M S D 6

[DanBadger]

I have found that Optima batteries do not like high amperage recharging- it is very likely that your "topping off" between runs is finding false peaks.  We lead-acid batteries don't care so much, but the acid-impregnated felt used in the Optimas care quite a bit about the amps/mins ratio.  Also, be careful charging and discharging an Optima too quickly- their construction leads to very poor heat dissipation.  Ten amps is OK, fourty is not. 

I would check input voltage to the 6AL next time you have the engine spun up on the dyno-  I have had spark fall apart when voltage drops below 11, and in a high-demand situation even closer to 12.  As mentioned above, the MSD guys are very easy-going and easy to work with if there is any problem with the 6AL- they really have the customer service thing figured out.

Good luck!

[racergeo]

  I used to run a stock car with an MSD and no charging system.    Start the race at 13.6 volts and run 30 laps be at about 12 volts at the end of the race,no problems. It's your gear ratio trans. combination. I'd bet money.

[jdincau]

If you are worried about running out of volts why not use a 16 volt battery, the MSD unit will tolerate it.

http://www.turbostart.com/

[Steve Walters]

Thanks for the info on the optimas, the times in between runs is at ten amps.  I liked the fact that last winter, I left them in the car with disconnect off, once a month I would check the charge, and they stayed at 12 volts all winter no heat and about 3 weeks of below zero weather (shop is not heated unless I'm working in it).  I don't understand the electronic ignition, my car went faster stock with the dual point distributer. 

Steve   

[Steve Walters]

 I used to run a stock car with an MSD and no charging system.    Start the race at 13.6 volts and run 30 laps be at about 12 volts at the end of the race,no problems. It's your gear ratio trans. combination. I'd bet money.

Thanks for info
Looking at my timing slip speeds there was definatly a problem either with my digital tack, or the output of the MSD.
At 142 I should have been at 5300 RPM and the tach said 4300.  At 148 the tach said 5300, that is when I bent the valves.  During one of the 142 runs I put it in 5th, realized then my rear 2:78 gears were way to high.  Going to have my sh-t together next year I'm to old for this once a year learn the hard way stuff.

Steve

[racergeo]

   It was a reference to the original poster, my bad.

[Steve Walters]

Sorry racergeo, I'm the one stepping on the original poster.  I was so wound up over realizing that my problems could be solved with the posts on his problem that I lost my etiquette.  As you can see I don't know how to shadow correctly a quote.  Know about as much about forum ethics as I do about electronic ignitions.
 DW told me at the flats that this web site could benefit my build and he was definitely right on that one.

Steve

[fastman614]

On recommmendation from a specialist in ignition systems, we run a six volt battery in series with our 12 volt battery- a total of 18 volts.... the MSD seems to keep working just fine.... extra ballast and easier to charge a 12 and a 6 volt battery with chargers I already own....

Pulling your gear ratio is a separate issue..... but it feels like all kinds of things are not working correctly as you watch the tach- climbing seemingly far too slowly..... so like how in the hell can we ge like 1200 horsepower over a 4000 rpm power band from our off the shelves at Summit Racing 355 CID Chevys anyway?