Are you guys having an issue?

 

A little. We're trying to figure out if we're at the limit of the stock coil for the gap/boost we're trying to run.

When looking around, it seems that every aftermarket company says their coils are rated for 40kV +/-. However, the MSD coils have been proven to show no gain. So...are the factory coils putting out 40kV, too?

 

Im not real sure, I believe Kurt did some actual testing on the coils at one point or another.

If im not mistaken, you have the round truck coils correct? Have you messed with the dwell settings on the coils any?

 

We haven't messed with the dwell. To be honest, I think when we choose the LS ignition in the Holley we're not able to alter the dwell. I'll have to check. I do know, though, that it defaults the dwell to 5ms.

We do have the round coils and we may just be at the limit of what they can do. We're going to tighten the gap and give it another shot tomorrow.

 

What LS could do you have ? Truck coils ?

 

Yes, the round truck coils.

 

You can.

Custom Ignition setup

Select your appropriate Reluctor at the top, then the right cam sensor then the bottom part is type, COP, Waste fire etc, then on the right is dwell time.

 

X2

 

What gap and boost?? Wide gaps only cause problems and make no more power. Top Fuel cars make 10,000hp running .014" gap so unless you are doing something that is beyond the coils output .014-.018 will work. Voltage is not where the gains from spark power come from, current output and length of spark event is what makes the difference. Hope this helps.

 

.018 gap and it only cuts off when we try to run 40lbs.

 

http://www.megamanual.com/seq/coils.htm This might help. 120milliamps on truck coils and less than half that for regular ls1 car coils.

 

What plug and fuel??

 

Methanol and an ngk -9.

Thanks for the help everybody.

 

Be careful with dwell time on the heat sink coils as they can autofire over 4.5ms at high RPM. How much power you can make will depend on chamber design and controller capability to fire the coils. On the square truck coils we could run 32psi and go 204mph to the 1/4 and no faster. The Mercury Marine style coils would not get us much further. This could be because of our small "fast" chamber or the BS3 controller. We ran up to 7ms of dwell at 8000rpm on both. We then put a MAG on the car and went from a best of 6.8x@204 to 6.5@223 in just three passes in one test and tune night.

 

THE PRO MAG 44 HAS NO EQUAL, no matter how many coils per cylinder you put on it. I would have never believed the difference it made but seeing is believing.

 

Yup it also takes the guessing out of the tune up . I think next year I will put a mag on my motor and be done with it

 

So is the thought that at 1500 hp on gas the ls truck coils are fine

 

Are your coils the round deals with or without the heatsink on the top?

Long winded video on the different LS coils and dwell testing on a scope. Once you get past the common knoledge intro, it has some good test data.

 

I had an issue with mine. I grounded the heads to the block and block to the battery. It seemed to be a ground issue more than spark output.

I'm not running nearly what you are but its worth looking at.

 

I don't have any coils yet
I have holley waste spark and would like to change to individual coils

 

Just had an issue on a car with d585s. They were doing the pre-fire thing at 20psi. Turns out they were genuine AC/Delcos, but not genuine GM. They were the crappy china coils. Make sure your coils are real GM and not chinese ac-delcos.

 

So is there a hp or boost limitation on the genuine ls truck coils?
Or is it not even worth trying with stock ls coils and about 1500 hp?

 

Buddy's Firebird is making more 1500 hp on stock car coils. 8500 RPM with a 58x stock reluctor and 37 psi so far. NGK #10 .016-.018 gap.

 

Didnt holley have an issue running the LS coils. Read it on here maybe a year ago?
People where pissed had to buy 500 bucks worth of coils. Found this information AFTER purchase.

 

They fixed that

 

Weren't there a few guys on here with alky / D585 coil deals making some good power without issue?

 

We think we got it. Ran 40psi without cutting out.

 

More timing ?

 

So the ls coils of choice are?
Truck coils ?
D585?

 

Yes sir

 

And the ones that are $70-80 new, or pulled from trucks in junk yards. NOT the $36 ones on amazon/ebay