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Midrange and low RPM grunt. Discuss please.

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Old 11-09-2014 | 05:05 PM
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Ok time to kick tires
502 mag
bravo 1 drive
want to still do tubing
stockish reliability
Cost effective
800 holley
Plug and play no machining
Msd ignition and distributor
496 exhaust
which head intake combo?
Bob madera cam only
87 octane

Last edited by stimleck; 11-09-2014 at 05:16 PM.
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Old 11-09-2014 | 05:43 PM
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Does anyone have any back to back dyno data on a 650-800HP N/A engine, comparing the numbers from a 4150 to a 4500 Dominator carb?

Something to consider also. The modern Dominator from Quickfuel, or Holley Ultra HP, are not your fathers Dominator. 25 years ago, a guy slapped a dominator on a 230HP 454 Truck engine and had bad results. Therefore everyone thinks Dominators are for 700ci 1500HP engines. You can get a modern Dominator carb to idle like a champ, meter fuel like a champ thruout the RPM band.

I've seen back to back dyno tests on a 500HP small block, where a 950 carb made more power(not drastic but around 8-12HP) than the 650 and 750 carbs it replaced, and gave up NOTHING from 3000-6500RPM as far as torque output. I dont know what it would have done at 1900RPM, but I wouldnt care, unless of course we are talking car street engines or tow rig engines.
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Midrange and low RPM grunt. Discuss please.-34948551-957-holly-1050-dominator.jpg  
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Old 11-09-2014 | 06:25 PM
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The 950HP was around 830cfm. Give or take afew.
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Old 11-09-2014 | 06:32 PM
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Originally Posted by stimleck
Ok time to kick tires
502 mag
bravo 1 drive
want to still do tubing
stockish reliability
Cost effective
800 holley
Plug and play no machining
Msd ignition and distributor
496 exhaust
which head intake combo?
Bob madera cam only
87 octane
That's damn easy. Even heavily modded motors built for I/O's can go tubing.

Black or Blue reliability ?
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Old 11-09-2014 | 06:43 PM
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Originally Posted by Black Baja
I agree 850 with a 4150 is no problem but you are going to sacrifice some up top to gain down low with the smaller carb. Depends how your gonna run it. That's how I would size a carb.
This is the where I benefit from owning a SuperFlow dyno. I use my air turbine(s) to see exactly what size carb a motor needs on it. You would be surprised how small of a carb you can get away with and not loose power.
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Old 11-09-2014 | 06:45 PM
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Originally Posted by stimleck
Ok time to kick tires
502 mag
bravo 1 drive
want to still do tubing
stockish reliability
Cost effective
800 holley
Plug and play no machining
Msd ignition and distributor
496 exhaust
which head intake combo?
Bob madera cam only
87 octane
Depends on budget.
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Old 11-09-2014 | 06:47 PM
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Originally Posted by Precision
This is the where I benefit from owning a SuperFlow dyno. I use my air turbine(s) to see exactly what size carb a motor needs on it. You would be surprised how small of a carb you can get away with and not loose power.
Thats what I have heard, I have 800cfm Hp500 carbs now, what can those be good for? some guys say I can hit my goals with them, some say not... what is average end for those?
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Old 11-09-2014 | 06:59 PM
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Originally Posted by Full Force
Thats what I have heard, I have 800cfm Hp500 carbs now, what can those be good for? some guys say I can hit my goals with them, some say not... what is average end for those?
You will need bigger carbs for a 540 Tim. Keep in mind those 800's don't flow 800 CFM.
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Old 11-09-2014 | 07:11 PM
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Originally Posted by Full Force
Thats what I have heard, I have 800cfm Hp500 carbs now, what can those be good for? some guys say I can hit my goals with them, some say not... what is average end for those?
This is where it usually goes wrong. "What size carb do I need for X". You can always get close using simple math, but there are variables that will show up only on a dyno. If the engine builder degreed the cam wrong, or preformed a poor valve job you can be given the illusion that you need a larger carburetor than what you actually need. This is why dyno tuning an engine is so important. Not only do you get the air fuel ratios, but you can also see how much air the motor is consuming as well as the brake specific air and fuel consumption numbers. If I have a unknown combo I usually start with a larger carb and work my way down.


I had another builder rent my dyno for a day not to long ago. The first motor that he was running was a 406 SBC that is suppose to make 650HP. Now, I could tell by looking at what heads were on the motor that wasn't going to happen. After a few pulls he was asking if our dyno read high or low compared to others because it was only making 480HP. One look at the volumetric efficiencies and the BCAC numbers I could tell that a large percentage of the air going through the carb wasn't staying in the motor. A leak down test confirmed that he botched the valve job therefore the motor wasn't generating any cylinder pressure.
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Old 11-09-2014 | 07:13 PM
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Originally Posted by Precision
This is where it usually goes wrong. "What size carb do I need for X". You can always get close using simple math, but there are variables that will show up only on a dyno. If the engine builder degreed the cam wrong, or preformed a poor valve job you can be given the illusion that you need a larger carburetor than what you actually need. This is why dyno tuning an engine is so important. Not only do you get the air fuel ratios, but you can also see how much air the motor is consuming as well as the brake specific air and fuel consumption numbers. If I have a unknown combo I usually start with a larger carb and work my way down.


I had another builder rent my dyno for a day not to long ago. The first motor that he was running was a 406 SBC that is suppose to make 650HP. Now, I could tell by looking at what heads were on the motor that wasn't going to happen. After a few pulls he was asking if our dyno read high or low compared to others because it was only making 480HP. One look at the volumetric efficiencies and the BCAC numbers I could tell that a large percentage of the air going through the carb wasn't staying in the motor. A leak down test confirmed that he botched the valve job therefore the motor wasn't generating any cylinder pressure.
Well, we will have to have lunch when you come here and have some good discussion.... I am able to limp around a little now lol
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