I'm completing the build of my MSI on V3 board and have a couple questions.

At the moment I will be running Spark only, NO FUEL, we're running a Holly 650 carb. I'm building the FC CAS and Coil Packs into this car.

I've read the FAQ's but still have 2 hopefully quick easy questions.

1. Can someone repost the Schematic for the Dual LM1815 setup?

2. On the coil output signal circuits (Squirt, Warmup, Accel) do I need to change the 2N3904BU component for the VB821ZFI as used in the High Current Ignition Driver?????


That's it, hopefully someone can answer these fairly quick, as that is all I need to know to complete my build and get the car running this coming week, well that and have our engine builder replace the Apex seals.

Thanks,

Matthew Kogan
JMC Motorsports
San Diego, CA

 

1) I didn't realize it was gone, I'll repost when I get home from work.

EDIT: I just reposted it.

2) a) On all my megasquirts, it's not a 2n3904bu, it's a 2n2222a, and you don't need to replace it.

b) Just put in the 4.7kohm pullup resistors from +5v to the negative leads of the LEDs, and run the coils also from the negative lead of the LEDs.

Ken

 

So those circuits are being used exactly as they are and not utilizing the "High Current" circuitry at all.

Ok. No another simple question, what happens to the functionality of those cicuits if I choose to go Fuel Injected at a later date? Do they retain their original functionality as well, or do I loose that? I'm guessing I lose the origanl function of those circuits once I'm setup in FC Trailing Spark mode.

 

yeah, those LED's are used for spark, they don't retain their original functionality. But they're still useful as you can use them to tell if the MS is actually trying to fire spark.