OK, after much searching and reading, I understand how the VAFC hack works, how to set it up and it's drawbacks. My question is - you work out the correction to dial in based on the size difference between your stock injectors and your new ones, right?

So, on a 95 H22A (stock injector size 345cc), running, say, 450cc injectors, the correction should be (345/450)-1= -23%. Right?

So why does everybody seem to run corrections in the -35 to -40 range?? or is that just on B/D16s with smaller stock injectors?

My other questions are:

Does anybody know how to work out the relationship between MAP voltage, how the VAFC corrects it per % of correction, so I can work out the limits of this setup compared to max boost pressure? (eg at 5 psi, x % of correction represents 3.2 Volts MAP voltage (or whatever the max is before ECU throws a CEL)

How much timing advance would you get with corrections in the -25 to -20 range? I'm presuming less severe than at -40ish?

Yes I KNOW there is a fantastic thread archived about the VAFC hack, but the pics of timing / fuel maps on it are down and the explanation doesn't really make much sense without them!!

 

Anyone?

 

Bump