Coil Pack Conversion - More Info Needed

[madkaw]

There’s no specific numbers I can brag on , but there’s no contest , especially if you want to run a performance cam or performance engine .

I run 45 degrees at cruise and can idle at 18 degrees . You can’t hardly get a dizzy to do that since the vacuum advance is linked to the total advance . 
 

Cam sensor really helps for smoother idle and getting that last % of precision from EFI . 

[Captain Obvious]

The thing about the cam sensor... If you're running a wasted spark system, you don't need cam sensor.

Two pistons will be approaching TDC at the same time. Of the pair, one of the rising pistons is approaching TDC on it's compression stroke, and the other one is approaching TDC on it's exhaust stroke. A cam sensor would allow you to differentiate between those two, but if you're running a wasted spark system, you don't care... Just spark both of them at the same time.

If you had a cam sensor, you could spark just the cylinder on it's compression stroke alone without "wasting" a spark on the other cylinder.

On edit - I don't know about the accuracy of the spark timing stuff. Maybe a cam sensor can get you a tiny bit more accurate with your spark timing, but I'm not sure.

Edited November 11, 2019 by Captain Obvious
I'm no timing expert

[Matthew Abate]

Thanks guys. CO, I’m adding that to the glossary.

I think what was meant in the thread I referred to is that crank sensors give you accuracy (flywheel versions specifically) whereas the cam helps you understand which valve position for spark. “Accuracy”

[Captain Obvious]

I've been casually rolling some ignition stuff around in recently as well. Stuff like who controls the dwell and advance, etc... Different options and the like about that.

Here's a bunch of links I was poking around on:

https://www.hotrod.com/articles/convert-a-ford-or-chrysler-ignition-to-gm-hei/
https://www.powerperformancenews.com/tech/spark-it-up-how-to-convert-a-ford-or-mopar-distributor-to-gm-hei/
http://megasquirt.free.fr/sources/MS/manual/ms2/GM_7pinHEI.htm
http://www.megamanual.com/ms2/GM_7pinHEI.htm
http://www.megasquirt.info/HEIgn.htm
https://www.hemmings.com/magazine/mus/2008/11/The-lost-art-of-servicing-GM-HEI/1719426.html
https://www.celica-gts.com/forums/index.php?PHPSESSID=m15m00cdf1sj27pk5r472sjv05&topic=11116.15

[LeonV]

There's a lot of information on this at HybridZ. I ran Megajolt on my previous 260Z, it's a relatively easy system to get running. The only real challenges are the trigger wheel and sensor, and those can be bought off the shelf to make it almost trivial.

[cgsheen1]

I love that the OP has never posted back to his thread and yet it's taken a life of it's own...

[duffymahoney]

Wasted spark is fine 99% of the time.  I went with full sequential, just because of how easy it was, 3 wires and a cam sensor.  I think it added 150$ to my install.  

[Zed Head]

For ignition purpose alone, "sequential" and wasted spark are the same, except that the spark jumps backward for three of the plugs with wasted spark.  For ignition spark is always sequential.  Sequential is a word used to describe injection, when the cylinders only get fuel on their compression stroke.  And sequential is really only effective at low RPM, and it's really mainly for emissions purposes.

Just wanted to put that out there.  Injection and ignition are two separate events.  Even when people go to something like Megasquirt, they can do it in two parts, completely independently.   Either one can go first.  And ignition timing is always done from the crankshaft because timing is based on piston position.

[SteveJ]

52 minutes ago, cgsheen1 said:

I love that the OP has never posted back to his thread and yet it's taken a life of it's own...

Actually, the OP hasn't returned to this site since a couple of hours after the initial post. I hope he is finding what he's looking for.

[z32 fairlady]

1 hour ago, SteveJ said:

Actually, the OP hasn't returned to this site since a couple of hours after the initial post. I hope he is finding what he's looking for.

I certainly am. Thank you all for your contributions, especially @Matthew Abate. Having all the info in one place or in a concise location as you've presented it is what I was hoping for in a response.

[SteveJ]

4 minutes ago, z32 fairlady said:

I certainly am. Thank you all for your contributions, especially @Matthew Abate. Having all the info in one place or in a concise location as you've presented it is what I was hoping for in a response.

Oh, you just wanted us to do the legwork for you.

[duffymahoney]

2 hours ago, Zed Head said:

For ignition purpose alone, "sequential" and wasted spark are the same, except that the spark jumps backward for three of the plugs with wasted spark.  For ignition spark is always sequential.  Sequential is a word used to describe injection, when the cylinders only get fuel on their compression stroke.  And sequential is really only effective at low RPM, and it's really mainly for emissions purposes.

Just wanted to put that out there.  Injection and ignition are two separate events.  Even when people go to something like Megasquirt, they can do it in two parts, completely independently.   Either one can go first.  And ignition timing is always done from the crankshaft because timing is based on piston position.

I can control individual spark dwell with sequential.  Can you do that with wasted?