After cutting one of these up today, I finally got to measure the wall thickness of the primaries.

Wall thickness is 1.5mm
Primary OD is 43mm (all the other JDM headers are 45mm.

 

Interesting! How about the ID and OD of the inner tube of the collector?

 

I'll take one guess....

Thanks for the info Dave.

Bryan

 

Stock Collector


Collector Going On A Diet






This will get cut off also




[Modified by SMSP, 7:27 AM 4/12/2002]

 

That collector looks familiar....

 

It's the newly designed SMSP collector!! 5 WHP gain compared to the old one!!

 

I'm going to try a H22 stepped 4-1 header and will open this collector up to receive some 1-7/8" tubes. This collector will also get a tapered outlet that will open to 2-1/2" and I'll replace that flange since it is much bigger than my regular 2-1/2" collector flanges. I'll hopefully have some pictures of the header Saturday night if all goes well.

I plan to do the same thing for a B18C set up. I just need another trashed ITR JDM header for another collector or I'll just make a cone and shape it into something similar.

 

So, you're trying to make one better than this:

 

What's that the JDM 4-2-1?

I'm going to be building a stepped 4-1 for the H22 today and I'm building a prototype for the B18C also.

 

It's the stock European spec Accord Type R 4-2-1. The stock Euro ITR 4-2-1 is similar but smaller... only 40mm OD!!!