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Thread: 2 circuit vs. 3 circuit dominators?

  1. #1
    Senior Member EXPERT BUILDER
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    2 circuit vs. 3 circuit dominators?

    i was wordering if anyone has done a (box stock) comparison with a 2 circuit vs. a 3 circuit dominators at the track?how much diffrence in quarter mile times?any other info???


    i have a 3 circuit on my car(transbrake installed with 9 in converter) and it runs reeeally rich on part throttle.i have an aem air to fuel gage and ordered air bleeds,so i can tune a little,but was wondering if im just better off converting to a 2 circuit cause i do drive on street to car shows a few times.how much will i loose on a low 9 sec car,and expect to run mid 8's with a 250 shot right off of transbrake(i have a retard box)..thanks !!!

  2. #2
    Senior Member RACING JUNKIE jmarksdragster's Avatar
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    I have a pair of 9377 non-HP 1150's I plan to test, one converted one not, I believe the 2-circuit will be cleaner at launch all else equal and should make it quicker. I can tell you the 1250 HP I converted will go from idle to wide open cleanly and when traction is good will repeat the #'s. I ran 4- 5.08's in a row at the last Orlando 1/8 mile race. What model is you Dominator and is it an HP or not?
    Mark Whitener
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    model 80556 dominator three circuit.i believe it is a hp carb.any other thoughts???

  4. #4
    Senior Member RACING JUNKIE jmarksdragster's Avatar
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    I am currently running an 80533 1250 that was converted, you won't be unhappy doing so. Try removing the intermediate air bleeds altogether and change the MAB's to 25, that should help a little. The closest to a comparison I did was going from an old style 9375 to a half converted 8896, primary only, and picked up .03 the next round. It was a day race and getting warmer. Instead of finishing the 1050 I used the blocks to mod the 1250 instead. I have one 1150 changed over and the other one clean to build stock, just haven't had time to finish and test. An O2 system like the Innovate is a good investment if you can spring for it.
    Mark Whitener
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    Good work isn't cheap, and cheap work can't be good.

  5. #5
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    IM RUNNING AN AEM AIR TO FUEL RATIO GAGE.AT TRACK WITH NO EXHAUST,IT DOESNT REGISTER...BUT STREET DRIVING IS WITH BULLETTS(HOMEMADE-ITS QUIET)

    HOLLEY ADVISED AGAINST RUNNING WITH NO AIR BLEEDS IN ITERMEDIATE,BUT MAYBE ILL TRY IT BUT ONLY ON STREET WHERE CAR DOESNT SEE MUCH ABOVE 5000 RPMS ANYWAY...

    LET ME KNOW WHACHA THINK...

  6. #6
    Senior Member RACING JUNKIE jmarksdragster's Avatar
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    Thats funny, I have an old style 9375 that came from the factory with no brass bleeds pressed in the holes and was built that way on purpose. One of the best working out of the box 1050's. I saw a jet chart at a well known carb builder, some of their 1050's had no bleeds either. It is not a complete fix, but will tell you if you are going in the right direction. The reason to convert to a 2-circuit.
    Mark Whitener
    http://racingfuelsystems.myfunforum.org
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    Good work isn't cheap, and cheap work can't be good.

  7. #7
    ok, I have working on this issue, the 3 circut carbs are designed to run on a trans brake only leaving flat on the floor(they don't tell you this in the specs) but if you try to leave part throttle(like we were doing) it runs like crap. the carbs have a extra circut for dumping fuel assuming you are already past the accel pump shot, so after talking to holley tech modifyed my 3 circut and made it a 2 circut and works great...Rob

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    Senior Member RACING JUNKIE jmarksdragster's Avatar
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    Quote Originally Posted by ezstriper
    ok, I have working on this issue, the 3 circut carbs are designed to run on a trans brake only leaving flat on the floor(they don't tell you this in the specs) but if you try to leave part throttle(like we were doing) it runs like crap. the carbs have a extra circut for dumping fuel assuming you are already past the accel pump shot, so after talking to holley tech modifyed my 3 circut and made it a 2 circut and works great...Rob
    While you went the right direction, 3-circuit carbs were not designed nor do they work well with transbrakes either unless you lean the 3rd circuit way out and fix the t-slots. 3-circuit Dominators were designed for IR manifold apps and also help with 4 and 6 cylinder apps where there is a lot of manifold pulsing. Here is some good reading material if anyone is interested.

    http://speedtalk.com/forum/viewtopic.php?t=9934
    http://www.motorsportsvillage.com/fo...pic.php?t=3283
    http://www.motorsportsvillage.com/fo...pic.php?t=3742
    http://www.motorsportsvillage.com/fo...pic.php?t=3811
    Mark Whitener
    http://racingfuelsystems.myfunforum.org
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    Good work isn't cheap, and cheap work can't be good.


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