It could be that with faster
combustion wave propagation that you would want the timing of the lead and
trail closer in timing rather than further or possibly vice versa
{:>).
.
Ed Anderson
Exactly
right Ed, or vice versa :-)
Through the
miracle of copy and paste, I'll attach the timing split from my old FD engine
computer. Keep in mind that this is NOT the stock Mazda timing, though
it's probably close to it. The top row is the scale in RPM, and the
first column is the scale in inches of mercury. The numbers in the box represent the difference in
degrees between when the leading, and trailing ignition will fire.
Positive numbers indicate that the leading fires before the trailing.
It's
interesting to note that aside from the idle range, the timing split is 0
until you get to around sea level pressure. From there, it quickly
increases to about a maximum level for the rest of the boost range. From
this, I would assume that increasing the split reduces the chance of
detonation.
Still hard
to say how important this is for us. How much greater is the chance of
detonation? How much power would you lose if you had to run on
trailing ignition only with the split built
in?
Cheers,
Rusty
(doing my turbo duties, though I'm not sure
why)