Best ignition setup to run

[Alky V6]

A beautiful explanation.

 

[quickt]

Use The Accel ICM with COP with your XFI. Its a little different using A Gen7 part with the XFI but it will work perfectly.

I forgot to add that a properly working MSD DIS4 can handle the rev limiting with your current C3I and give you a little more spark power. No where even close to the ICM though.

 

[TurboBob]

........ Keep in mind the Electromotive references timing and makes corrections 120 times in 720deg of rotation. The Gen7 and XFI make 1 correction every 720deg. This is based on the fact that the Electromotive uses a 60 tooth trigger wheel. More resolution more accurate

I'm pretty sure the BS3, XFI, etc. calclate spark based on the crank sensor signal which is 6 times per 720 degrees of crank rotation. The Stock ECM certainly does. While this isn't like using a 58X reference, it works pretty well.

timing. The electromotive can increase the ignition output based on demand. There is NO CDI Ignition that can do this. Ever put a timing light on the CDI with a 3 window crank trigger. Wonder why that timing mark bounces all over 3-5 degrees sometimes more? Try that with the Electromotive and the timing will be rock steady like an old mechanical distributor. There is nothing wrong with waste spark as a matter of fact there are advantages over COP. The C3I is just out dated waste spark and not up to the task. Best I can explain it.

The old style mechanical distributor setups had issues with spark scatter due to timing chain stretch and thrust bearing clearance. So they had issues as well.

How does the E-M sense load?

I agree that wastespark has no inherent flaws, when done well. It sounds like the E-M does it well.

Bob

 

[Alky V6]

It's a Speed Density system. MAP is the primary input. NO FREAKIN MAF sensor!
It also has a blend option primarily used for hot cammed engines with a jumping map signal at idle, to mix user definable percentages of map and tps signal and ramp that out to whatever rpm point back to full map input. Since the tps signal is much smoother at idle than the map signal with a lumpy camshaft, that will smooth out the load input into the ECM at idle, giving more stable ignition and fueling events.
As Lonnie already pointed out, by far, the thing that puts the Electromotive far ahead of the competition is the power and accuracy of the ignition system. Nothing comes close. I run my nitrous system very much on the rich side. On a cold day when the bottle is impossible to get up to temp, even richer. So much so, that I'm surprised it fires. Yet, it does. Talk to any veteran tuner that has experience with the EM system and they rave about the ignition power and accuracy.

 

[quickt]

I'm pretty sure the BS3, XFI, etc. calclate spark based on the crank sensor signal which is 6 times per 720 degrees of crank rotation. The Stock ECM certainly does. While this isn't like using a 58X reference, it works pretty well.



The old style mechanical distributor setups had issues with spark scatter due to timing chain stretch and thrust bearing clearance. So they had issues as well.

How does the E-M sense load?

I agree that wastespark has no inherent flaws, when done well. It sounds like the E-M does it well.

Bob

Hi Bob,
I have to admit a little assumption here on my part. Here is my thinking. On the stock setup if engine is running and the cam sensor rotor breaks the little tab the car will go out of sync and back fire. So I assumed that it would sync every 720deg as that is the only number 1 reference that it seen. I would assume from that observation the C3I did not count windows but would re sync on cam signal. Also with the timing light I would see the reference float out and jump back on track. Again assuming it seen cam signal. The Gen7 shows cam signal events and when for what ever reason the C3I missed one and timing goes out. Next time will pick it up and move the reference right back in line. Thats been my observation. If you say it will re sync 6 times in 720 deg that works for me. I would only say my testing does not show that. Another observation I have been seeing is some crank trigger rings are not spaced exactly 120deg apart. After Market ECU only acts on the info they receive. Garbage in garbage out. When in DIS Mode the aftermarket is looking for cam signal so I once again I believe it will re sync 1 time every 720. I think these are some of the reasons for the distributor craze over the last few years. Maybe the dist craze was only for rev limiting and 2 step don't know.

E-M tells me the ECU can sense the load placed on the coil and increase the driver voltage per coil per firing event needed up to maximum output. Not sure how they do it. I have seen this system operate over 9000 rpm with out one burp.

An old distributor has issues we all know it. At least some of us older fellas do. But the basic timing light test on a good setup after the mechanical advance shows a stable timing reference. Was used for an example not gospel.

When the C3I is removed and dist replaces it. It also seems spark scatter will get much better until you put the timing light on at the chassis dyno at hi RPM. Then you see the scatter again maybe only 3-5 deg but its there. The C3I is much worse. The E-M will be rock steady at 6K with 0 scatter seen on a timing light. We have done this trick to a V-8 turning over 8K and the timing was rock steady with E-M. I have done this test on all 3 myself. The Accel ICM does offer the same timing accuracy as it can use the 60-2 tooth wheel I have also had this one on the dyno for the timing test and its very comparable to the EM with 0 spark scatter seen.

 

[Alky V6]

On a finely tuned engine where you might have a tuned in safety margin of 2 degrees timing, 3-5 degrees of timing variance can be an engine killer.

 

[bison]

The answer to the original question imo is the stock coil setup with good wires and tight gapped AC or Autolite plugs. Why complicate a 700hp application with more than needed and wasted $. Low 10's high 9's. Come on be realistic. No more than stock is needed

 

[quickt]

The answer to the original question imo is the stock coil setup with good wires and tight gapped AC or Autolite plugs. Why complicate a 700hp application with more than needed and wasted $. Low 10's high 9's. Come on be realistic. No more than stock is needed

We must be looking at 2 different topics. Was this one not Best Ignition set-up to run?

Just testing the waters. What kindof ignition r u guys running in ur low 10sec high 9sec street driving TR. Just finishing up on the restoration and I've herd alot about the waste spark power loss. Don't really want to go to a distributor setup since I will be running A/C. RJC was talking about developing a mega coil that would eliminate the waste spark but that fell through (not enough demand). So what r we to do suck it up and run the 20+ year old technology on the type1 or type2 ignition systems? I would really appreciate some feedback on this since I am new at this. Go easy on me I a big block guy. My buildup is in my description at the bottom. Estimating to make around 700+hp. Thanx to all that reply

I was thinking he was looking for options.

Guess we could just do it this way. Nope you have no other options if you want to stay DIS.

 

[Alky V6]

Many don't realize this but DIS is Electromotive. They hold the patents. The systems found in production cars are a basic watered down version of the technology found in the EM systems.

 

[TurboBob]

I would say that up to a mid to high 10 car, the stock system works well if in good shape.

All of the ECM's I am aware of calculate ignition timing from the crank signal, the cam signal is used to "sync" i.e. identify which cylinder is which. I have quite a lot of data to support this. its still only 3 pulses per rev, but this is how it works.

If the EM indeed calculates from every crank trigger tooth, then it will certainly have a more accurate timing event.

If the EM "senses load" then it is truly a fancy system. If it increases dwell time with load (MAP) then it is doing the same thing every other system is doing. CDI systems don't / can't do this since they don't "dwell". I'm not sure if this is 'salesmanship' on the part of EM. Either way, their system seems to work.

Distributors on a GN became popular when the DIS-4's turned out to be unreliable IMO. You can toss a MSD system on there easily with 2-step. With the fancy MSD equipment (7531) you can have pseudo traction control also.

I run Speed Density with my stock ECM, I agree that for high HP cars, its the best way to go.


Bob

 

[TurboBob]

Many don't realize this but DIS is Electromotive. They hold the patents. The systems found in production cars are a basic watered down version of the technology found in the EM systems.

the only patent they quote on their site is their control algorithm. I haven't looked it up yet, but it sounds a lot like a standard dwell algorithm handles.

Most likely it involves the timing accuracy for their 58x wheel.

The coils appear to be regular type-II coils. Good coils, for sure.

I'm not trying to downplay the system, it sounds like it works very well indeed. Its just not rocket surgery.

Bob

 

[quickt]

I would say that up to a mid to high 10 car, the stock system works well if in good shape.

All of the ECM's I am aware of calculate ignition timing from the crank signal, the cam signal is used to "sync" i.e. identify which cylinder is which. I have quite a lot of data to support this. its still only 3 pulses per rev, but this is how it works.

If the EM indeed calculates from every crank trigger tooth, then it will certainly have a more accurate timing event.

If the EM "senses load" then it is truly a fancy system. If it increases dwell time with load (MAP) then it is doing the same thing every other system is doing. CDI systems don't / can't do this since they don't "dwell". I'm not sure if this is 'salesmanship' on the part of EM. Either way, their system seems to work.

Distributors on a GN became popular when the DIS-4's turned out to be unreliable IMO. You can toss a MSD system on there easily with 2-step. With the fancy MSD equipment (7531) you can have pseudo traction control also.

I run Speed Density with my stock ECM, I agree that for high HP cars, its the best way to go.


Bob

The EM truly does count teeth. The only time a cam sensor is needed if for sequential injection. The cam sensor does nothing for the ignition even when a cam sensor is used. If it looses cam signal it converts to batch or staged injection. The EM GT has built in Traction Control. Not real fancy but it works. The New ICM also works this way I am told.

 

[Alky V6]

I think the EM system is a little more complicated than dwell time versus map signal. I must admit, delving into the intricacies of how EM performs their ignition power magic is something I never got to involved in. The system did the job, I was happy. If someone does have some insight into how it's done, I'm all ears. Frankly, I think some of the technology is closely protected, but I'm just assuming. A dealer tried to explain it to me once and it just all sounded like garble to me. Again, it worked, I was happy.

 

[quickt]

All of the ECM's I am aware of calculate ignition timing from the crank signal, the cam signal is used to "sync" i.e. identify which cylinder is which. I have quite a lot of data to support this. its still only 3 pulses per rev, but this is how it works.




Bob

Question?? If the cam signal lines up the firing order would that not have any affect on ignition timing? What if it was say 10 deg off?

 

[Alky V6]

Quoted from a high performance ignition 'How to' book in my library.

Speaking of Electromotive.

"In fact, they hold several important patents regarding DIS operation and coil charging."

"Unlike the crank trigger systems we discussed earlier, the HPX uses a wheel with 60 teeth (okay, 58, due to the flat area indicating a complete revolution to the computer) with a magnetic pickup. The extra teeth trigger the pickup and provide the added information so ignition knows the location and angle of the crankshaft throughout every revolution. This means that the HPX can make firing and rev limiting compensations, plus this aids in precision charging of each coil pack."
"When GM and Ford started going with DIS systems, they turned to Electromotive's patented technology for their technique in charging multiple inductive coils. Now, these factory systems are licensed from Electromotive, though the factory doesn't use them to the capacity they're capable of delivering. We suspect that's all right at the Electromotive offices, so they can continue to offer higher-output performance components."

 

[Alky V6]

I'm sorry if I'm coming off as a salesman. I just think that the EM system has been largely ignored and deserves some recognition.

I can't help but find it amusing that after all these years, I've been using one simple box while everyone else is trying this and that, resorting back to the archaic distributor, and new boxes just coming out that can do what Electromotive has been doing all the while. As long as you switch to the 60-2 trigger wheel.
I know. Sticking to the flock is a strong urge.

 

[TurboBob]

I think the EM system is a little more complicated than dwell time versus map signal. I must admit, delving into the intricacies of how EM performs their ignition power magic is something I never got to involved in. The system did the job, I was happy. If someone does have some insight into how it's done, I'm all ears. Frankly, I think some of the technology is closely protected, but I'm just assuming. A dealer tried to explain it to me once and it just all sounded like garble to me. Again, it worked, I was happy.

In reading the information on their site it sounds like they control dwell to ensure complete "charging" of the coil (9 amps). I don't think they are doing any "in cylinder" sensing.

They talk about charging multiple coils at once, but this is what the stock LS1 PCM does.

Bob

 

[TurboBob]

Question?? If the cam signal lines up the firing order would that not have any affect on ignition timing? What if it was say 10 deg off?

well, the engine still runs if you unplug it......

The cam sensor simply identifies the firing order. The EM system does not need it because of the gap in the crank sensor wheel, it can find #1 with that.

The stock ECM triggers the spark based on a time delay from the crank sensor pulse. The EM system just has more pulses, so it can be more precise.

Bob

 

[TurboBob]

Quoted from a high performance ignition 'How to' book in my library.

Speaking of Electromotive.

"In fact, they hold several important patents regarding DIS operation and coil charging."

"Unlike the crank trigger systems we discussed earlier, the HPX uses a wheel with 60 teeth (okay, 58, due to the flat area indicating a complete revolution to the computer) with a magnetic pickup. The extra teeth trigger the pickup and provide the added information so ignition knows the location and angle of the crankshaft throughout every revolution. This means that the HPX can make firing and rev limiting compensations, plus this aids in precision charging of each coil pack."
"When GM and Ford started going with DIS systems, they turned to Electromotive's patented technology for their technique in charging multiple inductive coils. Now, these factory systems are licensed from Electromotive, though the factory doesn't use them to the capacity they're capable of delivering. We suspect that's all right at the Electromotive offices, so they can continue to offer higher-output performance components."

What book?

Bob

 

[Alky V6]

In reading the information on their site it sounds like they control dwell to ensure complete "charging" of the coil (9 amps). I don't think they are doing any "in cylinder" sensing.

They talk about charging multiple coils at once, but this is what the stock LS1 PCM does.

Bob

I can tell you that the more secondary load you demand from the EM system, the more voltage you will get. To the point that you'd better have some dang good plug wires to keep secondary leakage under control.

I run small plug gaps (.020") not because I have to inorder to control any missing problem. I do it to keep the seconday voltage under control. I could (and have) run larger gaps, but then I have to worry about wearing out the secondary leads.