hi, ive got a 1996 jdm itr its TOTALLY STOCK, no intake no exhaust system, NOTHING!
well the thing is i bought a jdm DC sports headder for itr and the car was like 30% slower than without the headder
why is this happening, could it be cause it has the catalyzer?

 

you just gotta love the butt dyno...

your stock manifold is a 4-2-1 design which promotes more low end grunt than a 4-1 (DC) design...

your *** says you are going slower bc you may have less torque than b4...

dyno the POS and you'll get your answer...

 

so im faster? with the catalyzer=?

 

if you want to know

put the stock exhaust manifold back on, do a baseline dyno run
then intall the DC header and do a dyno run

 

we dont have dyno here i installed the factory one again!
so ill trust your word and put the DC back

 

i'm only giving you a possible explanation based upon your description...

 

anybody that can give another explanation?

 

[QUOTE=BlueR]you just gotta love the butt dyno...

your stock manifold is a 4-2-1 design which promotes more low end grunt than a 4-1 (DC) design...

your *** says you are going slower bc you may have less torque than b4...QUOTE]

That's pretty much the size of it. In conjunction with the J's intake(torquey) you should feel a difference. Most headers, in my experience, make their power up top with a sacrifice of low end.

 

He's right, the butt dyno is the most unreliable source of information out there. If you want to know how much hp you have drive to a dyno, if not then just trust that DC is doing right and making their headers to actually give u hp

 

Do a few timed pulls on the street in third, start at 2000 rpms and stop at 8000.

Swap headers and do a few pulls, compare times.

 

that will be a good idea!
but it has NO torque