hennessey headers

[lsx ftl]

I'm just curious to why not many people run HPE headers. I tried the search but came up with little info on these headers.
Is there a benefit for running 1 3/4" primaries compared to the 1 7/8" with a 3" exhaust?

[Late Apex]

Best to just call John to get all the details but its hard to beat the Belangers.

[PaulP]

I was hearing that the American racing headers are out flowing the belanger headers ? anyone have any experience with this ?

[ViperDog]

Bigger isn't always better. I believe the factory size is quite small - 1.5 I think. 1.75 is plenty sufficient. Throttle response is better when staying on the smaller side. More performance isn't just about flow; it's also velocity at lower speeds.

[slowhatch]

Bigger isn't always better. I believe the factory size is quite small - 1.5 I think. 1.75 is plenty sufficient. Throttle response is better when staying on the smaller side. More performance isn't just about flow; it's also velocity at lower speeds.

Bingo. Port velocity, mixing, and scavenging effects as a function of header step design is crucial. Not just about having huge primaries or collectors.