I'm thinking that since a 3 bar map sensor will read about 2.9 volts at 11 psi of boost , one doesn't need to run a VAFC in order to run DSM 450 cc injectors. YOu could just replace the stock MAP with the GM 3 bar and voila... you've accomplished the same thing that turning down the fuel compensation -50% on the VAFC does. Am I wrong?

 

Dont have time right now to explain it, but it wont work. The voltage at atmospheric wont be low enough. The 3bar map is basically just cramming more reading into a small voltage scale, whereas the vafc hack justs shifts the entire voltage down.

 

So are you saying the VAFC hack changes the intercept of the voltage vs pressure curve not the slope and the 3 bar MAP sensor changes the slope but not the intercept? I'm not sure if this is correct because if the VAFC just knocked 2 volts off the peak MAP sensor output then at 11 psi it would read 3 volts but at 20 inches of vaccum it would read zero volts! Anyone else?


[Modified by filetofit, 10:24 PM 7/4/2002]

 

bump

 

I think it must be just a smaller scale across the board; the voltage difference between 1psi and 2psi is smaller on the GM than on the Honda MAP...

Somewhat related...did you ever get those rail-rail opamps? Any progress on that project?