Odd fire crank ignition questions.

[89shortbox]

So I was drawing up a crank trigger for an odd fire crank project I have here. EFI
I discovered that 1 6 5 are the only teeth that could possibly trigger at the correct time.
4 3 2 would will never be correct because the crank angles wont allow it.

Does everybody in aftermarket just use an odd fire distributor for this type of setup without a crank trigger.

Ive noticed some of the msd boxes have an odd fire setting. Not sure how they work in this aspect.

 

[nallj92]

Re: Odd fire crank ignition questions.

I have a oddfire set up as well, you would have to use crank angles built into the computer software to tell it to fire correctly. All the crank trigger will do is tell you #1 TDC, and a cam sensor will tell you compression stroke or not. the rest of the logic is built into the computer.

I do have a oddfire dissy and MSD box if you want part #'s or pictures.

HTH.

 

[MRKING]

Re: Odd fire crank ignition questions.

I have an Oddfire as well down here . Its not running in the truck yet , but i do have an oddfire distributor and Msd Digital 6 .To get the most out of the oddfire , an aftermarket ecm setup is your best bet . Personally , I hope that i can trade enough parts for one someday

 

[nallj92]

Re: Odd fire crank ignition questions.

Megaquirt is oddfire compatable and cheap. its very DIY but is capable with the oddfire stuff.

 

[RealFastV6]

Re: Odd fire crank ignition questions.

Not sure what you mean by crank angle, but the (Buick) odd fire systems I've seen (Classic Fast based) still used an even fire crank reluctor layout, and the ECU \ ignition did the math on the ignition timing.

 

[MRKING]

Re: Odd fire crank ignition questions.

If I ended up going diy , i wanted to run the fueling off of the stock ecm and the spark off of the oddfire dist, msd digital 6 ,cam trigger , and crank trigger . By the time I finish building the rest of my Sy , I'll be in a better position to address the efi situation .

Seems like all the oddfire's are slowly fading away as the years pass.

 

[MRKING]

Re: Odd fire crank ignition questions.

The buick oddfire and Chevy are not the same alternating firing degrees . Theres a few different oddfire and semi even fire configurations that look like they would work , but no dice .
Halfway into the "I'll make it work process,"you realize that the buy it/install it option is the 99% best option .At least I did anyway .LOL

 

[RealFastV6]

I'm talking Stage 2 Buick, equivalent to the Bowtie Chevy stuff. They're both 90/150 degree, same firing order.

 

[89shortbox]

Re: Odd fire crank ignition questions.

correction , looks like only 4 and 2 would fire wrong. they would be triggered 30 deg. to early.
The software must delay those firing events.

I noticed the odd fire setting in Megasquirt. Besides the setting I dont see any option to it. So is it assumed that all odd fires are the same. Cuz in my world things arent that simple. There could be multiple odd fire variations in this world with different motors.

thanks for the info guys