Dyno - headers

Cudafever said
I don't know if Engine Master ever did that test but i bet they have.
Here is my thoughts, chassis header, by design, has to have a sharp turn down at the flange. fender headers don't. chassis header have smoother, shorter bends.

My guess would be that the fender header would win in most case. If the eng would tune better with a shorter header length then maybe not................

I think the biggest down side for fender headers is tire clearance. But if your running a skinny up front already. it would be much less of a issue.

If someone wants to loan me a set of 2 inch chassis big block headers I’ll do the test.

As long as the chassis headers are adjustable they will beat up fenderwell headers every time. There isn’t an engine out there (with correct cam timing) that wants a primary tube that long.

In fact, IMO as the primary diameter goes up, the primary length needs to go down. That may seem counterintuitive but it’s not. In that case you are tuning primary length against primary diameter.