Quote:
Originally Posted by anthonydalrymple
I very much believe so. It think it has much to do with the combination: volumetric efficiency, cubic inc displacement, flow capabilities of the heads and exhaust, intended rpm use, etcetera. I've played around with porting intakes based extensively on the advice of Tmoss ( www.tmossporting.com.) and the info available on his website. I had an RPMII intake on my 302 that made good peak numbers (294rwhp & about the same in torque); but it really was a pain in slow driving and stop & go traffic. I decided to port an '96 Explorer intake since i felt it could nearly match the total flow numbers of the RPMII and still pick up the bottom end with the longer runner length. I ran the same engine combo with the exception of the intake only and on the same exact dyno in very similar atmospheric conditions. Imagine my surprise when both the torque & horsepower from 2G to 5G picked up 10-15. The peak was interesting; 280rwhp & 305rwtq. I also ran both combinations at LACR before it closed down; ran the same exact et's before & after. I chalked that up to the better acceleration in the mid-rpm range by the Explorer intake more than making up for the short high rpm advantage the former RPMII had IMHO.... |
Yeah Makes sense. It also implies pairing with exhaust headers is quite important because of the effects on back pressure and scavenging. It would be really interesting to do a study cominbining
Street Porting w/ stock headers, Tri-Ys, Mid Length, Long Tubes
Race Porting w/ stock headers, Tri-Ys, Mid Length, Long Tubes
My hypothesis would be that Street Porting with Tri-Ys would be the best option for most people and race porting with LTs reserved for people who are actually racing.
In my case, my Heads and Cam LS1 makes 391WHP with a mild tune and stock headers. However, the C5 Vette it came out of with a more agressive tune and headers made 432! (Some of that could be chalked up to different IRS, but not so much I don't think.)
Anyways, it do get complicated.
