What exactly does it mean to run an "open header"? Do you disconnect the exhaust where the end of the header and the catalytic converter meet? Or do you disconnect the exhaust where the catalytic converter ends, or in my case, the "test pipe"? What exactly are the pros and cons of doing this on an N/A car with I/H/E and no p/s, c/c, or a/c? Do you have to tune your car to take advantage of this?

 

Must tune it for this......going to be very noisy.
Depending on your power level and current exhaust it may or may not help you out.
The open header and 2.5" made about the same power on my ~200whp H22.

 

NirVtec is right where open header may help or not, and it is stupid loud to ride around the streets. Best way to find out is try it and go to the track or dyno. Open header on my h22 netted me 2-3mph at the end of the track. Tuning would only probably yeild the best results, as for disconnnecting in your case just remove after your test pipe IMO. GL

 

tuned you gain power, how much power idk i would imagine it depends on how restrictive the exhaust is. But you should gain, how much is the question. For a track car looking for a slight edge then yes, personally theres no question to do it, and also the weight savings from the exhaust you have to think about.


Modified by lude98SH at 11:13 AM 8/22/2007

 

Open header is only "really" beneficial in the forced induction world. The less restrictive the exhaust the better. Thats why all your hotrod/T4 cars have like 2ft exhausts off the turbo. In N/A setups gains are generally not as significant, not to mention the noise.

The car will gain something, anytime you can make your exhaust less restrictive you should make power improvements you might however also lose some midrange/low end. But my guess is that the loud noise and uncomfortable ride won't be worth the 1-2hp and 2-5 mph's in the 1/4.

For your car, it would make no noticeable difference in performance, other than it being loud as hell, which IMO is making the car worse.

 

Open header on most h22s will lose some down low and make a few more at the top end

open header sucks, trust me

 

Did I forget to mention this is on an H23A1? Anyways, I know that it is stupid loud to even try to ride around on the streets with an open header but I wanted to mainly know if anybody saw a difference on the track. I guess I will try it this weekend at the track. By the way, is anybody from here going to NOPI at MIR?

 

It would be a worse idea on an h23, the h23 relies on its great torque band for acceleration, open header will kill that, open header favors top end.

The h22 is "better suited" for open header because it revs higher.