Gross Vehicle Weight?
- Thread starter RonL
- Start date
R_Lefebvre
Expedition Leader
GVW is determined including factors other than just springs, bearings and spindle strength. Cooling and even dynamic performance are factors, and more. And I don't care about who has driven what, where. It was my full time job to worry about the cooling side (Davis Dam, Las Vegas Taxi, etc), and my friends full time job to consider the dynamics (Arizona Proving Grounds). That means high speed lane change manoevers at GVW, maybe with a flat tire or two for SNG, (and outriggers attached), etc.
And just to make absolutely clear, for those who like to argue: Springs, spindle strength and bearings are some of the factors. But that is not all of the factors.
And just to make absolutely clear, for those who like to argue: Springs, spindle strength and bearings are some of the factors. But that is not all of the factors.
H
Hank
Guest
Oh yeah??? Well my friends sister has an uncle who knew Harry Connick Jr. Harry's 2nd cousin was married to a dude from Greece that had an ex-brother-in-law that worked in this factory with a chick from Paris that was once married to the police chiefs son in Cumberland, OH. That dude was funny. Anyway, he talked to this guy at the Chevy dealership once and they got to talking about brakes and GVW. The dealership salesman said that you just like to hear yourself talk and no one really cares, or actually believes, anything you've got to say.
In other words, give it up.
R_Lefebvre
Expedition Leader
So you're saying, you don't like somebody taking one small part of your posting, ignoring the content of the rest, then making some argument about some other irrelevant topic? Funny that.
Wow, I have the *same* problem.
And all I stated was that tire selection had a much bigger influence. And that's a *fact*.
You love to talk about experience, and you're arguing with somebody who did this work with instrumented vehicles on controlled surfaces, as a full time job.
Unless you think that Land Rovers have some special exemption from the laws of physics?
Sorry, but to quote you:
I wouldn't want people reading your comments, and thinking "well, I've got the same bearings, spindles and springs as some other vehicle, therefore I can safely drive around overloaded, because Musky, who has no professional training, but has driven lots of vehicles in completely uncontrolled environments saying that's what matters.
And you're doing the same, waving around your "experience" like it actually means anything in a very complicated topic. Driving a lot of trucks around, and inferring whatever conclusion suits you does not give you exclusive rights to prognosticate on the internet.
R_Lefebvre
Expedition Leader
Tell us what relevance does the particular calipers on a particular vehicle have to a discussion about the generalities of how GVW is set?
Your having driven around a lot of places with a lot of Land Rovers has no relevance to a discussion about how GVW is set, when you're up against somebody who has actually worked in the company, actually helping to determine GVW.
Your knowledge of vehicles only extends as far, and only as deep, as the particular examples you have driven. And your conclusions and "knowledge" are only as deep as the suppositions you have made from those experiences.
As much as you like to believe you are, you are NOT the be-all end-all authority on all things automotive. Neither am I. But while I have shown an ability to listen to others and admit my mistakes, you cannot. Admitting mistakes is not a sign of weakness. It's a sign of having an open mind, and being able to learn. The sum of your knowledge is based on conclusions you've drawn from empiricle evidence. You sound like somebody arguing the world is flat, because you have sailed it far and wide, and if it wasn't flat, how come you've never fallen off?
Your having driven around a lot of places with a lot of Land Rovers has no relevance to a discussion about how GVW is set, when you're up against somebody who has actually worked in the company, actually helping to determine GVW.
Your knowledge of vehicles only extends as far, and only as deep, as the particular examples you have driven. And your conclusions and "knowledge" are only as deep as the suppositions you have made from those experiences.
As much as you like to believe you are, you are NOT the be-all end-all authority on all things automotive. Neither am I. But while I have shown an ability to listen to others and admit my mistakes, you cannot. Admitting mistakes is not a sign of weakness. It's a sign of having an open mind, and being able to learn. The sum of your knowledge is based on conclusions you've drawn from empiricle evidence. You sound like somebody arguing the world is flat, because you have sailed it far and wide, and if it wasn't flat, how come you've never fallen off?
proper4wd
Expedition Leader
Rob is not "full of it". The two of you both speak facts, that is why this argument has persisted for so long (weeks!). This is a classic, and epic, clash of theory vs. practice, engineer vs. mechanic. Rob speaks theoretical fact. Mathematic calculations and statistics would prove most of what he says to be true.
Most of the rest of us speak facts that we have gathered first hand from working on our own or others' vehicles. How many times have you (the collective you) been working on your Land Rover and cursed the engineer that designed something? Everything is designed a certain way for some reason. Some things work out better in practice than others.
I'm sure that Rob could argue for days about how the front driveshaft/differential design of MkIII Range Rovers is THEORETICALLY sound. But in practice it is not.
Ladies and Gentlemen, this is the capstone argument that will never end. Engineers arguing with mechanics... how could it ever draw to a peaceful close? This is the type of thing that incites riots.
I think that everybody here needs to understand that "the other side's" viewpoint is grounded very much in fact and reality. But reality is relative. I know that Rob could reference 1000 mathematical formulae and equations to point out why something SHOULD be true. The truth is, that the real world is full of so many variables and unforseen circumstances that most of us Land Rover mechanics could pull something out of our memory banks that dispells just about any "theoretical fact".
I appreciate both sides of the argument here; there has been some great debate despite the incessant name calling. Lets narrow this down slightly:
Rob: THEORY
Muskyman, Rupp, others: PRACTICE
That does not make one side right and the other wrong. They are just two different schools of thought and represent two vastly different approaches to problem solving.
Most of the rest of us speak facts that we have gathered first hand from working on our own or others' vehicles. How many times have you (the collective you) been working on your Land Rover and cursed the engineer that designed something? Everything is designed a certain way for some reason. Some things work out better in practice than others.
I'm sure that Rob could argue for days about how the front driveshaft/differential design of MkIII Range Rovers is THEORETICALLY sound. But in practice it is not.
Ladies and Gentlemen, this is the capstone argument that will never end. Engineers arguing with mechanics... how could it ever draw to a peaceful close? This is the type of thing that incites riots.
I think that everybody here needs to understand that "the other side's" viewpoint is grounded very much in fact and reality. But reality is relative. I know that Rob could reference 1000 mathematical formulae and equations to point out why something SHOULD be true. The truth is, that the real world is full of so many variables and unforseen circumstances that most of us Land Rover mechanics could pull something out of our memory banks that dispells just about any "theoretical fact".
I appreciate both sides of the argument here; there has been some great debate despite the incessant name calling. Lets narrow this down slightly:
Rob: THEORY
Muskyman, Rupp, others: PRACTICE
That does not make one side right and the other wrong. They are just two different schools of thought and represent two vastly different approaches to problem solving.
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ntsqd
Heretic Car Camper
And I just hate it when someone with experience only and no apparent formal engineering education on the topic or related topics seems to think that they know ALL of the answers and that we should just accept their word as legend. Then when someone with both the education and some experience counters their position they casually dismiss the experience as not substantial/applicable/whatever, and try to undermine the position by labeling it as theory.
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Experience and education, each has it's place. The engineers can't predict all of the system's behavior all of the time. That's what R&D is all about. Experiencing how the system does behave in as many scenarios as is reasonable. Doesn't mean that they've covered every possible situation.
Like-wise it is foolish to assume that just because you've experienced several to many situations with a particular system means that you have a complete and thorough understanding of how it will behave in every possible situation and fully understand all of the engineering that went into the design.
Just because the suspension LOOKS the same does not mean that it IS the same. It is very possible that components for any particular system were chosen based on meeting the minimum criteria and were already in the parts pipeline, not because they were the most economically ideal part that *just* met the need(s). Could very well be that some part was over-spec'd on the now common application, but as it turned out met the new model's needs precisely. Until the person who chose that part of that system pipes up and tells us what the decision matrix was we can only GUESS. Guess' very close cousin is named ASSUME.
A long time ago I got an Object Lesson in just how important the tires are to the effectiveness of the brakes. It can not be over-stated.
R_Lefebvre
Expedition Leader
Just to explain how things really work in an OEM: I had no text books at my desk, and didn't own a calculator. I just used the one built into Windows the few times it was needed. Most engineering work is in fact done out in the field, or on a test bench, or in a plant. The guy who signed off on the handling characteristics of a truck, a requirement for GVW, did not calculate it. He bolted a set of outriggers on, went out to the track , and tried to flip it. When the Ford managers were whining about how the F-150 doesn't stop as fast as the Tundra, the brake engineer took the tires off the Tundra, put them on the F-150, and tested it, then said "There, see you idiots, it's the tires, not the brakes!"
This is very much practical stuff. I determined the pressure capability of an oil system not with a finite element analysis. I take a bunch of prototype parts, assemble them, use a pressure gauge, and crank up the pressure until they blow up.
Now, there *are* guys who do a lot of advanced computer stuff, but that is usually done way before the grunts like me got to it. In your axle example, the Design and Release engineer (that's me), would take the axle he was told to use, and drive it around Bovingdon until it breaks, then make sure that met the requirements.
Now, when mechanics get mad at engineers for making things unservicable... that's not our fault. See... nobody cares about service. The service engineer is one voice, in the back of the room filled with guys trying to get things out the door as fast and cheaply as possible, and nobody listens to him. Not my rules, that's just the way it works.
This is very much practical stuff. I determined the pressure capability of an oil system not with a finite element analysis. I take a bunch of prototype parts, assemble them, use a pressure gauge, and crank up the pressure until they blow up.
Now, there *are* guys who do a lot of advanced computer stuff, but that is usually done way before the grunts like me got to it. In your axle example, the Design and Release engineer (that's me), would take the axle he was told to use, and drive it around Bovingdon until it breaks, then make sure that met the requirements.
Now, when mechanics get mad at engineers for making things unservicable... that's not our fault. See... nobody cares about service. The service engineer is one voice, in the back of the room filled with guys trying to get things out the door as fast and cheaply as possible, and nobody listens to him. Not my rules, that's just the way it works.
James86004
Expedition Leader
My contributions to this discussion:
I read in a magazine sometime in the 1990s the NAS D90 had stiffer rear springs than the rest of the world version, in order to get the GVW above 6000 lbs for the tax reasons. They opined the springs were too stiff, and gains in articulation could be made by swapping in the softer springs.
I also heard that Range Rover Classics had better front brakes than Disco Is. I don't know what is different, but they certainly have different part numbers.
I read in a magazine sometime in the 1990s the NAS D90 had stiffer rear springs than the rest of the world version, in order to get the GVW above 6000 lbs for the tax reasons. They opined the springs were too stiff, and gains in articulation could be made by swapping in the softer springs.
I also heard that Range Rover Classics had better front brakes than Disco Is. I don't know what is different, but they certainly have different part numbers.
R_Lefebvre
Expedition Leader
Sometimes that's down to things you wouldn't even expect, like firewall stiffness. If the pedal box is mounted to the firewall, the pedal feel can suffer. Some cars have had the master cylinder braced to help.
I know my D2 brakes feel pretty good compared to many other trucks I've driven. My dad's Yukon brakes are terrifying.
R_Lefebvre
Expedition Leader
Yay, another completely irrelevant argument. You're trying too hard. Maybe you should go back and read carefully, note I did not say that *was* the case, or even *could* be the case. Merely presented the possibility as an example of one of many things that can cause soft pedals since the original poster wondered "Of course I don't know why that is. "