Can anyone tell me if different brands are interchangeable? I have some MSD pills and some Autometer ones. They have the same prongs and I think they will work, but I just thought I would ask . . .

Thanks

Check their resistance with an ohmmeter, if the resistance is the same then the rpms wil be consistent from one pill brand to the other.If not, find out what resistance equates to what rmp and go from there...

Thanks.

The MSD 3000 RPM pill measured 1.887 KOhm, the Autometer 3000 RPM pill measured 1.897 KOhm. I think that's going to be close enough . . .

It sure is....This also means you can "make" your own rpm pills....

Just the other day, I was looking for a pill for my shift light. I needed a 5800 rpm pill, and all I had was 6000 6200 6400 and a few up in the 7000 and 8000. So I started measuring the resistance values of the 6000 series pills and immediatly saw they were increasing by approx. 200 Ohms for every 200 rpm increase. The 6000 measured 1.67K Ohms, I grabbed the 8k pill since my 540 will never see those Rs., and dug out the rtv they use to pot the resistor and removed it. I stuffed it with a 1.441k Ohm resistor and now hope it puts me in the ball park at 5800.

It would be great if maybe you guys could post some resistance values for different rpms Or some how come up with the data.

I was thinking a potentiometer across the pill would cover any rpm you desire.

Rich

here ya go graemlins/thumbsup.gif

http://members.aol.com/blownf1/pill_rework.html

Oh for cryin' out loud! :rolleyes: All they are is stinkin resistors?! I don't think I'll ever be buying another RPM pill again . . . A trip to radio shack and you can build your own super custom 6356 RPM pill for about $.50 :eek:

Thanks again.

[ 08-05-2003, 04:15 PM: Message edited by: Eric68 ]

How do you think the Super Stock boyz do it :D j/k. But yes, they are just resistors...get a pontentiometer in the range you want and you can change your RPM at whatever you want right from the dashboard........