distributor-less ignition, where to go Options

[02loftsmoor]

I'm check on going with distributor-less ignition system, some pointers please

[McMark]

Micro squirt running ignition only would be my route. Haven't used any standalone units and haven't heard of any standalone units that are tunable.

[jarred]

A slightly self-serving reply...

I vote megasquirt or megajolt plus my ignition trigger http://www.914world.com/bbs2/index.php?sho...p;#entry2132437

[stugray]

You could use a MSD with crank trigger and coil-on-plug.
The DIS-4 appears to be able to do this (for a 4-cyl), but I didnt read all the details.

[mikesmith]

I'm check on going with distributor-less ignition system, some pointers please

What are you trying to achieve?

Less maintenance?
Tunability?
Space in the engine bay?
Something else?

Knowing what your goals are would help folks make better suggestions...

[02loftsmoor]

I'm check on going with distributor-less ignition system, some pointers please

What are you trying to achieve?

Less maintenance?
Tunability?
Space in the engine bay?
Something else?

Knowing what your goals are would help folks make better suggestions...

Clean up the engine bay, fine tuning, twin plug heads--dreaming of.

[DBCooper]

A slightly self-serving reply...

I vote megasquirt or megajolt plus my ignition trigger http://www.914world.com/bbs2/index.php?sho...p;#entry2132437

Wow, that is exceptionally cool. Good job.

[jarred]

Quick correction: the megajolt only uses a 36-1 trigger wheel which isn't compatible with my distributor parts. I've only used the megasquirt and assumed (my bad) megajolt was just the spark side of a megasquirt, but in reality the megajolt is only compatible with EDIS and might not get you to twin spark... not sure if the "SAW" signal can be paralleled to two EDIS controllers for the second set of plugs and coil pack. That's be a pretty cluttered setup anyway.

For twin spark on a megsquirt based system you would parallel the logic level coil fire signals from the megasquirt to the two VW 2.0 coil packs ($30 each new on ebay). Haven't set this system up myself (don't have the heads), but there's no reason it couldn't be done that way.

[mikesmith]

Knowing what your goals are would help folks make better suggestions...

Clean up the engine bay, fine tuning, twin plug heads--dreaming of.

I have no experience with twin-spark setups so I can't really comment on what's involved there.

How "fine" do you want to tune things? Are you planning dyno sessions? Seat of the pants measurement?

Anything seriously analytical will benefit from a mapped setup, so something like Megajolt will be where you want to go.

Alternatively, you could have your existing 009 recurved (or learn to DIY).

Engine bay cleanup is a bit subjective; you can get that with some DIY ignition wires and zipties for some values of 'clean'. Other options might include the Compu-Tronix unit (it's very shiny, if that matters to you...).

[stugray]

Quick correction: the megajolt only uses a 36-1 trigger wheel which isn't compatible with my distributor parts. I've only used the megasquirt and assumed (my bad) megajolt was just the spark side of a megasquirt, but in reality the megajolt is only compatible with EDIS and might not get you to twin spark... not sure if the "SAW" signal can be paralleled to two EDIS controllers for the second set of plugs and coil pack. That's be a pretty cluttered setup anyway.

For twin spark on a megsquirt based system you would parallel the logic level coil fire signals from the megasquirt to the two VW 2.0 coil packs ($30 each new on ebay). Haven't set this system up myself (don't have the heads), but there's no reason it couldn't be done that way.

For a twin plug 4-cyl setup, you could use your trigger system with an arduino beetle (the size of a quarter, it would fit in the cap) and it would send your timing pulse to two separate MSD DIS-4s.
The Arduino would delay the timing pulse to the second MSD with a adjustable duration that would determine the spacing between the plug firings.
Both MSDs would drive 4 coil on Plugs.

[Harpo]

Clewett offers a system. Although it is for 4 plugs I have to believe that it could be easily changed to 8 plugs

http://www.clewett.com/index.php?main_page...products_id=291

[jarred]

Stugray: I've looked into developing the computing part of the ignition with a friend of mine who does a lot (more than me) embedded microcontroller work. The idea was to put it in the cap as you suggested. The arduino is probably capable (I've used them extensively for other work) but they might not be able to handle the heat. The Wiring code used for programming Arduino has it's limitations in i/o speed which might require programming the hardware in C/C++ instead. If you know of anyone or any project that have done it successfully, please pass it on, I'd obviously be interested.

[stugray]

Stugray: I've looked into developing the computing part of the ignition with a friend of mine who does a lot (more than me) embedded microcontroller work. The idea was to put it in the cap as you suggested. The arduino is probably capable (I've used them extensively for other work) but they might not be able to handle the heat. The Wiring code used for programming Arduino has it's limitations in i/o speed which might require programming the hardware in C/C++ instead. If you know of anyone or any project that have done it successfully, please pass it on, I'd obviously be interested.

I am positive that nearly all of the Arduinos could do this.
The "Beetle" that I speak of is of the Leonardo family and runs at 16Mhz.
So you easily have microsecond resolution of the timing of the output pulse.
The pseudo-code is so simple I could have it working overnight.
This is basically just a signal repeater with a programmable delay on one output.

You justuse an interrupt service routine to catch a rising edge of the tach signal.
Then it sets timers for X milliseconds in the future (plug set #1), and Y milliseconds in the future (plug set #2).
The timers would fire outputs to +12V Mosfets for the signal to the MSDs to simulate the Tach signal.
The delay is dependent on the value of the RPM and could be configured from a map, so the delay between plug set #1 & #2 could be variable based on engine RPM (or even load if you hook up a MAP).
You could change the parameters with a usb cable and a droid phone.

I have an Arduino as a datalogger in the racecar, so I have already written the code to read the TACH.
The tach signal is 0-200 Hz (0-6000 RPM) and I tested mine to 1000 Hz, so the processor would have no trouble keeping up.

edit: I would need to change my code for calculating RPMs because right now I "sit" for 1/2 a second to calculate RPMs while doing nothing else - so that would have to change.

[veekry9]

http://rusefi.com/wiki/index.php?title=Main_Page
You may find what you want here.

However,if cost is not important,an off the shelf is the way to go.
https://www.google.ca/#q=distributorless+ignition+retrofit

[jarred]

Interesting. Not sure if you looked at my advert, you could use the VW 2.0 coil pack VAG part 032905106B/032905106E and skip the igbt's or mosfets altogether. It's about $30 on ebay. Just two logic outputs for wasted spark, similar to MSD (?).

I think the megasquirt code used to use just one trigger per engine revolution to calculate engine speed and advance (ignore the others), what I think you propose, it now uses time between triggers (interrupts) to keep a running measurement of rpm. I don't think engines change speed fast enough under load to really matter in one engine cycle. But you do need some kind of sync to determine whether to fire coil bank #1 or #2 which is what the skip tooth is all about. Just an idea, if it used two opposed hall sensors and 1 trigger tooth like D-jet does for switching injectors (was it half-multiport?), you'd have two interrupts: one for each coil pack and no need to create or decipher a sync signal.

But I do think that an in-cap system on our air-cooled vehicles could have heat issues. The standard ATmega328p processor is only specified to 185 degrees F, and I kinda doubt it's going to be too happy at 184, or even 120, particularly if it's having to think very hard. That said, I haven't measured the temps in a cap. The ats617 sensor, an automotive part, was designed to operate up to 300 degrees F.

[stugray]

The simple MSDs require a tach signal that represents each cylinder firing, and it can be a nice clean signal like from a unilite optical pickup, a hall effect, or a noisy signal from a real coil/points.

My setup uses the mallory optical pickup straight to the MSD.
It is a perfectly clean looking 12VDC square wave.
You could split that signal to two MSDs and they would both fire simultaneously.
Now we just need to slow down the output for one of the MSDs and you have staggered firing.

So since the MSD can accept a nice clean 12VDC signal, I would just use two Mosfet "modules" for $5ea. to convert the Ard 5VDC IO to a 12VDC square wave.

And now that I thought about it, you could have either a second rotating pickup, or just a 5th "tooth" in the trigger wheel to determine crank position (TDC)
You could use that and provide a FI trigger signal to either a stock FI ECU, or a Megasquirt.

An encoder on the distributor is essentially "crank fired" anyway ( but you know that)

As far as overheating, if you are using the distributor to drive the COP style of MSD, then there is no "distributing" being done at the distributor, so it wont get very hot.
A fan on the distributor drive shaft could push air through the cap.
The operating temperature of the Atmega (+85C) is the same as the Renesas SH series CPUs in my BRZ, so I think it should be ok.

[PotterPorsche]

http://www.cbperformance.com/ProductDetail...roductCode=2094


Or wait for the next gen.

http://www.cbperformance.com/ProductDetail...roductCode=7075

[Jake Raby]

I go Electromotive. You can either buy a Tec-S and use just the ignition channels, (keeping the FI channels for upgrade later) or you can go to the XDI and run twin coil pack assemblies from one trigger and wheel.

I used an XDI on my 2.6 T4 in my 356, and back in the 90s, when we started twin plugging these engines, the predecessor to the XDI, known as the HPV-1 is all that was around. I have several of those HPV-1 fired engines running around on twi plugs today and they've never had an issue.

[Bills914-4]

For twin spark on a megsquirt based system you would parallel the logic level coil fire signals from the megasquirt to the two VW 2.0 coil packs ($30 each new on ebay). Haven't set this system up myself (don't have the heads), but there's no reason it couldn't be done that way.

It's being done that way (IMG:style_emoticons/default/smile.gif) , MS2xtra w/sequentil ignition & injection , I've been working on this for my 2.8 twin plug conversion , IT WORKS (IMG:style_emoticons/default/smile.gif) , will update my thread in the future,( couple weeks, my ECU is at the DUBSHOP for the sequentil injector modification, ) I test run the ignition part already (IMG:style_emoticons/default/smile.gif)

http://www.thedubshop.net/links.htm

http://www.914world.com/bbs2/index.php?sho...225696&st=0

here's few pic's enjoy , cheers Bill D.

[Mark Henry]

I don't know why you would bother doing this unless you are going FI (IMG:style_emoticons/default/confused24.gif)

Spend the money in the engine not on it. Only exception to this is headers which is the cheapest HP gain you can add to the engine.
This mod adds zero HP.