[2fast4love]

Hello everyone I'm a long time lurker here, this site is like a encyclopedia of hot rods. I'm building a 550hp 406, afr 210, 560 lift,240 duration behind a t56 and 410 gears. It's going into a 92 firebird, my dilemma is carb selection, I'm following a build on the afr website, shows 750dp, but when I called the original builders they recommended a hp950. I did research on hp 950 and found out they aren't exactly 950 so I'm at a lost. Can anyone help 750? Hp950? Dominator? Thanks in advance!!!

[2fast4love]

Anyone? Any help?

[GT23T]

Originally Posted by 2fast4love

Anyone? Any help?

Try this?

http://www.gtsparkplugs.com/CarbCFMCalc.html


If you input 406 cu in, 7000 max RPM, and a VE of .90, you get 907 CFM.

[blwn31]

Not to get off topic but, I hope you have a Viper T56 or an upgraded one. 550HP with equal torque won't do that trans any good.

Keith

[cobalt327]

Originally Posted by 2fast4love

Hello everyone I'm a long time lurker here, this site is like a encyclopedia of hot rods. I'm building a 550hp 406, afr 210, 560 lift,240 duration behind a t56 and 410 gears. It's going into a 92 firebird, my dilemma is carb selection, I'm following a build on the afr website, shows 750dp, but when I called the original builders they recommended a hp950. I did research on hp 950 and found out they aren't exactly 950 so I'm at a lost. Can anyone help 750? Hp950? Dominator? Thanks in advance!!!

The Holley HP series 900 doesn't flow 900 cfm. More- Holley 950 HP on my 406 SBC?.

That said, it will work fine on your engine once it's dialed in.

FWIW, BG carbs often didn't flow in cfm the numbers that were associated w/a particular carb, either. In at least some cases they went by the throttle bore and venturi diameter, really had nada to do w/actual flow. There was a thread that Tech @ BG and I 'discussed' this at some length but I can't seem to locate it just now...

[406 bug]

Originally Posted by 2fast4love

Hello everyone I'm a long time lurker here, this site is like a encyclopedia of hot rods. I'm building a 550hp 406, afr 210, 560 lift,240 duration behind a t56 and 410 gears. It's going into a 92 firebird, my dilemma is carb selection, I'm following a build on the afr website, shows 750dp, but when I called the original builders they recommended a hp950. I did research on hp 950 and found out they aren't exactly 950 so I'm at a lost. Can anyone help 750? Hp950? Dominator? Thanks in advance!!!

The holly 830 hp will work great on your engine.

[2fast4love]

Thanks everyone the t56 will be upgraded to viper specs to handle the hp.

I do believe I've stumbled upon that post with the bg tech
So by 830 you mean the "950"? I only have one shot at the carb want to make sure I get the right one. Thank you for your help again!

[starnest]

For a 4 stroke engine:

CIDxRPMxVE/2456=CFM

Divide by 2456 to account for 2 revolutions of engine for one intake of air/fuel, and dividing by 1728 to convert cubic inches to cubic feet.

As for the carb numbers actual flow, I know there are lots of factors, I always assumed they were rated at STP. Perhaps a carb engineer could explain.

[eloc431962]

Originally Posted by 406 bug

The holly 830 hp will work great on your engine.

X2 I'm running the Holley HP series 830 on my 400/408 and it works just fine. I don't know of any other carb i would put on mine . JMO



Cole

[2fast4love]

Im looking into the 830 right now, found a demon 850 for a good deal? Any advice?

[2fast4love]

Anyone?????

[PRO 48 fleetline]

750 is allllll you need.
Im running a 750 mighty Demon on mine they flow 830 just right and your combo is similar to mine!


By profleetline at 2011-04-16

[2fast4love]

What are you running?

[PRO 48 fleetline]

Originally Posted by 2fast4love

What are you running?

11.6.1 mahle forged flat tops
scat crank and rods internally balance
lunati solid roller 243/249 @.050 595
1.5 harland sharps
comp rev kit
210 profiler heads from chad speiers
2.08-1.60's
hurricane intake also ported by chad
1" hvh carb spacer
msd billet dist. With 6al
melling select pump 7 quart pan
cloyes billet roller chain
rossler t 400 3,800 neal chance
narowed 9" 4.56 with a 4 link

[barry425]

If your 950 Holley is a 3 barrel, then stay away from it. 950 cfm is the correct size for your engine, as long as it is a 4 barrel. A smaller carb (830 or 850) will run great and have more torque at lower rpms, but run out of power over 6,000 rpm. Bottom line: If this is a drag car go for the larger carb (950 cfm) since you won't be spending much time at lower rpms. If this is mainly a street machine, go with the 850 cfm carb since most of the time you will be under 6,000 rpm.