Distributorless ignition using GEMS coils and Hotwire system

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GDCobra
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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by GDCobra »

DaveEFI wrote:
Wed Oct 14, 2020 11:10 pm
The Nordiz does look promising - but why on earth omit a vacuum sensor, since pretty well every dizzy has one. To allow more advance to be used at low engine demand and improve economy.
I must admit I was a little disappointed with this, I'd prever a single box solution but I can see how it can be excused.
Different applications (FI) may need different MAP ranges - User has choice.
Some applicatoins will use TPS instead of MAP - Why have if you don't need?
Separate module easier to replace if problem occurs - Maybe over-planning for failure!

OK, not all of them completely hold water but bottom line is that's how its been decided to manufacture it.
I don't see it as a deal breaker, easy so sort out and not too expensive, and lets face it the MJ options also have a third party unit, EDIS, which I can't even buy new.



DaveEFI wrote:
Wed Oct 14, 2020 11:10 pm
If I were looking for the cheapest new solution, I'd check out Speeduino. You can buy the boards on Ebay for not a lot. It can cope with 4 ignition channels, and uses the same tuning software as MegaSquirt (Tuner Studio) which is pretty good.
I don't know if I come over as a bit of a tight git (probably because lets face it I am) but when I do spend money cheapness is not a primary concern, much prefer to look at value.
I'll look into the Speeduino system, thanks for bringing to my attention, but as with MS I don't really want to get involved with a DiY solution down to the level of constructing the unit. Also Tuner Studio may bring back flashbacks of my MS experience, and I don't want to have to go back to councilling.



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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by stevieturbo »

GDCobra wrote:
Thu Oct 15, 2020 11:58 am
stevieturbo wrote:
Wed Oct 14, 2020 9:46 pm
What exactly is the issue with GEMS coils, that you seem to think will be a problem for an aftermarket system ?
There may be no problem at all but I like to consider what pitfalls I may encounter and pre-empt a solution to them.
I've asked a MJ vendor if it will work with GEMS coils and was told "Maybe but you are on your own if there are any issues".
DaveEFi has since indicated that some attributes (dwell in particular) are handled by the EDIS not the MJ hence if the value EDIS uses is not suitable for GEMS coils they will not work to their optimum, maybe not at all.

stevieturbo wrote:
Wed Oct 14, 2020 9:46 pm
And what is the issue with the tacho that needs all that messing about ? What exactly drives the current tacho ?
Again, this may be a non-problem but want to know the options for working around.
Advice from Dave and Garry have provided 2 possible options for this.



stevieturbo wrote:
Wed Oct 14, 2020 9:46 pm
Another cheap ecu, although I don't think they do ignition only as such is Spitronics. But their systems are pretty cheap from South Africa and I think they can sell as complete kits.

But really, Nodiz is UK based....I'd expect support would be better because of that.
Thanks for the advice on Spitronics, I tried to have a look at their offerings on their web site but it's not very cooperative.
Also I agree a UK based manufacturer should be better able to support, and so far communications have been good. I suspect this is the way I'm going to go.
Surely only a very crap system would not allow you control over dwell ?...it's a basic necessity. Coils are pretty simple devices, it makes no sense for a supplier to say "you're on your own"
Obviously an EDIS system is a little different, but leaves you stuck with that.

I dont really see why an ecu would not be able to drive the tacho, although again....exactly what currently drives the tacho ?
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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by GDCobra »

stevieturbo wrote:
Thu Oct 15, 2020 9:50 pm

Surely only a very crap system would not allow you control over dwell ?...it's a basic necessity. Coils are pretty simple devices, it makes no sense for a supplier to say "you're on your own"
Obviously an EDIS system is a little different, but leaves you stuck with that.
I wouldn't necessarily call it 'crap', the system under discussion on the dwell issue is Megajolt. I'm no expert on any of these systems or the subject matter they involve (wouldn't be asking questions here if I were) but I'm told that when using EDIS that part of the system looks after the coil control with the ECU simply telling the EDIS when the coils should be fired. In that case it makes sense that MJ does not have dwell control.
I don't want the limitations imposed by the EDIS system so at this point I'm no longer considering MJ


stevieturbo wrote:
Thu Oct 15, 2020 9:50 pm
I dont really see why an ecu would not be able to drive the tacho, although again....exactly what currently drives the tacho ?
It has already been mentioned that the tach signal is currenlty attaced to the coil -ve terminal (along with a connection to the 14 CUX via a resistor, 6k7 I believe), from what DaveEFi has advised this causes a voltage pulse higher than 12v (around 50v indicated) and higher than the voltage signal from which the ECU would be using which is probably 5v.
The circuit diagram givne makes sense as it simulates the action of the single coil setup so hopefully will give similar results.

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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by DaveEFI »

stevieturbo wrote:
Wed Oct 14, 2020 9:46 pm

Surely only a very crap system would not allow you control over dwell ?...it's a basic necessity. Coils are pretty simple devices, it makes no sense for a supplier to say "you're on your own"
Obviously an EDIS system is a little different, but leaves you stuck with that.

I dont really see why an ecu would not be able to drive the tacho, although again....exactly what currently drives the tacho ?

EDIS is very nearly a self contained ignition system. It will spark away happily at fixed timing with no external ECU at all. The only connections to the external ECU are PIP (the engine speed (tach) from EDIS to the ECU, and SAW (spark advance word) from the ECU to EDIS module.
Coils are simple devices but are matched to their application - unless you think all coils fitted to cars with points ignition are the same.
Dave
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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by stevieturbo »

DaveEFI wrote:
Fri Oct 16, 2020 9:12 am

Coils are simple devices but are matched to their application - unless you think all coils fitted to cars with points ignition are the same.
Which is exactly why dwell control is a basic necessity. One size does not fit all, it needs to be flexible. If it isn't flexible...it is crap.

And I've never had an issue driving a tach directly from the ecu....that's kinda what the tacho output is for. Although yes there are some very old or odd setups that may require other work. But they would be the exception.
Again, any decent ecu will also offer a flexible output for whatever cylinder range you want the tacho to display too for engine swaps etc.
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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by DaveEFI »

MegaJolt is desined to work with EDIS complete. Very unfair to call it crap if you want to use it in a way it was never designed for.
Dave
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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by GDCobra »

stevieturbo wrote:
Fri Oct 16, 2020 3:40 pm
DaveEFI wrote:
Fri Oct 16, 2020 9:12 am

Coils are simple devices but are matched to their application - unless you think all coils fitted to cars with points ignition are the same.
Which is exactly why dwell control is a basic necessity. One size does not fit all, it needs to be flexible. If it isn't flexible...it is crap.

And I've never had an issue driving a tach directly from the ecu....that's kinda what the tacho output is for. Although yes there are some very old or odd setups that may require other work. But they would be the exception.
Again, any decent ecu will also offer a flexible output for whatever cylinder range you want the tacho to display too for engine swaps etc.
I think we're going around in circles to some degree. I opened this thread to ask for information on various systems, any positive or negative reviews and advice on some aspects which may or may not become a problem. I've been given information regarding the limitations of the Megajolt system, while I wouldn't describe the system as 'crap' (it works perfectly well when coupled with the parts it was intended for apparently) I'm not prepared to suffer some of the limitation so have decided that is not the system for me.

On the subject of driving the tach, well I don't know what systems you've used or if I'm going to have a problem, but I like to go into any new venture as prepared as I can be (failing to prepare is preparing to fail and all that), if I do hit problem I now have some ways to combat these.
I dont' know if my tach comes into the "very old" category, it was brand new only 23 years ago when I built the car, but who knows it could be an old design. I think it's Stewart Warner but could be wrong.
At the end of the day issues with the tach are not going to stop me in my tracks, obviously I'd sort it out but can take time over this.

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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by DaveEFI »

Tachs designed since electronic ignition mapping came along may well work off the ECU - it won't do any harm to try. The older factory fit Smiths RVC tachs, originally fed from the coil negative most likely won't. But again won't hurt to try.

All I can say is that the Smiths unit fitted to the SD1 (and similar in principle to on other cars) needs a higher voltage signal to trigger it than an ECU can provide. The same applies to the one fitted to a Stag.
Dave
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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by stevieturbo »

DaveEFI wrote:
Fri Oct 16, 2020 4:12 pm
MegaJolt is desined to work with EDIS complete. Very unfair to call it crap if you want to use it in a way it was never designed for.
And if you read, I had excluded the specific EDIS system, because it was a complete and limited system. I specifically called any system that is not flexible to allow use of any coil/dwell, crap. Which is true.
Last edited by stevieturbo on Fri Oct 16, 2020 7:53 pm, edited 1 time in total.
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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by stevieturbo »

GDCobra wrote:
Fri Oct 16, 2020 5:03 pm
I think we're going around in circles to some degree. I opened this thread to ask for information on various systems, any positive or negative reviews and advice on some aspects which may or may not become a problem. I've been given information regarding the limitations of the Megajolt system, while I wouldn't describe the system as 'crap' (it works perfectly well when coupled with the parts it was intended for apparently) I'm not prepared to suffer some of the limitation so have decided that is not the system for me.

On the subject of driving the tach, well I don't know what systems you've used or if I'm going to have a problem, but I like to go into any new venture as prepared as I can be (failing to prepare is preparing to fail and all that), if I do hit problem I now have some ways to combat these.
I dont' know if my tach comes into the "very old" category, it was brand new only 23 years ago when I built the car, but who knows it could be an old design. I think it's Stewart Warner but could be wrong.
At the end of the day issues with the tach are not going to stop me in my tracks, obviously I'd sort it out but can take time over this.
I've used I'm sure a dozen different makes of ecu, from ancient stuff nearly 20 years ago, to the best of the best like Syvecs and quite a few in between.

It almost sounds like you're using an aftermarket tacho then ?....which means there is even less chance of there being problems.

Really, there are dozens of ways you could achieve ignition only, with all manner of setups, a lot involving a full spark/fuel ecu. But in reality that sort of outlay probably makes no sense over a budget system.

What do you want to spend to achieve whatever the end goal really is ?
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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by GDCobra »

stevieturbo wrote:
Fri Oct 16, 2020 7:52 pm

I've used I'm sure a dozen different makes of ecu, from ancient stuff nearly 20 years ago, to the best of the best like Syvecs and quite a few in between.

He he, problem is I consider 20 years ago as being quite new!


stevieturbo wrote:
Fri Oct 16, 2020 7:52 pm

It almost sounds like you're using an aftermarket tacho then ?....which means there is even less chance of there being problems.
Well it’s a kit car, pretty much everything is aftermarket. Is that important? What really matters is how it works and more importantly what it needs to make it work.


stevieturbo wrote:
Fri Oct 16, 2020 7:52 pm

Really, there are dozens of ways you could achieve ignition only, with all manner of setups, a lot involving a full spark/fuel ecu. But in reality that sort of outlay probably makes no sense over a budget system.
It’s all well and good telling me there are dozens of way to do something what I’m looking for is specific products which will get the job done.

stevieturbo wrote:
Fri Oct 16, 2020 7:52 pm
What do you want to spend to achieve whatever the end goal really is ?

That’s not the way I operate. I come at it the other way around, what is my goal then work out what I need to do/get/spend to achieve it. In this case I’m looking to get rid of the distributor and replace it with a system where I can have control over the ignition timing rather than relying on springs and diaphragms and high tech stuff like that.

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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by stevieturbo »

An aftermarket tacho is more likely to be easy to trigger, vs something specifically made for an OEM vehicle. So yes it matters, and should be very easy.

And budget etc does matter.

Do you really need to spend say £1500 to do the job £300 will do ?

And of course the other aspect not mentioned....is who will be tuning it ? That is a key factor, as there's no sense buying the best you can afford....if there is nobody to tune it.
If you are doing it yourself, then download the various software and see how you like it, as it does matter.

And the problem is, there are dozens of ecu's that will do the job, but as the job needs are very open and vague other than using GEMS coils....the list of choices remains huge. Budget has to be a factor.

But really, The Nodiz seems a reasonable value option, Have you spoken to them directly ?

At the pricier end, I would consider a full fuel/spark ecu, simply because these are more common than sparks only, and there are still quite a few reasonably priced to use as sparks only.
Motorsport Electronics who make Nodiz also make some reasonably good value ecu's too, although a lot of the benefits of a full ecu would be just wasted with sparks only.

If it was me for a very basic setup, my main "wants" would be an ability to fire 8 coils....for a coil near plug setup, that allows short HT leads to each plug. Either that or find a pair of 4 tower coils with independent inputs, again so the install doesn't involve HT leads crossing from one side to the other, which is just messy.
Although the Nodiz does not seem offer that. It is a typical wasted spark setup that would see HT leads crossing over.

Another neat little unit is the MaxxEcu Mini.

It is a full ecu, but could drive 8 smart coils in the configuration I described, fired as a wasted spark setup, and is pretty reasonably priced. There are a few UK dealers. Their software is fairly straightforward too.

https://www.maxxecu.com/dealers/

https://www.maxxecu.com/products/mini
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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by GDCobra »

stevieturbo wrote:
Sat Oct 17, 2020 5:06 pm

And budget etc does matter.
Do you really need to spend say £1500 to do the job £300 will do ?
Well I'd have to be crazy or rich to say that price doesn't matter and I'm certainly not rich. However what I'm saying is it's not the primary concern or the point I start from. What I'm trying to achieve is to get rid of the distributor (because I don't like devices which use garbage technology such as springs, weights and diaphragms). I want a system which triggers off the cranks actual position, not some signal derived at a point several gears and chains removed from this hence open to variation. I also want to be triggering multiple coils as I really don't like the idea of one coil having to deliver 4 times per engine revolution.
I'd like to have coil per plug but don't expect (with my setup) I'd see any performance benefit.
Ultimately I'd like to be able to tweak the timing profile to optimise performance.


stevieturbo wrote:
Sat Oct 17, 2020 5:06 pm
And of course the other aspect not mentioned....is who will be tuning it ? That is a key factor, as there's no sense buying the best you can afford....if there is nobody to tune it.
If you are doing it yourself, then download the various software and see how you like it, as it does matter.
That's a good point, although I would not expect a spark only system to be too complex on the tuning software, there are only 3 basic inputs and any software would have to be seriously poor to be too much of a challenge (I don't think Apple or Microsoft make this kind of software!).
One reason why I'm looking for a spark only system. I'm not unhappy with the fuelling system and not heard anyone even attempt to make promises on how I can better it so why change?
Downloading and testing is good advice but obviously I can only follow this once I have identified candidate systems which is what I'm trying to do at the moment.

stevieturbo wrote:
Sat Oct 17, 2020 5:06 pm

And the problem is, there are dozens of ecu's that will do the job, but as the job needs are very open and vague other than using GEMS coils....the list of choices remains huge. Budget has to be a factor.
This is part of the problem though, it's OK saying there are dozens but I must be looking all wrong because I'm no seeing that degree of choice.
Thanks for the links to the additional systems you mention below by the way.


stevieturbo wrote:
Sat Oct 17, 2020 5:06 pm

If it was me for a very basic setup, my main "wants" would be an ability to fire 8 coils....for a coil near plug setup, that allows short HT leads to each plug. Either that or find a pair of 4 tower coils with independent inputs, again so the install doesn't involve HT leads crossing from one side to the other, which is just messy.
Although the Nodiz does not seem offer that. It is a typical wasted spark setup that would see HT leads crossing over.

Another neat little unit is the MaxxEcu Mini.

It is a full ecu, but could drive 8 smart coils in the configuration I described, fired as a wasted spark setup, and is pretty reasonably priced. There are a few UK dealers. Their software is fairly straightforward too.

https://www.maxxecu.com/dealers/

https://www.maxxecu.com/products/mini
As already mentioned, I'd like to have a coil per plug, just seems like a logical system to me, and I do like the idea of not having HT leads crossing over each other (as well as being short). Trawling through the Internet I did find one picture (somewhere on this site I think) where someone had use 2 VW coilpacks which I believe have 4 coils each, possibly still triggered wasted spark but neater wiring.

I'll checkout the maxxecu, thanks for the links.

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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by stevieturbo »

As I said, there are dozens.....I didn't say dozens of spark only systems.

But with a more free budget, then ALL EFI systems are an option, you'll just pay more for a lot of stuff you wont use. But if it gets you the hardware and software setup you want....so be it.

When you can buy LS coils for reasonable money second hand, they make a good option for a coil near plug setup and the Maxx Mini will be able to control them

The complication with any "grouped" coil pack, is most of them are wasted...which means the only way you'll get them to work on a V8, is with HT wires crossing from one bank to the other.
I have seen some 4 tower coil packs that have all 4 as independent channels...but damned if I can remember the application. But it would not be common.

LS coils are everywhere, they're fairly cheap, compact, and very powerful for a coil near plug setup.

Some pencil style coils might be an option....but they'd probably be difficult to actually fit.
9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0

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Re: Distributorless ignition using GEMS coils and Hotwire system

Post by stevieturbo »

If you do go LS coils...please do not mount them like this...that is horrific ! lol

http://forum.britishv8.org/read.php?6,39986,page=3
9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0

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