OK, I race a Honda Civic, GS R vtec motor, vtec kicks in at 5600, according to Hondata. I need more TORQUE. Hp seems okay, just doesn't pull good enough right before the vtec is kicking in. I can't change the gear splits in my class, so I need a header better than my modified street Comptech, with 1 1/2 primaries, 1 5/8 step and I welded in a 2 1/2 outlet (instead of 2").
All the guys from LA say I should get hellatight metric JDM tubing. They say that the 38.10mm JDM tubing will flow much better than the 1.50 inch tubing I have now. I figure that since my Honda was built in OHIO, that I can start with tubing from OHIO and build whatever header I want. I would like to use inch size tubing, because I called everywhere for the 38.1mm tubing, the 41.27mm tubing and the 63.50mm tubing, and it was special order from Japan, and I had to pay in advance and wait 16 weeks. I need my car to be bit faster by Nov 22.

BUT seriously folks, I need opinions on whether or not it will help to build a long, big tube header, perhaps even a 4:1 instead of a 4:2:1? I am not sure that my header is too small, but I am worried I will really hurt myself if I go TOO big.
Any help is appreciated.
J Morris and steak and sausage

 

SMS Products - Dave Stadilus

He's "SMSP" on here, PM him. His headers are the ****.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JM3 &raquo;</TD></TR><TR><TD CLASS="quote">All the guys from LA say I should get hellatight metric JDM tubing. They say that the 38.10mm JDM tubing will flow much better than the 1.50 inch tubing I have now.</TD></TR></TABLE>

38.1mm = 1.5"
if you want midrange then 4-2-1 would be the way to go

 

Walt Puckett at Delta Group.
"metalworker" on this board.

His stuff is the **** too.