can anyone either post a dyno chart, or direct me to a website with one??

i'm having a bit of trouble finding any solid info...

 

here's what i have heard, so correct me if i am wrong.... the 4-1 design is made to produce power starting around 4K rpm, and make peak power near redline. whereas a 4-2-1 design is made to produce more power in the mid range. just my .02
-Scott

 

well what i heard, is 4-1 is made for 0-60, and 4-2-1 is made for long run power....

 

Search under "great header test."

A good 4-2-1 can make as much power as an average 4-1.

 

This is what i've heard too. From what i've read around here and what others have told me, you would want a 4-1 for top end power. Since VTEC is a powerband in the top, you would opt for a 4-1 in a VTEC car. 4-2-1 is better for midrange i think, so something like an LS that's powerband isn't restricted to high-end.

 

so get a 4-1 if u have VTEC???

 

Not exactly. When you are more concerned about just having more hp than 4-1 is for you. This is ideal of course for VTEC motors....since their power is in the upper powerband till redline.....In the case of the B18B non-vtec motors...4-2-1 is ideal because it is mainly to produce torque. But looking at spoon they incorporate the 4-2-1 exhaust manifold to their b18c5 motor. I guess the logic is if you have already have high end power why not try to gain more torque.

 

4-1 headers are better for top end. I'd recommend these for a VTEC engine. 4-2-1 is more midrange as well as top end, but not as much as the 4-1. I'd recommend 4-2-1 for non-VTEC engines.

 

I'm not sure I agree. Yes, the 4-1 headers are better for top end while the 4-2-1 are better for midrange, but I don't agree that that means get the 4-1 for VTEC, especially the B18C1.

My reasoning is this- the B18C1 doesn't need that much help at the top end; it needs more help midrange, esp. 4000-5500, which is where most 4-2-1 headers seem to be the most effective. Sure, for peak power, the 4-1 will do the best, but in terms of area 'under the curve', I'd want that midrange boost.

Look up the Great Header Test (SCC, about a year or so ago) to find out exactly which headers are the best for the Integra GS-R.

 

to me its simple, if you redline a lot, go 4-1, if you dont, 4-2-1. thats how i look at it, am i wrong?

 

This topic has been beaten to death!

If you got VTEC, get the 4-1 design. Top end it where it matters most. Who here will shift under 4000rpm when they race? No one. You stay at the top end and thas where it counts most. 4-1

 

I have my Comptech 4-2-1 on its way,I now have the dc usdm 4-1,i believe its garbage(just my opionion)Remember the Comptech did just as good on the ITR in the great header test as the all mighty jdm and jdm dc 4-1,so I know it produces good figures on a Vtec motor,So 4-2-1 will give it a nice power curve as well,not all thow I think the comptech is one of the best and no ground clearence problems.