Carb recommendations for a 454
Thread Starter
Safety Car
Joined: Jan 2001
Posts: 4,660
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From: South Central Louisiana
St. Jude Contributor
Re: Carb recommendations for a 454 (427Hotrod)
Thank you everyone for your post. I have learned alot so far.
427, I am glad you mentioned the no vac secondaries on a low vac engine.
I knew from the first day I bought my car I didn't have much vacuum. I wouldn't have considered a vac secondaries carb.
Now can anyone tell me the difference between a race demon and a street demon?
427, I am glad you mentioned the no vac secondaries on a low vac engine.
I knew from the first day I bought my car I didn't have much vacuum. I wouldn't have considered a vac secondaries carb.
Now can anyone tell me the difference between a race demon and a street demon?
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From: Corsicana, Tx
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Re: Carb recommendations for a 454 (oger)
I don't want to get into a battle over it. Everyone has their preferences.
Yes, a vacuum sec. carb can work great on race cars. They can also work great on street cars. They are "foolproof". That is why Holley and everyone recommends them. It's much easier to know that no matter what you put it on it will work pretty well. Saves them a lot of grief. Same with cams,heads etc. They always err to the mild side. It's safer. But slower! Also on a race car with optimum traction you can just "flatfoot" it and go. No matter what you do it will act the same. They will only allow airflow at a certain rate. But often times that rate is not correct for optimum acceleration. That's why DP's were invented in the first place.
My preference even on the street is to have full mechanical control with my foot. I can accelerate just as hard as I need to to control traction. No worries if the carb opened up or not. I can't count how many times I've watched dyno tests where the carb either opened super slow or never fully opened and killed power. Even with the lightest springs, no check ***** etc. Reach over and shove open the secondaries and watch it take off!
Yes, Holley made PV Dominators in the past. My point is that they are now advertising them with the combinations that would appeal to folks wanting to run them on the street.
I guess it all depends on what your strreet combo is.
Mine works great, and gets decent mileage considering what it is on.
The point is that if you want to stay conservative and run mild combos, then always use hyd. cams, 9.5 compression, iron heads, dual plane intakes, vacuum carbs and be happy with what you get.
If you want to outrun all those guys, adapt stronger technology to your application.
A double pumper carb can be an absolutely great street carb if done correctly. Set up well, it will spank a well set up vacuum sec. carb everytime. There is no reason for a mechanical sec. carb to get worse mileage or driveabilty. The only difference is how you operate the secondaries. IF you find that you are always ENJOyING the new power, then it's hard to complain about mileage etc. It's doing what you wanted.
No flames intended, I just like to try to help folks get the most out of their combos. I hate hearing of weak Vette's getting spanked by "lesser cars"!!
I'll let someone else talk about Demons. I'm not a giant fan of them. I can tell you of another Forum member with a 540" engine that we recently replaced the Vacuum 850 Demon with an 850 DP Holley. He had also been told that a DP is not good for the street. He was very much impressed with the driveability and most impressed with the new found traction problem he had as he tried to keep it straight! Trust me, if you can tune a little bit, you will NEVER go back!
Jim
[Modified by 427Hotrod, 1:06 PM 6/28/2002]
Yes, a vacuum sec. carb can work great on race cars. They can also work great on street cars. They are "foolproof". That is why Holley and everyone recommends them. It's much easier to know that no matter what you put it on it will work pretty well. Saves them a lot of grief. Same with cams,heads etc. They always err to the mild side. It's safer. But slower! Also on a race car with optimum traction you can just "flatfoot" it and go. No matter what you do it will act the same. They will only allow airflow at a certain rate. But often times that rate is not correct for optimum acceleration. That's why DP's were invented in the first place.
My preference even on the street is to have full mechanical control with my foot. I can accelerate just as hard as I need to to control traction. No worries if the carb opened up or not. I can't count how many times I've watched dyno tests where the carb either opened super slow or never fully opened and killed power. Even with the lightest springs, no check ***** etc. Reach over and shove open the secondaries and watch it take off!
Yes, Holley made PV Dominators in the past. My point is that they are now advertising them with the combinations that would appeal to folks wanting to run them on the street.
I guess it all depends on what your strreet combo is.
Mine works great, and gets decent mileage considering what it is on.
The point is that if you want to stay conservative and run mild combos, then always use hyd. cams, 9.5 compression, iron heads, dual plane intakes, vacuum carbs and be happy with what you get.
If you want to outrun all those guys, adapt stronger technology to your application.
A double pumper carb can be an absolutely great street carb if done correctly. Set up well, it will spank a well set up vacuum sec. carb everytime. There is no reason for a mechanical sec. carb to get worse mileage or driveabilty. The only difference is how you operate the secondaries. IF you find that you are always ENJOyING the new power, then it's hard to complain about mileage etc. It's doing what you wanted.
No flames intended, I just like to try to help folks get the most out of their combos. I hate hearing of weak Vette's getting spanked by "lesser cars"!!
I'll let someone else talk about Demons. I'm not a giant fan of them. I can tell you of another Forum member with a 540" engine that we recently replaced the Vacuum 850 Demon with an 850 DP Holley. He had also been told that a DP is not good for the street. He was very much impressed with the driveability and most impressed with the new found traction problem he had as he tried to keep it straight! Trust me, if you can tune a little bit, you will NEVER go back!
Jim
[Modified by 427Hotrod, 1:06 PM 6/28/2002]
