yeah i know its been beaten to death but here's my ?

VAFC and no FPR - can you add more fuel than stock?

my impression is that u can add fuel that you took away with the VAFC, but you can't add any more than stock at a given point.

please edumacate me

 

You can add fuel and subtract fuel. But, in my experience, it is not as consistant as when you subtract fuel. Hence why we all suggest using a AFPR and the V-AFC. There is a point where you can add additional fuel and it makes no difference, but I forgot where I ran into that.

Jason

 

vafc will help tune in increments as far as your fuel maps..but u need fpr for primary fuel pressure.

 

I think you can add it to a certain point, but after you max out the map, it won't add anymore. I would say buy a FPR, rise the pressure and then use a VAFC to lean it out where it needed.

 

I think you can get about 10% more fuel in most cases. Basically watch your vacuum reading at WOT once it reads 0 that is the limit of any more fuel increase as the MAP signal can't be modified any further. So increase fuel in small increments until the Map signal is basically 0. that should be the limit of the fuel increase.