Deamon vs Quickfuel Carbs

Knebel

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I have been doing a lot of reading up on Carbs lately and i came across two possible candidates for my mild 360.

First is a Street Demon 625cfm with the tripple stack boosters,
Second is a Quickfuel SS 650cfm with Annuel Boosters

I'm so fed up with my Carter AFB and it's little quirks all the time (perfectly Adjusted and then a couple days later its all C.R.A.P again... It stalled on me today in the middle of an intersection, Idle AFR goes out of whack all the time, Choke has its on mind and has been adjusted to death.... and let alone the flooding in fast curves..i swear that thing is possesed tho:BangHead:), anyways,
I look for something what stays in tune and gives a good mileage and I want to only buy one time instead of an EFI System. I like the Idea of the Annuel Boosters in the Quick Fuel which is supposed to give really good Fuel Atomization which the Demon does not have, therefore the Demon has smaller Primaries and "Triple Stack Boosters"... I also look for something tuneable into the last notch (screw in airbleeds prefered ect.)

I read that the Quickfuel has a killer throttle response and is almost as good as EFI. I was wondering what your Peoples thoughts are on this?

Demon is about $350 and Quickfuel is about $550...is it worth it?
 
The Quickfuel stuff seems to be getting raved about a lot. Personally I haven't used one. I have used Demon products several times. I would not buy any Demon. They are very good carbs, but (still) suffer from poor machining, and even porrer cleaning before being boxed up. I've had to clean off "hanging chads" of aluminum in side the metering blocks, finish drill passages, clean metal filings out of them (every one I've had suffered from that issue right out of the sealed box). My advice - get the Quickfuel, or get a Street Avenger Holley for it.
 
I think most of us have been down that road with carters, that's how I ended up with a holley that is now a antique itself, I have a new fondness for eddy thunder series which I previously stayed away from because of their similarity to carters but have had good luck with them.
 
Three of my friends swear by the quick fuel carbs. All are drag racer hobbiests.
 
Already some good advice here, thank you! Now, i dont want to drag race, i was hoping to squeeze a little more than 9.5 mpg out of it too but its fine as long as it wont decrease haha its a daily driver, sorta....

I just saw that the quickfuel with the annular boosters has mechanical secondaries and is basically a double pumper, the one with the vacuum secondaries dosent have annular boosters. What has a greater effect on fuel economy? I hardly ever floor it, unless I HAVE to.

And yeah, that carter is just very annoying. I adjust the choke perfectly. That day it starts fine, the next day it dies on me 3 times 10sec after startup before it keeps running... the other day it starts and runs at 500rpm while it should be 1400. Aargh!?
 
I have a Mighty Demon 850 with annular boosters, easy to set up, holds a tune fine. I like the 4 corner idle setting and the sight gauges to set fuel level. I didnt find any shavings or anything like some of the horror stories I've read about.
 
I was looking at the street demon which is like a thermoquad/edelbrock mix. But i really like all the little jets to mess with at the quickfuel! :)
 
I have a Mighty Demon 850 with annular boosters, easy to set up, holds a tune fine. I like the 4 corner idle setting and the sight gauges to set fuel level. I didnt find any shavings or anything like some of the horror stories I've read about.

I have a 650 demon on my Pantera. I have never set anything but the idle. Great carb in my experience.
 
So, the quickfuel with the annual boosters comes with mechanical secondaries.... does that have any negative effect on driveability? I really like all the tuning options on it but I battle with "annual boosters and mech. Secondaries" vs "downleg boosters and vacuum secondaries"
 
Annular boosters discharge the main circuit air / fuel emulsion from typically eight (8) or more discharge holes in the booster whereas, a down leg booster discharges the air / fuel emulsion from one.

Annular boosters are greater in area and mass and therefore reduce the total of CFM. How much depends on the specific annular booster.

Annular boosters are more sensitive to the metering signal allowing a better tune and with a cold / cooler intake track will make more horsepower.

Annular boosters typically deliver smaller fuel droplet size which provides a number of benefits. An engine with a hot intake may make less horsepower when using annular boosters, but may still make more torque across the curve.
(plagiarized)
 
The annulars are more sensitive and the double pump carbs tend to do better with a booster that works better with slower airspeeds. The vacuum carbs don't usually come with them because by virtue of the vacuum controleld secondary don't have an issue with lower airspeeds like a mechanical secondary. Personally I steeer away from mechanical secondary carbs if this is primarilly a street/cruiser car.
 
I read a lot that the vacuum secondaries are better for a street car cause they are more fuel efficient. That seems odd to me because with the mechanical sd. I have control over when they open, and with a 40% linkage i dont see the issue. The vacuum secondaries open when the engine wants it and not when i would want them to open, right?

How does the annual booster and its ability to atomize fuel better affect the fuel efficiencey? Is that neglectable because the efficiency of the annual boosters is negated by the mechanical secondaries? The best would be annual with vacuum seconds i guess... but thats not availabe unfortunately.
 
From reading a little more, I guess the Quick Fuel SS 650 Annular Double Pumper for almost $600 would be overkill for what I do with it. I think i have decided against the Annulars and will look for a Carb with vacuum secondaries. What I really look for and whats a MUST on my list is exchangeable Air bleeds and Idle feed restrictors and Power valve restrictors ect. That seems to come with billet metering blocks which most all of those carbs have...

Now another thing, whats the benefit of a 4 Corner Idle over 2 Corner Idle System?

My Carter mainly gives me problems at Idle (wont hold a freakin tune, one Day its my set AFR 13.5:1, the next it runs at 12.5:1 the next it runs at 16:1 and if i tune it again its all off again if i have the Car parked for lets say an hour, the Idle is ULTRA lean and the car dies after pulled out of a parking spot) and in the lower cruise speeds going over 50mph and flooring it is not an issue, also I discovered yesterday that there is a delay with the accelerator pump i cant get rid of.
 
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