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Author Topic:   holley 500 or quadrajet?
Dirt Freak

Total posts: 417
posted November 09, 2002 09:03 PM UIN: 13209501
Supposedly we are going to have the option of either running a quadrajet or a holly 500 cfm 2 barrel next year. Which one would be better? We run a 9:1 compression 350 with stock manifolds, intake and exhaust. I know they let a few people try them out last year and they didn't seem to run any slower with the 2 barrel. What are the pros and cons of each. We run on a 1/2 mile track and turn slightly less than 6000 rpm. Thanks.


Dirt Forum Champ
Total posts: 620
posted November 10, 2002 12:47 AM
anytime i had a choice over a 2bbl. or a 4bbl., i'd choose the 4bbl. a quadrajet can be an excellent carb, if it's set up right. i think throttle response should be better with the q-jet because of the smaller primaries and it will certainly have longer legs than the 2bbl.

Dirt Forum Champ
Total posts: 1565
posted November 10, 2002 08:58 AM UIN: 54865418
myself the only thing i would put a quadrajunk on is a junk pile i have never had any luck with them on anything i was fighting with them for yrears on my pick up and took the **** thing off put a rochester 2 brl on it and haven't had a carb problem for 4 years now. and i have raced in a class that was a mix of 2 and 4 brls and never seen any advantage to the guys with the 4 brls.

Dirt Forum Racer

Total posts: 80
posted November 10, 2002 03:28 PM
Did you know that if can tie enough Q-jets together that they make a pretty good boat anchor. lol

Dirt Freak

Total posts: 408
posted November 10, 2002 08:32 PM
Both the previous posts probably never had a quadrajet that was specifically built for racing. We do them all the time and can guarantee they'll open your eyes wide.
As far as the original question goes, if given the choice, and the proper things are done in the motor from cam to heads, intake, etc, a quadrajet that is built right for racing will always make more power than a 4412, especially one that has to remain stock.
Quads most commonly will flow about 750cfm. Some that were from big blocks will flow 800cfm.
There is no stock 4412 on the planet that will flow that much, let alone have the flexibility (i.e. variable cfm flow based on the needs of the motor) that a quadrajet has.
The fuel curve in a 4412 is NOT set up right from the factory for feeding a typical short track motor.
Now, before you get the idea I'm slamming Holley here, the positives are that the 4412 is more easily tunable, tends to be cheaper and easier to find and easier to rebuild. It also will be easier to tech (guages are available, as opposed to having to make them for quadrajets).
The idea, probably, behind what is happening there is the track is probably trying to standardize the rules more and make them easier to tech as well as cheaper (yeah, right)!

Hope that helps,

Dirt Newbie

Total posts: 3
posted November 10, 2002 08:33 PM
OutlawStock is right. Quadrajets are an excellent carb. Only problem is that it takes more than a weekend parts changer to get them set up right. They are a very precise carb and have many adjustments available for fine tuning. Parts such as jets, metering rods, etc. are not as readily available as the Holley parts, but they can be found. I have always leaned towards Holley, but in your case on a 1/2 miler, the 4 BBL may prove useful.

Dirt Forum Champ
Total posts: 620
posted November 10, 2002 09:22 PM
dang! it took you guys long enough to back me up!

i've seen SS/Eliminator cars with q-jets run 10's in the quarter mile and i've seen a guy win a factory stock championship with a q-jet when everyone else had a holley 600 or 750 vacuum secondary.

what you don't know WILL hurt you!

Dirt Freak

Total posts: 417
posted November 10, 2002 09:22 PM UIN: 13209501
Well in our case the reason behind considering the 2 barrel is that most of the other tracks around here run a 2 barrel holley, so they are losing a few cars that don't wan't to swap carbs and intakes every week, and the carbs don't have to be stock.


Dirt Roller

Total posts: 10
posted November 23, 2002 06:28 PM
i can build a quadrajet for you.

Dirt Full Roller

Total posts: 44
posted November 24, 2002 05:01 PM
On a 1/2 mile track you might be better off with a Quadrajunk. All our tracks around here are near 1/4 mile length. There I prefer a 4412 on engines without headers,
the throttle response off the corner will rip your head off, also very easy to jet at the track.....Have you ever had the top off a Q-jet changing meetering rods or jets and they call for your feature to line up, If so you can forget making it.....LOL
We have turned 7500rpm (by accident) with a 4412 on a Limited Mod with a 355 , so the air is there......

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