I know the "pills" are chips for the built in rev limiter, but does anyone know what they are? are they just resistors?, or are they some kind of special diode or transistor?

Thanks-

Eric

 

They're just a resistor. You can buy an adjustable one to plug in.

The problem with the MSD pills and them being resistors, resistance will change with temperature. From a cool morning to a hot afternoon inside a car, the temperature can change the resistance enough to make them relatively inaccurate. Since the majority of us bracket race, inaccuracy doesn't win races. If all you're using it for is a high end rev limiter, you shouldn't have a problem unless you're continually bouncing off the limiter. Using them in RPM switches, shift lights etc is where accuracy is needed.

Many people are switching to the digital ignitions systems that don't use pills. The digital systems are not affected by temperature changes as much if at all.

 

thanks, any Idea of the resistance values? I assume low resitance=low rpm limit, any Idea where 6000 rpms would lie? I just can't justify spending $30 on a pack of 5-6 resitors!

 

0 rpm's = 0 ohms. 6000 RPM's is just under 4600 ohms, IIRC.

I've got a detailed chart somewhere when I was doing RPM's my SB2. I'll see if I can find it.

The pills themselves are actually pretty easy to modify with a couple bucks from radio shack and a solder gun.