Tracy Crook wrote:

Perry Mick wrote:

I think Tracy says in his book that Mazda uses different timing
between leading and trailing plugs ( I may be wrong about this,
haven't looked at the book for awhile) for emissions control
reasons.

However, when I look at the output of the Mazda ECU with an
oscilloscope, I see the leading and trailing pulses exactly in
sinc, at least at low rpm (<=2000).

The leading & trailing sparks are 15 degrees apart on the 86 & later 13B.
There are even two separate timing marks on the E-shaft pulley to check for
this.   I changed to same timing on both on my system as did Everett Hatch
on the Powersport engines.  Are you sure you had the sync setup right on the
scope Perry?

That was an interesting comment by Allan Tolle about the optimum timing.  I
agree that there is no sea-level  power advantage beyond 18 - 20 degrees
advance.  I do think there is a small but measurable improvement in BSFC
(fuel consumption) at low power settings and at high (> 10,000 ft) cruise
altitudes with slightly more advance.

On a previous subject,  I will be giving a forum talk on my rotary
development at Sun 'n Fun.  Schedule has not come out yet.

Tracy Crook   rws@altavista.net

 
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