Home » Public Forums » GMCnet » Re: [GMCnet] Higher the line pressure the better the braking power
| Re: [GMCnet] Higher the line pressure the better the braking power [message #300720] |
Tue, 17 May 2016 17:32  |
Tom Whitton
Messages: 235
Registered: February 2004
Location: Paducah, KY
Karma: 0
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Senior Member |
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One of our well-informed members developed the following and sent it to Bob Stone who asked me to post it here for him. (Bob doesn't use a computer)
"Master cylinder booster combinations and theoretical pressure"
1. Force available from vacuum booster Dave Lenzi panic stop 1,473 lbs.
2. Force available from Hydroboost 1.56" piston diameter and 1,350 PSI steering pressure 2,579
Vacuum Bob Stone
Booster Hydroboost
1.25" master cylinder 1,198 PSI 2,098 PSI
34 mm master cylinder 1,048 PSI 1,835 PSI
37 mm master cylinder 852 PSI 1,549 PSI
40 mm master cylinder 761 PSI 1,332 PSI
The Hydroboost force does not include additional force that can be applied by the pedal.
Vacuum boost force does include additional force that can be applied by the pedal.
Hydroboost conversion description here: http://appliedgmc.com/images/hydro.pdf
Please phone Bob Stone if you have questions: 618-964-9124
Thanks,
Tom Whitton
26 foot updated GMC
Paducah, KY
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #300721 is a reply to message #300720] |
Tue, 17 May 2016 17:39  |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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How much pressure does it take to lock the wheels on dry pavement? If we
know that, then we can determine if we need 2000 pounds of pressure at the
master cylinder.
Jim Hupy
Salem, Or
78 GMC ROYALE 403
On May 17, 2016 3:34 PM, "Tom Whitton" wrote:
> One of our well-informed members developed the following and sent it to
> Bob Stone who asked me to post it here for him. (Bob doesn't use a
> computer)
>
>
> "Master cylinder booster combinations and theoretical pressure"
>
> 1. Force available from vacuum booster Dave Lenzi panic stop 1,473 lbs.
>
> 2. Force available from Hydroboost 1.56" piston diameter and 1,350 PSI
> steering pressure 2,579
>
> Vacuum Bob Stone
> Booster
> Hydroboost
>
> 1.25" master cylinder 1,198 PSI 2,098 PSI
>
> 34 mm master cylinder 1,048 PSI 1,835 PSI
>
> 37 mm master cylinder 852 PSI 1,549 PSI
>
> 40 mm master cylinder 761 PSI 1,332 PSI
>
>
> The Hydroboost force does not include additional force that can be applied
> by the pedal.
>
> Vacuum boost force does include additional force that can be applied by
> the pedal.
>
> Hydroboost conversion description here:
> http://appliedgmc.com/images/hydro.pdf
>
> Please phone Bob Stone if you have questions: 618-964-9124
>
> Thanks,
>
> Tom Whitton
> 26 foot updated GMC
> Paducah, KY
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #300733 is a reply to message #300720] |
Tue, 17 May 2016 19:09 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Senior Member |
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In other words, the Hydroboost provides 75% more line pressure than the
vacuum booster. In line with my own testing, though I haven't yet gotten
as high pressures with either as Wally does. I'm bleeding the rebuilt
power steering pump right now, trying for better Hydroboost performance
(and silence).
Ken H.
On Tue, May 17, 2016 at 6:32 PM, Tom Whitton
wrote:
> One of our well-informed members developed the following and sent it to
> Bob Stone who asked me to post it here for him. (Bob doesn't use a
> computer)
>
>
> "Master cylinder booster combinations and theoretical pressure"
>
> 1. Force available from vacuum booster Dave Lenzi panic stop 1,473 lbs.
>
> 2. Force available from Hydroboost 1.56" piston diameter and 1,350 PSI
> steering pressure 2,579
>
> Vacuum Bob Stone
> Booster
> Hydroboost
>
> 1.25" master cylinder 1,198 PSI 2,098 PSI
>
> 34 mm master cylinder 1,048 PSI 1,835 PSI
>
> 37 mm master cylinder 852 PSI 1,549 PSI
>
> 40 mm master cylinder 761 PSI 1,332 PSI
>
>
> The Hydroboost force does not include additional force that can be applied
> by the pedal.
>
> Vacuum boost force does include additional force that can be applied by
> the pedal.
>
> Hydroboost conversion description here:
> http://appliedgmc.com/images/hydro.pdf
>
> Please phone Bob Stone if you have questions: 618-964-9124
>
> Thanks,
>
> Tom Whitton
> 26 foot updated GMC
> Paducah, KY
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #300735 is a reply to message #300733] |
Tue, 17 May 2016 20:20 |
Hal StClair
Messages: 971
Registered: March 2013
Location: Rio Rancho NM
Karma: -12
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Senior Member |
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Ken Henderson wrote on Tue, 17 May 2016 18:09In other words, the Hydroboost provides 75% more line pressure than the
vacuum booster. In line with my own testing, though I haven't yet gotten
as high pressures with either as Wally does. I'm bleeding the rebuilt
power steering pump right now, trying for better Hydroboost performance
(and silence).
Ken H.
I've not been too happy with my Hydroboost either Ken. I swapped the brake lines around and seem to have improved things but it takes more pedal pressure than I like. Maybe a more aggressive pad compound is the answer? No funny noises though.
Hal
On Tue, May 17, 2016 at 6:32 PM, Tom Whitton
wrote:
> One of our well-informed members developed the following and sent it to
> Bob Stone who asked me to post it here for him. (Bob doesn't use a
> computer)
>
>
> "Master cylinder booster combinations and theoretical pressure"
>
> 1. Force available from vacuum booster Dave Lenzi panic stop 1,473 lbs.
>
> 2. Force available from Hydroboost 1.56" piston diameter and 1,350 PSI
> steering pressure 2,579
>
> Vacuum Bob Stone
> Booster
> Hydroboost
>
> 1.25" master cylinder 1,198 PSI 2,098 PSI
>
> 34 mm master cylinder 1,048 PSI 1,835 PSI
>
> 37 mm master cylinder 852 PSI 1,549 PSI
>
> 40 mm master cylinder 761 PSI 1,332 PSI
>
>
> The Hydroboost force does not include additional force that can be applied
> by the pedal.
>
> Vacuum boost force does include additional force that can be applied by
> the pedal.
>
> Hydroboost conversion description here:
> http://appliedgmc.com/images/hydro.pdf
>
> Please phone Bob Stone if you have questions: 618-964-9124
>
> Thanks,
>
> Tom Whitton
> 26 foot updated GMC
> Paducah, KY
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
_______________________________________________
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"I enjoy talking to you. Your mind appeals to me. It resembles my own mind, except you happen to be insane."
1977 Royale 101348,
1977 Royale 101586, Diesel powered,
1974 Eagle Bus 45',w/slideout,
Rio Rancho, NM
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #300740 is a reply to message #300735] |
Wed, 18 May 2016 00:39 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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I had our guys install Bob Stones Hydro Boost System on my 403 Kingsly we
market for him, and our guys noticed the difference when they road tested
it.
Bob has invested considerable time researching and visiting with people
that manufacture the components and have developed an outstand kit that is
easy to follow to install.
You'll find it on our sight.
On Tue, May 17, 2016 at 6:20 PM, Hal StClair
wrote:
> Ken Henderson wrote on Tue, 17 May 2016 18:09
>> In other words, the Hydroboost provides 75% more line pressure than the
>> vacuum booster. In line with my own testing, though I haven't yet gotten
>> as high pressures with either as Wally does. I'm bleeding the rebuilt
>> power steering pump right now, trying for better Hydroboost performance
>> (and silence).
>>
>> Ken H.
>>
>> I've not been too happy with my Hydroboost either Ken. I swapped the
> brake lines around and seem to have improved things but it takes more pedal
>> pressure than I like. Maybe a more aggressive pad compound is the
> answer? No funny noises though.
>> Hal
>>
>> On Tue, May 17, 2016 at 6:32 PM, Tom Whitton
>> wrote:
>>
>>> One of our well-informed members developed the following and sent it
> to
>>> Bob Stone who asked me to post it here for him. (Bob doesn't use a
>>> computer)
>>>
>>>
>>> "Master cylinder booster combinations and theoretical pressure"
>>>
>>> 1. Force available from vacuum booster Dave Lenzi panic stop 1,473
> lbs.
>>>
>>> 2. Force available from Hydroboost 1.56" piston diameter and 1,350 PSI
>>> steering pressure 2,579
>>>
>>> Vacuum Bob
> Stone
>>> Booster
>>> Hydroboost
>>>
>>> 1.25" master cylinder 1,198 PSI 2,098 PSI
>>>
>>> 34 mm master cylinder 1,048 PSI 1,835 PSI
>>>
>>> 37 mm master cylinder 852 PSI 1,549 PSI
>>>
>>> 40 mm master cylinder 761 PSI 1,332 PSI
>>>
>>>
>>> The Hydroboost force does not include additional force that can be
> applied
>>> by the pedal.
>>>
>>> Vacuum boost force does include additional force that can be applied
> by
>>> the pedal.
>>>
>>> Hydroboost conversion description here:
>>> http://appliedgmc.com/images/hydro.pdf
>>>
>>> Please phone Bob Stone if you have questions: 618-964-9124
>>>
>>> Thanks,
>>>
>>> Tom Whitton
>>> 26 foot updated GMC
>>> Paducah, KY
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> --
> 1977 Royale 101348,
>
> 1977 Royale 101586,
>
> 1974 Eagle Bus 45',w/slideout
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #300751 is a reply to message #300721] |
Wed, 18 May 2016 10:32 |
Justin Brady
Messages: 769
Registered: April 2015
Location: Bell Buckle, TN
Karma: 11
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Senior Member |
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I think this is the real question. If it takes 1100 psi to lock the wheels then spending time and money to get 2200 psi is doing you no good, other than maybe locking the wheels earlier in the pedal movement.
I think the problem is contact with the road more so than line pressure. Mine has stock brakes and I have no problem locking up the rear. It seems to me that reaction arms are more likely to improve braking distance vs additional line pressure. The tires have more grip on the road just before they lock than they do once locked up. (coefficient of static vs kinetic friction)
Just my observations.
James Hupy wrote on Tue, 17 May 2016 17:39How much pressure does it take to lock the wheels on dry pavement? If we
know that, then we can determine if we need 2000 pounds of pressure at the
master cylinder.
Jim Hupy
Salem, Or
78 GMC ROYALE 403
On May 17, 2016 3:34 PM, "Tom Whitton" wrote:
> One of our well-informed members developed the following and sent it to
> Bob Stone who asked me to post it here for him. (Bob doesn't use a
> computer)
>
>
> "Master cylinder booster combinations and theoretical pressure"
>
> 1. Force available from vacuum booster Dave Lenzi panic stop 1,473 lbs.
>
> 2. Force available from Hydroboost 1.56" piston diameter and 1,350 PSI
> steering pressure 2,579
>
> Vacuum Bob Stone
> Booster
> Hydroboost
>
> 1.25" master cylinder 1,198 PSI 2,098 PSI
>
> 34 mm master cylinder 1,048 PSI 1,835 PSI
>
> 37 mm master cylinder 852 PSI 1,549 PSI
>
> 40 mm master cylinder 761 PSI 1,332 PSI
>
>
> The Hydroboost force does not include additional force that can be applied
> by the pedal.
>
> Vacuum boost force does include additional force that can be applied by
> the pedal.
>
> Hydroboost conversion description here:
> http://appliedgmc.com/images/hydro.pdf
>
> Please phone Bob Stone if you have questions: 618-964-9124
>
> Thanks,
>
> Tom Whitton
> 26 foot updated GMC
> Paducah, KY
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Justin Brady
http://www.thegmcrv.com/
1976 Palm Beach 455
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #300756 is a reply to message #300751] |
Wed, 18 May 2016 13:16 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
|
Senior Member |
|
|
Justin,
Your correct in what our saying, however each coach brakes perform
differently in the way they behave .
believe it or not some do not lock up in the rear so much and depending on
how you use the peddle, you can drop the speed more rapidly and let up on
it slightly to avoid the skidding of the very rear wheels.
We know the value of the Reaction Arm System as we have spent several
weekends testing our Chuck Auguer kits and Tom Pryor's kit.
On Wed, May 18, 2016 at 8:32 AM, Justin Brady wrote:
> I think this is the real question. If it takes 1100 psi to lock the wheels
> then spending time and money to get 2200 psi is doing you no good, other
> than maybe locking the wheels earlier in the pedal movement.
> I think the problem is contact with the road more so than line pressure.
> Mine has stock brakes and I have no problem locking up the rear. It seems to
> me that reaction arms are more likely to improve braking distance vs
> additional line pressure. The tires have more grip on the road just before
> they
> lock than they do once locked up. (coefficient of static vs kinetic
> friction)
> Just my observations.
>
> James Hupy wrote on Tue, 17 May 2016 17:39
>> How much pressure does it take to lock the wheels on dry pavement? If we
>> know that, then we can determine if we need 2000 pounds of pressure at
> the
>> master cylinder.
>> Jim Hupy
>> Salem, Or
>> 78 GMC ROYALE 403
>> On May 17, 2016 3:34 PM, "Tom Whitton" wrote:
>>
>>> One of our well-informed members developed the following and sent it
> to
>>> Bob Stone who asked me to post it here for him. (Bob doesn't use a
>>> computer)
>>>
>>>
>>> "Master cylinder booster combinations and theoretical pressure"
>>>
>>> 1. Force available from vacuum booster Dave Lenzi panic stop 1,473
> lbs.
>>>
>>> 2. Force available from Hydroboost 1.56" piston diameter and 1,350 PSI
>>> steering pressure 2,579
>>>
>>> Vacuum Bob
> Stone
>>> Booster
>>> Hydroboost
>>>
>>> 1.25" master cylinder 1,198 PSI 2,098 PSI
>>>
>>> 34 mm master cylinder 1,048 PSI 1,835 PSI
>>>
>>> 37 mm master cylinder 852 PSI 1,549 PSI
>>>
>>> 40 mm master cylinder 761 PSI 1,332 PSI
>>>
>>>
>>> The Hydroboost force does not include additional force that can be
> applied
>>> by the pedal.
>>>
>>> Vacuum boost force does include additional force that can be applied
> by
>>> the pedal.
>>>
>>> Hydroboost conversion description here:
>>> http://appliedgmc.com/images/hydro.pdf
>>>
>>> Please phone Bob Stone if you have questions: 618-964-9124
>>>
>>> Thanks,
>>>
>>> Tom Whitton
>>> 26 foot updated GMC
>>> Paducah, KY
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> --
> Justin Brady
> http://www.thegmcrv.com/
> 1976 Palm Beach 455
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #300757 is a reply to message #300756] |
Wed, 18 May 2016 13:59 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
|
Senior Member |
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What I was hinting at was the fact that once the tires lose contact with
the road surface (skid) the drums/rotors are no longer turning. From that
point into infinity, it makes no difference how much line pressure you
have. 2000 psi, 10,000 psi. makes no difference. With a properly set up GMC
coach with good, properly inflated tires and brakes that are adjusted to
spec's, depending upon temperature and road conditions, yada, yada, you
need somewhere in the neighborhood of 500 psi. to lock up the wheels. A
stock master cylinder produces almost twice that much pressure. WHERE IT
DOES LACK, IS IN DISPLACEMENT VOLUME WHEN USED WITH 6 WHEEL DISC BRAKE
SYSTEMS. That is why we substitute the P-30 master cylinder when going to 6
wheel discs. The P-30 lacks a bit of total pressure compared to the stock
master cylinder, but it still possesses almost twice the capability
necessary to lock up the wheels. Just for your information. Brake systems
carry a HUGE LIABILITY if you mess with them, so make damn sure you
understand that when you swap out parts in these coaches. Be sure, because
the lives of others depend upon these things working right every time you
have to use them. 'Nuff said.
Jim Hupy
Salem, Or
78 GMC ROYALE 403
On May 18, 2016 11:30 AM, "Jim Kanomata" wrote:
> Justin,
> Your correct in what our saying, however each coach brakes perform
> differently in the way they behave .
> believe it or not some do not lock up in the rear so much and depending on
> how you use the peddle, you can drop the speed more rapidly and let up on
> it slightly to avoid the skidding of the very rear wheels.
> We know the value of the Reaction Arm System as we have spent several
> weekends testing our Chuck Auguer kits and Tom Pryor's kit.
>
> On Wed, May 18, 2016 at 8:32 AM, Justin Brady wrote:
>
>> I think this is the real question. If it takes 1100 psi to lock the
> wheels
>> then spending time and money to get 2200 psi is doing you no good, other
>> than maybe locking the wheels earlier in the pedal movement.
>> I think the problem is contact with the road more so than line pressure.
>> Mine has stock brakes and I have no problem locking up the rear. It
> seems to
>> me that reaction arms are more likely to improve braking distance vs
>> additional line pressure. The tires have more grip on the road just
> before
>> they
>> lock than they do once locked up. (coefficient of static vs kinetic
>> friction)
>> Just my observations.
>>
>> James Hupy wrote on Tue, 17 May 2016 17:39
>>> How much pressure does it take to lock the wheels on dry pavement? If
> we
>>> know that, then we can determine if we need 2000 pounds of pressure at
>> the
>>> master cylinder.
>>> Jim Hupy
>>> Salem, Or
>>> 78 GMC ROYALE 403
>>> On May 17, 2016 3:34 PM, "Tom Whitton" wrote:
>>>
>>>> One of our well-informed members developed the following and sent it
>> to
>>>> Bob Stone who asked me to post it here for him. (Bob doesn't use a
>>>> computer)
>>>>
>>>>
>>>> "Master cylinder booster combinations and theoretical pressure"
>>>>
>>>> 1. Force available from vacuum booster Dave Lenzi panic stop 1,473
>> lbs.
>>>>
>>>> 2. Force available from Hydroboost 1.56" piston diameter and 1,350
> PSI
>>>> steering pressure 2,579
>>>>
>>>> Vacuum
> Bob
>> Stone
>>>> Booster
>>>> Hydroboost
>>>>
>>>> 1.25" master cylinder 1,198 PSI 2,098 PSI
>>>>
>>>> 34 mm master cylinder 1,048 PSI 1,835 PSI
>>>>
>>>> 37 mm master cylinder 852 PSI 1,549 PSI
>>>>
>>>> 40 mm master cylinder 761 PSI 1,332 PSI
>>>>
>>>>
>>>> The Hydroboost force does not include additional force that can be
>> applied
>>>> by the pedal.
>>>>
>>>> Vacuum boost force does include additional force that can be applied
>> by
>>>> the pedal.
>>>>
>>>> Hydroboost conversion description here:
>>>> http://appliedgmc.com/images/hydro.pdf
>>>>
>>>> Please phone Bob Stone if you have questions: 618-964-9124
>>>>
>>>> Thanks,
>>>>
>>>> Tom Whitton
>>>> 26 foot updated GMC
>>>> Paducah, KY
>>>> _______________________________________________
>>>> GMCnet mailing list
>>>> Unsubscribe or Change List Options:
>>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>>
>> --
>> Justin Brady
>> http://www.thegmcrv.com/
>> 1976 Palm Beach 455
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
>
> --
> Jim Kanomata
> Applied/GMC, Fremont,CA
> jimk@appliedairfilters.com
> http://www.appliedgmc.com
> 1-800-752-7502
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #300758 is a reply to message #300756] |
Wed, 18 May 2016 14:22 |
Keith V
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
|
Senior Member |
|
|
A couple of my opinions about braking.
1. Tire / road friction is not your high school friction. Rubber is sticky, the surface you are driving on may be sticky or it may be loose both of those interfaces, and others, do not follow simple friction physics. a sliding tire is not the same as sliding a block of steel on a steel plate, static and dynamic friction are a huge misnomer here. It's more like adhesive than friction
2. stopping a vehicle involves much more than locking up wheels. If you lock both rear wheels you have a high chance of the rear coming around on you, thats bad as it prevents you from applying maximum braking force to the front wheels. A well designed brake system will lock the front wheels first and the rears right after that. Then you can stop straight and fast even on a corner or while you are avoiding the dumbass in the honda that just pulled out in front of you.
3. Yes you only need enough line pressure to lock the front wheels on a hot summer day on good new asphalt. I know some roads that you will not be able to lock any wheels on, very rough and sticky even my Vette can't lock them up on it. Of course the more pressure you have the harder it is to modulate the brake pedal to NOT lock them up on a slippery surface, think of an old polished concrete road in the rain. Too much brake here could put you into Mr Hondas rear seat, or the ditch.
4. The reaction arm is the single best thing for GMC braking engineering wise. The forward swing arm is a crazy design and the RA at least removes the brake jacking from the list of issues it has. The forward arm is bad on it's own, but paired with a backwards arm does bad things during braking. If we could just reverse the front arm, all these problems would go away...if just.
Tough choices sometimes
>
> Justin,
> Your correct in what our saying, however each coach brakes perform
> differently in the way they behave .
> believe it or not some do not lock up in the rear so much and depending on
> how you use the peddle, you can drop the speed more rapidly and let up on
> it slightly to avoid the skidding of the very rear wheels.
> We know the value of the Reaction Arm System as we have spent several
> weekends testing our Chuck Auguer kits and Tom Pryor's kit.
>
> On Wed, May 18, 2016 at 8:32 AM, Justin Brady wrote:
>
>> I think this is the real question. If it takes 1100 psi to lock the wheels
>> then spending time and money to get 2200 psi is doing you no good, other
>> than maybe locking the wheels earlier in the pedal movement.
>> I think the problem is contact with the road more so than line pressure.
>> Mine has stock brakes and I have no problem locking up the rear. It seems to
>> me that reaction arms are more likely to improve braking distance vs
>> additional line pressure. The tires have more grip on the road just before
>> they
>> lock than they do once locked up. (coefficient of static vs kinetic
>> friction)
>> Just my observations.
>>
>> James Hupy wrote on Tue, 17 May 2016 17:39
>>> How much pressure does it take to lock the wheels on dry pavement? If we
>>> know that, then we can determine if we need 2000 pounds of pressure at
>> the
>>> master cylinder.
>>> Jim Hupy
>>> Salem, Or
>>> 78 GMC ROYALE 403
>>> On May 17, 2016 3:34 PM, "Tom Whitton" wrote:
>>>
>>>> One of our well-informed members developed the following and sent it
>> to
>>>> Bob Stone who asked me to post it here for him. (Bob doesn't use a
>>>> computer)
>>>>
>>>>
>>>> "Master cylinder booster combinations and theoretical pressure"
>>>>
>>>> 1. Force available from vacuum booster Dave Lenzi panic stop 1,473
>> lbs.
>>>>
>>>> 2. Force available from Hydroboost 1.56" piston diameter and 1,350 PSI
>>>> steering pressure 2,579
>>>>
>>>> Vacuum Bob
>> Stone
>>>> Booster
>>>> Hydroboost
>>>>
>>>> 1.25" master cylinder 1,198 PSI 2,098 PSI
>>>>
>>>> 34 mm master cylinder 1,048 PSI 1,835 PSI
>>>>
>>>> 37 mm master cylinder 852 PSI 1,549 PSI
>>>>
>>>> 40 mm master cylinder 761 PSI 1,332 PSI
>>>>
>>>>
>>>> The Hydroboost force does not include additional force that can be
>> applied
>>>> by the pedal.
>>>>
>>>> Vacuum boost force does include additional force that can be applied
>> by
>>>> the pedal.
>>>>
>>>> Hydroboost conversion description here:
>>>> http://appliedgmc.com/images/hydro.pdf
>>>>
>>>> Please phone Bob Stone if you have questions: 618-964-9124
>>>>
>>>> Thanks,
>>>>
>>>> Tom Whitton
>>>> 26 foot updated GMC
>>>> Paducah, KY
>>>> _______________________________________________
>>>> GMCnet mailing list
>>>> Unsubscribe or Change List Options:
>>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>>
>> --
>> Justin Brady
>> http://www.thegmcrv.com/
>> 1976 Palm Beach 455
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
>
> --
> Jim Kanomata
> Applied/GMC, Fremont,CA
> jimk@appliedairfilters.com
> http://www.appliedgmc.com
> 1-800-752-7502
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
_______________________________________________
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Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #300760 is a reply to message #300720] |
Wed, 18 May 2016 14:55 |
Chris Tyler
Messages: 458
Registered: September 2013
Location: Odessa FL
Karma: 7
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Senior Member |
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Curious why 6 wheel discs would require more MC volume? I would think the pressure requirement would increase over volume as discs need more line pressure and do not retract as wheel cylinders do on drums. This is what I have found doing 4 wheel disc conversions on cars anyway. Maybe I'm missing something.
76 Glenbrook
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #300763 is a reply to message #300758] |
Wed, 18 May 2016 15:04 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
|
Senior Member |
|
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There is absolutely no way to dispute the effectiveness of Chuck Algur's
reaction arm brakes. After it was refined by Denney, Kanomata, and others
into what we are using now, it offers a huge advantage in stopping ability
on these coaches. I was present at Auburn, California at a GMCWS rally when
Rick was demonstrating his coach equipped with the reaction arms. 20 or so
attendees drove his coach and used the brakes very hard. Every one, upon
dismounting the coach, had wide eyes and positive comments. Those brakes
were so hot that the Alcoa wheels on the front would blister your fingers.
Coach still stopped great. Best braking improvement you can have.
Jim Hupy
Salem, Or
On May 18, 2016 12:23 PM, "Keith V" wrote:
> A couple of my opinions about braking.
>
> 1. Tire / road friction is not your high school friction. Rubber is
> sticky, the surface you are driving on may be sticky or it may be loose
> both of those interfaces, and others, do not follow simple friction
> physics. a sliding tire is not the same as sliding a block of steel on a
> steel plate, static and dynamic friction are a huge misnomer here. It's
> more like adhesive than friction
>
> 2. stopping a vehicle involves much more than locking up wheels. If you
> lock both rear wheels you have a high chance of the rear coming around on
> you, thats bad as it prevents you from applying maximum braking force to
> the front wheels. A well designed brake system will lock the front wheels
> first and the rears right after that. Then you can stop straight and fast
> even on a corner or while you are avoiding the dumbass in the honda that
> just pulled out in front of you.
>
> 3. Yes you only need enough line pressure to lock the front wheels on a
> hot summer day on good new asphalt. I know some roads that you will not be
> able to lock any wheels on, very rough and sticky even my Vette can't lock
> them up on it. Of course the more pressure you have the harder it is to
> modulate the brake pedal to NOT lock them up on a slippery surface, think
> of an old polished concrete road in the rain. Too much brake here could put
> you into Mr Hondas rear seat, or the ditch.
>
> 4. The reaction arm is the single best thing for GMC braking engineering
> wise. The forward swing arm is a crazy design and the RA at least removes
> the brake jacking from the list of issues it has. The forward arm is bad on
> it's own, but paired with a backwards arm does bad things during braking.
> If we could just reverse the front arm, all these problems would go
> away...if just.
>
> Tough choices sometimes
>
>>
>> Justin,
>> Your correct in what our saying, however each coach brakes perform
>> differently in the way they behave .
>> believe it or not some do not lock up in the rear so much and depending
> on
>> how you use the peddle, you can drop the speed more rapidly and let up on
>> it slightly to avoid the skidding of the very rear wheels.
>> We know the value of the Reaction Arm System as we have spent several
>> weekends testing our Chuck Auguer kits and Tom Pryor's kit.
>>
>> On Wed, May 18, 2016 at 8:32 AM, Justin Brady wrote:
>>
>>> I think this is the real question. If it takes 1100 psi to lock the
> wheels
>>> then spending time and money to get 2200 psi is doing you no good,
> other
>>> than maybe locking the wheels earlier in the pedal movement.
>>> I think the problem is contact with the road more so than line
> pressure.
>>> Mine has stock brakes and I have no problem locking up the rear. It
> seems to
>>> me that reaction arms are more likely to improve braking distance vs
>>> additional line pressure. The tires have more grip on the road just
> before
>>> they
>>> lock than they do once locked up. (coefficient of static vs kinetic
>>> friction)
>>> Just my observations.
>>>
>>> James Hupy wrote on Tue, 17 May 2016 17:39
>>>> How much pressure does it take to lock the wheels on dry pavement?
> If we
>>>> know that, then we can determine if we need 2000 pounds of pressure
> at
>>> the
>>>> master cylinder.
>>>> Jim Hupy
>>>> Salem, Or
>>>> 78 GMC ROYALE 403
>>>> On May 17, 2016 3:34 PM, "Tom Whitton" wrote:
>>>>
>>>> > One of our well-informed members developed the following and sent
> it
>>> to
>>>> > Bob Stone who asked me to post it here for him. (Bob doesn't use
> a
>>>> > computer)
>>>> >
>>>> >
>>>> > "Master cylinder booster combinations and theoretical pressure"
>>>> >
>>>> > 1. Force available from vacuum booster Dave Lenzi panic stop 1,473
>>> lbs.
>>>> >
>>>> > 2. Force available from Hydroboost 1.56" piston diameter and
> 1,350 PSI
>>>> > steering pressure 2,579
>>>> >
>>>> > Vacuum
> Bob
>>> Stone
>>>> > Booster
>>>> > Hydroboost
>>>> >
>>>> > 1.25" master cylinder 1,198 PSI 2,098 PSI
>>>> >
>>>> > 34 mm master cylinder 1,048 PSI 1,835 PSI
>>>> >
>>>> > 37 mm master cylinder 852 PSI 1,549 PSI
>>>> >
>>>> > 40 mm master cylinder 761 PSI 1,332 PSI
>>>> >
>>>> >
>>>> > The Hydroboost force does not include additional force that can be
>>> applied
>>>> > by the pedal.
>>>> >
>>>> > Vacuum boost force does include additional force that can be
> applied
>>> by
>>>> > the pedal.
>>>> >
>>>> > Hydroboost conversion description here:
>>>> > http://appliedgmc.com/images/hydro.pdf
>>>> >
>>>> > Please phone Bob Stone if you have questions: 618-964-9124
>>>> >
>>>> > Thanks,
>>>> >
>>>> > Tom Whitton
>>>> > 26 foot updated GMC
>>>> > Paducah, KY
>>>> > _______________________________________________
>>>> > GMCnet mailing list
>>>> > Unsubscribe or Change List Options:
>>>> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>> >
>>>> _______________________________________________
>>>> GMCnet mailing list
>>>> Unsubscribe or Change List Options:
>>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>
>>>
>>> --
>>> Justin Brady
>>> http://www.thegmcrv.com/
>>> 1976 Palm Beach 455
>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>
>>
>>
>>
>> --
>> Jim Kanomata
>> Applied/GMC, Fremont,CA
>> jimk@appliedairfilters.com
>> http://www.appliedgmc.com
>> 1-800-752-7502
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
_______________________________________________
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #300783 is a reply to message #300760] |
Wed, 18 May 2016 21:34 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
|
Senior Member |
|
|
Kieth,
Your very correct in your understanding.
I know from experience since 1980 that the only rear that skids are the
very rear ones, not the intermediate.
Coefficient of friction drops dramatically when it starts skidding.I do not
recall in my engineering course where we needed to solve a problem when
something was skidding, so I have no worthwhile answer.
On Wed, May 18, 2016 at 12:55 PM, Chris Tyler
wrote:
> Curious why 6 wheel discs would require more MC volume? I would think the
> pressure requirement would increase over volume as discs need more line
> pressure and do not retract as wheel cylinders do on drums. This is what I
> have found doing 4 wheel disc conversions on cars anyway. Maybe I'm missing
> something.
> --
> 76 Glenbrook
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #300799 is a reply to message #300720] |
Thu, 19 May 2016 09:34 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
|
Senior Member |
|
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As an empiricist, I'll add a personal observation. Both my new and old coaches have rear drums. The brakes work 'properly' in both. The coach with reaction arms stops a hell opf a lot better than the one without. Conclusion - mod is in the near future for the new to me coach.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #301119 is a reply to message #300763] |
Wed, 25 May 2016 23:54 |
Richard Denney
Messages: 920
Registered: April 2010
Karma: 9
|
Senior Member |
|
|
I'm seeing what sorta looks like my name, but I only wish I had the
reaction rods installed or any role in their creation. Musta been somebody
else, heh.
To the topic, in a panic stop, I'm not happy until I can lock the FRONT
brakes. The rear rear wheels might lock up at 1100 psi (I dunno) and more
pressure won't make them more locked. But more pressure will still create
more gripping force in the brakes that have not yet locked. In a panic, I
have bigger concerns that preventing flat spots.
Rick "too much can be modulated, but not enough has no cure" Denney
On Wednesday, May 18, 2016, James Hupy wrote:
> There is absolutely no way to dispute the effectiveness of Chuck Algur's
> reaction arm brakes. After it was refined by Denney, Kanomata, and others
> into what we are using now, it offers a huge advantage in stopping ability
> on these coaches. I was present at Auburn, California at a GMCWS rally when
> Rick was demonstrating his coach equipped with the reaction arms. 20 or so
> attendees drove his coach and used the brakes very hard. Every one, upon
> dismounting the coach, had wide eyes and positive comments. Those brakes
> were so hot that the Alcoa wheels on the front would blister your fingers.
> Coach still stopped great. Best braking improvement you can have.
> Jim Hupy
> Salem, Or
>
--
'73 230 "Jaws"
Northern Virginia
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #301120 is a reply to message #301119] |
Thu, 26 May 2016 00:46 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
|
Senior Member |
|
|
Chuck Algur, Rick Flanagan, Nick and I spent few weekends testing them.
We can tell you it works using our caliper system.
Rick elected to make it very beefy and the cost shows it.
Tom Pryor came to me and asked me if he could do a drum drum reaction
system.
Chuck and Rick felt it would be rather complicated to do drum reaction back
then.
Tom did come up with drum drum unit, and we tested them here for few days
ad got good results.
I can tell you things like how the drum brakes do not function linear like
the caliper and not as predictable.
Manny copied our Disc unit, but used the smaller calipers.Results speak for
themself.
Most people do not really understand the way the reaction arm works, Chuck
got very upset at a person when he realized he did not fully understand it.
We learned from brake suppliers that the smaller calipers do not hold a
candle to our standard calipers.
Albert Branscome gave a seminar on the performance of our system vs. the
other as he is very studious engineer.
Anyone that want to know more can call me.
On Wed, May 25, 2016 at 9:54 PM, Richard Denney wrote:
> I'm seeing what sorta looks like my name, but I only wish I had the
> reaction rods installed or any role in their creation. Musta been somebody
> else, heh.
>
> To the topic, in a panic stop, I'm not happy until I can lock the FRONT
> brakes. The rear rear wheels might lock up at 1100 psi (I dunno) and more
> pressure won't make them more locked. But more pressure will still create
> more gripping force in the brakes that have not yet locked. In a panic, I
> have bigger concerns that preventing flat spots.
>
> Rick "too much can be modulated, but not enough has no cure" Denney
>
> On Wednesday, May 18, 2016, James Hupy wrote:
>
>> There is absolutely no way to dispute the effectiveness of Chuck Algur's
>> reaction arm brakes. After it was refined by Denney, Kanomata, and others
>> into what we are using now, it offers a huge advantage in stopping
> ability
>> on these coaches. I was present at Auburn, California at a GMCWS rally
> when
>> Rick was demonstrating his coach equipped with the reaction arms. 20 or
> so
>> attendees drove his coach and used the brakes very hard. Every one, upon
>> dismounting the coach, had wide eyes and positive comments. Those brakes
>> were so hot that the Alcoa wheels on the front would blister your
> fingers.
>> Coach still stopped great. Best braking improvement you can have.
>> Jim Hupy
>> Salem, Or
>>
>
>
> --
> '73 230 "Jaws"
> Northern Virginia
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: [GMCnet] Higher the line pressure the better the braking power [message #301125 is a reply to message #301119] |
Thu, 26 May 2016 06:29 |
bdub
Messages: 1578
Registered: February 2004
Location: Central Texas
Karma: 5
|
Senior Member |
|
|
Hi Rick
Long time, no see.
I believe the Denny Jim speaks of is the late Denny Alan.
Rick, I hope you're able to join us more frequently these days. We've missed your excellent posts.
bdub
-----Original Message-----
From: Gmclist On Behalf Of Richard Denney
Sent: Wednesday, May 25, 2016 11:55 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Higher the line pressure the better the braking power
I'm seeing what sorta looks like my name, but I only wish I had the
reaction rods installed or any role in their creation. Musta been somebody
else, heh.
To the topic, in a panic stop, I'm not happy until I can lock the FRONT
brakes. The rear rear wheels might lock up at 1100 psi (I dunno) and more
pressure won't make them more locked. But more pressure will still create
more gripping force in the brakes that have not yet locked. In a panic, I
have bigger concerns that preventing flat spots.
Rick "too much can be modulated, but not enough has no cure" Denney
On Wednesday, May 18, 2016, James Hupy wrote:
> There is absolutely no way to dispute the effectiveness of Chuck Algur's
> reaction arm brakes. After it was refined by Denney, Kanomata, and others
> into what we are using now, it offers a huge advantage in stopping ability
> on these coaches. I was present at Auburn, California at a GMCWS rally when
> Rick was demonstrating his coach equipped with the reaction arms. 20 or so
> attendees drove his coach and used the brakes very hard. Every one, upon
> dismounting the coach, had wide eyes and positive comments. Those brakes
> were so hot that the Alcoa wheels on the front would blister your fingers.
> Coach still stopped great. Best braking improvement you can have.
> Jim Hupy
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
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bdub
'76 Palm Beach/Central Texas
www.bdub.net
www.gmcmhphotos.com
www.gmcmotorhomemarketplace.com
www.gmcmhregistry.com
www.facebook.com/groups/classicgmcmotorhomes
www.facebook.com/groups/gmcmm
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