Replacement ECU: Fuel vs Spark

[cinquecento]

Hi all.

Could I get some feedback on ballpark expectations on the improvments controlling spark on top of the improvements controlling fuel.

Have more or less finished tuning my Megasquirt to control fuel..and abt to embark down the EDIS path. I haven't had my Griff dyno'd but controlling fuel has made a noticable difference in the engines output.

How noticable will the EDIS upgrade be... ?? Could I expect the same improvement again??.. or will spark control have a lesser impact.. or even a greater impact??

Just curious..??

[Pupp]

It's just anecdotal but the comments I've seen over the last two or three years I've been interested in this indicate that moving to mapped ignition transforms the response of the motor.

[eliot]

Probably lesser impact at a guess. Because I assume you removed the AFM when you went to megasquirt.
But you should still expect it to feel crisper, plus you can tune advance to your fuel type.

[dnb]

Mapped sparks do make a big difference, but not in terms of overall power compared to a dizzy. You will get much better part throttle operation because you can run more advance where you need it and still be able to retard the timing in the "hot" areas to contain detonation (where appropriate) unlike a mechanical dizzy.

[cinquecento]

Many Thanks..

I did my changes in stages, changed the ECU/dump AFM, then plemnum and trumpet base..all of which made a very noticable difference.. but what interestingly helped too was changing the number of injections per engine cycle from 2 large ones to 4 smaller ones.

info is at: http://www.msefi.com/viewtopic.php?t=29656