11 replies to this topic

[minilee94]

Basically just wondering what does a mapping ecu system do

What does it do for the engine ?
Can you performance map it ?
Does it improve performance if so how much ?

Disadvantages ??

[TimmyG]

In a nutshell, a mappable ignition ecu does all the basic functions that a conventional distributor ignition will do, except much more precisely controlled and matched to your engines exact requirements under all operating conditions,(if mapped correctly). This means the engine can then make the most of the fuel burnt which in turn gives better torque, and therefore horsepower and economy. It will usually also have other auxiliary functions such as a rev limiter, shift light output and such.
If converting from a points ignition you also have the benefits of the extra power of an electronic system, and zero maintenance.
There's not really such a thing as a performance map when it comes to mappable ignition, as by its very nature it should be optimum at all times once correctly set up, and therefore can't be improved upon.
The amount of performance benefit when changing from a mechanical system depends entirely on how wrong the old system was to start with. If, by some miracle the vacuum dizzy was giving exactly what the engine needed anyway then no change in performance would occur as nothing was wrong to start with.
On the other end of the spectrum you may have modified your engine and been told to use a non vac dizzy. In which case you will gain a large amount of power and response in the part throttle ranges atleast, and also big improvements in economy.
The engine will also run cooler and quieter with less exhaust boom and induction noise as the engine is not working so hard for any given speed.
The only disadvantges i would say are that if it breaks you cant necessarily fix it as easily on the side of the road.

Hope this helps

Tim.

[M44K TS]

Megajolt basically is distributor-less ignition. It uses a toothed wheel attached to the crank pulley and a crank position sensor to determine top dead centre, the Megajolt unit works in conjunction with the Ford 'EDIS' igniton system, you can precisely control your ignition timing using a laptop. Basically, the toothed wheel, (trigger wheel) has one tooth missing which is how the crank position sensor knows where TDC is, that info is then sent to the EDIS unit which interprets the signal which is then sent to the Megajolt unit. The MJ unit then allows you to set when the spark is delivered, usually using manifold vacuum from the carb to determine how much throttle you're giving it. The MJ unit then feeds the signal to the Ford coil pack which then creates the spark at the plugs. It uses a wasted spark system so sparks on both the compression and exhaust stroke although the spark on the exhaust stroke has no effect, hence 'wasted'

Pro's, bin the conventional coil & distributor set up so you shouldn't have any problems with worn out points, fewer damp related problems when driving in the rain, you can virtually eliminate flat spots caused by too advanced or retarded ignition that you normally wouldn't be able to do with the conventional distributor & it can look neat and tidy under the bonnet.

Con's, can be a fairly expensive conversion & unless you understand ignition curves, can be a bit tricky to get the settings right without havin it set up on a rolling road, having said that, there's plenty of maps available on the like of the Autosport Labs website which should roughly give you what you need map wise.

I found when I converted mine to Megajolt, even with a sort of generic map downloaded from the ASL forum, the 1800 rpm flat spot I had under partial throttle disappeared and it's much more drivable.

There's plenty of info about it on the forum to.

Here's what mine looks like when finished

[rally515]

Cn this system be used on injection minis also or is megajolt carb specified ?

[minilee94]

Okay thanks guys

[holmesy]

megajolt is for carb mini's, for injection you want the megasquirt.

I have a group buy going on for a new system which is much improved than the megajolt and has a lot more features than the megajolt. head over to the mini chat and look for 'nodiz group buy'.

it will tell you everything

[rally515]

megajolt is for carb mini's, for injection you want the megasquirt.

I have a group buy going on for a new system which is much improved than the megajolt and has a lot more features than the megajolt. head over to the mini chat and look for 'nodiz group buy'.

it will tell you everything

Ahhh right thanks for that,I unfortunately cant afford it at the moment as i have a project mini to do, but as soon as thats done im doing a 850 engine based project to see how much mpg i can get out of a A-series (stage 1 kits & dtm exhausts are dated in my opinion), so efficency is the way im going.

Was thinking of using a spi/mpi head & manifold setup for the ecu to plug into (for the sensors & what not) as it injection theres less wastege think someone mentioned on here.

Is there any other ecu bases to use other than megasquirt ?

Thankyou.

[minilee94]

to be honest I might just opt for an electronic dizzy instead off all the gaff of setting up a megajolt

[icklemini]

Cn this system be used on injection minis also or is megajolt carb specified ?

in the same way you can fit a 'proper' dizzy to an spi and leave the ecu to control fueling. . I cant see why you couldnt fit a megajolt to give you programmable ignition...

[rally515]

Cheers icklemini just planning for now so thought i'd take the oppertunity to ask .

[icklemini]

I cant recall the name bit there is a plug n play direvt replacement ecu for the injection minis.. am being a bit vague here as I dont know the full details...

[M44K TS]

Specialist components do the typhoon ecu kit for the SPI...

http://www.twinkam.c...aid=SC0127.001