| Re: 1 ton question [message #268444 is a reply to message #268041] |
Sun, 28 December 2014 12:06   |
bwevers
Messages: 597
Registered: October 2010
Location: San Jose
Karma: 5
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I commend the person who took the time and effort to produce the drawing:
https://www.facebook.com/photo.php?fbid=10204172125838153&set=o.183025891821956&type=3&theater
It illustrates the improvement in brakes.
But sometimes drawings are not to scale.
The drawing shows the control arms angled downward.
In reality the bottom control arm is closer to level at normal ride height.
And the upper control arm is not parallel to the lower control arm with the one ton modification.
I don't believe that there is a 5 degree angle difference between stock and one ton.
From what I've observed it's more like one ton steering axis = 12.5 degrees
and the stock is 12 degrees (with camber set to zero).
Regards
Bill Wevers GMC49ers, GMC Western States
1975 Glenbrook - Manny Powerdrive, OneTon
455 F Block, G heads
San Jose
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| Re: [GMCnet] 1 ton question [message #268446 is a reply to message #268442] |
Sun, 28 December 2014 12:27 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Well, here we go. A person can stare at drawings until they are blurry
eyed, and "bench race" them until doomsday, BUT never own the actual
article. They will form their own opinions, and argue their point of view
based on misconceptions.
I personally have installed more than a dozen 1 ton front ends. The only
problem that I personally have encountered was with a coach that I did not
do the initial install on. That one was converted by Bill Hubler, the
originator of the 1 ton conversion, and the owner of the coach. Both Manny
T. and I replaced every component under the front end of that coach twice,
and torque steer still persists to some degree. I am convinced that the
frame geometry is incorrect, perhaps due to a collision somewhere in the
coaches past. I have noticed, however, that higher horsepower engines
aggravate torque steer in the GMC. So do bad engine mounts, as well as tie
rod ends. As far as front ride height goes, my personal experience has
demonstrated to me to try and keep it as close to original specification as
is possible. But I have heard "I don't like how the coach looks with the
front end high" Back in my racing days, we had a saying "if it don't go,
chrome it". Usually the ugly race cars were the ones that ran the best.
Looks don't count for much when it comes to performance. That's my take on
this deal. No, I don't have all the answers, but I do have a lot of
practical experience with 1 tons.
Jim Hupy
Salem, Or
78 GMC Royale 403
On Dec 28, 2014 9:35 AM, "Ken Henderson" wrote:
> On the other hand, I was surprised at how little difference there is.
>
> If the drawings came from anyone except Stan (I'm assuming Edwards), I'd
> doubt the accuracy since there's no dimensional difference between the
> A-arms -- I don't see where the 16*-11*=5* difference in the steering axis
> comes from. The knuckles are obviously sufficiently different to account
> for it, but I'd have thought that when we adjust back to the same camber,
> that would be negated.
>
> Since Stan very likely did the drawings before he did the modification (he
> did his own), I'm confident they're accurate.
>
> Ken H.
>
>
> On Sun, Dec 28, 2014 at 11:26 AM, Keith V wrote:
> ...
>
>
>>
>> https://www.facebook.com/photo.php?fbid=10204172125878154&set=o.183025891821956&type=3&theater
>> if
>> that drawing is accurate, it looks like a big difference to me.
>>
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| Re: [GMCnet] 1 ton question [message #268447 is a reply to message #268446] |
Sun, 28 December 2014 13:28 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Jim I am not complaining I feel Manny's and Bill Hubler's 1 ton conversion was a good thing that we all should consider. Most folks would never encounter the steep terrain that some of us encounter in mountain states . In the past week I have found the new front end did well going up and down mountain passes except on secondary really steep short climbs. My coach has never had frame damage nor are the parts or mounts loose. I have found that if the coach is more level the problem seems to almost go away. If anyone has the experience I had maybe they will find it would help to lower the front a little or raise the rear a little may help? I am far from an engineer just really old hot rodder.
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: [GMCnet] 1 ton question [message #268459 is a reply to message #268447] |
Sun, 28 December 2014 19:54 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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I think we have been through this several times. There are a few things we are arguing about that are separate issues. One of the most important things that affects on center handling is the toe change curve. IIRC the 1 Ton system has a pretty good curve untill the ride height gets high and at that point the curve goes way beyond acceptable limits. If you keep the ride height low enough you won't have a problem with the 1T design. As far as torque steer, that is affected by effective spindle length and nothing else. I try not to throw my background around but sometimes I can't help it. I spent most of my career designing front suspensions and am totally taken aback when back yard mechanics become experts. You need computer simulations to get this right--toe change, roll steer,anti lift, anti dive, torque steer. and so on--all at the same time.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: 1 ton question [message #268505 is a reply to message #268041] |
Tue, 30 December 2014 09:49 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Senior Member |
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In the drawing the axis is at the inner portion of the tread contact patch. Not being a fan of front wheel drive vehicles in general, i know that all is pretty benign until higher torque levels and reduced traction come into play. Any disruption of designed geometry will have an effect. Moving 11,000 pounds up a grade is a higher torque situation. I tolerate the FWD in the GMC as it allowed the vehicle to be what it was (too many advantages to list) but prefer RWD or driver controlled 4WD as a daily diet.
John Lebetski
Woodstock, IL
77 Eleganza II
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