Thread: New side project, update with virtual dyno

The only thing that will suck is the bend right after the choke. Might cost you some power. Curious to see results of this. I would make it a little shorter than 25". Can be a fun high revving motor with the proper IM setup.

I was able to verify the length and size of the primarys. The first step is 7-8" long and the second step is 14-15" long. So thats a total of 21-22" long before the collector. Close to 25" which i think is a good length compared to other custom headers, which made sick horsepower.

The choke is 2.5" (outside of pipe if that makes a difference) and the outlet is 2.75". If the downpipe part needs any modification i will modify if to have a 2.25" choke. Hopefully it fits close enough at first (the downpipe) so i can make dyno or virtual dyno comparos of the different choke sizes.

A sneak peak. I still have to get cylinder #2 primary mocked up. Then test fit the header. I know I will have to modify the pipe after the collector also.

Looks good so far man. Curious to see how it works out.

I like the welds. G-spec has a nice 4-1 header liike that for the SR20 but its really expensive ($900)

Nice choice on the header, Same one I'm getting. I heard great things about these

Got the primary tubes all mocked up to the new flange. Now it's time to put the header on the car and mock up the down pipe.

Can you fit a megaphone off the collector under the motor? Looks pretty cool though, stepped primaries and all. Not sure how those motors respond to the megaphone, I just know that Kojima and them had good luck with it on their VE motor builds.

Brent

So the final length of the primarys ended up to be 20.5" to 22"... not exactly equal length but hopefully it will be ok. Length is actually good i think. IIRC the 25"-30" headers did worse.

That length should do great. It would be cool to have another collector that points straight down versus one with the bend. Keep us posted.