Quote:
Originally Posted by freebeard
Four cylinders? Four into one isn't as good as four into two into one; at least for flat fours.
Also, there're anti-reversionary headers.
|
I don't want to go Julian Edger on you but.
I built,and raced aircooled VW engines from 1999 to 2009. I had access to a dyno, and different measuring equipment, etc. The four into one header is the best design. Gene Bergs extractor exhaust when properly sized will pull a
VACCUUM at the exhaust port when matched with the correct stroke, bore, ETC. It will literially suck the exhaust from the cylinder. There is no need for anti reversion cones on a well designed header. This one subject I have extensive expertise in. I have built NA asperated VW engines that produce over 100 hp per litre. you can google my name "James Beahm" and "hot VWs".
Trust me when I say a long tube 4 into one header is best for low end torque. The problem is the packaging it all , plus the further you move the cat from the head, the lower exhaust temps, and the cat doesn't work as well.