Is a double pumper "better" then a VS carb ?
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Is a double pumper "better" then a VS carb ?
I feel my car should be quicker then it is now with the 750VS Holley I have. I used to have an Edelbrock 750 that just felt a lot quicker. Do you guys think a doulbe pumper would give me any gains at all ? Thanx
Joined: Mar 2000
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
In theory, when either a 750 DP or VS carb is wide open, they should flow the same and therefore make the same power.
In reality, every side-by-side comparison I've seen the DP makes more power.
Go figure.
The conventional wisdom is to a use DP for manual tranny, VS for auto.
The other part of the conventional wisdom says use a DP if your setup can handle the WOT mash at the line without bogging. If not, then use a VS. To back that up, I know 4 fast guys who run out at Bandimere, all 4 have auto trannies, all 4 use DP Holleys. Of course, they have loose torque converters to go with their race-only setups.
In reality, every side-by-side comparison I've seen the DP makes more power.
Go figure.
The conventional wisdom is to a use DP for manual tranny, VS for auto.
The other part of the conventional wisdom says use a DP if your setup can handle the WOT mash at the line without bogging. If not, then use a VS. To back that up, I know 4 fast guys who run out at Bandimere, all 4 have auto trannies, all 4 use DP Holleys. Of course, they have loose torque converters to go with their race-only setups.
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From: NY, NY
Spend some time with the carb before tossing it. Whick secondary spring are you using? The white/yellow spring will open faster but may drown the motor with a tight converter. What do your plugs look like? if they are black it is a pretty easy call. A DP will make more power on the dyno, but may not be faster on a street car. FYI, I run a 1250 Dominator on the street, but it took some time to get it tuned right. Dan
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A good friend let me borrow his 850 DP. It has annular boosters, jet extensions in the back and it's currently jetted with #74's up front and #78s in the back. It runs better at WOT but getting it to idle correctly, starting on the first key or stop dieseling is another story... 
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From: Homestead, Fla
Originally posted by five7kid
In theory, when either a 750 DP or VS carb is wide open, they should flow the same and therefore make the same power.
In reality, every side-by-side comparison I've seen the DP makes more power.
Go figure.
In theory, when either a 750 DP or VS carb is wide open, they should flow the same and therefore make the same power.
In reality, every side-by-side comparison I've seen the DP makes more power.
Go figure.
I run a Dominator and a double pumper on my two cars, both on the street, so you can guess which one I like. However, I agree that you shouldn't ditch your VS just yet. It should still show a healthy gain over the Edelcrock, you just need to spend some effort in tuning it.
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