I use an optical reader from Honeywell, and I'm curious what the rest of the distibutorless guys are using. I'm looking to try something else because my current set-up has suffered damages from heat.

 

most systems use magnetic pickup, which is of course largely immune to heat.

 

Variable reluctance sensor, very immune though output falls with RPM decrease. Gives a zero crossing, a pseudo single sinusoid cycle per timing wheel groove.

Hall effect sensor, a little bit more problem with temperature, though very immune to noise. Nice squared timing edges. I prefer the Hall.

Regards,
BigMoose