The Project Pad

Who's using what?

I was at 3ms with a MAP scale of 5 but I'm peaking at 4ms since I'm only running 200kpa. I've been chasing a missfire above 5k which I attributed to fuel richness and low advance but now I am thinking it is just dwell.

Seems the LS coils (EFI Express) are fine with more dwell but should I simply increase the base or the scale?

After more reading, nothing is to be gained after 5ms @12v but do you still need more to deal with CR, KPA, and E85?

Also, need some new plugs these BKR7Es are about a yr old.

I would get new plugs, copper plugs get eaten alive in applications like this. I usually only get 7-9k miles out of the FR5DTCs, and the NGKs typically don't last as long.

That being said, do you actually have control over dwell with those TTL coils? I thought I remembered that many of them control dwell on their own, always running at a fixed duty cycle per-se. The trigger from the ECU just tells them when to go.

Sam

e85 needs more dwell typically. I had Marc cut me a custom fireware so my multiplier was 200% vs 140%, that way I could run 3ms on cruise, 6MS on boost. That was on the 034 coils that kick ass, but I think the LS coils aren't far behind.

At only 200kPa 4ms is probably enough from those coils. As Hank said you could push towards 6ms and see what happens but I'd look elsewhere for the problem.

Ed, try either Bosch FR5DTC's or the NGK equivalent(5509). They seemed to work much better for me. I never had any luck with the BKR7E's, although I'm running 034's HO coil kit so that might have something to do with it?

Yeah, I am trying to isolate the issue to fewer variables. Going to try and get a good pull on the WG spring and see if it still goes lean over ~4800 (regardless of ve map) then work my way up.