Just wanted to know how much more horse power all you guys got from ether a 4-1 header or 4-2-1 header.

Please let me know what you guys like or dislike about one or another. Im trying to fine then best header for my 12:1 lsvtec engine! im more of a boost guy and im tryin to go na on a hatch im building for my project car. So lets see what ppl can come up with in here!!! Thx peeps!

 

For that kind of compression, I would go for 4-1 for more top end. HP can vary depending on tuning.

 

also depends on what exhaust your matching up to the header, but keep IF your lowered more than 2" than 41 header not the choice for you...

41 high RPM
421 Low RPM

but in the end HP comes down to tuning

 

hey thx guys i got 3 in all the way bak so 4 to 1 sounds good to me for power top end thx!

 

Is this car a street car or track car? For the street, 4-2-1>>4-1 due to ground clearance. There are some good try-Y designs as well that eliminate the ground clearance issues.