G(287) Head spark curves

[RedDeerGLH]

Alright im not sure what kind of response im going to get with this but I figured i'd better try here first. I'm going to be running a megasquirt standalone and I was wondering what kind of spark advance or retard the G head prefers and what the total timing is running one of these head on a 2.5L t2 omni. I always hear about the 782 swirl and its so much better but I have a g head on my omni right now and want to run with that. So if anyone knows it would be greatly appreciated.

Thanks
Jay

[cordes]

I would look at a G head cal, and go from there. They should have one on D-cal that you can look at.

[mw6886]

The G head requires more advance down low. That is really about it, and that is for throttle response.

Once the RPMs go up, and the boost increases, the FB and G are about the same when it comes to spark.

[glhs875]

The G head requires more advance down low. That is really about it, and that it for throttle response.

Once the RPMs go up, and the boost increases, the FB and G are about the same when it comes to spark.

And I think Matt knows his stuff on this subject! That's exactly what the G head likes on my car. I made things on the rich side and then Iam bleeding the map a little to bring the air/fuel ratio back to right, which in turn added some timing in the lower boost levels. The map and timing values eventually catch back up in the higher boost levels with a 2 bar stock cal. Iam using a stock 86 swirl cal (slightly modified) with the G head. (= lots of boost on pump gas). :thumb:

[RedDeerGLH]

Sweet thanks guys. I have one more question as well, what is the difference in spark curves between the 2.2 and 2.5 motors?