S54 Header Design talk

[m3racer]

Sure, here they are. I did the PipeMax a while ago, but can try and answer any questions if you have any. And here is a diagram of the SuperSprint measurements. You can see that the second steps in the primaries are really not equal length, and the secondaries are not either.

The Burns design was a while ago too, but from what I remember they had found through testing that straight 6 engines liked short secondaries on the dyno.

[digger]

Sure, here they are. I did the PipeMax a while ago, but can try and answer any questions if you have any. And here is a diagram of the SuperSprint measurements. You can see that the second steps in the primaries are really not equal length, and the secondaries are not either.

The Burns design was a while ago too, but from what I remember they had found through testing that straight 6 engines liked short secondaries on the dyno.

Thanks for the SS data.

Just for reference. A Tri-Y is a 6-3-1 not 6-2-1. Also in pipemax to do a 6-2 you need to setup as a V6 and not tri-y

as for secondaries being short, that's fine if you arent after a wide power band. Below 4000/4500 rpm short secondaries are a torque killer due to reversion

[digger]

i have done some more sims with the simple engine model after adding a collector and will do a proper update over the weekend but it does explain some

[digger]

This is supersprint V1 as per above dimensions with different collector harmonic ~1800, 900, 450

You see that that 4th harmonic 450mm loses a bunch of low end torque for little benefit. this is why the merge whether H, X or Y should not be too close to the engine for a street engine as it's a poor compromise. I also suspect with vanos (or bigger cams) the loss would be higher and the slight midrange a little higher too though kind of exacerbating the differences

[digger]

This compares the SSV1 with its variable primaries to the same pipe sizes but made equal length (lengths are equal to the shortest of the primaries and the longest)