Just trying to clarify what these boxes do (or don't do) for LT1's. Do they eliminate any part of the opti or does it just assist the opti? Assume we're only talking about N/A motors.

and crank triggers: Do they eliminate any part of the opti? Or do you have to switch to aftermarket pcm?

 

Ignition boxes increase the spark and allow rev limiters to be set. Some do more. Crank trigger, yes, the opti would be gone depending on how you use it. Some just use for a cam signal while others will use for cam signal and distributor only...no hi or low res signal to worry about. But you'll need an aftermarket ecu etc.

If you just looking for a hotter spark etc, I've got a Crane HI-6 I'm selling w/ coil.

 

Is your goal to eliminate the opti or are you wanting to advance/retard timing?

I'll tell you right now that although vanquishing the evil opti from your engine bay is
a noble quest, it is not a cheap or rewarding one unless you have some other reason to
do so. (IE: your PCM can't do what you want it to do)

 

The low end boxes don't do much, but the dig 6 and the 685 mallory aren't bad.



If you want to use aftermarket parts to get rid of the opti then you have to get a crank trigger setup with a distributor.
Edit: you would also want a stand alone computer, BS3, DFI, FAST to remove the opti entirely and run the extra rpms.

 

Since this subject is open. What happens is you have an MSD and a plug wire falls off? Will it arc in the Opti's cap? I'm thinking about where the jumpers from the pins in the cap to the actual terminals cross in the potting. Anyone come up with a test for the cap?

Al

 

My uncle wants me to put one on my car because he thinks it will eliminate part of the opti that fails. I know better, but he's been racing and building race motors longer than I've been alive so it's hard to convince him otherwise. You know how the old school guys can be set in their ways. I'm trying to save myself some money if I can talk him out of it, since I don't think it will help me out. He can build an SBC or BBC in his sleep and tune a carb too, but when it comes to EFI and the newer stuff, he's not as educated with how the motors are fed and the engineering that goes into it.

I've had trouble with opti's but I've seen people on here that have had worse luck than me. I would love to eliminate it but I'm not spending the coin. There should be no reason my motor can't work with the stock pcm and opti. I was looking into the Dynaspark too, any opinions on that?

P.S. More comments please. I'm going to print this out and have him read it, so the more comments I can get the more convincing it will be. I should probably delete or edit this post before I print it, huh?

 

Ign boxes are very good for setting rev limiters when running nitrous and/or boost. Instead of the stock computer pulling fuel to limit rpms; the box cuts out spark. MUCH safer than pulling fuel.

Also, ign boxes generally allow the addition of other components like, two steps, nitrous retard, timing adv/ret, boost retard, etc...

tey do give the coil it own "power" by allowing the box to charge the coil; which is fed through the larger power wire. This isn't a big concern until the motor gets into higher rpms. Many do have the multiple sparks below 3000 rpms. this ensures good ignition of the mixture which at low rpms/low VE can be sparse in the cylinder and not in the ideal location for proper flame front.

 

ok ive been here, done it and broken it and im a BSEE so i got a little bit of electrical background too lol

the way the ignition box will work on a stock system is as follows........the opti spark will still function exactly the same it will send the same signals to the pcm as it is now....however now the trigger wire from the pcm that after the icm eventually energizes the coil will go to the new ignition box.....you will then have the two coil wires from the ignition box that will hook up to the coil......all the box will do is increase sparking power by a bit and will also (depending on the box used) give you mulitple sparks at lower rpm.........unless the car is moderatly modifed its not really worth it.......you wont see any gains at all..........i ran a gm opti vented properly with an msd cap and rotor on my 355 for 4 years with no issues and i was revving it 6800 regularly.......only thing i broke once was a rotor but it was my own fault i didn't expoxy in the rotor screws so they backed out.......on that car i ran an MSD 6AL box for the rev limiter and also for the stronger spark....it was a pretty potent 355....used to trap 120mph+

on this new motor i ran the opti with a fast xfi because i operate above 7000rpm......the opti lived for a short while but i was experiencing random misfires up at high rpm 7500-8200........i gutted the opti and used it as just a cap and rotor to deliver the spark.......i then ran a crank trigger on the front of the motor....this fixed the issue...only issue with that is when u run a crank trigger only and no cam signal the motor will run in bank to bank fire mode and not sequential.......after grenading a couple of rotors due to the excessive rpm i just ditched the opti this winter and ran a regular msd pro billet dizzy out back in the intake........so now i also have a cam signal so i can run in SEFI again........i also upgraded to a MSD 7AL2 box on this motor with a bigger coil.......again it allows me to be able to light off exotic race fuels at 14:1+CR with a big plug gap..........but in ur case its not needed....

back to the original question......NO.....adding a box will not affect the opti at all or its operation.......and running a crank trigger will not work either because the cam signal is still derived from the opti..........plain and simple is an opti will operate just fine and will last if its built and assembled and maintained properly........i wouldn't be afraid of the opti at all.......half the horror shows you read on here about opti's are usually the builder/assemblers fault.......

hope this helps,
Mike V

 

NECRO POST TIME!

I just want to pull timing for nitrous, I don't see listings anymore for the Mallory and I don't trust MSD very much. What is my best option? Brand new Opti BTW....