3inch single exit exhaust too big for N/A

awkwardturtle

Yeah, I'd definitely like to see a dyno of the 3" vs. stock. Here's a dyno of a 70mm exhaust vs. a 3" exhaust on a measley 2.0L Civic SI motor. No tuning:



You can see that the 3" gains probably 5 whp up top, and maybe as much as 10 ft lbs of torque at the vtec crossover.. and it loses maybe 2 ft lbs of torque down low. That's with zero tuning. If a 2.0L 4 cylinder motor can benefit from a 3" exhaust, it stands to reason that a much larger motor such as the Z's can as well. Enough with the backpressure nonsense, we need to see some dynos!

Red__Zed

Strong source....runs weren't even made on the same day, made by the manufacturer of the exhaust, and they are comparing max power runs rather than averages. Besides, the flow characteristics of the k20a are completely different...it's an freaking inline four.

3" exhaust on the z makes sense if for some reason you go single, or dual for FI.

I do not understand why someone would run a single on the z(single turbo build notwithstanding) in the first place. Might as well take advantage of the scavenging afforded by an x or h pipe. The firing order across banks supports it, and the gains are proven by systems like berk. Hell, even the nismo picks up a couple horses through the h.


EDIT: People that truly believe there are gains to be had do it themselves, they don't post about it asking others to do legwork for them. I look forward to seeing your dyno results when (if) you ever do it.