

357MAGNOLE

Cant run a TP here in Va, we have state inspections and down pipes/test pipes are automatic fails and I am not willing to deal with the stink of a TP either. HFC I can get away with, but that's it.

I am not overly concerned with gains since eventually I am going FI any way. Just looking to replace the worn out cat/exhaust. The car is 16 years old, it needs a facelift.

357MAGNOLE

Switched up a little. Going to go with the HKS hi power DUAL over the single, and the Berk 63.5MM HFC vs the 70MM HFC along with the K&N FPIK....

Ill probably pick up a Apexi AFC NEO after I get a AFR installed and find someone local and experienced to help with making minor adjustments.

dane795

That's the setup I'm gonna have one day, good taste I only have the intake so far though.