 
Main Menu
|
|
Nevada Classics
|
|
Advertise at CC
|
| S |
M |
T |
W |
T |
F |
S |
| |
|
|
|
|
|
1 |
| 2 |
3 |
4 |
5 |
6 |
7 |
8 |
| 9 |
10 |
11 |
12 |
13 |
14 |
15 |
| 16 |
17 |
18 |
19 |
20 |
21 |
22 |
| 23 |
24 |
25 |
26 |
27 |
28 |
29 |
| 30 |
|
|
|
|
|
|
|
|
CC Advertisers
|
|
11-18-2014, 10:58 AM
|
|
CC Member
|
|
|
Join Date: Nov 2014
Location: austin,
tx
Cobra Make, Engine:
Posts: 11
|
|
Not Ranked
carb size formula for street and race apps
what do yall think of this formula for sizing a carb to a particular motor
for street: cubic inches x max rpm x .85 divided by 3456
for race cubic inches x max rpm x 1.15 divided by 3456
|
11-18-2014, 12:00 PM
|
 |
Senior CC Premier Member
|
|
|
Join Date: Nov 2004
Location: SoCal,
CA
Cobra Make, Engine: CSX #4xxx with CSX 482; David Kee Toploader
Posts: 3,574
|
|
Not Ranked
__________________
All that's stopping you now Son, is blind-raging fear.......
|
11-18-2014, 12:25 PM
|
 |
CC Member
|
|
|
Join Date: Feb 2014
Location: White City,
SK
Cobra Make, Engine: West Coast, 460 CID
Posts: 2,916
|
|
Not Ranked
Quote:
Originally Posted by lon
what do yall think of this formula for sizing a carb to a particular motor
for street: cubic inches x max rpm x .85 divided by 3456
for race cubic inches x max rpm x 1.15 divided by 3456
|
Would 'performance street' be somewhere in the middle? Something like: cubic inches x max rpm x 1.0 divided by 3456 |
11-18-2014, 03:25 PM
|
 |
CC Member
|
|
|
Join Date: Apr 2008
Location: Melbourne,
Vic
Cobra Make, Engine: Some polish thing... With some old engine
Posts: 2,286
|
|
Not Ranked
Quote:
Originally Posted by lon
what do yall think of this formula for sizing a carb to a particular motor
|
1 x (Pick up phone) + (Dial) 502.759.1431 = best carb for any application 
Enjoy |
11-18-2014, 04:04 PM
|
|
CC Member
|
|
|
Join Date: Apr 2012
Location: Bay Area (Peninsula),
CA
Cobra Make, Engine: ERA 427, 427/487 side-oiler
Posts: 1,248
|
|
Not Ranked
That formula seems to work pretty well for my application. It gives a size of 850 and that's essentially what I have. But I agree you should speak with a carb guy and get him to optimize for you.
I hear very good things about ProSystems and AED. But several people swear by Braswell if you can afford the extra dough. Dave Braswell is apparently one of the top carb guys on the planet, so you may want to speak with him. Also, their carbs are not modified Holleys. They are 100% Braswell made and have some neat features and beautiful construction.
Last edited by lippy; 11-18-2014 at 06:20 PM..
|
11-18-2014, 04:47 PM
|
 |
CC Member
|
|
|
Join Date: Apr 2009
Location: Little Rock area,
AR
Cobra Make, Engine: ERA Street Roadster #782 with 459 cu in FE KC engine, toploader, 3.31
Posts: 4,533
|
|
Not Ranked
Seems a bit short for the street - works out about 633 CFM for my 459 hydraulic lifter motor. Half way in between for street-performance works out about 745 CFM and that is probably believable.
|
11-18-2014, 08:00 PM
|
|
Senior CC Premier Member
|
|
|
Join Date: Nov 2004
Location: SoCal,
CA
Cobra Make, Engine: CSX #4xxx with CSX 482; David Kee Toploader
Posts: 3,574
|
|
Not Ranked
Quote:
Originally Posted by lippy
That formula seems to work pretty well for my application. It gives a size of 850 and that's essentially what I have. But I agree you should speak with a carb guy and get him to optimize for you.
I hear very good things about ProSystems and AED. But several people swear by Braswell if you can afford the extra dough. Dave Braswell is apparently one of the top carb guys on the planet, so you may want to speak with him. Also, their carbs are not modified Holleys. They are 100% Braswell made and have some neat features and beautiful construction.
|
I went with Pro Systems. I did their initial spec questionnaire which asks all about your build. Then I ended up talking with Patrick about my specific uses of the car. Ended up with an 858cfm with manual secondaries and all the good stuff (race floats, etc). Patrick will tell you that once you have one of his carbs, you are part of the family. In my case, he just said not to ever touch it without calling him first. The Dude abides! 
__________________
All that's stopping you now Son, is blind-raging fear.......
|
11-18-2014, 06:52 PM
|
|
CC Member
|
|
|
Join Date: Nov 2014
Location: austin,
tx
Cobra Make, Engine:
Posts: 11
|
|
Not Ranked
this formula is from the Edelbrock website
|
11-19-2014, 06:09 AM
|
 |
CC Member/Contributor
|
|
|
Join Date: Feb 2000
Location: Greenville,
SC
Cobra Make, Engine: 70 Shelby convertible, ERA-289 FIA, ERA 289 roadster hybrid, mystery Ford powered 2dr convertible
Posts: 12,763
|
|
Not Ranked
Quote:
Originally Posted by lon
what do yall think of this formula for sizing a carb to a particular motor
for street: cubic inches x max rpm x .85 divided by 3456
for race cubic inches x max rpm x 1.15 divided by 3456
|
There is no magic formula that covers all engine configurations, the formulas out there are just a starting point and nothing beats an engine, in the car, on a chassis (forget about an engine dyno tune) dyno.....So with that said, what are your engine specs?
Bill S.
__________________
Instead of being part of the problem, be part of a successful solution.
First time Cobra buyers-READ THIS
|
11-19-2014, 07:06 AM
|
|
CC Member
|
|
|
Join Date: Dec 2001
Location: Louisville,
KY
Cobra Make, Engine: I'm Cobra-less!
Posts: 9,417
|
|
Not Ranked
Exactly. Lots of things play into what size carb you need...engine efficiency being one of them.
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -7. The time now is 03:33 AM.
Links monetized by VigLink
|
Hybrid Mode
