Timing tuning on the street

[SS2win]

I'm wondering how everyone goes about getting the timing tuned off the dyno. Are you looking for the most timing with the least amount of throttle opening or what?

[SS2win]

nopebody has any recommendations for me? i figured you'd get the most torque with the least throttle opening. Is ther any other things to watch for?

[southern]

Best I can tell you is to up the timing till it start to retard it then back off a couple degrees. That is about the most I know that you can do without a dyno.

[dfe1]

Your theory is fine, but execution will be a bitch. Theoretically, if you drive at a steady state and alter spark timing, vehicle speed will be highest at the optimal timing point. Talking about that and getting it done are two different things. In order to dial your timing map in, you'll have to test at virtually every data point in the map. Five years from now when you get that all done, you'll find that performance and fuel economy aren't any better than with a spark map that was derived from flirting with detonation.

[SS2win]

(in reply to southern) yeah that is what I've been reading. My car was professionally tuned and I converted to the COS3 and 2bar sensor. AutoVE was a breeze but I've been reluctant to mess with the timing. I'm working on another project (4x4 truck) for which I'm preparing to retrofit a 7727 computer with a custom modded single plane intake and reading the EFI DIY docs from Grumpy got me thinking there must be other ways to tune the timing. One thing was the throttle position should be as low as possible and that should be an indication of max efficiency. Wondering what others have to say.

dfe1, I can see how it would take a lot of time. Just wondering if there is anything I can do that would be sensible before the next dyno session. waiting to get a RR before I go back...

[Delco]

(in reply to southern) yeah that is what I've been reading. My car was professionally tuned and I converted to the COS3 and 2bar sensor. AutoVE was a breeze but I've been reluctant to mess with the timing. I'm working on another project (4x4 truck) for which I'm preparing to retrofit a 7727 computer with a custom modded single plane intake and reading the EFI DIY docs from Grumpy got me thinking there must be other ways to tune the timing. One thing was the throttle position should be as low as possible and that should be an indication of max efficiency. Wondering what others have to say.

dfe1, I can see how it would take a lot of time. Just wondering if there is anything I can do that would be sensible before the next dyno session. waiting to get a RR before I go back...

Doesnt always work like that , especially if you are chasing fuel economy , one trick is to get the blade open more to reduce pumping losses on steady state cruise and lean of the mixture to achieve this making the requirement for more throttle.

near impossible to get optimium timing on the street.

[cmitchell17]

Ive heard the optimal timing table was good to follow it as a guide. But I guess you would need to still have your stock heads.

[SS2win]

Thanks for the responses guys. I'll no doubt spend a lot more time thinking about this before I pull the binary trigger.