Brake boosters, Does size make a difference? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Suspension - Brakes - Steering
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 01-25-2006, 06:26 AM
blacklotus's Avatar
Greg
 

Last journal entry: Wiring begins
Last photo:
Join Date: May 2004
Location: Rome GA
Age: 49
Posts: 64
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Brake boosters, Does size make a difference?

I have a 77 Ford F-100 that is enduring a frame off. The OEM brake booster is a single diaphragm (i believe) 11" booster.
I am looking at a dual diapragm 8" booster.
Can someone tell me what they believe the performance diff will be, Oh it is disc/drum, everything was replaced except for the proportioning valve.


Thanks

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 01-25-2006, 07:34 AM
powerrodsmike's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Make a fiberglass fan shroud
Last journal entry: Next.. ..Bagging the king B (barge)
Last photo:
Join Date: Jan 2005
Location: gilroy, california
Age: 53
Posts: 4,108
Wiki Edits: 161

Thanks: 0
Thanked 3 Times in 3 Posts
An 8" dual booster should have about the same boosting effect as an 11" single. area of 11" diaphragm=95 sq in. Area of 8"=50.2 sq in. Add a second diaphragm of 50.2 sq in and you have a total diaphragm area of 100.4 sq in. That is not a big difference in area, so I would expect not much diff in performance. ( Although internal differences may make the dual diaphragm booster less efficient than the single, so even though there is more area ,it will give slightly less boost) It will make the firewall look cleaner though. Hope this helps,Mikey
__________________
my signature lines...not really directed at anyone in particular..

BE different....ACT normal.

No one is completely useless..They can always be used as a bad example

Last edited by powerrodsmike; 01-25-2006 at 09:23 AM. Reason: no good ones
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 01-25-2006, 10:05 AM
Registered User
 

Last journal entry: 1978 Mercury Cougar Xr7 Cruiser Project
Last photo:
Join Date: Oct 2005
Location: MA
Posts: 61
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Why then, on several Bronco/truck forums, they all list to use the double diaphragm booster along with different wheel cylinders, and your braking will increase dramatically?

Why do they list two for my car? a 12" single and 9" double, (I'm guesstimating).

All things being equal, which one is better?
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 01-25-2006, 02:08 PM
thewrongshop@yahoo.com
 
Last photo:
Join Date: Oct 2004
Location: New Jersey
Age: 63
Posts: 206
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
Why not go with a Hydro Boost system, better stopping power
and if your going to go with high tires it's the ticket .
Smaller in size than an 8" Vacuum unit, I have it on my 84 van
and my 39 coupe. Bone yard one out of any GM 1 ton and up.


http://www.wildhorses4x4.com/hydro.asp
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 01-25-2006, 02:35 PM
blacklotus's Avatar
Greg
 

Last journal entry: Wiring begins
Last photo:
Join Date: May 2004
Location: Rome GA
Age: 49
Posts: 64
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks for the information I will most likely go with the 8" booster, I can get it in chrome
Anybody know what the thread size is on the Ford master cylinder on the brake lines I am looking for a custom master cylinder as well.

This is definitely a street truck wiht street tires 60's on the rear and 70's on the front.

I call it a stoplight special

Greg

Last edited by blacklotus; 01-25-2006 at 02:41 PM.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 01-25-2006, 07:58 PM
powerrodsmike's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Make a fiberglass fan shroud
Last journal entry: Next.. ..Bagging the king B (barge)
Last photo:
Join Date: Jan 2005
Location: gilroy, california
Age: 53
Posts: 4,108
Wiki Edits: 161

Thanks: 0
Thanked 3 Times in 3 Posts
Quote:
Originally Posted by Psquare75
Why then, on several Bronco/truck forums, they all list to use the double diaphragm booster along with different wheel cylinders, and your braking will increase dramatically?

Why do they list two for my car? a 12" single and 9" double, (I'm guesstimating).

All things being equal, which one is better?
I could answer your question better if you told me the baseline specs of the truck you refer to. The physics of a booster are not hard to figure out. Many times the physical size of the booster is the governing factor in the selection process, not the amount of boost it provides. I suspect that a wheel cylinder change would increase brake performance if the original wheel cylinders were wrong from the factory or if you were compensating for some other change like bigger tires or better shoes but again, without knowing the baseline and deviations from baseline that were done on the truck in question, it is impossible to say which is better. The system must be matched. here is a spiffy website with alot of information that will help you figure out your system.
http://www.stoptech.com/tech_info/te...e_papers.shtml
And here is a car craft article that is helpful
http://www.carcraft.com/techarticles/76680/
hope this helps, mikey
__________________
my signature lines...not really directed at anyone in particular..

BE different....ACT normal.

No one is completely useless..They can always be used as a bad example
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 01-25-2006, 10:52 PM
Registered User
 

Last journal entry: 1978 Mercury Cougar Xr7 Cruiser Project
Last photo:
Join Date: Oct 2005
Location: MA
Posts: 61
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
http://www.ford-trucks.com/article/i...d_Broncos.html

I see this posted all over the place

QUOTE:

The next part of the system is the vacuum booster. I'm sure you found out by now, the OEM 11" vacuum booster is simply too weak to assist in pressurizing the hydraulic system. The '78-'79 Ford F350 tandem booster (dual 9 1/4" diapragm) is a bolt in retrofit with twice the power output.
:
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 01-25-2006, 11:46 PM
powerrodsmike's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Make a fiberglass fan shroud
Last journal entry: Next.. ..Bagging the king B (barge)
Last photo:
Join Date: Jan 2005
Location: gilroy, california
Age: 53
Posts: 4,108
Wiki Edits: 161

Thanks: 0
Thanked 3 Times in 3 Posts
Quote:
Originally Posted by Psquare75
http://www.ford-trucks.com/article/i...d_Broncos.html

I see this posted all over the place

QUOTE:

The next part of the system is the vacuum booster. I'm sure you found out by now, the OEM 11" vacuum booster is simply too weak to assist in pressurizing the hydraulic system. The '78-'79 Ford F350 tandem booster (dual 9 1/4" diaphragm) is a bolt in retrofit with twice the power output.
:
That is a very informative article. It refers to 78-79 broncos. He didn't state why he was upgrading the brakes,but I would suspect it was because of the addition of big tires. That would explain his dissatisfaction with the stock system. (guesstimate on my part) The article details the results of 6 months of research on the part of the author for his project. If you really want to, put the 9 1/4" booster on your truck. It does have more diaphragm area than the 11" which would give it more boosting ability. BUT, the laws of physics do not change from one forum to another. the 9 1/4 booster can not have twice the power output of the 11". Do the math. 11" booster @18" vacuum will give about 855 pounds of force @ the rod. 9 1/4 dual diaphragm @18" vac gives about 1200 pounds. No doubt better, but not twice. You should also follow the authors advice and install all of the other parts on his upgrade list, so you will have a matched system. It will stop on a dime, provided you have the tires and enough weight in the back to make use of those big discs that he reccommends.. Blacklotus wanted to know what the difference between 11" single and an 8" dual. I answered him. He didn't ask what is the best brake upgrade to stop his truck faster. I would have told him to call Baer or SSBC. They look better than the ford stuff. Probably would have his research done in a matter of minutes. BTW I had a 79 f150 2WD with the 11" booster and stock brakes. That truck stopped just fine. Thanks for reading this, mikey
__________________
my signature lines...not really directed at anyone in particular..

BE different....ACT normal.

No one is completely useless..They can always be used as a bad example

Last edited by powerrodsmike; 01-26-2006 at 12:07 AM.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 01-26-2006, 06:22 AM
Registered User
 

Last journal entry: 1978 Mercury Cougar Xr7 Cruiser Project
Last photo:
Join Date: Oct 2005
Location: MA
Posts: 61
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I too, had a 79 F100, 2wd. with larger (30/32? I forget, it's been 4 years) tires.



Started out as a 302, ended up a 460 before selling it. Come to think of it. I don't recall the brakes ever being an issue. They weren't stop on a dime, but they weren't awful either.

Also, Mike, If you read my other post on here about the Ford rear discs in my Cougar... I'm beginning to wonder if the double diaphragm booster will help my braking woes, as I have copied the author of that article's setup, in an argueably slightly lighter vehicle.

Last edited by Psquare75; 01-26-2006 at 06:24 AM. Reason: uploaded picture
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 01-26-2006, 09:49 AM
blacklotus's Avatar
Greg
 

Last journal entry: Wiring begins
Last photo:
Join Date: May 2004
Location: Rome GA
Age: 49
Posts: 64
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Just to clear up a few item.

1. This truck has stock rear drum brakes and stock front disc brakes, the tires are 255/60/15 on the rear and 245/70/15 on the front. I have installed stainless flex brake lines on the rear and the front from inline tube. All of the rear drum components are new and the calipers are new as well.
The truck major modifications are mechanical in nature (engine, trans, rear end, etc). It will probably be very close to stock weight ( I am not sure of that).

The smaller booster is to clean up under the hood a bit and for show purposes as well as functionality.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 01-27-2006, 09:38 AM
Registered User
 
Join Date: May 2005
Location: HUNTINGTON BEACH
Posts: 25
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Vacuum Vs Hydroboost

The Problems With The "wonder Booster", The 8" Dual, Is That It Is Measured At The O.d. Of The Crimp. The Rear Dia Actually Is 7" Dia, And The Front Dia. Is Actually 5.5". The Inside Hub That Supports The Dias. Is A Larger Than Most Hubs, And Further Reduces The Dia. Area. If You Have Normal Vacuum, This Booster With A 1.125" Master Will Push The Pressure Guage Only To 850 Psi. Disc Brakes Like 1200psi And Over. The Popular 7" Single Dia Will Only Reach 450psi. We Like The Hydroboost System, Because It Can Deliver Up To 2000psi, With A Normal To Great Pedal Feel. They Can Be Bolted Directly To The Firewall, And Eliminate The Bracket Extensions. Almost Any Master Can Be Used. On Frame Mounted Brake Boosters, They Are Flat Underneath, And The Big Exhaust Pipe Can Be Run Alongside, As The H/b Is Oil Cooled. They Also Can Clear Those Huge 572 Motors, Hemi's, And Others With Tall Valve Covers. Vacuum Is Not An Issue, As It Receives It's Pressure From The P/s Pump. Any Cam Can Be Run, Any 4 Disc Combo Can Be Used, And They Can Stop 1000hp Cars. If You Do Shop Junkyards For Used, They Can Rebuild Them, And Provide Stainless Hose Sets To Hook Them Up. They Can Fit Camaro, Chevelle, Mustangs, Street Rods, Jeeps, And Trucks.

Last edited by Deuce; 01-29-2006 at 11:37 AM.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 01-27-2006, 11:33 AM
thewrongshop@yahoo.com
 
Last photo:
Join Date: Oct 2004
Location: New Jersey
Age: 63
Posts: 206
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by POWERBRAKEBOB
The Problems With The "wonder Booster", The 8" Dual, Is That It Is Measured At The O.d. Of The Crimp. The Rear Dia Actually Is 7" Dia, And The Front Dia. Is Actually 5.5". The Inside Hub That Supports The Dias. Is A Larger Than Most Hubs, And Further Reduces The Dia. Area. If You Have Normal Vacuum, This Booster With A 1.125" Master Will Push The Pressure Guage Only To 850 Psi. Disc Brakes Like 1200psi And Over. The Popular 7" Single Dia Will Only Reach 450psi. We Like The Hydroboost System, Because It Can Deliver Up To 2000psi, With A Normal To Great Pedal Feel. They Can Be Bolted Directly To The Firewall, And Eliminate The Bracket Extensions. Almost Any Master Can Be Used. On Frame Mounted Brake Boosters, They Are Flat Underneath, And The Big Exhaust Pipe Can Be Run Alongside, As The H/b Is Oil Cooled. They Also Can Clear Those Huge 572 Motors, Hemi's, And Others With Tall Valve Covers. Vacuum Is Not An Issue, As It Receives It's Pressure From The P/s Pump. Any Cam Can Be Run, Any 4 Disc Combo Can Be Used, And They Can Stop 1000hp Cars. "powerbrakesonline.com" Has Many Photos Of Installations, Featuring New Hydroboosts. If You Do Shop Junkyards For Used, They Can Rebuild Them, And Provide Stainless Hose Sets To Hook Them Up. They Can Fit Camaro, Chevelle, Mustangs, Street Rods, Jeeps, And Trucks.
Ditto on the Hydro Boost the only way to go !
Reply With Quote Quick reply to this message

Recent Suspension - Brakes - Steering posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Do stronger rear diff covers make that much of a difference? 84Z Transmission - Rearend 4 06-30-2004 08:21 PM
How much difference does the rear axle ratio make ? acr Transmission - Rearend 2 05-20-2004 02:16 PM
Hotrodders Knowledge Cluster: Disc Brake Conversions Jon Suspension - Brakes - Steering 0 08-29-2003 03:34 PM
how to prepare a block blndweasel Engine 14 08-15-2003 12:28 PM
Brake Job Finally Finished 454impala69 Suspension - Brakes - Steering 1 04-24-2002 10:00 AM


All times are GMT -6. The time now is 08:22 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.