Die Hard Edel AFB (Performer) Fan - May have to use PIPPED Holley now...
Good comments on the "Quadrajunks" - the design is a decent reliable one frequently overlooked, even though they have more than sufficient fuel enrichment systems and are available all the way up to 795CFM, IIRC. As with most of their products, I'm sure the Edlebrock manufactured version is even better than the originals, just like with their AFB line.
I have been an AFB
freak since I put the first on on one of my heaps ten years ago. Available in 600, 750, and now a new version with adjustable secondaries at 800, the design is robust and most importantly very tolerant of overcarburetion. Since it doesn't have really mechanical
or vacuum secondaries, but an on-demand arrangement you can safely put on a big enough carburetor without worrying about carefully matching the normal air flow resulting in stumbling and other problems (which is critical with the Holley design.) Basically, you pick an AFB up out of the box, whether 600, 750 or 800, plop it on anything from a stock Mopar 318 to a Caddy 501 to a higher end 413 small block and the SOB fires up and runs great with
no further adjustments. You just can't do that with a Holley design. I don't even do anything with the choke other that wire it full open - and it starts fine in the abominable 30 degree Dallas "winters." :L
Adjusting them is super easy and quick and there are no parts to screw up or gas to drain all over yourself. Nor have I ever had one leak. As there is no "power valve" enrichment portion, a backfire doesn't make most of your carb cease to function as it does with an unimproved Holley.
Many complain the AFB's two sidemounted fuel bowls, as opposed to the fore and aft ones on a Holley design, are better for the g-forces on straight line acceleration but can run out under hard cornering. I have yet to observe this, but always used the spring loaded "off road" (four wheeler) needle and seat setup instead of the stock ones or the high flow ones - plus I set the floats at the top end to 1/16" higher as the AFB design does not flood too easily.
Bear in mind the Carter AFB and Edelbrock Performer are essentially the same thing and many components are completely interchangeable - the Carter uses three step metering rods instead of two step, but they work in either. I think Carter is a wholly owned subsidiary of Edelbrock now anyhow.
The new AVS line from Edlebrock (Adjustable Vacuum Secondary) offers an additional adjustment to bring them in earlier or later than the preset draw-through force and counterweight arrangement of the typical AFB. They also all have dual fuel lines, unlike the regular AFB's which commonly have this as a modification. I have not used one yet.
Holley designs come in three big generations, with even more improvements between them than the AFB-Performer-AVS evolution. Ignoring the super high flow Dominator Holley design, the basic stock Holley is still probably the most common and available from 500 to 850 CFM with several options on number and size of fuel metering systems, accelerator pumps and external fuel distribution (single line, double line, etc.)
Barry Grant came out with a new Holley design, just like Edlebrock did with the Carter, and it incorporated a number of design improvements everone did to Holleys anyhow - especially power valve protection and externally adjustable float and some mixture adjustments (without requiring disassembly.) I believe they label theirs as Road and Street Demons for the regular Holley design upgrades and King Demon for the Dominator version, but I am not sure. I have not used any of them yet, although this may shortly change as my new engine (we dyno TOMORROW! YAY!!!) really needs a lot more flow than my old trusty AFB can provide.
Holley got tired of Barry Grant decimating the sales of their own design, so they came out with their own improved line - the Avengers. The Street Avenger is the only one I have any passing familarity with, although I understand their is another one also. They have all the built in upgrades to the original Holley design. I have heard good things about them, but not had any first hand experience.
Their are also a number of almost custom made carbs which have even more effective metering, flow sensing, etc. Some advertised are the DaVinci and Predator lines. The problem with some of these is the price approaches a decent entry-level aftermarket EFI system.
I am at the point of maybe having to switch from my dependable, easily adjusted AFB's since the simulators all agree with my engine builder - showing I run into max flow around 6KRPM with the new mill - and that's at optimum. I might go with the new AVS and all the flow straightener gadgetry (like the "stubstacks") which at least gives me a ceiling of 800...but an improved 850 Double Pumper from either Holley's new line or Barry Grant's might be just the ticket.
Whichever system you pick, you should be able to learn it's peculiarities and get what you need out of it - and for $500 or less - a lot cheaper than a $1250 EFI system to do. exactly. the. same. thing.
BTW, how come
every car
I have uniformly gets 10MPG when every one
else has a top fuel dragster that gets 17/21 highway?!?!?!?!
