CARB SIZE???

MiracleMax · 08-07-2001, 11:55 PM

C.I.D x MAXRPM/3456 = Carb size @ 100% volumetric efficiency.

If you are shooting for a known amount of power then the formula is

1.6 x HP = Airflow needed

Or another way of saying is 1 hp requires 1.6 cubic feet of air to generate.

My not so handy HP sim says your in the neighborhood of 440 to 450 hp with your current setup with a peak VE of 101%

the closest models I have are a set of Windsor SRs and A Xtreme Energy cam (35-522-8).

Is your cam a hydraulic roller, solid roller, hydraulic flat tappet, solid lifter?

Hydraulic rollers are heavy and limit the RPM potential of the engine (my bet) I have a brand X with a 650 mech DP and solid roller with VERY HEAVY springs (to heavy in fact), the car doesn't break up, it just revs to 8500 rpm and stays there until you lift off of the gas! I had a Vic Jr on it 3 inch exhaust and a 750 mech dp so it used to rev higher (seen 9000 on the tach), but the cam was a mild 278 degrees adv and I used 1.6 rockers with an .025 lash so it had a net lift of .567 and was probably 278 or 280 deg adv on duration

Anywhosit by changing to a 1-3/4 header your can get into the 450-460 hp range and your VE jumps to 102%

306 x 7000/3456 x 102% = 632 cfm by Holley's math or 460 x 1.6 = 736 cfm based on hp

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
change jets or increase carb size	82 GT	Windsor Power	4	06-29-2004 07:30 PM
Need opinions on new combo about headers and carb size.	ciara	Windsor Power	2	10-05-2003 10:36 PM
carb size	lskarritt	Classic Mustangs	9	01-05-2003 03:01 PM
to carb, or not to carb...this is my question.	black86notch	Windsor Power	4	08-06-2002 08:24 PM
Carb size?	84_GT350	Windsor Power	23	02-27-2001 11:14 PM

08-07-2001, 11:55 PM	#1
MiracleMax Registered Member Join Date: Apr 1999 Location: Hayes, Va, USA Posts: 798	C.I.D x MAXRPM/3456 = Carb size @ 100% volumetric efficiency. If you are shooting for a known amount of power then the formula is 1.6 x HP = Airflow needed Or another way of saying is 1 hp requires 1.6 cubic feet of air to generate. My not so handy HP sim says your in the neighborhood of 440 to 450 hp with your current setup with a peak VE of 101% the closest models I have are a set of Windsor SRs and A Xtreme Energy cam (35-522-8). Is your cam a hydraulic roller, solid roller, hydraulic flat tappet, solid lifter? Hydraulic rollers are heavy and limit the RPM potential of the engine (my bet) I have a brand X with a 650 mech DP and solid roller with VERY HEAVY springs (to heavy in fact), the car doesn't break up, it just revs to 8500 rpm and stays there until you lift off of the gas! I had a Vic Jr on it 3 inch exhaust and a 750 mech dp so it used to rev higher (seen 9000 on the tach), but the cam was a mild 278 degrees adv and I used 1.6 rockers with an .025 lash so it had a net lift of .567 and was probably 278 or 280 deg adv on duration Anywhosit by changing to a 1-3/4 header your can get into the 450-460 hp range and your VE jumps to 102% 306 x 7000/3456 x 102% = 632 cfm by Holley's math or 460 x 1.6 = 736 cfm based on hp