Disty Vacuum

[FestYboy]

Advance should increase with engine speed... base idle timing should be "0" +/-1. With vacuum present, you should see something like 14*, and it should be all in at just over 3000 with ~26*. You would only retard the timing at higher rpm if you were under boost, and that's just to help control pinging/pre-ignition. I'll grab one of my dizzys and double check the spring advance theory.

[dliverance]

Oh man. I thought when the 88 timing was set, it was set at around 8-10* with the vacuum off.

I was also thinking about taking apart a distributor to see if it had centrifugal advance as well.

[FestYboy]

^ that's if you want more out of the b3, on 89+ oct, you bump the timing to those numbers. Factory timing specs are as stated above. I honestly believe they left ALOT on the table when they put the b3 in production. The exhaust runner is a good example...

[dliverance]

I wasnt thinking correctly earlier. I forgot to mention that the engine is a b6d that I am trying to time.

[FestYboy]

OK so it should be using the EFI dizzy, not the carb unit.

[william]

If he's using the capri harness it has a vaccum disty.

[dliverance]

OK so it should be using the EFI dizzy, not the carb unit.

I'm running a b6d with carbs. No efi in my system. I went with the carb distributor because that's what I had. I'll keep looking into what formula works best. I did find this table for miata advance and since it's essentially the same motor, I figured I need to get it close.

[FestYboy]

Wow, all in at 5500...

Yeah you need the carb dizzy then for the vac advance.

[dliverance]

I'm just hoping that I can get 36*. Might have to go 12 static and figure out how to get 24* more from the vacuum advance.

[FestYboy]

That shouldn't be too difficult, I'll tear one apart in the afternoon.

[zoe60]

Deliverance, what intake you running with that b6d? You got my interest up!

[dliverance]

It's a mazdaspeed dual dcoe manifold. Pics can be found in my build thread.