Guys,
I know there is a sticky and that there have been other threads regarding verification of actual timing vs what is indicated in spark timing table in your XFI, Big Stuff, chip etc. and I hope I'm not being redundant but I wanted to share the results I found on my current car.
The car has been a race car for years and has an XFI with a distributor setup. I have been going thru double checking things and decided I should verify the timing. I decided to start at the begining and see if TDC on the balancer was correct. I put a piston stop in the #1 cylinder and found true TDC. The mark on the balancer was off by 2 degrees.
Then I put the XFI in diagnostic mode that locks the timing at 25 degrees (or whatever you select) and used a timing light only to find that the reluctor ring was off by another 3 degrees. All told the timing was retarded by 5 degrees. Needless to say once I adjusted the reference angle to account for the disparity the car runs much better. If you have a BHJ balancer and haven't done this you might want to check this out.
Neal
