I do have the Summit RPM switch which I will swap out whenever I have the time. Until then, I'll just stick with the Harlan. I'm not sure if it's just my Harlan, but I found out it's not very accurate. When I set it to 5000 rpm, the light on the Harlan didn't blink and the actuator didn't activate until 5500 rpm. I want it to activate at around 5200-5300 rpm. Anyway, I played around with it more. I tried 4800 rpm, it worked. The light turned on and actuator activated at 5300 rpm. Anyone else noticed this or is it just mine? Not sure if it had anything to do with my bad running at the track. I originally had it set at 5400 rpm, so it probably didn't activate until 5900 rpm. So, is it just me? I hope the Summit RPM switch is more accurate.


Btw, where are you guys activation point? Which is best?

 

I have 3 Harlans (2 years old now) and they're both precise and accurate with both one another and my SAFC II. I do know that our tach lags compared to the real rpm especially in low gears. Try activating the Harlan in a higher gear to see if it matches the rpm you want it to activate at.
-hype

 

Where is your harlan connected too? Coil or tach wire? I have my switch over at 5100 RPM's, and my tach reads around 5000-5200 when the VI opens. Also I have my shift light set to 6300 RPM's and it lights up when the tach reads about 6500 RPM's.