Carter AFB tuning

[Shollt]

I'm trying to locate arnolt.com/articles/carterafbtuning.pdf . The web tells me its not available or been renamed or there's trouble with the site.
I'm running a sbc 350 modified with an Edelbrock 650 AVS 1806 that has poor throttle response.
Thanks
Tom Sholl

[Skip Fix]

Where is the poor throttle response ? Off idle, part throttle and nail it , WOT

[Shollt]

Skip Fix:

My sbc 350 has an Edelbrock air gap manifold, Comp roller cam and a Edel 650 thunder series AVS carb. This combination of manifold and performance cam is alleged to give the 650 carb problems off idle to cruise. I've drilled out the idle channel restrictor from .055 to .058 with little improvement. My Innovate A/F monitor still indicates 15 to 16 A/F idle to gentle acceleration. Installed a Carter street fuel pump in place of a Delco stock pump. Delco was 60 gph Carter is 120 gph. Fuel pressure now holding about 6 psi. Engine has AFR 180 heads 9.8 C/R 4.11 rear and 2004R 4 speed. Car weighs 3200 lbs. Feel car is under performing throughout all speed ranges. Haven't had opportunity to go through the gears since the fuel pump change. Did have fuel delivery issues with Delco pump.

Tom Sholl

[MonzaRacer]

First of all, put the accel pump rod in hole closest to carb mounting, giving max squirt travel, dont worry if it bottoms out thats what the spring is for inside on the pump.
Next sometimes you need to verify the passages that link up to the upper part, and make sure your floats are at least level or tipped down opposite the pivots with top upside down gasket on. If your using the banjo fitting this will really mess with the fuel feed. Best deal is the fitting that Earls or Russel sell that screws in remove the stock filters and use a remote one and redo the line to the carb, 3/8 only and you may need some small amount of good braided steel line (preferably teflon lined ). Another liitle issue I have seen is the transfer passage to opposite side of carb can be blocked. One model allows the use of a long bit to clean it out the other you will need a speedo cable and drill. And yes you can take the swedged in seal on opposite side if it has one .
Oh and make sure the passage under the needle seats ar drilled all the way into the passage.
Good Luck
Lee

[Skip Fix]

Idle screws fatten up the idle AFR any? Idle circuits blend into the accelerator circuit as well as main circuits cruising. A lean idle circuit can affect part throttle.

What vacuum at idle? Softer springs in the primaries may be needed to allow the rods to kick up on the taper easier. There are also different rod tip and total OD that can fatten it up also. The rod/jet combination may need to be bigger too, smaller rods or bigger jets. That also affect idle circuit some.

The owner's manual should have a chart for different combinations for you.

And like he said be sure the acel pump is in the closest hole. They do make different acel pump nozzles but I don't know too many folks that have had to use them.

[Socrates]

Did the car actually have better throttle response before the carb/intake/cam/etc swap, that is, did you drive the car with factory parts for a baseline to compare? It may very well be that, 1) it's not the carb but your distributor that needs tuning in your case, or 2) that your shiny new "go fast" parts have left a big hole in your low RPM power band that you'll never get back no matter how much you tune. Just a thought...

I've always had to use the max pump shot on Ebrock carbs to work properly on all of my cars, as well, street or track. The Ebrock AFBs only go on my driver vehicles now, and my high performance vehicle get more tunable/adjustable/better carbs (Q-jets, Thermoquads or 950HPs...).