step

[nesse]

how can step-headers
1.5/8 - 1.3/4 give you more
tq/hp than you get with just
1.5/8 header ? I mean the exhaust go no bigger anyway..!?

 

[duster340]

the idea is probably that you will get higher velocity like you get with the smaller headers but the flow from bigger headers. without loosing the velocity from the smaller size headers. my thought is that the smaller first part of the headers are a nice advantage if you want easy to reach bolts

 

[inkjunkie]

a bit of reading, granted this probably applies to all out race motors, but the theory is probably the same...
http://www.perfweldheaders.com/primary.html

 

[rumblefish360]

Nice read. I'd say, yep, your right. Even small low output engines could have a custom header designed for them that would out perform OOTB on the shelf headers.
Pricey though, a bit outta reach for me. I'd like to read more on the subject.

 

[Burntorange70]

My dad has had two sets of custom headers made for his LS-7. Both have been a step design. I don't know why though. The header guy said it was the way to go.

 

[inkjunkie]

Nice read. I'd say, yep, your right. Even small low output engines could have a custom header designed for them that would out perform OOTB on the shelf headers.
Pricey though, a bit outta reach for me. I'd like to read more on the subject.

a bit more reading
http://www.perfweldheaders.com/headertech.html
Mark, the owner of Performance Welding Racing Headers is a member here.