Headers

What is the pros an cons to running 4 to 1 stepped headers ( 2-1/2"-2-3/8"-5" collector) compared to 2-1/2" zoomie,,, I'am running a 511 hemi with AJ heads an a PSI D screw....THANKS FOR THE HELP

 

im glad you ask this im building a 2 1/2 ton mudracer with a 540 with a psi d blower and realy need to run a conventinal style header,hope to see some feedback

 

I wouldn't recommend it. I ran a 510 BBC with an 8-71 making 25lbs in a dragster and when I swithed from zoomies to Borlas it lost about half a tenth and 2mph in the 1/8th. I would guess that with the motors yall are running it would make an even bigger difference.

 

I have always thought that with a blower motor, you want to get the exhaust out as fast as you can. With an NA motor, you want to use the exhaust to scavenge the cylinder for the next charge. I know that when we ran an NA motor and switched from collector headers to zoomies, there was a substantial loss of power. Just my "experienced" 2 cents. JW

 

You think it may have been due to the additional weight of the Borlas over the zoomies. I am sure they are about 40-50 lbs heavier than std zoomies.
not questioning it, just making an observation. i would like to run headers, but zoomies may be my option also. I did notice on my blown/injected motor that the EGT's cylinder to cylinder were more consistant when we switched to zoomies from 2.5" headers.