[mwebb]

Originally Posted by nemesis

V8 has to be treated as 2 v4 engines, not 2 inline 4's, so the exhaust will have to be treated differently.

that does agree with what i have read in the hotrod article as well

but
i have pressure waveforms from the exhaust on V8s
most of it is UNusable hash , there are no distinct pressure / vacuum pulses that can be attributed to any one cylinder

at low rpm or up to about 2k rpm with little to no load

UNLESS you just add ignition timing value + known or measured Exhaust valve open time to measured spark waveform ....
even then , it is just hash , but you know where the hash would change if an event were to happen

to design a "tuned exhaust" for such a mess must involve something
akin to alchemy
===============================
remember
on a V8 there is another exhaust valve opening every 90 degrees or every 180 if you use 2 separate dual exhausts , and Exhaust valve open duration is around 250 degrees ,
4 or 8 events do not fit into 720 degrees without overlapping ....
which creates
hash
=====================================
the only exhaust pressure / vacuum pulses i have captured driving at load are done with a 4 cylinder engine
and you can see where the pulses all line up nice nice
and where they do not

even with the overlap
i am assuming , when the pulses are lined up
nice nice
that is the load and rpm or one load / rpm the exhaust is "tuned" for

and after reading this
i think the test probe in the tail pipe may be introducing something else to be reflected off of
or
another possible source of hash ....