Jalai has more accurate info on the IGN-1A coil too. If you offer to send him coils he'll probably agree to provide a direct comparison graph listing them all together. Pulling ingo from various sources can result in inaccuracies.

ps: was wondering when you were finally going to start this thread

 

Subs. A lot of good info here

 

Something you may wish to try which I have used for several years is 6V coils, for example Bosch GT40R, any coil which is fitted to a vehicle with a ballast resistor. I run 4x 6V coils on my 12A PP and punish it (circuit car) the thing does 10K rpm constantly. Obviously Boost and water etc change spark requirements but I'd be interested to see how a 6V coil performs on your scope, I'm guessing from your previous experiments with increased voltage on 12V coils is that it would simply achieve full saturation very quickly.

 

I'll admit this isn't 100% relevant but I ran across this a few weeks ago and thought it was interesting especially when it talks about the MSD 6A. The link is to a post by Paul Yaw (you know that carburetor guy and who is now involved with Injector Dynamics) about the ignition system but also about the plugs.

ignition

 

agreed, that's a good article.

i actually did use the autolite spark plugs 2526 to tune the P port, as they are $3 each, so i had no problem going through a couple sets while tuning the carb.

i can't comment on power as i didn't use the autolites @wot, but the autolites will actually idle leaner than the NGK's.

 

Any test results of the LS2 coil with the dwell set at 4.5ms?

 

i can, but really you shouldnt even mess with those. i believe the problem high output/low energy coils is spark blowout. sure they may be good a initially lighting a rich mixture, but if the spark gets extinguished by turbulent flow or non-uniform mixture conditions (super rich or high water content), they do not have enough energy to re-light the spark. The long combustion chamber of the rotary engine makes this a bigger issue than with cylinder engines. I believe this is why CDI and big inductive ignitions work so well with rotaries. i noticed a night and day difference switching from IGN-1A coils (high output/low duration) back to factory FC coils (low output/long duration)

imo, the best ignition you can get would be four FC trailing coils with a Bosche 4-channel ignitor like this:
Bosch 0 227 100 211 Ignition Control with MegaSquirt-II
It has higher current limit than the FC ignitors, charge to 4ms.

if you are having misfires with that setup, move up to CDI.

If you must go aftermarket, IGN-1A coils would be the next best option

 

I completely understand your reservations against them, however for the price I paid (36 bucks for a set of four), I definitely want to give these a try. I'm slowly working through a dwell table to find a happy medium of good output and a decent duty cycle that doesn't overstress them. Obviously a stock table will work, but wanting to push them a bit harder on the high end for a bit more output.

 

Could you please clarify: are you referring to high output as meaning high output current or ? And energy as to total energy stored?

 

high output as in voltage and current (power output). Power is instantaneous, energy is a measure of power delivered over time

if power is how fast you pour water out of a bucket, energy would be how much water was in the bucket

 

general rule of thumb is double voltage, half the dwell time or is it no so easy? the idea of using 6v coils seems the way ahead with a good ignitor that can cope with the current. is there infoi out there of the 12A J109 ignitors in term of dwell and current limit? On our PP rx3 we now run 4 of these in direct fire layout. I noticed that one ignitor is having different dwell than the other 3 when checking with a scope. but even at 10k rpm the coils feel they were only doing 5k in stock wasted spark dizzy config =)

We are running the ls2 truck coils on a renesis with 5ms dwell and megasquirt ecu. no prolbems to 9000 rpm on circuit for 2 years..

 

Are you running your FC coils in wasted spark mode, or direct fire with the bosch ignitor?

 

Very glad to hear this. Knowing others have pushed them in higher duty cycles than what I'm planning to. Makes me feel even better for my 36 dollar coils.

 

I must say we run in direct fire, so not wasted spark, maybe when running wasted spark you might run into problems? With the megasquirt you can easy find out by using the output test and having them run for half an hour or an hours to check the temperature on the coils.

 

I'm actually planning on direct fire. Don't think they could handle being ran in a wasted spark setup as it would exceed 100% duty cycle in wasted spark.

 

Can you tell me what kind of amperage draw 4 trailing coils would have?
This is a great thread btw.

 

we can use Ohms law, v=i+r. the FSM says the coil resistance is under 1ohm, so

12v/1ohm = 12 amps.

at 14v/1ohm = 14 amps.

for a normal car you would probably run a 20A fuse, and maybe for something used harder a 30a fuse.

Mazda runs a 30A fuse, so maybe the coils don't draw 12amps constantly

 

ARMCHAIR : GOLDEN Rule #1 6000 RPM=10ms, thus 12000 RPM=5ms !

WHEN 8500 RPM is reached @ 6ms Coil Dwell a "duty cycle" of about 90% is reached.
Safe with ONLY an accurate "degree bases" EMS though not recommended.
A better SAFE coil dwell would 5.5ms.

This will produce 150mj of coil energy

Next, the IGN-1A coil specification for testing, set by Mercury Racing, IS 14volts @ 8 amps providing 102mj @ a 2.05ms coil dwell.

FEED your coils the 25 AMPS they require AND the dwell they can support 8.8ms.

YOU WILL get the same results as Jalai Lane, about 280mj.

The OLD version IGN-1CD NOW sold by M&W, will also solve the charge time though they state 115 mj of energy.
The PRO-DRAG CDI could by higher though it is "run time" limited to 10 seconds AND draws the same current ?

THE MOST COMMON mistake made by installers IS coil boot length, including Peter's (Rice Racing), boot design.

The plug boot MUST touch the steel of the sparkplug leaving NO "air gap".

Lance

 

Your saying that Ign-1a needs 25amps to run at it's full potential? I've been running 6 of these off my Haltechs 20amp relay fused feed at 4.7ms. Do I need to rewire for a 25amp feed? Can you eleborate on the plug boot touching the steel? Also were does someone get the long plug leads? I just re-did my spark plugs with Magnacore KV-85 wires and boots.

 

Tested yesterday on the 13B PP with first gen ignition times 2 in direct fire more. draws 11A at 10k rpm wit 12v at the coil

 

2 1st gen stock coils?

 

Watching thread with interest. Probably will be converting my car to a four CNP setup, maybe eke a little more fuel economy from the engine than I am getting through the distributor/MSD setup. Plus four little coils will weigh less and take up less space than the pile of stuff I have under the hood now. And getting rid of the distributor will make room for the supercharger.

 

4 stock coils. I use stock setup times 2, so 4 pickups on the dizzy and 4 stock igniters. Removed 2 of the 4 lobes on the reluctors so this makes it a cop direct fire system.

 

No. The amp draw of the coil is directly related to the charge time. The longer your charge it, the more amps it's draws. You'll never, in practical use, draw 25A through one of these coils. When running with a 4.5ms charge time, we see about 10-12 amps TOTAL for four coils. Lance is say, if you charge the coil to it's max 25A limit with an 8.8ms charge time at an unstated voltage, you can see 280mJ output.

That said, when I build harnesses for 20B engines with one of the Haltech harnesses, I use one of the spare fuse/relay spots in the box to add a second ignition power circuit and run 3 coils per circuit. That way i know I'm well within the design limits of the circuits. Running six coils off the single circuit will get you close to the 20A limit on a continuous basis. That's not good for longevity or coil performance.

 

FIRST, look at Jalia's work showing the MAX CURRENT draw of the IGN-1A coil.
THIS SHOULD NEVER HAPPEN : When a coil is saturated the primary windings become a dead short "frying" a coil/IGBT.

MY "term" is Dwell Truncation when this happens@25 AMPs.

The Jalia Lane method IS a safe way to test, in a lab, using current limiting equipment.

Review of the current@6ms dwell may state 16 AMPs max understanding the duty cycle x number of coils will calculate the RMS required current supply.
You COULD have "overlapping dwell" at higher RPMs stating a higher primary current supply NEED.

This is just ALL math, not my law, Gods law.

NOW for the "boot" question, free air is a good conductor.

AGAIN, the spark plug boot needs to completely cover the plug insulator, using internal silicon grease, leaving NO air gap at the plug steel.

MANY here on the site HAVE witnessed this occur, (leaks) at my facility, when viewing spark plugs/plug boots being tested using my CO-2 eight channel pressure chamber, (a product/item a sell to all who ask).

Magnacore products are first class, they make MANY boots of different length.
When I have a fitment problem, I will buy a "longer" boot then trim to size.

Lance