I have a chipped P28 that has a VAFC II connected to it as well. I used to have a B16, and the digital read out on the VAFC would say im at 4000 rpm for example, but when i looked at my tach it read about 3700 rpm... So i thought that my EK cluster was slightly off since the VAFC is wired into the ECU it must the correct reading right? Well i recently swapped a JDM B18C-R into my Civic and also swapped a JDM ITR cluster into it as well. Well i hooked up the P28 last night, and it seems that the cluster is off by around 300 rpm again! The weird thing is that when i had the JDM ITR cluster in, everything seemed to be right on.

Any help with this?

Dc2

 

I dont think the honda clusters are as accurate as an aftermarket tach, or in your case VAFC. I dont think you should worry much, but if you need the very accurate rpms i would look at the vafc and not the cluster.