Header tube length ?
Burning Brakes
Joined: Dec 2003
Posts: 1,004
Likes: 7
From: Adelaide South Australia
google some info ...
here's an example:
http://www.sandersonheaders.com/tech_get_technical.php
Basic opinion is short tube provides more torque at lower rpm, whereas long tube provides more horsepower at high rpm.
primary pipe sizes play a role too, as does the pipe configuration (4 into 1 pipes, or Tri-y design).
Although not indicated in the above link, larger primary pipe size tend to shift peak torque to a higher rpm, whereas smaller pipe size shifts peak torque to lower rpm.
IMO tri-y is a better config for overall street performance... more torque at lower rpm than long tubes, but also more hp than short tubes at higher rpm.... best of both worlds.
It really depends a lot on what you want to use your car for.
Optimising power with a set of custom headers can get very expensive as it's NOT easy to get it right the first time...
Back to back dyno testing is only way to really determine benefits...
or track ET's of course
here's an example:
http://www.sandersonheaders.com/tech_get_technical.php
Basic opinion is short tube provides more torque at lower rpm, whereas long tube provides more horsepower at high rpm.
primary pipe sizes play a role too, as does the pipe configuration (4 into 1 pipes, or Tri-y design).
Although not indicated in the above link, larger primary pipe size tend to shift peak torque to a higher rpm, whereas smaller pipe size shifts peak torque to lower rpm.
IMO tri-y is a better config for overall street performance... more torque at lower rpm than long tubes, but also more hp than short tubes at higher rpm.... best of both worlds.
It really depends a lot on what you want to use your car for.
Optimising power with a set of custom headers can get very expensive as it's NOT easy to get it right the first time...
Back to back dyno testing is only way to really determine benefits...
or track ET's of course
Racer
Joined: Nov 2007
Posts: 279
Likes: 0
From: Forrest City Ar
look at post about fiberglass covers for side pipes on 2nd page is a link to a in depth artical about exhast science by D Vizard. I tried to copy link to here but couldn't. I just bought a new engine and am looking for header, but din't realize it was so complacated.
Drifting
Joined: Sep 2006
Posts: 1,986
Likes: 21
From: Columbus MN
Exhaust Science
This web site really help me design the complete exhaust system for my '80:
Exhaust Science Demystified
Exhaust Science Demystified
