Somebody school me on Dominators

[Royce]

2 circuit vs 3 circuit..   What applications are each one the better choice, and what are the basic differences.. I acquired an older 1150 3 circuit cheaply  Jewel in the rough or PITA?

[blykins]

A 2 circuit Dominator just has an idle/transition circuit and a main circuit. 

A 3 circuit Dominator has an extra intermediate circuit.  That circuit is based off of little tubes above the throttle blades.  When the throttle blades open, it adds fuel. 

In a lot of cases the 3 circuit Dominators are hard to get right on street cars and in most race applications.  Most of the carb builders I know prefer the 2 circuit carbs, although a good carb guy can make a 3 circuit carb run ok. 

Some of your really high end carbs can be 4 circuit or 5 circuit. 

[Barry_R]

Older carb?
Plug the third circuit and tune from there.

[gt350hr]

  .3rd circuit was added for drag cars held wide open on gear shifts ( Pro Stocks with planetary transmissions) to help when the RPM pulled down from 9500-10,000 to 7.500 or so.

[Royce]

It's a 9377  will the intermediate circuit be obvious when I remove the metering block?

[Royce]

Wild guess on how much to jet up when removing the 3rd circuit?

[blykins]

Does it have a power valve in it?

[Royce]

It does not... The metering block is not drilled for one...

[Barry_R]

  .3rd circuit was added for drag cars held wide open on gear shifts ( Pro Stocks with planetary transmissions) to help when the RPM pulled down from 9500-10,000 to 7.500 or so.

Some of the old school Cup stuff used third circuit to fill the hole when rolling back up from corners when all the other circuits were "used up" at half throttle or better.

[gt350hr]

    Especially when the "tuners" at the track removed the secondary accelerator pump arm for better fuel mileage. ( top secret trick in the day)

[Barry_R]

    Especially when the "tuners" at the track removed the secondary accelerator pump arm for better fuel mileage. ( top secret trick in the day)

Like old drag racers that would set up the primary pump with a bunch of free slack at idle so they could get the pump shot at higher RPM where they launched...

[Falcon67]

Like old drag racers that would set up the primary pump with a bunch of free slack at idle so they could get the pump shot at higher RPM where they launched...

This is current school, not old school LOL.  Have mine set to contact the arm around 1800 RPM, I stage at 2000~2200 usually.  If on a two step over 3000, you're kinda past all that pump shot stuff.  No two steps in Footbrake.