Quadrajet vs. 4412

[Blackandblue3]

My division is a factory stock oval 1/4 mile metric gbody cars. Engines are 350ci 76cc heads 8.5 to 1 comp. Allowed to run a qjet or "stock" 4412. Pros and cons of both?

[Keith Morganstein]

My division is a factory stock oval 1/4 mile metric gbody cars. Engines are 350ci 76cc heads 8.5 to 1 comp. Allowed to run a qjet or "stock" 4412. Pros and cons of both?

That seems an unusual choice between those two. The 4412 should be easier for the driver to control. The Qjet will make more power.

[rustbucket79]

Any chance it’s a Rochester dual jet in the rule book?

Qjet would be killer with a good driver and careful tuning of the secondary air door spring.

[mag2555]

If Q jet you want one, or make one with the square notches in the air flap for the pull over tubes!
The big Q jet secondary's work better for a duel plane Intake.

[kimosabi]

4412 is a 500cfm? I'd just pick one and set it up for whatever it is you want it to do.

I LOVE a Qjet though. But do you need one? Do you need 750+cfm for this application?

[mag2555]

With a duel plane Manifold you should have a atleast a 600 cfm Carb if your looking to make 400 hp above 5000 rpm.
Remember the Q jet is vacuum secondary so it could be 900 cfm and it would not much matter!

[kimosabi]

Qjet is not really a vacuum secondary, the secondary air door above the butterflies can open whenever and how fast you want it to. Butterflies themselves open via linkage mechanically and progressively.

[Tuner]

My division is a factory stock oval 1/4 mile metric gbody cars. Engines are 350ci 76cc heads 8.5 to 1 comp. Allowed to run a qjet or "stock" 4412. Pros and cons of both?

You sure the rule isn't QJet or "stock" 1850? Use a QJet in either case.

[Blackandblue3]

Yes, rules are 4412 stock 500cfm or quadrajet stock. Both on cast iron gm intake. Most guys run the qjet but im hearing good things of the 4412 but im running against cars with alot more money under the hood so i cant afford to give up any gain i can get. Im a new guy and still learning!

[ZIGGY]

Are you and Phantomfab cousins?

[Ks Fats]

"Im a new guy and still learning" Based on this then I would say choose the q-jet. Don't take this wrong but most new racers don't have lap to lap consistency developed yet. A 500 requires a smooth consistent driver who doesn't have to lift much (if any at all) from lap to lap. I know your racetrack and it is called "highbanks" for a reason; lap to lap consistency and momentum wins races there; a q-jet will allow you to make those small momentary lifts sometimes necessary to settle the car and/or driver and have power to recover momentum. Not saying a 500 can't win races; they do everyday, they just require a different driving style . The adjustable air door on the secondary will allow you to tune the secondary opening rate to suit your driving style as it develops.

[Walter R. Malik]

It seems that a 4412 is allowed for those who haven't got the knowledge to tune a Q-Jet because there is really no contest here, unless it is merely for a totally stock engine which won't benefit much from a lot larger carb.

[Blackandblue3]

@ks fats do i know you? And thank you for the advice!

[Blackandblue3]

Are you and Phantomfab cousins?

Whats that mean

[tresi]

It seems that a 4412 is allowed for those who haven't got the knowledge to tune a Q-Jet because there is really no contest here, unless it is merely for a totally stock engine which won't benefit much from a lot larger carb.

I'm going agree with you on this. The 4412 is going to be much easier for the novice to tune and be easier to find parts.