4 ECU coil drivers or EDIS8

[Chassis 33]

Hopefully just a quickie, hat are the pros and cons of using on board coil drivers against using a setup like the EDIS8 to run a V8 on coil packs?

Regards
Iain

[stevieturbo]

Obvious pro, is that it saves running a seperate amplifier.

I guess it depends on the quality/power of that amplifier. Some might be good, some might be bad. But Im sure that also applies to any combined coil/amp units too.

[GreenV8S]

Mainly simplicity (fewer components to fail) I would have thought?

[That Daddy]

The other thing is(and it does happen)if the coils short internally(common fault,especially Ford/motorcraft)then you run the risk of blowing the ECU drivers(internal) rather than just having to renew the EDIS module,just a small heads up,you would have to be unlucky though,i certainly wouldent use second hand units for this very reason.

[trackcar]

Why not use a coil with its own built in amplifier. I use some lovely KMS (audi?) coils to go with my KMS ecus which I sit on the RV8 plenum like this:




though of course the thor plenum is different so maybe stick them on the inner wings?

Edited by trackcar on Tuesday 27th November 10:28

[Chassis 33]

Cheers folks, just curious, the setup Im looking at is running Megasquirt with Disco II coil packs (becasue I have two working pairs). The idea of running EDIS is that it frees up some of the other optional input/output pins that the coil drivers would otherwise be using.

Regards
Iain

[That Daddy]

trackcar said:

Why not use a coil with its own built in amplifier. I use some lovely KMS (audi?) coils to go with my KMS ecus which I sit on the RV8 plenum like this:




though of course the thor plenum is different so maybe stick them on the inner wings?

Edited by trackcar on Tuesday 27th November 10:28

Trackcar,push that breather hose on properly(in your post),its winding me upi wont get any sleepnice idea with the bundled coil packs by the way

[trackcar]

haha, don't worry it will all be sorted before the car leaves .. it's only like that because that's not the plenum for that car, it's a 72mm plenum I was trying on to see what hp the engine gained over the std 65mm plenum .. the answer is nearly 20hp!

[That Daddy]

trackcar said:

haha, don't worry it will all be sorted before the car leaves .. it's only like that because that's not the plenum for that car, it's a 72mm plenum I was trying on to see what hp the engine gained over the std 65mm plenum .. the answer is nearly 20hp!

Bloody hell

[eliot]

I went edis - mainly because its tried, tested and relatively simple. The fact that it will still work without any signal from the ecu at-all was also appealing. I tested mine by spinning the trigger wheel round in the lathe!

[rev-erend]

Someone recommended mounting 3 * 4 cylinder EDis units..

That way you have a spare Edis (redundancy) with just a few cables to swap if there is a problem..

Food for thought - especially if it's a race car !

[spend]

Those VAG(KMS) coil packs, do seem surprisingly heavy tho, has anyone done any comparisons out of interest?

Dave
ETA: VW!=VAG :-)

Edited by spend on Wednesday 28th November 15:31

[Chassis 33]

rev-erend said:

Someone recommended mounting 3 * 4 cylinder EDis units..

That way you have a spare Edis (redundancy) with just a few cables to swap if there is a problem..

Food for thought - especially if it's a race car !

Have you any pictures, diagrams or links to this Rev?

Regards
Iain

[trackcar]

I don't know anything about EDIS .. what is it exactly? a combined amplifier and spark-advancer in one unit? does it have any other inputs except engine speed? how can you get a 3d map from it? don't understand how it functions if it doesn't need an ECU signal ...

[Chassis 33]

Joo, from what I gather it can run in a limp home mode with out any ECU input, just taking a signal off the crank sensor, I guess if you want to run coil packs from an MSD unit or something? Don't know any more than that.

The way things are looking though it sounds like its just adding an unnecessary complication to my MS install.

Regards
Iain

[GreenV8S]

trackcar said:

I don't know anything about EDIS .. what is it exactly? a combined amplifier and spark-advancer in one unit? does it have any other inputs except engine speed? how can you get a 3d map from it? don't understand how it functions if it doesn't need an ECU signal ...

Not used it myself, but from what I understand it's basically the same as a dizzy but taking the engine position off a toothed wheel signal, and with the mech/vac advance controls replaced by a simple digital signal from the ECU. I assume that in the absence of the digital signal you just get the default timing.

Not clear how V8 EDIS would work, I guess you would have two toothed wheel sensors 90 degrees apart driving two separate EDIS-4 units.

[rev-erend]

Sorry - think I've confused everyone.

What I meant to say was 3 * 4 coil units..(not Ford EDIS)

The coil units driven off the ECU (like an Emerald) and the 3rd coil not being connects but just there in case of a misfire etc..

[spend]

GreenV8S said:

trackcar said:

I don't know anything about EDIS .. what is it exactly? a combined amplifier and spark-advancer in one unit? does it have any other inputs except engine speed? how can you get a 3d map from it? don't understand how it functions if it doesn't need an ECU signal ...

Not used it myself, but from what I understand it's basically the same as a dizzy but taking the engine position off a toothed wheel signal, and with the mech/vac advance controls replaced by a simple digital signal from the ECU. I assume that in the absence of the digital signal you just get the default timing.

Not clear how V8 EDIS would work, I guess you would have two toothed wheel sensors 90 degrees apart driving two separate EDIS-4 units.

I think there is an EDIS-8 unit, but not very common to find V8 fords over here The unit links to 2 separate 2 coil (wasted spark) coil packs.

As I understand it you can send a SAW signal to tweak advance / retard - if this is missing it is capable of operating 'limp home' as a stand alone unit just fed from the crank sensor. The ecu is fed the CPS signal from the EDIS controller (PIP IIRC), but as I understood it with no timing info - just rpm?.

Dave

[Steve_D]

spend said:

GreenV8S said:

trackcar said:

I don't know anything about EDIS .. what is it exactly? a combined amplifier and spark-advancer in one unit? does it have any other inputs except engine speed? how can you get a 3d map from it? don't understand how it functions if it doesn't need an ECU signal ...

Not used it myself, but from what I understand it's basically the same as a dizzy but taking the engine position off a toothed wheel signal, and with the mech/vac advance controls replaced by a simple digital signal from the ECU. I assume that in the absence of the digital signal you just get the default timing.

Not clear how V8 EDIS would work, I guess you would have two toothed wheel sensors 90 degrees apart driving two separate EDIS-4 units.

I think there is an EDIS-8 unit, but not very common to find V8 fords over here The unit links to 2 separate 2 coil (wasted spark) coil packs.

As I understand it you can send a SAW signal to tweak advance / retard - if this is missing it is capable of operating 'limp home' as a stand alone unit just fed from the crank sensor. The ecu is fed the CPS signal from the EDIS controller (PIP IIRC), but as I understood it with no timing info - just rpm?.

Dave

The EDIS8 unit takes the signal from a single VR sensor which is looking for the missing tooth. You position the sensor to give 10 degree advance.
The EDIS sends this signal PIP (Profile Ignition Pick-up)to your ECU which then modifies its timing and sends it back SAW (Spark Angle Word) and the EDIS uses that to decide when to fire and which coils of the two coil packs it connects to. If it gets nothing back it will use the PIP as limp-home at a set 10 degree.

Steve

[eliot]

EDIS info for those that want to understand it:
http://www.megamanual.com/ms2/EDIS.htm
EDIS8 modules are quite easy to get hold of, even in the UK. Paid about £45 (and I have a spare also, because you certainly wont find one easily on a sunday afternoon - but then again most custom / aftermarket stuff is hard to find on a sunday afternoon)