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Megajolt mapping logic check
r1_pete - 18/7/12 at 07:02 PM

I just want to check my logic, I'm mapping the megajolt on my 4.2 jaguar engine, starting from scratch as there is nothing out there to clone.

I have taken the initial and centrefugal advance curve from the stock distributor, and mapped that to the maximum load, figuring that regardless of load, RPM is RPM and the centrefugal advance will behave the same whatever the load.

I then added the vacuum advance to the initial and centrefugal advance, and used that for the minimum load curve.

Finally creating the values in between to create a smooth 3d map.

I know it will need some tweaks, but can anyone see any faults in the logic? all other mjlj maps I've used I have started with a downloaded map from a similar spec engine.

Cheers.

Pete.

John P - 18/7/12 at 07:22 PM

Can't comment on your logic but I did find this on line:

http://dl.dropbox.com/u/8496016/S1%204.2LVacuumStock.zip

It's supposedly a map for a Jaguar engine. I don't have anything to open it but you may want to check it out.

John.

MikeRJ - 18/7/12 at 11:05 PM

quote:
Originally posted by r1_pete
I know it will need some tweaks, but can anyone see any faults in the logic?


No logic faults, this should get you up and running to a reasonable level pretty quickly. However you will effectively be configuring your Megajolt to emulate the inherently compromised timing that a mechanical distributor limits you to.

Nickp - 19/7/12 at 06:37 AM

I'm going to do the same when I MJ the twin cam my Montecarlo, but mine's even simpler with no vac advance. This will give me a base map to get me to the rollers, which can then be tweaked to get the best out of it.