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MG MGB Technical - EDIS Electronic Ignition

Gentlemen,

Has anyone of you alreday fitted the EDIS ignition?

What is your experience?

Frank
Navest

Frank
Check out this site, a bit of info about it there!
http://www.upgrades4mgs.co.uk/
Eric
Eric Martin

To summarise the experience I wrote about on that page:
1) Do not attempt this unless you are handy with the tools, it requires a few fabricated brackets, and skill with the soldering iron.
2) If you do not have a lap-top or at least a PC near the car, then go 123, especially if you are just not computer literate as it takes a little effort to install the MegaJolt software.
3) If originality is important, then forget it, it doesn't fit under the bonnet as inconspicuously as a 123 or other electronic kit inside the distributor - the EDIS will stick out like a sore thumb.
4) Fitting a new distributor properly set-up for your advance curve needs will probably bring equal improvement in starting and engine tick-over and smoothness - that is, until the points gap starts closing up again as the heel wears, but for similar money a new distributor is the alternative for the reasons given in points 1-3 above.

That said, then yes, it is a worthwhile upgrade:
1) It uses production car parts from a Ford so is generally reliable.
2) If a fault occurs with the EDIS, assuming the old distributor and coil are still in place, these can be reconnected within a minute (I timed it out of curiosity) so no hanging around at the roadside.
3) If your engine is tuned beyond the factory design, then an advance curve can be mapped to suit it exactly, and easily re-mapped should you make any other modifications to the engine at a later date.
4) Once set it won't go off tune - so it minimises loss of performance between services, and extends the plug life.
5) On an electronic level a fatter spark can be achieved, and along with the improved running, there's a gain in fuel economy - I have had as much as 35mpg (12.5km/L or 8.5L/100km) on a motorway run at 70mph (110kph) or a little over (I won't say how much over!).
6) I have also seen an increase in max rpm from 5500 to well over 6000rpm (my engine is balanced). This has allowed me to exploit the full benefit of my engine set-up, and I find that when using the full revs, and changing up to 3rd I don't have the lag owing to the big gap in the ratios.

As said above, a new distributor could probably bring you most of these benefits until it wears out again, whereas the EDIS is solid state so maintains optimum performance. Is it for everyone? No, not at all! It works for me for my needs, but others will beg to differ based on their needs or opinions.

As to the webpage Eric linked above (thanks, Eric, hope you are ok?) I have provided the details as my BGT was a test car for the package Matt Kimmins offers. I don't get any commercial gain so I hope I have been as honest as possible above.
Martin ZT

Martin,

How hard is it to create the map that suits the car? It seems this is quite a lengthy process that also requires some serious understanding of the influence of the parameters?
Still, I think this is a very nifty system!

Alex
Alexander M

Alex
The MegaJolt software, once installed, is fairly easy to play with, being a 3 dimensional grid with input for advance against revs and TPS (or rather MAP - but we are not using MAP, rather TPS). We used TPS because of the pulsating pressure from the manifold on the B, although I am told that a basic petrol filter would help dampen these pulses but I have not tried that as yet.

The first problem is installation of the software as so few laptops now have an RS233 port so you need a USB adaptor, and there are two types, the later type 2 works fine, but it needs drivers installing.

Once that is done then you are clear to start playing. Matt supplies a basic map which is what I am still using with a few tweaks on idle but by listening to tickover we can platy easily enough with the advance at idle (the top left hand corner of the grid as per the diagram on my web page - which is an Excel chart built on the CSV file exported from the MegaJolt s/ware). This is the same as rotating the dizzy.

Now the cheaper option would be to take a passenger and laptop and do the same basic set up as you would with a distributor - that is try some acceleration runs and keep advancing the map until you find the pinking then back off. Obviously this is easier on a rolling road, but if you allow for the basic 3-D curve, then just keep pushing up all the figures accordingly.

Where it will get more tricky is changing the curve at various points, but here you are into the realms of seeking expert advice - as you would in any case with setting up a distributor correctly; where years of experience will tell the tuner exactly where in the rev range and at what throttle opening the advance would benefit from tweaking. However, this is a matter of typing in new numbers as opposed to filing bob-weights and changing spring tension.

Hope that helps!
Martin ZT

Great (at least it sounds so to me) explanation, Martin. Doesn't sound like something I'd tackle without having a rolling road available nearby.

Now what are the chances of a selection of advance curves being offered, in the same way that the 123 dizzy does?

Derek Nicholson

Derek, I will ask Matt Kimmins about that.
Martin ZT

Since the standard MGB 'curves' are published freely, and that is what the 123 for the MGB contains, I don;'t see any difficulty in programming something else to replicate those curves. However that would surely be deafeating the object of the exercise. The original curves are a crude approximation to the ideal for the original engines, given the crudity of the original mechanical and vacuum advance mechanisms and the need for a safety factor. Given that they were also (except for late model US versions) applicable to high octane leaded fuel the original curves are even further away from the ideal today. The only way to find the ideal curve is with a lot of experimentation or time on a rolling road. The site referenced also repeats the incorrect statement that some MGBs had vacuum advance and some had vacuum retard. Off-idle they were all the same - light throttle means more vacuum and higher advance, heavy throttle means low vacuum and less advance.
Paul Hunt 2

I did the EDIS conversion on my B roadster last summer, using Matt's kit, and I have to say it was pretty easy. It now starts much, much better than it ever did before, idles better, revs much happier, and should be way more reliable than the old dizzy (no more points). The only problem I had was getting the rev counter to work - which Matt fixed with a slight tweak to the controller box (one wire re-soldered to a different pin, I did this myself).

I am now seriously considering doing my V8 too.
Andy Torode

This system, using the MegaJolt for a controller, which is an offshoot of the MegaSquirt EFI controller is something I've been using for several years now so I'll pass along some of the things I've learned about it. But first I'd like to say that although combining the Ford EDIS module into the same case makes a simple and attractive system, in the process you lose the advantage of easy parts replacement and availability that makes the Ford system so attractive in the first place. I feel that keeping the two separate is a better approach, even though it adds another component and a few more wires.

But having said that I will also say that the Ford module has proven to be remarkably reliable and the need to replace the module is not likely to be a concern. "You pays yer money and you takes yer choices."

The MegaSquirt (MS) controller and the MegaJolt (MJ) can operate with as little as a tachometer input. Better is tachometer and MAP (a vacuum accumulator is advised to dampen fluctuation) but TPS can be used as noted. Additional inputs such as coolant temp (CLT), inlet air temp (IAT),and Knock Sensor (KS) add tunability for warm-up and other conditions, and a barometric sensor (2nd MAP ported to atmosphere) can give dynamic ambient compensation. From that point on more features can be added but may require code modification and circuit design so the curve steepens. The best and simplest balanced installation will use tach, MAP, CLT and IAT and stop there. This is because the vast majority of installations are set up that way and a tremendous amount of testing and design has been done there, and a support system is in place that you can tap into by simply joining an online forum. There you will find downloadable files that give an excellent starting point for your tuning efforts, and plenty of expertise to help you make the right tuning choices.

Three things are of incalculable value in tuning, should you choose to install them. They are, in order of importance:
1) Wideband O2 sensor (WB), available from Innovative Motorsports and others at prices from $200 US on up. However this is mostly useful for mixture control rather than timing, so where ignition only is concerned it goes to the bottom of the list. If Carb or injector tuning is also to be done it goes back to the top;
2) Knock sensor, various control/display devices are available, choice of sensor may need some research. All of the V8's and V6's commonly used have the correct sensor available and I would be very surprised if there is not an application of the B series engine that does also. Something like the Super 7 might be a good place to start looking but the Brits would know the most about that. Costs are around $50 US or less for the sensor and the display cost can vary widely, from a few bucks for components to build one on up into the hundreds if you want data logging capabilities. The MS is now capable of handling these duties, but you'll still want a display device, if nothing more than a red LED;
3) Exhaust Gas Temperature gage (EGT), about $160 US, with sender.

With these three devices, you can do a proper job of tuning on the road and feel reasonably confident of the results. If you feel the need to get every possible fraction of available power, then an accelerometer like the G-Tech is very useful, ranging in price from about $30 for an older unit off ebay to the $300 state of the art units.

With this instrumentation you are in the position to get an extremely effective real-world tune, something where even a dyno sometimes misses the mark.

Starting with a basic curve, about 10* of initial or static advance and full advance of maybe 40*, initial, mechanical, and vacuum combined, and splitting the 30* of dynamic advance between mechanical and vacuum as you feel appropriate, probably favoring the mechanical by a few degrees, you can extrapolate the table or map to give smooth transitions and a curve similar to a mechanical/vacuum distributor. Hey, it ain't rocket science. Then go for a drive.

Keep an eye on the KS and check your mixtures for reasonable ratios throughout the operating range, but at the same time watch the EGT and water temp for any indications of excessive heat. If either start to spike, check mixture first for lean conditions and if that's good advance the timing and re-evaluate. (Retarded timing creates heat)

Once the mixture is good you can begin to advance timing based on the indications of your knock sensor, and of course your ears, but be conservative and work your way up gradually. Induce knock at several part throttle areas of the map to establish limits and a general curve, and work your way up once you are satisfied that you have the lower areas well mapped. After you have gotten accustomed to the system and the characteristics of your engine you can begin to work your way up into the higher areas where knock is no longer detectable by ear. *BUT* do not be tempted to fiddle with the mixture while you are mapping the timing! If you do, it will be necessary to back off the timing and start over. Once you have a good timing map you can go back to the mixture and then begin to balance one against the other. Keep in mind that both mixture and advance affect knock and temperatures so don't make any large changes in one without re-evaluating the map for the other in the same operating range, and as you do this keep a close watch on your instrumentation, particularly the EGT.

Finally but perhaps most importantly, do not push your advance or mixture settings to extreme values without first verifying through experienced tuners that those values can be made to work successfully. Doing that and/or disregarding your instrumentation can rapidly destroy an engine.

Incidentally, with very little work the MegaTune (MT) dashboard is capable of displaying all of these outputs and more. It is very good software for the application and is freely downloadable. Also much work has been done with wireless links to the controller. Although I do not know the current state of those developments, it is possible to plug a device into the controller and another into the laptop and dispense with the cord. Either a laptop mount or a trained passenger is extremely helpful. But note I said "Trained".
Your buddy isn't going to casually pick it up and be any help the first time out.

Jim
Jim Blackwood

Thanks for the explanation guys!
This system sounds very interesting, but (and this is a huge but) as Jim says, I'd be terrified of destroying my engine... I just might look into it further.

(slight hijack: I'm also considering getting a MSD 6AL as most reports seem to state that it improves part throttle / low rev range drivability, not that my car is running badly!)
Alexander M

Vacuum advance is NEVER considered when calculating total advance as its only active at cruise and light load conditions when the air is restricted entering the engine and giving a low compression pressure and therefore a slow burn. However it can add to the problems of ping if it hangs on too long.
People are still talking about setting timing by the ping and this might have been OK once in the dark ages. All engines have a sweet spot where its happy and performing at its best, but many engines can be advanced further withing ping and without visibly loosing power. These engines will have a shorter life and as they heat up can develop detonation. I have seen engines that could be advanced until they almost ran backwards and still no ping. Denis
DENIS H

I use Polestar system originally designed and developped for type A engine. I fit one to my type B 1950 engine without problems.
Regards
http://www.polestarsystems.com
michel

"therefore a slow burn"

Does the burn rate vary - apart from when the pressure rises during the burn so much it causes the unburnt mixture to detonate? I though it burnt at a relatively constant rate which is why centriufugal advance is required.

I also believe vacuum advance *is* a factor. Even at part throttle although the risk of detonation is reduced because of the lower cylinder pressures, the fact that vacuum advance is applied increases the risk again. I've been getting part-throttle pinking. Applying full throttle stops it, as does switching off the vacuum advance using a TCSA solenoid.

Modern engines do use ping to control timing and have done for many years. First in closed-loop systems where it was a major factor, but also in more recent open-loop systems where timing is basically controlled from a programmed map knock sensing is still used as a backstop, to compensate for different grades of fuel for example.
Paul Hunt 2

Burn rate is variable.

High engine speed allows less/no time for detonation.
Paul Wiley

Dennis, it's all in how you calculate it. At WOT, yes, vacuum advance is never a factor. But to say it is not a factor in total advance it incorrect. To clarify how I am using these terms consider a high RPM coast down. Maximum mechanical advance, maximum vacuum advance, maximum total advance.

Alexander, I understand your fear. However if you like you can simply duplicate one of the stock curves and leave it at that. Or if you have good instrumentation, that will warn you before you have a problem. What Dennis says about a "sweet spot" is very true. If you are advancing the timing or leaning the mix and not seeing an improvement it is time to stop and go back a smidgen.

Jim
Jim Blackwood

Jim,

A duplicate wouldn't quite work for my engine I'm affraid (derrington xflow head that was modified by peter burgess so now has 44 & 34 mm valves, piper 285 cam, 11:1 cr, sidedraught carbs, etc etc). The current dizzy is an Aldon modified one. I presume the curve for those isn't widely available...

Is it possible to add sensors and use these as input? For example a knock sensor, temp sensor, lambda sensor, ... This would obviously make the setup a bit more complicated but could provide some ease of mind :-)

Alex
Alexander M

Alex
The latest version of the Emerald engine management hardware and software may well be able to do this but the EDIS and MegaJolt is not that sophisticated as yet from what I understand.
Martin ZT

To be honest Alexander I haven't kept up with the work on MJ because I've gone over entirely to the new version of MS-II and it has the ignition control built in. Best thing to do is browse the website and check the BB postings to see what it can and can't do. But I would be very surprised if it does not use everything except the KS input and a warning light is probably best for that anyway. With WB you have a similar situation, a visual indicator is most helpful, but using the MT dashboard is good enough. Possibly MJ does not automatically pull advance, but a proper tune eliminates the need in most cases.

Now the MS-II does have those capabilities, though as yet I have not experimented with everything. MS-II is not a great deal more expensive than MJ and is very sophisticated. Plus, should you want to try EFI you'd be set up for it. The MT software looks better too.

http://www.msefi.com/
http://www.bgsoflex.com/mjl/mjl_edis.html
Sorry I couldn't find a link for a MJ forum, probably because it is such old technology. But I suggest you post a question to this forum, where any questions you might have with the Bowling & Grippo systems can be answered.
http://www.msefi.com/viewforum.php?f=92

Jim
Jim Blackwood

Jim The reason vac adv is not included in the total is that its not there under the load or rev conditioned except for when backing off the throttle at higher revs. I know what you mean, you can get both at the same time under certain conditions but not when making power. A too sensitive vac unit can produce mid range ping.
Paul As you know engines require the maximum pressure of combustion to be produced 12-15* ATDC which is the reason for spark advance which lets say is 40*. The first 10% of the charge takes 50% of the available time to burn, the remaining 90% burns much quicker due to things such as turbulence, the added heat and pressure from the mixture already burnt and squish. As the piston approaches TDC the pressure in the cylinder is only about 10% above compression pressure, then the squish and the main burn.
This change in combustion rate is the reason for the initial advance (it takes almost 10* rotation for the spark to propagate combustion) The fast early advance (light dizzy spring) then the second part of the curve to the point that any further advance is unnecessary as the turbulence and other things cause the rate of burn to increase equal to the increasing engine speed
Knock sensors do use ping to set the advance on most modern engines but their picking up the first minute inaudible knock, then retarding that cylinder a certain amount which can be as much as 4*. Also they have many other sensor inputs into the computer to get the timing right in micro sec. but it dose not mean there on the point of detonation all the time.
I know it sounds like I/m blowing my bags but I taught this subject for many years in automotive college and I like to think I can help.
It does worry me a little when I see the effort different people are putting into ignition systems without appearing to understand the combustion processes involved. All the best Denis
DENIS H

Denis,
I defer to your expertise in matters of flame propagation. So would it be possible for you to suggest to Alex some suitable points that could be used to lay out a reasonably usable map for his application? Say perhaps in terms of manifold pressure (vacuum) and RPM for the x and y and advance degrees for the z axis? I'm sure that would be very helpful, and not just for him. Not to make it too much work, but I was thinking maybe a few points on the curve for each axis and perhaps a few more in the midrange where most of the driving is done, perhaps at the points where the map transitions rapidly? With your knowledge of how the combustion process takes place I can't think of anyone who could do a better job of it. Regards.

Jim
Jim Blackwood

Jim I/m not sure whether your trying to throw me a
curved ball or not but here goes.

Where trying to achieve the same job that the distributor has been doing but with more accurate ignition control, therefore I would not start off trying to reinvent the wheel.
If we start off with what Alex already knows. He knows that Peter B dynoed the car, got a lot of horse power and I would guess at what advance (my guess 34*)
A Timing light on the motor should tell him at what REVS the advance hits 34* usually on a B by 3000RPM(from memory Alex does not run vacuum advance because of the webber and has an Aldon dizzy).
He probably knows his static advance. Most hot naturally aspirated B engines seem to like about 15* and idle at about 1000 RPM. These of cause are all guesses but would be close.
So we know what the max total adv is and at what revs and the advance at 1K. These figures would have been proven on the dyno and it does not matter what you ignite the plug with, EDIS or a model T trembler coil, as long as its hot enough and at the right time they wont alter.
This means were right up to 1000revs and OK after 3000revs. So to be on the side of safety and because its very easily set later, I would start off with a linear curve, and carefully play with it later gradually making the lower part of the curve steeper. As we have already established the other points must be correct.
In Alex case I would not worry about other inputs as its not EFI and is performance oriented.
It is important to remember that no ignition is going to increase peak power if the old one is doing the job but it can improve drivability and reliability(some times) I/m trying to keep this simple because a lot of other people read these threads besides us Denis
DENIS H

There is a 3D map on the EDIS page of Martin's website link as above.
Paul

I guess that would be this link:
http://www.kimmins.info/

Using the information Denis has provided and these maps it should be relatively easy to come up with a workable map.

Jim
Jim Blackwood

Paul's referring to this page for 3D map:
http://www.kewengineering.co.uk/upgrades4mgs/welcome_to_the_edis_page.htm
Martin ZT

Martin

I was but Jim found better examples clicking on 3D maps.

Any from a RR set up?
Paul

Paul
When I clicked on the 3D Maps link, it got a failure, and consequently I thought that page was down as I know Matt has been doing work on the site. I'll try again.
Martin ZT

Gentlemen,

Your feedback is overwelming.

My car is a 67 B with a Burgess stage 2 head and further goodies.

Similar to Mr Alexander from Belgium my aim is to have a good and reliable ignition system including present day sensors that can provide my with some durability.
It is the intention to have fun instead of destroying the engine.
Possibly I am a bit over-sensitive. Can you recommend
an address having mapping experience on modified engines?

Frank
F. Navest

Gents,

Thanks for the very good information! This is turning into one of those threads I'll print to pdf and keep for future reference!

Frank,

No mister here, just Alex ;-)

I think Tovami in Goes (quite close to Belgium) might be a possibility regarding mapping the engine.


Alex
Alexander M

Gents,

I have just passed a mail to Matt to produce a kit on my behalf.

Thanks for the good support. I am convinced this is very sophisticated system when comparing it to the original mechanical system. In many respects this system will more fun driving my B.

See you out there

Frank

F Navest

Keep us posted Frank! How about a web-log of the installation/mapping/...?
Alexander M

Hi Frank- Seems that for my purpose, a MS2 as noted above by JB with the edis function on board, and the efi for later. I am now wringing hands over the Jenvey or TWN throttle Bodies. Someone said motorcycle injectors/tb, but I can find no reference. Do one of yall know the fine points on why for the motorcycle TB's. Bear with me please, I'm in new territory as the concept of an EDIS/EFI on the Burgess cross flowed head ( without that pesky siamese porting) has me fascinated and the wallet out. Cheetos, Vic
vem myers

This thread was discussed between 25/01/2007 and 04/02/2007

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