Contemplating Ignition Options (EDIS, VR sensors, vb921's OH MY)

[fryea]

I've been pondering lately about the various ways of achieving spark with megasquirt.

It seems we have 2 options for trigger angle if we don't use the hall sensor in the dizzy:
-VR input from a 60-2 bosch wheel (aka, 2.4 flywheel)
-VR input from a 36-1 edis wheel (custom mounted)

Are there more input options? if so, I'm wondering with these 2 options at our fingertips, what is the best setup to go with for efficiency and power, the end goal of megasquirt?

-1 coil power by onboard vb921, triggered using cap/rotor
-1 coil power by bosch 139 module, triggered using cap/rotor
-Entire EDIS system
-Dual VB921's triggering an EDIS coilpack with wasted spark
-4 vb921's triggering individual coils

And every now and again I hear a mention of "multiple spark". Sounds cool, is it furthering the "power and efficiency" agenda or is it just jabber?

We can leave the wiring and hardware mods for another day, but conceptually speaking for now.

[740ATL]

Well... if your goal is more power and efficiency, then I would think you'd want to cut down on the number of times your single coil charges and discharges... thus the multiple coil setup.

You can do wasted spark with either the 60-2 wheel/vr sensor or the 36-1 wheel/vr sensor, using either a 2-coil coilpack (ford 4-cylinder, mitsu/hyundai 4-cylinder, toyota, etc.) or a 4-coil setup (one per cylinder) but triggering a pair of coils at a time.

If you have the 36-1 wheel/vr you can also use EDIS for wasted spark.... setup is also much simpler for EDIS as you don't need any vb921's... just the EDIS hardware... found on what seems like billions of cars... especially at the JY. The more I look at it, the more attractive it is... but I lack the mounting hardware.... the 60-2 setup was just an easier option for me, and provided me more flexibility for the future...

I've used wasted spark with both the Mitsubishi DSM coilpack (2-coils) and 2 vb921 modules, and with four individual toyota coilpacks with built-in ignition modules, using a simple pullup resistor on LED17/LED19 to trigger the coils.

Lastly, there's sequential ignition, firing one single coil per cylinder. This is done with a crank sensor and cam sensor. I'm currently in the process of getting this running... although it's been a pisser and I've already stupidly fried my first MS chip.

So far, it seems like I got fewer misfires with the DSM/vb921 setup than I do with the 4-coil-toyota setup... but this could be as simple as having the dwell set improperly on the toyota coils.

It's a tossup so far... I like the individual coils better because they fit better in my application. To me it seemed like the vb921's just ran hot... even when bolted directly to the top cover of my MS board.... and there's always the risk of a code corruption (well maybe for me there is :)) and having the output being set to non-inverted and melting the vb921's.... Don't get me wrong... I'm not biased, just stating observations. I may go to a 4-vb921 setup when/if I switch to the gsxr coils I have (non-integrated ignition module).

At any rate, I'm not sure where I'm going... I had something in mind that I was going to say but perhaps more coffee can flush it out of me.

Mike

[The Aspirator]

As cool and awesome as distributorless ignition is, regular 'ol MSnS works like a charm. It's stupidly easy to setup and lasts like the energizer bunny.

Fryea I forget exactly what you're running right now as far as MS setups go, but if you want something easy/cheap/simple to get you stared, definitely just use a dizzy and 139 ignition module. Something tells me that you're running MS for fuel only, though that could be someone else..?

John

[fryea]

No, i've been using MSnS-E from the start on my 245 project (which as since been abondoned).

Lesson learned is dont swap engines, install turbos, rip out previous wiring, buy a bunch of cool ****, and get MSnS-E runnning all at the same time. You (I) will forget the necessities like a water pump, shuttering brakes, and worn out suspension components, and you will be so frustrated that you wont even want to install the cool ****.

Anywho, I ran it with the Dizzy and 139 module for about 5 months. I don't know why, but I just can't stand the look of the dizzy and cap with wires sitting on top of the engine. And it has been proven by a few high HP swedish beasts that wasted spark/multiple spark is the way to go, and the dizzy just can't provide that. And it seems that a trigger wheel seems much more accurate than a hall sensor. Just looking inside the cap, the rotor metal piece is huge. Maybe thats irrellevant, but whatever. Facts are that with more coils, you give them longer time to charge, more pop. Wasted spark may be "wasted", but in my mind its just cleaning house (and by house, i mean cylinder).

So for when my next project comes along, i want to take my time and get the essentials done right first, and when it comes time for the MSnS-E, I wanna have a rock solid ignition setup.

Thanks for the insight on your experience with multiple coils and vb921's 740atl, gives me some new perspectives. One thing I've seen as far as mounting a 36-1 ring is what xntrx (i think thats his name) did, in that he took a slimmed down ring, and mounted it on the engine side of the harmonic balancer, and mounted the sensor to a fabbed bracket that attaches to the oil pan. Look up his buildup in the project section to see what I mean. Pretty innovative if ya ask me.

Right now EDIS has been winning my heart, but I dont want to shut the doors yet as far as options (as the ignition/MS re-install will probably be a at least a few months out), so just kind of keeping my ears open. I like the VB921, but im terrrrrrrible with a soldering iron, bought a premade MSv.3 so i wouldnt have to worry about things as such.

[740ATL]

cool. If soldering's not your thing, edis is a great way to go... but don't fear the iron! ya get better! Try very small solder... .032" radio shack. Put a dab of solder on the iron first, then touch the wet part of the iron to your piece... the liquid dramatically increases the heating rate and you can solder faster without holding the iron on the piece forever.

The EDIS implementation has been made fantastically simpler by Matt and Dale... pick up one of their edis adapters for the b21/b23 or b230... I've only seen the b21 unit and it was seriously pretty. A quality piece.

For me the 60-2 wheel just worked better at the time... but I despise the stepped flywheel's mass... with a front mounted trigger wheel like the EDIS setup uses, I could drop about a half million pounds by going to the flat flywheel, and still use the 36-1 wheel to fire my toothed decoder software.

Mike

[adrianpike]

You still need to solder on your Megasquirt for EDIS, but even a clumsy oaf like me can do it! :-D

[740ATL]

You still need to solder on your Megasquirt for EDIS, but even a clumsy oaf like me can do it! :-D

it's still less soldering than this tho! :nod:

http://i5.pbase.com/g6/75/540175/2/71676011.QY1gx2dS.jpg

[fryea]

I CAN solder.... i just avoid it at every cost. Maybe it has to do with the black and decker iron im using...

Worst case scenario is I have a friend of mine who used to work in an electronics repair shop do it for me.

Good point on the stepped flywheel, I never thought about that, switching to the flat would make the rev's a bit more happy. does the flat flywheel works on every redblock and clutch?

740, with your current ignition setup, what does your external wiring look like (what pins go where)?

[740ATL]

I CAN solder.... i just avoid it at every cost. Maybe it has to do with the black and decker iron im using...

Worst case scenario is I have a friend of mine who used to work in an electronics repair shop do it for me.

Good point on the stepped flywheel, I never thought about that, switching to the flat would make the rev's a bit more happy. does the flat flywheel works on every redblock and clutch?

740, with your current ignition setup, what does your external wiring look like (what pins go where)?

You should practice at it man... IMHO, every MS'er should be comfortable with soldering... Having never soldered before, I picked up a tech edge 2A0 DIY unit, with like 300,576 more pieces than even the ms3 box... and got it all together.... and it actually works great. Start small... buy a MS stimulator and solder that together... remember the small solder and dab of solder trick.

Yup on the front mount crank trigger... the 36-1 doesn't have to be used with only EDIS... The flat flywheel will work with every redblock... although you will also need to change the disc/pressure plate, and the engagement changes slightly, so you'll need to tighten/loosen the cable a bit.

The picture above shows what my wiring looks like... I had to add an aux db25 connector to handle all the ignition/msns-e outputs... way more than the 4 supplied on the db37 connector for v2.2

So far, the db25 handles duties for the 4 coil outputs, 1 efan, 1 boost, 2 vr, 1 hall, a tach, 12v in, 5v in, and ground.... messy messy. looks like this... http://www.pbase.com/740atl/image/71121019

[domox]

cool. If soldering's not your thing, edis is a great way to go... but don't fear the iron! ya get better! Try very small solder... .032" radio shack. Put a dab of solder on the iron first, then touch the wet part of the iron to your piece... the liquid dramatically increases the heating rate and you can solder faster without holding the iron on the piece forever.

I'm modding the MS box right now for EDIS and outputs. If its been a while since you've soldered, then best to practice before you start. The instructions are easy to follow and shouldn't scare you off. Just practice.

The EDIS implementation has been made fantastically simpler by Matt and Dale... pick up one of their edis adapters for the b21/b23 or b230... I've only seen the b21 unit and it was seriously pretty. A quality piece.

Yes, I agree, it's a nice piece. You still have to manufacture a mount for the VR sensor. Can you weld or know someone who can weld?

http://i51.photobucket.com/albums/f386/domoxaz/Car%20Stuff/Volvo%20Stuff/MegaSquirt/DSC00642.jpg