Bob,
That might be the case, but if it were true with the supposedly superior
(to conventional ignitions) Ignitor II and FlameThrower II combination,
I'd be disappointed. The distributorless crank trigger setup I built
years ago used two of the dual-output GM coils. I forget what their
impedance was (around one ohm probably), but I built a current-limiting
(non-CD) driver circuit that would ramp the coil current from 0 to 7
amps in about 1.6 milliseconds, and the ignition would produce full
spark energy up beyond 10,000 RPM. I agree that doing this with a single
coil system is just not feasible without a high-voltage coil drive
setup, but the the current ramp that I measured is slower than I
expected the Ignitor to be able to produce, so maybe they're purposely
limiting the current ramp as well as the peak current.
What I expect to see (when I get a sufficiently capable distributor
drive going) is that the circuit will switch to a faster current ramp at
or near 3000 RPM. If it doesn't do that, then my opinion will be that
anyone buying these for a V8 engine is wasting their money, even if the
application isn't primarily performance oriented. Maybe that's overly
harsh, but they're not the only ignition system on the market, and they
do make some pretty extravagant claims. We'll see - I'm not jumping to
any conclusions at this point.
Best regards,
Theo
-----Original Message-----
From: owner-tigers@autox.team.net [mailto:owner-tigers@autox.team.net]On
Behalf Of Bob Palmer
Sent: July 8, 2003 9:51 AM
To: Theo Smit; tigers@autox.team.net
Subject: RE: Pertronix coil current.
Theo,
I think at 3,000 rpm you hit the limit of a purely resistive source like
the
Ignitor. Beyond that you need a capacitive discharge circuit (e.g., an
MSD)
to overcome the inductive impedance of the coil.
Bob Palmer
rpalmer@ucsd.edu
robertpalmer@paulhastings.com
rpalmerbob@adelphia.net
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