I had posted this also in the all motor forum, but I'm wondering now if you ITR guys would maybe have the answer for me on this.

I'm looking for a dyno comparison of back to back runs with the OEM 96 Spec JDM ITR header (cast 4-2-1 with 2.5" collector) and any other known performance header. I currently have a Hytech replica that is bashed in on the bottom, and I found one of these ITR headers for very cheap locally and wondering what I'll lose in WHP if I go to this for the added ground clearance.

The only post I found from a ways back with a comparison which started out with this header in particular seemed to only run in un-tuned as a baseline, then tuned for the other headers that they put on later. The 96 Spec made about 10 WHP peak less, but un-tuned vs. tuned is like comparing apples to oranges.

There is tons of info out there on the 98+ ITR 4-1 header, but not much that I can find on the 96-97 ITR 4-2-1. Any help would be greatly appreciated.

 

96header is turd

 

Very insightful and informative.

 

Here's Honda's test dyno comparing the 96-spec header (middle) and the 98 spec header (right). As you can see, contrary to popular belief, the 98-spec actually brought the peak torque down a few thousand rpm for a wider powerband with the same horsepower.



The left graph is the SIR-G (JDM GSR) with 2-stage intake manifold.

 

Thank you very much for this sir, this helps. The two dynos look similar enough to me that I'd be happy with the 96 spec, assuming that these similarities would also translate through after being tuned.

As far as torque under the curve, it almost looks to me like the two are the same, just that the peak is shifted slightly lower with the 98 spec. Either way, if the 96 spec can perform to within a couple WHP of the 98 spec then I am happy to trade that off for the ground clearance.

If anyone has any personal dynos with this header tuned that would also be great.