Anyone using the GM DIS 2 tower coils?

[slow_hemi6]

Hey all, I am running 4 of these coils on my V8 now and I have calculated the dwell to be about 2.3 mS for these. Revs out to 5300rpm no problems. That's as hard as I have run it so far. Will probably never push it much over 6000rpm.
Anyone else running these? What are you safely using for dwell mS if you don't mind sharing.

[billr]

Off what M/M/Y car? There are at least two versions of those coils that I know of.

Edit: I'm using ones that look like the Standard Motor Products #DR39 (mine are so old I don't know for sure what they are), running "standard dwell", 3 ms dwell and 1 ms spark (defaults); no problems up to 6400 rpm rev-limit.

[slow_hemi6]

They are what we call the series 2 coils. Like these from Buick V6's approx 1996.

[billr]

Yep, that looks like the SMP DR39, used on Buicks and a lot of other GMs, over many years.

[slow_hemi6]

I measured the primary resistance of mine at 0.35 ohm. The MSD versions of these advertise primary resistance of 0.35 ohm also and give 4.2mH for inductance so I used those figures 13.7V and 6 amp for the dwell calculation. When I first fired it up I had the dwell at 3mS and let the car go through warm up. The VB921's heat sink seemed to be ok temperature wise but I guess it's safer to use the calculated dwell.

[mike2coupe]

ive ran them at 3ms dwell for a while but the ms box started feeling warm. so i backed down to 2 ms everything is running fine and cool with the 4 bip chips.

[slow_hemi6]

Good to know. The VB's aren't all that robust when driven into current limiting, so best to stay on the safe side. It's not missing or breaking down where it is now so I am pretty happy to have wasted spark working again. I was using 2 ford focus coil packs previously but getting a decent set of HT leads for my V8 using those was going to cost more than changing over to these coil packs. I can buy HT leads for these at any auto store in town.

[Joe]

I'm running 4 of those also on a small block. Turned my dwell down to 2.5ms.
Been running that set up for years without issue.

Joe