carb size

General Engine Discussion

Moderator: John_Heard

Post Reply
Message
Author
wfw70ss
Posts: 8
Joined: Sun Mar 23, 2008 10:39 am

carb size

#1 Post by wfw70ss » Sun Sep 26, 2010 6:39 pm

i have a tube chassis cavalier 1/8 mile bracket footbrake car that has a 385 ci sbc. the carb on it now is a bg 825 race demon. the heads are pro topline 242cc w/ 2.125 intake valves.49cc comb chambers. a 686 640 lift bullet roller. 13.3 to1. 2 inch headers. car weighs 2350. 5800 conv. 5.38 gear. 2 things im trying to get,a tenth out of it and the car slows down in the evenings when it cools off. ive tried jetting it up. the carb came w/ 84 jets and i have run the best with 87s in it(6.00 @ 115) went to 88s it slowed. the car still slowed in cooler air w/87s. tech guy at bg told me to put 85s in it but it loses about 400 rpms. was thinking of going to a 1025 demon rs. the calculators say between 1043 cfm and 1150 cfm. any opinions are appreciated.

User avatar
supernova
Posts: 2552
Joined: Sat Feb 02, 2008 7:35 pm
Location: Ft.Worth Tx

Re: carb size

#2 Post by supernova » Sun Sep 26, 2010 9:27 pm

What kind of rpm are you turning?
I've had better luck with the Holley HP's over the Demons although I have made Demons work very well. Demons seem to be very finicky with temp. changes. Holley's aren't near as much trouble to tune and keep tuned.
Give Patrick a call at Pro Systems and see what he can do for you. I have one of his Holley 1000 hp's on my 525 motor and love it.......

http://www.prosystemsracing.com/index1.html
Attachments
IMG_4446.JPG
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
572 C.I. BBC

Best to date: 1/8
et: 5.28
mph: 134
new wt. 3340 lbs

wfw70ss
Posts: 8
Joined: Sun Mar 23, 2008 10:39 am

Re: carb size

#3 Post by wfw70ss » Sun Sep 26, 2010 10:28 pm

when its making power 7200. might turn more with a better carb. will call pro systems thx

User avatar
spib
Posts: 173
Joined: Fri Feb 05, 2010 4:42 pm
Location: wenatchee, WA

Re: carb size

#4 Post by spib » Mon Sep 27, 2010 9:46 am

x2 on pro systems carb, I got one on my 385 good carb
http://www.youtube.com/user/spib43
10.56 @128 best to date


Image

User avatar
Hitchcock
Posts: 1535
Joined: Fri Sep 12, 2008 6:57 pm
Location: Wichita

Re: carb size

#5 Post by Hitchcock » Mon Sep 27, 2010 10:53 am

You wont regret calling pro systems. Good quality any customer support.
73 Vette, moly back half
Pump gas 496
Two Pro Systems 950's
Chance 6000 converter

User avatar
jmarkaudio
Posts: 278
Joined: Fri Oct 26, 2007 4:22 pm
Location: Florida

Re: carb size

#6 Post by jmarkaudio » Sat Oct 02, 2010 10:04 pm

http://www.jegs.com/i/Quick%20Fuel/793/ ... /-1?CT=999

All the metering is adjustable, and will allow you to keep the 4150 bolt pattern.
Mark Whitener
Image
____________

Good work isn't cheap and cheap work can't be good.

wfw70ss
Posts: 8
Joined: Sun Mar 23, 2008 10:39 am

Re: carb size

#7 Post by wfw70ss » Sun Oct 03, 2010 11:06 am

spoke to patrick at pro systems. he told me my bg fuel curve was probably off. so i have a 840 cfm 4150 coming from him. we will see how it does. :roll:

wfw70ss
Posts: 8
Joined: Sun Mar 23, 2008 10:39 am

Re: carb size

#8 Post by wfw70ss » Sun Dec 26, 2010 5:48 pm

hey forgot to let you guys know the results from my carb swap. i put it on my car did all the fine adjusting. didnt change anything else but that and a set of fresh autolites and the went from 6.18-6.20 to 5.96. been to the track with it twice ran 5.96 to 5.98 both weekends. pro systems are the true carb specialist!

User avatar
Hitchcock
Posts: 1535
Joined: Fri Sep 12, 2008 6:57 pm
Location: Wichita

Re: carb size

#9 Post by Hitchcock » Sun Dec 26, 2010 10:50 pm

wfw70ss wrote:hey forgot to let you guys know the results from my carb swap. i put it on my car did all the fine adjusting. didnt change anything else but that and a set of fresh autolites and the went from 6.18-6.20 to 5.96. been to the track with it twice ran 5.96 to 5.98 both weekends. pro systems are the true carb specialist!
Damn dude that's awesome. :thumb: for someone like me who's ignorant as to how to tune a Carb. You just can.'t beat Pro Systems. Liked it so much I bought two. Congrats on the nice gain.
73 Vette, moly back half
Pump gas 496
Two Pro Systems 950's
Chance 6000 converter

User avatar
supernova
Posts: 2552
Joined: Sat Feb 02, 2008 7:35 pm
Location: Ft.Worth Tx

Re: carb size

#10 Post by supernova » Sun Dec 26, 2010 11:10 pm

Very nice! :thumb: :thumb: :thumb: :thumb: :thumb: :thumb: :thumb:
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
572 C.I. BBC

Best to date: 1/8
et: 5.28
mph: 134
new wt. 3340 lbs

User avatar
spib
Posts: 173
Joined: Fri Feb 05, 2010 4:42 pm
Location: wenatchee, WA

Re: carb size

#11 Post by spib » Mon Dec 27, 2010 11:59 am

damn good news :!:
http://www.youtube.com/user/spib43
10.56 @128 best to date


Image

User avatar
slightly tweeked
Posts: 55
Joined: Wed Dec 01, 2010 11:21 pm
Location: AZUSA CA,

Re: carb size

#12 Post by slightly tweeked » Mon Dec 27, 2010 5:46 pm

Glad to hear you guys had such great luck with PRO SYSTEMS.Friends of mine ordered them and put them on right out of the box and they ran great.Me I had hell with mine,put it on hooked up the fuel lines turned the pump on and it looked like a lawn sprinkler,Gas shooting every where.Took off the float bowls and they were full of aluminum shavings,Call Pat and gave him a little ass chewing but he did help me work it out and explained what had probably happened.After a lot of apoligies and some adjusting the carb runs great I guess I just got one of those freak ones... yikes:
72 Nova
548 cu in,900hp
Turbo 400
5600 stall
Ford 9in,457 gears
3640 lbs,all steel car.except hood.
Runs low 9s in 1/4.High 5s in 1/8.

Dave Yonemura
Posts: 74
Joined: Sun Dec 19, 2010 5:24 pm
Location: Ogden, Utah

Re: carb size

#13 Post by Dave Yonemura » Tue Dec 28, 2010 7:15 pm

Next try NGK sparkplugs. Autolites are hard to read. Foul easily, and just plain SUCK! :smt005

User avatar
10scnd70
Posts: 24
Joined: Tue May 10, 2011 9:37 pm

Re: carb size

#14 Post by 10scnd70 » Thu Jun 23, 2011 10:04 pm

Predator. It'll run quicker and be more consistant. You'll also never have to guess on jets again.
732-367-8487. Ask for Dale.
Just another 10 second Camaro...

Post Reply

Who is online

Users browsing this forum: No registered users and 31 guests