my SAFR is about 500 RPMS off of what the tach displays, i connected it to what other people connected it to which is the crank or camshaft indicator i don't remember exactly but its what i found in the forums, which everyone is connecting too.

my question is how can i correct this?

 

The Tach isn't always accurate. It all depends on which of the two has a higher sampling rate. Call HKS and see if they know the sample rate. It should be 400hz at the minimum. If I engineered it I wouldn't use anything under 16,000hz. But that's me. If it's a really low number then chances are the AFR is experiencing quantizing errors. If it's a higher number than 400, my money is on your tach being off.

 

thanks

 

Didn't someone say to switch it to the 2 cylinder setting on this unit ...to get it in sync with stock tach. I thought I read something like that on this...could be wrong

 

Yep. I have the S-afc II on my evo and it is on 2cyl. The rpms will match up. I even called Apexi to confirm.

 

Strange... I just install SAFC II on my car and I have the setting set to 4 cyl. The rpms match or at least close to match the car RPM.

So should I set to 2 cyl or use 4 cyl setting?