I am not worried about gas mileage i want performance. Now secondaries that use vacuum to open.
Race Vs Street Carbs Picking The Right Carb For Your Motor
Vacuum secondary vs double pumper. Double pumper manual secondaries. Or in actuality lack of vacuum. S15v8 this sport takes 2 balls. In summary mechanical secondary carbs are much more sensitive to engine size drivetrain gearing vehicle weight and rpm range compared with the controlled secondary configuration which is why. Discussion starter 1 may 19 2009. I have a 750 holley vacuum secondary in my streetstrip truck.
Mike is right on the money. Vacuum secondaries vs double pumper. If the vs carb is more reliable much better gas mileage more driveable around town it probably would be better for me. You floor it they open vaccum secondaries secondaries operated by primary venturi vacuum different from manifold vacuum it is the same as the signal that pulls fuel into the primaries it increases in proportion to air flow through the primaries. Have a fairly stock 351c with holley 650 double pumper. My wife is very sensitive to fuelexhaust smells.
I was hoping not to sacrifice too much performance. Not on a dyno. Thus if you are puttering around with a double pumper and stay out of the secondaries it should get the same fuel economy as a vac secondary assuming they have the same size throttle bores primary jetting and idle mixture qualities. Jump to latest follow 1 19 of 19 posts. If there isnt much difference ill go with the dp for the power. Would a 750 vacuum secondary be a little more friendly to her at idle and normal driving rpms.
I have a 650 and an 800 avs. I drive it maybe once a week around town but bring it. First there are no differences in the primary sides of a 750 vac secondary and a 750 double pumper holley. Leaned the carb up a bit. Vac secondarys generally get better economy and are better street carbs while the double pumper is better for the track. Tuned it with a narrow band o2 sensor.
Marlan davis author jul 29 2019 holley type vacuum secondary carbs are more forgiving compared with mechanically actuated double pumpers. Relatively few vacuum secondary carb sizes can be made to. This is primarily a street car i know that the double pumpers are worth about 10 hp over the vacuum secondary but how is drivability. They are same and work the same and if you dont get the secondaries open will get the same mpg.
Gallery of Vacuum Secondary Vs Double Pumper
