Visit The Dirt Forum for More Information

Author Topic:   q-jet or holley 4412
marksracing
Dirt Forum Racer

Total posts: 79
posted July 05, 2004 09:42 PM  
WITH ONE DO YOU RUN AND WHY ????????

neil rucker
Dirt Forum Champ
Total posts: 799
posted July 06, 2004 09:43 PM  
the quad is definitely got the potential (with tuning) to make better power and throttle response than the 4412. ive heard stories for years from other racers about the q-jet starving in the corners as well as other problems. on the other hand, when i was a kid in high school everone thought a quadrajet was better than a holley any day. the reason was simply because no one knew how to tune one. 2cents worth

speedyd1
Dirt Maniac

Total posts: 170
posted July 07, 2004 06:50 AM  
the qjet will obviously produce more power simply because of the greater flow potential.
it will need to be set up properly to function. its gotten a bad rap all these years because it was more complicated that the holleys'and most people just didnt understand it. the qjet was designed to only provide as much fuel and air as the motor required at any particular rpm. once you get into it and learn a little bit about it, you should blow away those guys running the 500 holley. there are lots of good books out there or you can buy them built from most good performance carb shops.

crc1124
Dirt Maniac

Total posts: 143
posted July 08, 2004 09:56 PM  
With more parts in the q-jet aren,t there more possibilities for failure? The biggest problem I've had is the pump sticking wide open. It happened to me twice on a 72 chevelle street car. I almost wrecked it because I had trouble stopping. I prefer the simplicity and parts availability of the Holley. Besides if your setup isnn't right you won't run well anyway

[This message has been edited by crc1124 (edited July 08, 2004).]

ryan
Dirt Forum Champ
Total posts: 776
posted July 08, 2004 10:15 PM  
I run a quad and I beleive it is better than a 4412 if your quad it setup right. Quadrajets a very finicky it doesn't take much for them to get out of whack. I don't have any experience with the 2 barrel but if you are just starting out it might be easier to maintain. JMO

racin2much
Dirt Full Roller

Total posts: 46
posted July 08, 2004 10:17 PM  
Quad hands down. Read up on them and learn them, we don't even run Holleys in the unlimited class and win alot. Everybody keeps telling us how much better we could do with a Holley, but how much better can you get than first? JMO.

crc1124
Dirt Maniac

Total posts: 143
posted July 09, 2004 12:40 PM  
I guess either you love them or hate them. I'm no carb man by far I just had bad luck with one on a street car. I don't know anything about tuning a quad. What do you guys think about the demon carbs? They just came out with a 2 barrel for racing. Anybody ever run a predator carb? Those look real interesting but are illegal at most tracks. Are the rochester dual jet carbs worth messing with ? We have to run a 2 bbl. in our class. I would like to learn as much about carb tuning as I can. Is there any web sites you guys would suggest as a learning tool?

Speedway65
Dirt Freak

Total posts: 344
posted July 09, 2004 12:59 PM  
If you have to run a rochester 2bbl you need a 2 jet not a dual jet carb.Duel jets were on 231 buick motors.

crc1124
Dirt Maniac

Total posts: 143
posted July 09, 2004 04:35 PM  
I told you I didn't know very much ,lol. I'm trying to learn that's why I ask so many questions.

bigcityracer
Dirt Freak

Total posts: 431
posted July 09, 2004 07:29 PM  
The best I could tell you is what I due. And that's pay about $200 to $325 for a race ready carb. Run with no problems for three years and have them freshen the carb. Lots of fun with out the problems.

udecide66
Dirt Freak

Total posts: 229
posted July 09, 2004 10:01 PM  
The new Demon two barrels are awesome, just bolted one on a friends car.
I believe myself to be a good 4412 carb guy, as soon as I tore into the new Demon 2 barrel I was sold, no modifications needed, like a stock 4412 needs, demon has it all done.
The next best carb I have worked on is the Keith dorton series 2 barrels, has the same modifications already done that is needed for a circle track carb, downfall is they are $500
For the best bang for your buck I would buy the Demon carb 2 barrel($300),I run a Demon 750 on my Mod, no problems and easy to tune.
I have never played with a quadrajet, but I am sure they are good carbs if you know how to tune them and troubleshoot, but for the "not so mechanically inclined" sort of racer I would stick to a simple reliable carb.
Stick to my "K.I.S.S." theory
"Keep It Simple Stoopid"

[This message has been edited by udecide66 (edited July 09, 2004).]

snowman
Dirt Freak

Total posts: 241
posted July 09, 2004 11:24 PM  
WHICH ONE DO YOU RUN AND WHY???????


Curious question......Simple answer, RULES.......For the most part, guys running either of those carbs are doing so because the rules require them to do so......Usually, chosing between the two is not an option......(quad wins of course)

The 4412 is a very common "spec" carb for two barrel classes.......

The q-jet is often required for 4 barrel stock classes......

With few exceptions, if given the option of a holley double pumper or even a 3310, Most racers would not even consider the Q-jet or 4412.......However, as racin2much has already mentioned, the quad can perform great properly set-up.

Speaking of Carb Experts, I, (snowman the great), am a carb expert.....I know everything I need to know about carbs......
OK, OK, I don't know jack about carbs. But,I know KP's phone number.....and thats all I need to know........LOL He builds a great quad (thanks KP)and the 4412 as well. My KP quad has out run alot of big buck Holleys.

Good Luck,
snowman


rico 08
Dirt Forum Champ
Total posts: 1139
posted July 11, 2004 08:31 AM  
I'm running one of KP's Q-jets on my car,reason being i was intending on running some enduro races that require it..ending up running it in the pure stock class that allows single line holley carbs,i think it's just as fast as long as the secondary air valve is adjusted for the motor/track.Only gripe i have is if the track is super rough it will sometimes flutter off the corner but it's rare.

o5racer
Dirt Freak

Total posts: 402
posted July 12, 2004 08:43 PM  
I have ran both the 4412 and the q-jet on my car in the last couple of years. The 4412 idles much better and is a bit smoother in the lower midrange but it doesent have the top end or flat out grunt the the q-jet does.

marksracing
Dirt Forum Racer

Total posts: 79
posted July 12, 2004 11:57 PM  
how can i get a kp q-jet

snowman
Dirt Freak

Total posts: 241
posted July 13, 2004 04:57 AM  
607-277-6462........Kinetic Performance...He is a forum sponsor, You can click on his banner and see his site.....contact info there.....

Good Luck,
snowman

KPLugnut
Dirt Forum Champ
Total posts: 1019
posted July 13, 2004 07:58 AM  
Thanks for the support, Snowman! You're great!
Yep, we help out where we can around here on the forums.

email is the best way to reach me during the daytime (kineticperformance@thedirtforum.com), since with a day job, I'm away from the shop phone all day (but feel free to leave a message there and we'll call ya back).

We have a few quads in stock, but none are built ahead of time for 2 reasons: First, I'm too busy all the time to get that caught up where I could do any carbs ahead of time, and secondly and most important is that we build each carb specifically for that customer and their engine.

thanks,
Dayton Umholtz, co-owner
Kinetic Performance

hobby10k
Dirt Freak

Total posts: 226
posted July 14, 2004 08:35 AM  
well I have been wondering about those demon 2 brls myself. sounds like they are good carbs. the only question I have is there a place to fine tune them, set them up for circle track and get more than 500 CFMs out of them? I would like to find a place to send my carb before I get one. thanks

hobby10k
Dirt Freak

Total posts: 226
posted July 14, 2004 08:37 AM  
well I have been wondering about those demon 2 brls myself. sounds like they are good carbs. the only question I have is there a place to fine tune them, set them up for circle track and get more than 500 CFMs out of them? I would like to find a place to send my carb before I get one. thanks

iowatoolman
Dirt Freak

Total posts: 369
posted July 16, 2004 12:58 AM  
i have been watching the demons and they are going to be releasing a rs series 2bbl that sounds like the setup to have. it can flow upto 725 cfm (sounds good for a 2 bbl carb if you need more you can goto c&s specialities they have a 2 bbl that flows 890 cfm) come on bg release the rs series 2bbl i am waiting!!!!!!!!!!!!!!! go fast or go home

KPLugnut
Dirt Forum Champ
Total posts: 1019
posted July 16, 2004 08:32 AM  
Keep in mind, that C&S themselves have admitted that in reality, the "890" only really flows about 720cfm on an "honest" flowbench.
Remember, cfm ratings are for advertising purposes and bragging rights only....

the real winners are the carbs that get to their max flow the fastest...

JMHO...

KP

PEDDLER
Dirt Freak

Total posts: 446
posted July 17, 2004 01:47 PM  
I'll have to second Snowman's recomendation...
KP's carbs work really well. We have a 750 alky and a 4412 (Peddler & Rockit) thats been done by him and they are great.

[This message has been edited by PEDDLER (edited July 17, 2004).]

stockcar5
Dirt Forum Champ
Total posts: 578
posted July 18, 2004 02:17 PM  
we did some dyno testing last week and we switched between a dorton 500 and a c&s 890...we gained 35hp and the numbers held alot stronger in the upper rpm range with the bigger carb. the nice thing i liked about it was that the fuel trim numbers were real consistant from idle up to 7000rpm.


luke

------------------
www.geocities.com/dirtstockcar5

Kent
Dirt Maniac

Total posts: 102
posted July 21, 2004 10:34 PM  
I have run both the 4412 and the qjet and both carbs have their place. For a wet tacky track the qjet is superior and for the dryslick track I like the holley 4412. Doing your homework and reading up on these carbs is the only way to maximize their potential. I bought a $20 qjet and reworked it myself after doing alot of research and minor modifications to the secondary hangers and selected the proper metering rods and am really impressed with it. The secret to the holley is knowing what your intake manifold vacuum is so you can get the proper power valve so it will dump enough fuel when you need it under wide open throttle condition. Good luck!

iowatoolman
Dirt Freak

Total posts: 369
posted July 22, 2004 12:28 AM  
try a power valve eleminator and jump up about 6 or 7 jet sizes it helps on WOT
and you don't have to worry about power valve sizes or blowing out

stockcar5
Dirt Forum Champ
Total posts: 578
posted July 23, 2004 03:24 PM  
we flow benched 3 carbs weds. night and they flowed as follows.

all carbs @ 28inches of water..

stock dorton 4412...490cfm
modified 4412 1 3/4 throttle plates... 550cfm
c&s "890"...680cfm

luke

------------------
www.geocities.com/dirtstockcar5

    

Back to the Archives