I am thinking about getting a MSD dis 2....what else do I need? where have you mounted it? anything else I should know about the dis 2?

you will need the tach adapter for your tach to work.

Terry

No you won't.

I have a DIS 4, no tach adapters. The "tach adapter" is just a high wattage resistor to trick the ecu into thinking its still triggering the coils directly. it keeps a CEL away, that is all.

Really..what size resistor so i know not to spend the extra cash.....

Terry

any ignition amplifier will have a high input impedence (resistance across the coil pack terminals will be very high), mainly because it isn't interested in drawing current from the ECU, it's just looking for the signal so it knows exactly when to can generate it's own spark.

the ECU will notice this high impedence, and it will say "wow, the coil packs aren't drawing any current. something must be wrong. CEL!"

i tried to duplicate the MSD 8912 tach adaptor. i bought one myself, i put in a lot of effort.

it's not just a resistor. as far as i can tell, it has a capacitor and a diode in there somewhere. it's also potted (filled with epoxy) so you can't take it apart to reverse engineer it or else you will destroy it.

i think it has a relay in it too. when i fired up my new ignition system, i heard a few things clicking. the DIS box will click, and the tach adaptor clicks too.

i guess it would be possible to try to make your own, not sure if it will work or not... the impedance of the coil pack (NOT the resistance at the terminals that the spark plugs go to) would have to be known, and the impedance of the MSD DIS-2 would also have to be measured. a voltage divider circuit would have to be designed and conscructed, where most of the current would go through a resistor to ground and a little would leak through to the DIS-2.

i know that the 8912 tach adaptor gets HOT after about 15-20 minutes. almost too hot to touch. there's some real current going through that thing.

how did you get a dis 4 to work on your car?

Originally posted by Journeyski
how did you get a dis 4 to work on your car?

Just like a DIS 2. I only use two trigger inputs.