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Trip Report (in segments). [message #343137]

Mon, 06 May 2019 11:53

Scott Nutter

Messages: 782
Registered: January 2015
Location: Houston/San Diego

Karma: 4

Senior Member

First of all, this is our first trip with all systems at 100%!!
It has been 4 years of sweat, research, phone calls, and money. But she is worth it!!

1st leg, Houston to New Orleans.

The Paterson 455 with the MSD EFI is purring like a kitten. Zero issues, but with all the drag from the AC's, roof pod, and towing a Tracker my MPG is right at 7 MPG. But I'm good with that because she likes doing the speed limit plus about 5 MPH on top of that at times. The 80mm brakes are working fine, especially with being as heavy as we are. But I do see Dave Lenzi's mid wheel disc brake setup in the future.

The biggest improvement I've noticed on this leg is the drivability after putting on new ride height sensors that actually work! It really is driving with a couple of fingers with crosswinds and passing semi's to boot. It's a whole new experience! I actually think a person could drive this while drinking a martini and smoking a cigar (maybe more on that on the 2nd leg update!). But I also see the Keith V Microlevel system in the future.

It was amazing how much les fatigued I was after the 400 mile drive to New Orleans. Another first for me... I know I will have some issues in the years, or months ahead, but I'm a believer in "if you treat the coach right, she will treat you right".

I would like to thank everyone who has helped out to get her to 100%, and the forum members with their informative posts.
This truly is our funnest trip to date!!
Next leg, New Orleans to Gulf shores state campgrounds!!

Scott Nutter.

Scott Nutter 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI Houston, Texas

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Re: [GMCnet] Trip Report (in segments). [message #343143 is a reply to message #343137]

Mon, 06 May 2019 14:43

powwerjon

Messages: 849
Registered: March 2013

Karma: -2

Senior Member

Scott,

If your running across I-10 running 70 to 75 MPH and running heavy then your doing extremely good on fuel milage. I typically run at 64-65 MPH on the interstates as I get the best milage which with our coach is 7+MPG. Does your cruise control work? That takes a lot of fatigue out of driving too.

J.R. Wright
GMC Great Laker MHC
GMCGL Tech Editor
GMC Eastern States Charter Member
GMCMI
78 GMC Buskirk 29.5’ Stretch
75 GMC Avion (Under Reconstruction)
Michigan

> On May 6, 2019, at 12:53 PM, Scott Nutter via Gmclist wrote:
>
> First of all, this is our first trip with all systems at 100%!!
> It has been 4 years of sweat, research, phone calls, and money. But she is worth it!!
>
> 1st leg, Houston to New Orleans.
>
> The Paterson 455 with the MSD EFI is purring like a kitten. Zero issues, but with all the drag from the AC's, roof pod, and towing a Tracker my MPG is
> right at 7 MPG. But I'm good with that because she likes doing the speed limit plus about 5 MPH on top of that at times. The 80mm brakes are working
> fine, especially with being as heavy as we are. But I do see Dave Lenzi's mid wheel disc brake setup in the future.
>
> The biggest improvement I've noticed on this leg is the drivability after putting on new ride height sensors that actually work! It really is driving
> with a couple of fingers with crosswinds and passing semi's to boot. It's a whole new experience! I actually think a person could drive this while
> drinking a martini and smoking a cigar (maybe more on that on the 2nd leg update!). But I also see the Keith V Microlevel system in the future.
>
> It was amazing how much les fatigued I was after the 400 mile drive to New Orleans. Another first for me... I know I will have some issues in the
> years, or months ahead, but I'm a believer in "if you treat the coach right, she will treat you right".
>
> I would like to thank everyone who has helped out to get her to 100%, and the forum members with their informative posts.
> This truly is our funnest trip to date!!
> Next leg, New Orleans to Gulf shores state campgrounds!!
>
> Scott Nutter.
>
> --
> Scott Nutter
> 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, tankless water heater, everything Lenzi. Alex Ferrera
> installed MSD Atomic EFI
> Houston, Texas
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

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Re: Trip Report (in segments). [message #343144 is a reply to message #343137]

Mon, 06 May 2019 16:14

Scott Nutter

Messages: 782
Registered: January 2015
Location: Houston/San Diego

Karma: 4

Senior Member

Hi John,
I've never liked cruise control, so I disconnected It. Just mental I guess.
But to be fair on the gas mileage, I will have a more accurate tally at the 1,000 mile mark on this trip. I'm guessing it's going to drop to 6 to 6.5 MPG. On this next leg we will be running with the dash AC on.
Scott.

Scott Nutter 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI Houston, Texas

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Re: [GMCnet] Trip Report (in segments). [message #343145 is a reply to message #343137]

Mon, 06 May 2019 18:31

Ken Henderson

Messages: 8726
Registered: March 2004
Location: Americus, GA

Karma: 9

Senior Member

Scott,

It's always great to hear of a routine GMC trip. I've had many over the
past 21 years, including the 400+ miles to TN last Thursday and the return
yesterday. I don't attempt to compute gas mileage, but since I made that
trip in a rare configuration (without toad), I probably got close to the
fabled 10 mpg, cruising at the speed limits.

What I wanted to suggest to you is that you reconsider your plan on
mid-wheel brakes. With all due respect to Dave Lenzi, the physical fact is
that improving mid-wheel braking can only worsen the very worst feature of
the GMC's suspension system. Unless you include some variant of a
"reaction arm" system, improved center braking WILL worsen the tendency to
slide and flat-spot the rear-most tires. I've tried almost every variation
of mid- and rear-wheel brakes and every one of them, until I installed the
rear Manny Brakes, had that result. To the extent that I was running
4-wheel brakes before the Manny Brakes. Now, I have good, useable, 6-wheel
brakes with no "pole vaulting". I do wish the rear calipers were larger,
but I probably wouldn't really have better braking.

JMHO,

Ken H.
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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: Trip Report (in segments). [message #343146 is a reply to message #343137]

Mon, 06 May 2019 19:15

Scott Nutter

Messages: 782
Registered: January 2015
Location: Houston/San Diego

Karma: 4

Senior Member

Thanks Ken,
Something to think about.
BTW, your wiper system is a vast improvement. Especially the intermittent cycle.
Scott.

Scott Nutter 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI Houston, Texas

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Re: [GMCnet] Trip Report (in segments). [message #343148 is a reply to message #343145]

Mon, 06 May 2019 20:09

emerystora

Messages: 4442
Registered: January 2004

Karma: 13

Senior Member

Ken
With Lenzi’s system on my mid axle and no brakes on the third axle I have fantastic braking even when pulling a toad and driving in the mountains. Since everyone has said that the rear axle gives very little braking I thought I’d try using no brakes there.

And, of course, I cannot slide or flat spot the rear tires or “pole vault” as I have no brakes on the rear axle.

The brake system was originally designed for a 30 to 40,000 pound two axle truck with duals on the rear axle. At first I was concerned that I might slide the center tires since they were not duals but that has not occurred in over 15,000 miles.

I used the system to replace the TSM 4 rear disk brake system. I thought I had good braking with that but the Lenzi single rear caliper on each side with the 13” disks gives me much, much better braking.

I also save the $1600 to $1800 cost of the reaction arm system as I don’t need one with my setup.

I’ll have my GMC at the Mansfield, Ohio GMCMI convention in October if anyone wants to drive it.

Emery Stora
77 Kingsley
Frederick, CO

> On May 6, 2019, at 5:31 PM, Ken Henderson via Gmclist wrote:
>
> Scott,
>
> It's always great to hear of a routine GMC trip. I've had many over the
> past 21 years, including the 400+ miles to TN last Thursday and the return
> yesterday. I don't attempt to compute gas mileage, but since I made that
> trip in a rare configuration (without toad), I probably got close to the
> fabled 10 mpg, cruising at the speed limits.
>
> What I wanted to suggest to you is that you reconsider your plan on
> mid-wheel brakes. With all due respect to Dave Lenzi, the physical fact is
> that improving mid-wheel braking can only worsen the very worst feature of
> the GMC's suspension system. Unless you include some variant of a
> "reaction arm" system, improved center braking WILL worsen the tendency to
> slide and flat-spot the rear-most tires. I've tried almost every variation
> of mid- and rear-wheel brakes and every one of them, until I installed the
> rear Manny Brakes, had that result. To the extent that I was running
> 4-wheel brakes before the Manny Brakes. Now, I have good, useable, 6-wheel
> brakes with no "pole vaulting". I do wish the rear calipers were larger,
> but I probably wouldn't really have better braking.
>
> JMHO,
>
> Ken H.
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

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Re: [GMCnet] Trip Report (in segments). [message #343149 is a reply to message #343148]

Mon, 06 May 2019 20:32

sgltrac

Messages: 2797
Registered: April 2011

Karma: 1

Senior Member

I’ve had two gmc coaches. Both 77s. One with six disc and one stock
configuration. The stock braked coach had better pedal feel and braking
power/ response. It is likely that the pedal and response on the all disc
system was due to the integration (or lack thereof ) of the modified system
but that does not really change the arguememt. The stock brake system in
proper condition is plenty adequate. I am always towing something and
frequent the cascade mountain range.

My 2c

Sully
Bellevue. Wa

On Mon, May 6, 2019 at 6:10 PM Emery Stora via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Ken
> With Lenzi’s system on my mid axle and no brakes on the third axle I have
> fantastic braking even when pulling a toad and driving in the mountains.
> Since everyone has said that the rear axle gives very little braking I
> thought I’d try using no brakes there.
>
> And, of course, I cannot slide or flat spot the rear tires or “pole vault”
> as I have no brakes on the rear axle.
>
> The brake system was originally designed for a 30 to 40,000 pound two axle
> truck with duals on the rear axle. At first I was concerned that I might
> slide the center tires since they were not duals but that has not occurred
> in over 15,000 miles.
>
> I used the system to replace the TSM 4 rear disk brake system. I thought I
> had good braking with that but the Lenzi single rear caliper on each side
> with the 13” disks gives me much, much better braking.
>
> I also save the $1600 to $1800 cost of the reaction arm system as I don’t
> need one with my setup.
>
> I’ll have my GMC at the Mansfield, Ohio GMCMI convention in October if
> anyone wants to drive it.
>
> Emery Stora
> 77 Kingsley
> Frederick, CO
>
>> On May 6, 2019, at 5:31 PM, Ken Henderson via Gmclist gmclist@list.gmcnet.org> wrote:
>>
>> Scott,
>>
>> It's always great to hear of a routine GMC trip. I've had many over the
>> past 21 years, including the 400+ miles to TN last Thursday and the
> return
>> yesterday. I don't attempt to compute gas mileage, but since I made that
>> trip in a rare configuration (without toad), I probably got close to the
>> fabled 10 mpg, cruising at the speed limits.
>>
>> What I wanted to suggest to you is that you reconsider your plan on
>> mid-wheel brakes. With all due respect to Dave Lenzi, the physical fact
> is
>> that improving mid-wheel braking can only worsen the very worst feature
> of
>> the GMC's suspension system. Unless you include some variant of a
>> "reaction arm" system, improved center braking WILL worsen the tendency
> to
>> slide and flat-spot the rear-most tires. I've tried almost every
> variation
>> of mid- and rear-wheel brakes and every one of them, until I installed
> the
>> rear Manny Brakes, had that result. To the extent that I was running
>> 4-wheel brakes before the Manny Brakes. Now, I have good, useable,
> 6-wheel
>> brakes with no "pole vaulting". I do wish the rear calipers were larger,
>> but I probably wouldn't really have better braking.
>>
>> JMHO,
>>
>> Ken H.
>> _______________________________________________
>> 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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Sully 77 Royale basket case. Future motorhome land speed record holder(bucket list) Seattle, Wa.

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Re: Trip Report (in segments). [message #343150 is a reply to message #343137]

Mon, 06 May 2019 21:10

Scott Nutter

Messages: 782
Registered: January 2015
Location: Houston/San Diego

Karma: 4

Senior Member

I really do appreciate everyone's opinion on the rear brakes.
I'm still giddy because of the ease of driving with a working ride height sensor!
My 1st GMC was a fairly light 77 Palm Beach that I had for about 18 years and never left California with (except for the last ride to Texas).. That one would stop with no problem, but I was never towing.
My 78 Royale is a heavy beast... and always towing.... the stock brakes are totally inadequate.. 80 mm's upfront are a improvement, but not the solution..
Pedal feel is very important to me, and I hate the fade of brake shoes.. and I also think the most rear boogie brakes are completely useless. The only reason I say that is that mine completely lock up when ever there is moisture on the pavement (and that is with minimal pressure on the brake pedal). Why even use them? Maybe they give me 5% braking at most?
Scott.

Scott Nutter 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI Houston, Texas

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Re: Trip Report (in segments). [message #343151 is a reply to message #343150]

Mon, 06 May 2019 22:33

Carl S.

Messages: 4186
Registered: January 2009
Location: Tucson, AZ.

Karma: 13

Senior Member

I kind of hate to contribute to this discussion, since everyone has their opinion on what the best brake system is, kind of like oil and air bags, but I really like my Applied GMC six wheel disc brakes and the Chuck Aulgur reaction arm system:

http://www.gmcmhphotos.com/photos/g5831-disc-brakes-2fchuck-aulgur-reaction-arm-install.html

With the possible exception of the P-30 master cylinder not being a perfect fit for the system, it has been great and has saved my bacon more than once since I installed it. Before that, I had adequate brakes, but would skid the rear wheels under a panic stop condition. With the reaction arm system, the coach hunkers down and stops like a sports car.

I also do my share of mountain driving (out here in the West, if you're not going up, you're going down) and I don't need to worry, as much, about brake fade or overheated drum brakes. As an added bonus, the 'torque boxes' attached to the sway bars act the same as the true track system to keep the back wheels in line.

Next to the recent engine/transmission replacement, it was the most expensive thing I have done to the coach, but totally worth it. The thing that sold me on it was the substantial reduction in stopping distance as explained in the following Slide from Chuck:

http://www.gmcmhphotos.com/photos/cad-photos/p34215-swaybar-reaction-arm-combo-10.html

Carl Stouffer '75 ex Palm Beach Tucson, AZ. Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member

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Re: [GMCnet] Trip Report (in segments). [message #343154 is a reply to message #343151]

Tue, 07 May 2019 11:49

jimk

Messages: 6734
Registered: July 2006
Location: Belmont, CA

Karma: 9

Senior Member

Were not comparing brake system properly.
TSM disc brakes are what we refer to as Baby caliper system and is no
better than the drum.Al Banscombe can validate what I'm saying as he is an
Engineer that can still crank out numbers and equations.
The Auguer reaction system utilizes the larger calipers and out stop the
drums and the TSM.
I dare anyone to slam on the brake at 60mph and see what happens. One will
go into a skid that will scare you.
Chuck Augler, Rick Flanagan, Nick G, and I spent few days doing tests on
our long parking lot and on two weekends on a closed road, so we know what
can happen.
Frank Condos, a Mechanical Engineer also addressed the design of the
massive intermediate braking as not very desirable.
Bottom line is that if it brakes well at lower speeds does not mean it will
behave at higher speeds, or panic stop.
Please do NOT compare the Chuck Auglur Reaction arm to the Manny unit as
our unit have the larger calipers. Manny system uses the TSM, which is way
smaller.
JUST BE CAREFUL when doing panic stops at higher speeds.

On Mon, May 6, 2019 at 8:33 PM Carl Stouffer via Gmclist <
gmclist@list.gmcnet.org> wrote:

> I kind of hate to contribute to this discussion, since everyone has their
> opinion on what the best brake system is, kind of like oil and air bags, but
> I really like my Applied GMC six wheel disc brakes and the Chuck Aulgur
> reaction arm system:
>
>
> http://www.gmcmhphotos.com/photos/g5831-disc-brakes-2fchuck-aulgur-reaction-arm-install.html
>
> With the possible exception of the P-30 master cylinder not being a
> perfect fit for the system, it has been great and has saved my bacon more
> than
> once since I installed it. Before that, I had adequate brakes, but would
> skid the rear wheels under a panic stop condition. With the reaction arm
> system, the coach hunkers down and stops like a sports car.
>
> I also do my share of mountain driving (out here in the West, if you're
> not going up, you're going down) and I don't need to worry, as much, about
> brake fade or overheated drum brakes. As an added bonus, the 'torque
> boxes' attached to the sway bars act the same as the true track system to
> keep
> the back wheels in line.
>
> Next to the recent engine/transmission replacement, it was the most
> expensive thing I have done to the coach, but totally worth it. The thing
> that
> sold me on it was the substantial reduction in stopping distance as
> explained in the following Slide from Chuck:
>
>
> http://www.gmcmhphotos.com/photos/cad-photos/p34215-swaybar-reaction-arm-combo-10.html
> --
> Carl Stouffer
> '75 ex Palm Beach
> Tucson, AZ.
> Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive,
> Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American
> Eagles,
> Solar battery charging. GMCSJ and GMCMI member
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,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] Trip Report (in segments). [message #343157 is a reply to message #343154]

Tue, 07 May 2019 13:01

emerystora

Messages: 4442
Registered: January 2004

Karma: 13

Senior Member

Well, Jim — I am not comparing TSM brakes to the Auguer system or to the Manny system. I am comparing Dave Lenzi’s system to previous systems I have used. I have never used the reaction arm system so I cannot address that. It doesn’t sound like you have ever tested the Lenzi system so you also really cannot compare it to what you have tried. I respect your expertise in a lot of areas but until you road test that specific system you cannot really opine on it.

When I put on the Lenzi brake kit and left the brakes off the rear axle, I tested the system to determine if I wanted to put the rear brakes back onto the rearmost axle, which I could easily do. One of my tests was to do panic stops, not at 60 mph but first at 35 mph, then at 50 mph and then at 65 mph. I DID NOT ”go into a skid that scared me” but rather had a very controlled stop. It did shove my torso forward but I had expected it to do so. I had been concerned with the amount of tread contact with the road on my rear braking tires but that did not prove to be a problem.

I am extremely happy with my setup and don’t expect to make any changes.

I also have an Engineering degree, from the University of Michigan which included Chemical Engineering as well as courses in Mechanical, Electrical and Nuclear Engineering so I can also “crank out numbers and equations” but I feel that can assist in the design of a product but the final product has to be tested to see if it works. I did adequate tests to satisfy me and Lenzi did several months of road tests before making it available to others.

I guess you and I will just have to disagree on the suitability of Lenzi’s system but I am a believer. It was designed to stop a 30,000 + pound truck with one rear axle and it does a super job stopping a 12,000 pound motor home.

Emery Stora
77 Kingsley
Frederick, CO

> On May 7, 2019, at 10:49 AM, Jim Kanomata via Gmclist wrote:
>
> Were not comparing brake system properly.
> TSM disc brakes are what we refer to as Baby caliper system and is no
> better than the drum.Al Banscombe can validate what I'm saying as he is an
> Engineer that can still crank out numbers and equations.
> The Auguer reaction system utilizes the larger calipers and out stop the
> drums and the TSM.
> I dare anyone to slam on the brake at 60mph and see what happens. One will
> go into a skid that will scare you.
> Chuck Augler, Rick Flanagan, Nick G, and I spent few days doing tests on
> our long parking lot and on two weekends on a closed road, so we know what
> can happen.
> Frank Condos, a Mechanical Engineer also addressed the design of the
> massive intermediate braking as not very desirable.
> Bottom line is that if it brakes well at lower speeds does not mean it will
> behave at higher speeds, or panic stop.
> Please do NOT compare the Chuck Auglur Reaction arm to the Manny unit as
> our unit have the larger calipers. Manny system uses the TSM, which is way
> smaller.
> JUST BE CAREFUL when doing panic stops at higher speeds.
>
>

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Re: [GMCnet] Trip Report (in segments). [message #343158 is a reply to message #343148]

Tue, 07 May 2019 14:20

Ken Henderson

Messages: 8726
Registered: March 2004
Location: Americus, GA

Karma: 9

Senior Member

It's beyond my understanding how anyone can expect 4 tires to apply more
retarding force to the road than can 6 tires. And that is exactly what the
result is when anyone uses ANY brakes, whether OEM or any other, including
ANY discs, with the original rear suspension system. It's simply
impossible for the rear-most wheels to apply full force to the pavement
when being lifted by the "pole-vaulting" center arms. Only reaction arms
allow the torque about the center wheels to be transferred to the chassis,
and thence to the front wheels, rather than to the center suspension arm
and thence to raising the rear of the coach -- to the extent of unloading
the rear wheels.

Personally I wouldn't for a moment consider again owning a GMC without
reaction arm rear brakes, whether Aulgur, Justico, Manny, Pryor, or some
other. There's simply way to achieve maximum braking force without
eliminating that leading suspension arm's adverse load transfer.

Ken H.

On Mon, May 6, 2019 at 9:10 PM Emery Stora via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Ken
> With Lenzi’s system on my mid axle and no brakes on the third axle I have
> fantastic braking even when pulling a toad and driving in the mountains.
> Since everyone has said that the rear axle gives very little braking I
> thought I’d try using no brakes there.
>
> And, of course, I cannot slide or flat spot the rear tires or “pole vault”
> as I have no brakes on the rear axle.
>
> The brake system was originally designed for a 30 to 40,000 pound two axle
> truck with duals on the rear axle. At first I was concerned that I might
> slide the center tires since they were not duals but that has not occurred
> in over 15,000 miles.
>
> I used the system to replace the TSM 4 rear disk brake system. I thought I
> had good braking with that but the Lenzi single rear caliper on each side
> with the 13” disks gives me much, much better braking.
>
> I also save the $1600 to $1800 cost of the reaction arm system as I don’t
> need one with my setup.
>
> I’ll have my GMC at the Mansfield, Ohio GMCMI convention in October if
> anyone wants to drive it.
>
> Emery Stora
> 77 Kingsley
> Frederick, CO
>
>> On May 6, 2019, at 5:31 PM, Ken Henderson via Gmclist gmclist@list.gmcnet.org> wrote:
>>
>> Scott,
>>
>> It's always great to hear of a routine GMC trip. I've had many over the
>> past 21 years, including the 400+ miles to TN last Thursday and the
> return
>> yesterday. I don't attempt to compute gas mileage, but since I made that
>> trip in a rare configuration (without toad), I probably got close to the
>> fabled 10 mpg, cruising at the speed limits.
>>
>> What I wanted to suggest to you is that you reconsider your plan on
>> mid-wheel brakes. With all due respect to Dave Lenzi, the physical fact
> is
>> that improving mid-wheel braking can only worsen the very worst feature
> of
>> the GMC's suspension system. Unless you include some variant of a
>> "reaction arm" system, improved center braking WILL worsen the tendency
> to
>> slide and flat-spot the rear-most tires. I've tried almost every
> variation
>> of mid- and rear-wheel brakes and every one of them, until I installed
> the
>> rear Manny Brakes, had that result. To the extent that I was running
>> 4-wheel brakes before the Manny Brakes. Now, I have good, useable,
> 6-wheel
>> brakes with no "pole vaulting". I do wish the rear calipers were larger,
>> but I probably wouldn't really have better braking.
>>
>> JMHO,
>>
>> Ken H.
>> _______________________________________________
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>
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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] Trip Report (in segments). [message #343160 is a reply to message #343137]

Tue, 07 May 2019 15:00

Richard Denney

Messages: 920
Registered: April 2010

Karma: 9

Senior Member

Maybe it’s just me, but I cower in fear when words like this are uttered
out loud.

When I bought the GMC, mechanic friends said, “Cool! Buy a good set of
tools.” And, “it’s like your house—something always needs repair.” It’s
true with any RV, no matter what its age.

But we are quiet about these things. The RV gods are capricious and don’t
like to be taunted.

(It’s great to have all systems working as they should, isn’t it?)

Rick “who has had many perfect trips in the last 16 years of GMC ownership,
but never with a perfect coach” Denney

On Mon, May 6, 2019 at 7:29 PM Scott Nutter via Gmclist <
gmclist@list.gmcnet.org> wrote:

> First of all, this is our first trip with all systems at 100%!!
>

> --
'73 X-Glacier 230 "Jaws"
Northern Virginia
Offlist email: rick at rickdenney dot com
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Re: [GMCnet] Trip Report (in segments). [message #343167 is a reply to message #343160]

Tue, 07 May 2019 19:43

jimk

Messages: 6734
Registered: July 2006
Location: Belmont, CA

Karma: 9

Senior Member

I know we all have discussion, and take this as discussion.
I'm not here to put anyone down, but to point out what I feel I know.
Emory knows I respect him as a person and an Engineer, so as you read our
discussion, do not think for a second we are arguing.
One needs to hear me having discussions with lot of other people on other
issues and they all are my friends.

On Tue, May 7, 2019 at 1:16 PM Richard Denney via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Maybe it’s just me, but I cower in fear when words like this are uttered
> out loud.
>
> When I bought the GMC, mechanic friends said, “Cool! Buy a good set of
> tools.” And, “it’s like your house—something always needs repair.” It’s
> true with any RV, no matter what its age.
>
> But we are quiet about these things. The RV gods are capricious and don’t
> like to be taunted.
>
> (It’s great to have all systems working as they should, isn’t it?)
>
> Rick “who has had many perfect trips in the last 16 years of GMC ownership,
> but never with a perfect coach” Denney
>
> On Mon, May 6, 2019 at 7:29 PM Scott Nutter via Gmclist gmclist@list.gmcnet.org> wrote:
>
>> First of all, this is our first trip with all systems at 100%!!
>>
>
>> --
> '73 X-Glacier 230 "Jaws"
> Northern Virginia
> Offlist email: rick at rickdenney dot com
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,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] Trip Report (in segments). [message #343173 is a reply to message #343154]

Tue, 07 May 2019 22:21

78 Barbi

Messages: 80
Registered: August 2004
Location: Tiverton, Ontario , Canad...

Karma: -1

Member

ITEMS TO CONSIDER WHEN UPGRADING TO LARGE MID WHEEL DISCS ON GMC-MH

1/ Frank Condos made the following statement back in Dec. 2000 regarding possible problems one could encounter when using the mid wheel Harrison disc system.
" The configuration with the large 12.5" discs clearly shifts much of the braking to the rear. Under dry pavement conditions this high percentage of rear braking may not be a problem. However with wet or icy conditions an emergency stop can cause rear lock up and loss of control with excessive rear braking (the reason ABS is standard on most pickup trucks)."

2/ One must remember that it's not your rotors, your brake pads or your calipers that ultimately stops your coach , It's your tire patch in contact with the road surface that stops your coach. For those folk that are relying on 4 discs instead of 6, you are potentially sacrificing 1/3 of your total braking capacity .

3/ With the design of our forward bogie arm we have not only the standard " pitch forward component " to contend with but also the " pitch forward component " caused by the " pole vaulting " effect of said forward bogie. Even with 4 OEM rear drums at approx. 950 pounds braking force per wheel , it is possible to skid the rear most wheels due to bogie lift. This phenomena has been documentated many times by coach owners, myself included. The " Reaction Arm " systems eliminated this problem completely and afforded owners maximum braking on all 6 wheels.

4/ With a " pitch forward" component of slightly greater than 50% , one winds up with 6000 pounds plus on the two front wheels , this is where the " One Ton" front kits shine because they have the capability to address such loads. With that said; this leaves approx . 6000 pounds or slightly less shared by the 4 rear wheels, But with between 0 and 175 pounds down force on each rearmost wheel , the weight load on the mid wheel set is still approx. 6000 pounds shared by essentially 2 wheels at maximum braking with an OEM master cylinder at 1,000 PSI.

5/ Depending upon tire composition, temperature , road surface composition and whether the road surface is wet or dry , the friction component between tire patch and road surface can vary from 0.85 G all the way down to 0.25 G. With the Harrison mid wheel disc system , the braking capability per wheel at maximum braking of 1,000 PSI on an OEM master cylinder is 2,700 pounds braking force per wheel, assuming the worst case of a full 3,000 pound load on the mid wheel , 2,700 pounds braking force / 3,000 pounds down force on the wheel , equates to 0.9 G braking force on said wheel. Therefore even with maximum traction on dry a dry road surface , the Harrison system has the capability of locking the mid wheels in a panic stop situation . Obviously at a higher master cylinder pressure or a larger rotor or caliper , the risk of lock up would be higher. Therefore the Harrison system cannot even come close to competing with a reaction arm system when addressing a panic stop on a GMC motorhome , for every day general use the Harrison system is fine BUT all brake systems are engineered for that ultimate " panic stop " situation . As the old saying goes " Pays your money and takes your chances" .

Albert Branscombe, 78 Barbi , the 23 foot Birchaven

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Re: [GMCnet] Trip Report (in segments). [message #343181 is a reply to message #343173]

Wed, 08 May 2019 05:07

rjw

Messages: 697
Registered: September 2005

Karma: 4

Senior Member

78 Barbi wrote on Tue, 07 May 2019 23:21

ITEMS TO CONSIDER WHEN UPGRADING TO LARGE MID WHEEL DISCS ON GMC-MH

What a great discussion on brakes. Too bad I almost missed it because the topic is "Trip Report".

Richard
76 Palm Beach
SE Michigan
www.PalmBeachGMC.com

Roller Cam 455, TBI+EBL, 3.42 FD, 4 Bag, Macerator, Lenzi (brakes, vacuum system, front end stuff), Manny Tranny, vacuum step, Tankless + OEM water heaters.

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Brakes - used to be Re: Trip Report (in segments). [message #343195 is a reply to message #343137]

Wed, 08 May 2019 10:28

jhbridges

Messages: 8412
Registered: May 2011
Location: Braselton ga

Karma: -74

Senior Member

I put reaction arms (I floated the brake backing plates, once a biker always a biker:)))on both the coaches I've kept and driven. Doing this let the coaches stop much better before rear wheel lockup occurs. In the Southeast, I see no need for rear disks. Their benefit is basically that they don't fade as quickly as drums. Neither Monteagle nor Culowee, the two mountains I often cross, result in the rears fading, so I'll save the money. I haven't flat spotted a tire since. If/when I progress to a heavier toad I will have to get some sort of braking system for it. Does anybody make a towbar with surge brakes?

--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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[GMCnet] Brakes - used to be Re: Trip Report (in segments). [message #343200 is a reply to message #343137]

Wed, 08 May 2019 11:06

glwgmc

Messages: 1014
Registered: June 2004

Karma: 10

Senior Member

http://www.readybrake.com/store/p4/ReadyBrute%E2%84%A2_Elite_RV_Tow_Bar.html

I use this to tow my Mini Cooper S Clubman behind the Prevost.

Jerry
Jerry Work
The Dovetail Joint
Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR

glwork@mac.com
http://jerrywork.com
==============

Message: 10
Date: Wed, 08 May 2019 09:28:51 -0600
From: Johnny Bridges
To: gmclist@list.gmcnet.org
Subject: [GMCnet] Brakes - used to be Re: Trip Report (in segments).
Message-ID:
Content-Type: text/plain; charset="utf-8"

I put reaction arms (I floated the brake backing plates, once a biker always a biker:)))on both the coaches I've kept and driven. Doing this let the
coaches stop much better before rear wheel lockup occurs. In the Southeast, I see no need for rear disks. Their benefit is basically that they don't
fade as quickly as drums. Neither Monteagle nor Culowee, the two mountains I often cross, result in the rears fading, so I'll save the money. I
haven't flat spotted a tire since. If/when I progress to a heavier toad I will have to get some sort of braking system for it. Does anybody make a
towbar with surge brakes?

--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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Jerry & Sharon Work
78 Royale
Kerby, OR

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Re: Trip Report (in segments). [message #343202 is a reply to message #343137]

Wed, 08 May 2019 11:44

Scott Nutter

Messages: 782
Registered: January 2015
Location: Houston/San Diego

Karma: 4

Senior Member

***UPDATE LEG #2****
Not much to add, short leg of 200 miles.
Everything operating perfectly.
New Orleans to Gulf Shores Al. Staying at the state campground. BEAUTIFUL, full hookups, I highly recommend it.
The official drink is the Bushwhacker. I also highly recommend it!!
500 miles burnt 70 gallons, if my math is correct, that's 7mpg.
I learned a lot about rear brakes the last few days!!
Scott.

Scott Nutter 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI Houston, Texas

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Re: [GMCnet] Trip Report (in segments). [message #343205 is a reply to message #343202]

Wed, 08 May 2019 12:28

Sandra Price

Messages: 709
Registered: May 2006

Karma: 1

Senior Member

We have stayed there, too, Scott. It IS a beautiful park. Enjoy!

Sandra and Bob

On Wed, May 8, 2019, 12:13 PM Scott Nutter via Gmclist <
gmclist@list.gmcnet.org> wrote:

> ***UPDATE LEG #2****
> Not much to add, short leg of 200 miles.
> Everything operating perfectly.
> New Orleans to Gulf Shores Al. Staying at the state campground. BEAUTIFUL,
> full hookups, I highly recommend it.
> The official drink is the Bushwhacker. I also highly recommend it!!
> 500 miles burnt 70 gallons, if my math is correct, that's 7mpg.
> I learned a lot about rear brakes the last few days!!
> Scott.
> --
> Scott Nutter
> 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final
> drive, Quad bags, tankless water heater, everything Lenzi. Alex Ferrera
> installed MSD Atomic EFI
> Houston, Texas
>
> _______________________________________________
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> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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