Uprated single coil - hot or not?

[twoqu]

There is a guy over the pond that was talking about something similar. Haven't heard anything though. Quote:

I am also working on a black box solution to eliminate the distributor cap and rotor in order to facilitate coil on plug or coil near plug – independent coil per cylinder ignition.- keep posted or enquire for details and anticipated availability early '08.

[S2central.net]

OK - it is a sound idea then... but once again I'm too late for a patent application

This could be lashed up with some cheap simple programmable counter and five solid state relays once the relationship to the 54 tooth window and the CMP pulse is established... Dead easy if the CMP pulse just zeroes the counter for #1

Anybody got a 3B and a 2-channel oscilloscope ?


Paul

[Jonas_R]

Yeah I got both.

[S2central.net]

Great - can you sanity check some of my timing calcs here and help me understand the relative positions of the various signals.

At 960rpm you should see 8 (eight) CMP pulses per second - thats a 125ms period
At 960rpm you should also see 2160 sawtooth pulses per second from the RPM sensor to validate my 135 tooth memory (960 x 135 / 60)

Then it would be very useful to see plots of the CPS (crank reference which should be 62 BTDC on #1) and the CMP to establish the gap between them.

FInally it would be great to see plots of the CMP signal along with the primary voltage trigger from the ECU (which gets to the amp on the 3B coilpack at pin #1 from memory).

PS - CMP is CaMshaft Position sensor... The hall effect doobry in your dissy - monitor the middle pin of 3-pin plug for that. The other two sensors (CPS and RPM) are inductive devices.

Good luck and Thanks - is this a good project or what ?

[S2central.net]

Bumpity bump - any other techies with insight on this idea ?

[Jonas_R]

Paul, I know you did not understand me the first time, but will try again.

Dont you think that it is possible to use the dizzy as a trigger instead of it distributing a high current? I
If you send small current through the dizzy, then hopefully this current can jump as well. Then this small coil will go through the roter arm and then simply trigger each point in the distrubutor. Then all you need is power to the coils and then the dizzy to trigger each coil every time.

Does it make any sense?

I think this was the same Mihnea was thinking off:
"Hey guys, in the following months I'll be developping a dizzy removal kit for the 3B, or at least a kit that will allow removing the HT part from the dizzy and to use it to drive 5 separate coils, all this by retaining the stock ECU and wiring harness. Basically it should be a bolt-on part that will go on the dizzy and 5 coils that will drive each spark plug."

[S2central.net]

I have completed the high level design for a low tension distributor (LTD) that will provide a 5-coil direct ignition (DI) system for the WR, MB, RR and 3B engines. I also cooked up some failsafe logic as well to ensure that only coil can be fired at a time.

I'm going to need some time to build a prototype and I'll need to get expert inputs from some hardware guys I know locally on the best/cheapest/simplest way to construct the thing.

Physically it will be a small sealed black box that uses a number of inputs from the Motronic sensors (CPS, RPM & CPM) and will steer the ECUs primary trigger voltage into the right coil. This will NOT make any timing adjustments - it simply opens the right window to steer the spark to the correct destination.

I need to do some homework first to measure the important inputs, understand how best to get reliable clock edges from them and gradually build up a test harness that I can use to verify its operation.

In order to install the finished item I would like to get some form 'piggyback' AMP connectors so that it can hook into the sensor wiring in a non intrusive manner (and that it can be removed easily if required). Does anyone know of such a thing ?

The 5 x coils can come from AAN/ABY/ADU or go with external 034 or whatever items. I'll need to work on how best to cover those options. Something else I need to verify is if the existing single channel POS unit can be retained or whether it needs the 2 x 3 channel POS units from the DI engines to prepare a suitable signal for those kinds of coils.

I can do a lot of this work on a breakout box with my ABY to examine the signals, but I'd love an 8-channel scope to view everything on the same screen and make absolutely certain I have the sequencing right.

Failure / disconnection of input sensors is going to disable all outputs so there will be no more sparks. This is same as factory Motronic with exception that it can cater for CMP failure after the engine is running - I don't intend to add that complexity.

If there is sufficient interest in this gizmo I will seek out a suitable partner to build them and sell them - I simply wont have time to hand craft them in any numbers.

Does anyone thing there would be wider market appeal for a 4-cyl version of this on turbo cars that carry a traditional HT dissy ?

There will be some customisation required for different engine types due to timing reference points, but in theory it could be adapted for use on many engines.

Would there be general appeal in the 5-cyl community for the non-turbo applications ? AFAIK the reference points are all the same so you could have the concept of a DI powered KV, NG, NM or 7A engine.

This black-box will NOT interact with the ECU in anyway nor require any other hardware or software tweaks - its a stand-alone thing.... Oh it could also be bolted onto an aftermarket single coil ECU system such as Emerald for a DI application. Cool or what ?

The dissy will need to be retained on order to get the hall-effect CMP signal - unless an ABY/RS2 style CMP sensor is grafted onto the head. Alternatively an early AAN dissy without the HT gubbins could be used instead of the original item.

Paul

[urquattro-island]

Hello

is it not also possible to change some wiring to the ecu, and use dizzy as in early aan, of course this would mean you have to have a new ecu for the 3b. But is this not possible to make it 5coil?? I am thinking of doing this, any tips or pointers..

[S2central.net]

What you are talking about is a loom and ECU swap for a DI system on your 3B - that has been done before but its a large / expensive undertaking unless you are very lucky sourcing parts at good prices... And most people are clueless about wiring.

My idea is a lil more clever than that (if I ever build it) and will only require the simplest of plug and play wiring (I hope).

Paul

[Sonic]

Bloody hell Paul - sounds like you're going to town on this one.

Why don't these 3b boys just get an ABY?

[Jonas_R]

This is really excelent Paul, Iam up for one

[twoqu]

Paul,
Not sure if its similar in any way, but Cossy owners can upgrade to coil packs using this:
http://www.motorsport-developments.c...stedspark.html
They do have the advantage of being able to run wasted spark mind!

[Acidburn]

Paul,
Not sure if its similar in any way, but Cossy owners can upgrade to coil packs using this:
http://www.motorsport-developments.c...stedspark.html
They do have the advantage of being able to run wasted spark mind!

Its only been from what i've read recent years that they've felt the need to swap over to coil on plugs as most i've seen have been dizzy's.

I think what ur quattro island is thinking is something like what stu/4wheeldrifter is doing afaik in keeping the 3b wiring loom and changing the pins in the ecu plug and using a aby ecu?

Please correct me if i'm wrong. I'm also thinking of changing to aby setup but not 100% sold on it yet.

[urquattro-island]

yup

Its only been from what i've read recent years that they've felt the need to swap over to coil on plugs as most i've seen have been dizzy's.

I think what ur quattro island is thinking is something like what stu/4wheeldrifter is doing afaik in keeping the 3b wiring loom and changing the pins in the ecu plug and using a aby ecu?

Please correct me if i'm wrong. I'm also thinking of changing to aby setup but not 100% sold on it yet.

you hit the spot, exactly what i mean. Where do i find some info on this??

[S2central.net]

Paul,
Not sure if its similar in any way, but Cossy owners can upgrade to coil packs using this:
http://www.motorsport-developments.c...stedspark.html
They do have the advantage of being able to run wasted spark mind!

Yep - there's a couple of funky devices out there for 4-cyl engines that can get away with the wasted spark and only require 2 coils. We can't do that here !

Got to thinking I should investigate the dwell timing on 3B single coil and the ABY multi-coil as its very possible on the DI system that the ECU allows longer dwell time without overheating the coil than the 3B.

This means the 3B-DI system could work in two ways ---

1 - where the trigger pulse is passed straight thru to correct coil from ECU
2 - where the pulse can be extended, by some variable control, to create longer dwell and potentially bigger spark.