Autosport Labs

I have a Megajolt Lite I built last summer from the current kit for a 4 cyl. car. The car is on hold while I build up a motor for a boat I just bought. This engine is a NA BBC Dart block and heads, 509 cu in. Can I use this box on my new motor? I realize I have to get a V-8 coil and V-8 EDIS, but I assume that the VR sensor is the same?

Also can I use the 36-1 hole method for the trigger wheel? I can have that milled into the crank pulley during assembly by my engine shop. Due to circumstances I have a very good Vertex magneto to use, but I think I using my MegaJolt would gain HP, TQ and some altitude compensation using MAP sensing.

This boat will be used on Western lakes from 300 ft to almost 4000 ft and is pretty heavy at 5000 lbs so will need a lot of power. I am hoping for a reliable 600 HP on 91 pump gas and digitelly mapping the ignition will help civilize this.

Essentially, yes- the MJLJ is designed to work with 4, 6 or 8 cylinder engines- just use the appropriate EDIS module. Our installation guide shows the appropriate wiring for these applications. VR Sensor and coil packs are the same.

For the trigger wheel, so long as you create a wheel with the appropriate "teeth" profile (expressed in holes) you will be fine. Thing is, to know for sure you would need to measure the signal with an oscilloscope to ensure it has the same signal pattern and strength as a typical Ford ignition wheel. Barring that type of equipment, if you make the profile as close as possible and it seems stable with your engine, you will likely be OK.

Keep us posted on your project- it would be great to see a boat in the "Powered by" Section!

Don't forget the the vr sensor should only be 50 deg ahead of the missing tooth on an 8 cylinder and not 90 deg like on a 4 cylinder.

Will a Chevy V-8 start and run on the Ford limp-home mode to get going, or does anyone have a base map for a Big Block Chevy? Or a small block for that matter. I just don't know if the firing order of the Ford is different than the Chevy. Also, would the Boat run better with TPS or MAP? Will MAP allow some automatic alteration of timing when going from Havasu @ 340 ft to Powell @ 3600 ft or will I need to make two maps? I can just solder up another box if TPS is better (my current one is MAP).

Hello-

Most any engine will run on the fixed 10 degrees the limp home mode offers, so you should be fine there.

You should stick with the MAP sensor, as a TPS configuration is more suited towards engines with multiple side-draft carbs, where it's difficult to get a MAP reading. Since you're likely running a single downdraft carb, you should have no problem tapping into a spot on your manifold to get the stable vacuum reference you need.

Beyond that- the factory default MAP on the MJLJ should get you going for tuning. It's fairly conservative, yet we've received good feedback on it as it stands.