How much mph did it pick up switching carbs ?12.920 with tuned 750 dp with proform main body, 12.082's with QFT 950 constistantly no other changes. Motor was 9.5:1 466 with DOVE's with 2.245/1.8 valves and comp294S with tired valvesprings and Stealth intake. The motor was my street bracket motor for 7 years in my mustang that ran [email protected] spinning for first 100ft. Had over 500 passes on it.
As you can see now, those calculators are crap! Experience gives the best info. Our Fords like bigger carbs than most other brands anyway.wow, guys when i'm able to start making wide open tuning passes i'll put my vac gauge on it and check to see if there is any when i run it ! i just checked on a carb calculator and it said 750cfm for street use 850cfm nominal and 950cfm for racing ! i'm only going to twist it about 6000 rpm unless it wants more.
I agree with Dave. The problem with most of the carb calculators is they are assuming ~80%ve and some of todays intakes are close to 100%ve. If you imput the correct ve(volumetric efficiancy) then you will be very close to perfect size assuming all other info is correct.Those calculations are not crap they are intended to give you a carburetor that's sized to give about 1.5 inches of Hg at max RPM for a 4 barrel and 3 inches for a 2 barrel. The reason for this is because it virtually guarantees that the carburetor will perform well under all operating conditions not just WOT.
Making the carburetor smaller will slow you down less than you might think.