Having spent a fair amount of time with carbs in the last 7 years I have found out a few things relevant here. Lets assume the pump can supply the volume the engine needs, and enough pressure to overcome g-force. The biggest restriction is almost always the N&S, and the biggest source of having fuel aerate on the bowl. When fuel aerates it makes delivery thru the jets inconsistent, so jetting has to be made larger to cover the inconsistency. This is bad for power. With smaller N&S's you have to try to force more fuel thru, so you increase the pressure. This makes aeration worse. I use .128 N&S on gas 4150's, .140's on Little Bo and Dominators on gas and on all E85 carbs. For methanol I jump to .164's. The second restriction point to address is the regulator, and this can be as bad and in rare occasions more restrictive than the N&S. When I started running E85 I put a new regulator on at the same time. The car ran out of fuel before the end of the track, once I put the old regulator on all was well.

I currently run a large port Magnafuel Regulator, It has supplied enough fuel to run 4.90's in the 1/8 at 5 psi with methanol. You need volume at the lowest possible pressure to minimize aeration. The following videos made by BLP show the reality of it. First is a .150 N&S, second a new design bowl with a N&S around .250.Pressures are 5 psi with the .150, at or under 2 psi with the new design. And the new design has been in the 6.70's in the 1/4 at under 2 psi.

https://www.youtube.com/watch?v=PehQUKwQX8E

https://www.youtube.com/watch?v=FOJKcvTKQAg

No, that was an idiot calling his subjective guess "science".

And it was 60 years ago - 200 mph was done in 1960 by Karamasines.

http://www.4secondsflat.com/BLP%20N_S.jpg

Has anybody tried these? I wonder if they help.

EDIT: Just seen where BLP has these too.

Either BLP makes them or 4 seconds flat and BLP gets them from the same place. Probably available from other sources if BLP isn't making them in house.

Stick with a standard N&S, .140's work well and will supply a lot of fuel. Bottom feeds don't flow as much for the same N&S size.

I bought a 2007 spitzer dragster from Rick Forish (general manager at Spitzer race cars) When I showed up to pick it up I noticed it had a holly blue fuel pump on it .I jokingly asked him if he was trying to pull a fast one and where was the good pump. He then took me over to his brand new car fresh off the jig and showed me the fuel pump on it holly black.

my car went well into the 6ixes when rick had it (holly blue). I had it go 7.18 (holly blue)

He was at the us nationals when his bg 400 failed him for the third time and all he could find was a holly blue he switched it out at the track and went well over 200 mph (same performance as bg 400)

I have never changed a fuel pump and gained performance do to it being too small. If its plumed properly a 110 pump will go a long way.

Today I have a run a Aeromotive mechanical pump driven off the back of the dry sump pump (use to run alky) however just to prove a point we dead headed -6 lines out of the regulator and put my 1200 alky dominator on a b1572 and it worked fine with a a-2000 pump.

most running out of fuel problems at the big end is do to pi$$ pore pluming rather than fuel pump being too small.

Sit down with a good fuel system company like Aeromotive and design a good system plumed properly and you will be surprised at how small of a pump you can get away with.

Even though we dead headed a system to see what would happen I think all systems should be bypassed out of the regulator back to the tank,after I went to this design my fuel gauge was thought to be defective do to it being so steady. On the race pak graft it is almost a flat line.

one more thing -8 coming out of a pump = -10 feeding it to combat cavitation (very important)

I have to agree with all the plumbing comments above. I still use a Carter race pump on my Savoy with -10 inlet and -8 out to 1/2" hard line to the dead head Holley regulator.
Car has been 10.91 at 125 with a 3.54 gear
I still have a hard time spending $300 on a pump that I don't need

Gus

Hey Thumper,

What's the difference between Quickfuels 34-100 and 34-101? 101 shows "Special fuel chute fuel technology" 100 is $101. 101 is $175. Will the 34-100 get the job done?

Never used the "chute" ones and can`t imagine needing to so I`d just get the regular ones myself..........

Cool. Thanks. Running dual 850's on a sheet metal intake. Never thought that the carbs themselves would become a source of fuel restriction. Thanks for the heads up.
If I can get one more piece of free advise from you: How important is it to mount the regulator up front. Never did that before, but then again, I never ran as fast as I plan on running this year.

Most of the tunnel rams have em mounted up ft. which just makes sense and even non t-ram carbs do the same although mine`s mounted on the inlet lines hanging on the pass side.......

I've run six packs and dual quads before with the regulator to the side of the carbs/motor, but like I said, I don't know how much G force plays into the equation as the cars potential speed increases.

Apparently it`s important, just look at Pro-stock or other fast classes and I cant remember NOT seeing em mounted in ft.except on a few occasions.......

Mount the fuel regulator in front of the front fuel bowl so the high pressure from the pump doesn't get reduce before the needles and seats on the front fuel bowl

FWIW, I think this has been a great thread/subject. Lots of knowledge and experience has been thrown around here. This is why I joined Moparts in the first place, and I'm glad that I can participate in it from time to time. Thanks to everyone here.

I have the fuel chute bowls on my carb and as Thumper has said they do look like they can flow more fuel than other bowls I have seen.
Gus

The 100's have a 7/8-20 Holley standard thread, the 101's have 8AN boss fittings. Otherwise they are the same.

Couldn`t agree more and I`ve learned and applied info from here and other sites and learned AND am learning every day which is awesome for all of us..........Thankxx to all who participate in these posts and hopefully it will continue and we can ALL grow together in this awesome sport/hobby we enjoy.......

I know I'll be putting on dual relays as well as lowering fuel pressure slightly. Probably go to a .130 N/S too.

Sure has been a lot of great info in this thread for sure! It sure would save some money to just do a few things to what I have and make it work. I would be really pissed if I dumped 600-700 bucks into something I did not need!