Calypso wrote: ↑Sun Dec 01, 2019 7:57 am
ptuomov wrote: ↑Tue Nov 28, 2017 8:23 am
What’s unknown to me is how the various merge angles etc influence the issue. Koenigsegg and LS7 manifolds seem to suggest that collector with parallel inlets/flow paths and no choke that is directed towards the cat or the turbine somehow works well.
Old, but good thread...
Wondering if parallelelish primary exits prevents the interfering pulse and flow to almost directly hitting the suffering cylinder. High flow velocity at primary exit point also would mean low pressure communicated to the suffering cylinder. Königsegg collector case, 90deg cylinders would be close together, so it might be beneficial. LS case, because of the design constraints, a big area collecting point would at least delay the pressure raise in the collector and adjacent suffering primary.
Yeah, I never really understood why it works. It’s counterintuitive to me that an expansion chamber before the turbine would somehow help more than just a larger turbine.
I still like the Coyote still arrangement of maximizing separation between 180-degree pulses and minimizing the separation between 90-degree pulses while increasing the cross sectional area after the two 90-degree pulses combine.
I can tell you that the exhaust pulse interference is real in the log turbo manifold and cross plane V8. Every cylinder seems to work a little differently, including required valve seated spring loads. When the exhaust manifold pressures approach 3bar absolute, these seem to be a big deal.