1000-1200hp on 850cfm blow thru carburetor

Discussion in 'Engine Topic' started by phantom69, Jun 10, 2021.

  1. phantom69

    phantom69 Member

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    lookin at the screamin demon annular blow thru carb and im wondering if it can handle being on top of a procharger that may be flowing to push out to the 1000-1200hp range just curious..or is EFI the only option?
     
  2. 1980RS

    1980RS Veteran Member

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    I would not use a A/D carb with a Procharger as those boosters in that application are more of a restriction than help, down leg boosters would be a better choice.
     
  3. 1320feet

    1320feet Veteran Member

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    What fuel are you going to use?
     
  4. G72Zed

    G72Zed Veteran Member

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    What cfm is the carb rated for now?

    As an example, I’m building a 1000 cfm blow through for a Procharger 850-950hp ish big block Chrysler, and it’s going to use the Annular boosters, and, even though I’m a carb guy, I think he should go EFI, but he wants a carb!!!

    It was my understanding that the carb requires additional booster signal, and all the help it can get due to the use of the Procharger.

    Perhaps things have changed, maybe I’m lagging behind in this particular forced induction Procharger area. I’m a N/A fan.
     
  5. phantom69

    phantom69 Member

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    gas would be the fuel!
     
  6. phantom69

    phantom69 Member

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    how would annular boosters be a detriment with a centrifugal blower?
     
  7. Lowend

    Lowend Administrator. .a car, a man, a maraca. Staff Member Lifetime Gold Member

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    What size / type of engine is this?
    I'm not much of a carb guy - and the rules change with boost, 850CFM for 1000+ horsepower sounds light to me.

    Can you run a 1000 HP Procharged setup on a carb... yes. Is it optimum... no
    When running that much boost, timing and knock prevention become extremely important in not destroying the engine. The only real way to control these things in real-time is with an EFI setup and a knock sensor.
    You can make it work with a carb and conventional distributor, but need to use very conservative timing.
    Considering the blow-thru carb is going to cost ~$1000 by itself, and the costs of building an engine like this, the extra cost of EFI is pretty nominal.

    To be clear, I wouldn't attempt an engine build like this with less than $25K in the warchest just for the engine. Not to mention the rest of the drivetrain.
     
  8. 1980RS

    1980RS Veteran Member

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    2 same size venturi carburetors, one with A/D boosters and the other with down leg boosters. Even though they are both listed as 850's the one with A/D boosters will not flow as much as the other with smaller booster which is more of a restriction. I have 2 Mighty Demons that are like this, the venturi's and throttles are the same, recently I tested both the one with down leg boosters on my BBC is quicker and faster than the A/D carb.
     
  9. Rustbucket350

    Rustbucket350 Veteran Member

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    You can do it with one carb as long as its properly sized. Take my build for example. Holley 750 on a 366 flat bed truck motor with twin 50mm turbos. Will it flow enough? Absolutely. I intend on making a minimum of 800 hp and 1200 lb ft. Do I want to use an intercooler? No. Do I want to use methanol? Yep. Maybe I'll run it solely on alcohol. Who knows til I see what it likes.

    Is it possible? Sure.

    Ignore what people said about boosters. It makes zero difference since you'll probably be using an AFR gauge anyway. Honestly the Holley mechanical secondary style carbs are the best for any kind of blow through induction but you'll have to modify them after a certain point.

    A blow through (carbureted) forced induction setup is really not for the faint of heart or for anyone unfamiliar with tuning a blow through carb. It is a nightmare but it is possible.

    I plan on making my Proform 750 a blow through. Sure it was $700 but its worthless to me if it doesn't do what I want. I even called quick fuel with their forced induction carb and they said it maxed out at 9 psi. Why would I spend extra money when I'll still have to modify it myself? I plan on 20-30 psi. When it blows I'll make a 447 out of my parts. No loss.
     
    Last edited: Jun 11, 2021
  10. phantom69

    phantom69 Member

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    very sound words..i was lookin at a screamin demon specifically are you familiar with them? how would you feel about just runnin a dual 650cfm or dual 750cfm blow thru carb setup?
     

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