It's not as outlandish as some might think, to buy a car on spec's. The covered wagon example provided was unrealistic, since everyone knows that a new vehicle on the market today from a mainstream maker will have certain equipment to meet regs and federal standards. No ProudPony, I would NOT buy your wagon. But if CHEVROLET offers a new vehicle with these specs, that's a little different now isn't it?

Millions of buyers have made performance value the driving factor in their buying decision. No point denying it folks.

 

I have no problem admitting it, and I have no problem with people who make that their #1 priority.

What I do have a problem with is close-minded people who will pretty much tell you that you're an idiot if you think that anything else matters. In other words, I get tired of people who look at my car- a mid 14 second car stock - and tell me that I'm an idiot for buying it because I could have bought a low 13 second / high 12 second C5 for the same amount of money.

The type of people who not only feel the way you described, but feel that anyone who values anything outside of pure acceleration is retarded.

 

OMG, PacerX.......I just passed a cup of coffee thru my nose (yup, that big 'honker' on the front of my head) while reading your post!!!

 

You should have seen what I passed through my nose when I read it!

 

lol Threxx by Pacer, man you just got POwn3d bigtime kid, go back to your nakamichi and leave the pickup discussions to us real men.

Ford's new F150 may be 900 or 9000xtimes stiffer than the old one but they still have missed the boat on Quadrasteer 4 wheel steering, midgates, XM radio and Onstar....

This 04 F150 will probably put Ford that much closer to bankrupcy as much as I hate to say it. I have read on F150online.com from a supplier of interior plastic that he would never want one of these trucks as they are "cutting corners like you wouldnt believe"

 

It's interesting to see how intelligent your average person is who throws around the word "ricer" without a second thought. The image of bubba in an old pickup truck comes to mind.

Believe me when I say I know plenty about pickup trucks. I sold my 2000 Chevy Silverado less than two months ago, and am an active member at a handful of GM and Ford truck sites.

The only reason I put the time in my signature is because I was having wayyy too many people asking what it ran. Most people aren't very familiar with GS4s at all. So I figured what the hell and ran it simulated in cartest2000 which actually has proven to be a very accurate and perfectly consistent program.

I'm a computer geek by profession and a physics buff on the side... Cartest2k is a great culmination of the two of those.

I would understand the negative sentiment if I had tried to pass off the cartest time as something I actually ran at the track... but I'd say it's fairly obvious by the giant 800x600 graphic with big bold red letters that says this was ran with cartest and it's the best I can do until I actually run my car at the track.

Don't like it? That's fine. But the "ricer" comments - especially being that I don't have a single appearance mod or exhaust mod and never will, have a V8 with more power than an LT1, and have previously owned a Z28.... Those comments are just retarded and a sight of a lack of intelligence and/or a problem with insecurity.

 

Glad you enjoyed it Red.

Flame wars aside, be sure to tell your friends in the truck group that overall they're doing great stuff.

 

My only statement on this matter is this:

Saying something is 900% better than the current thing (I use thing as a general term in this case) ... doesnt that just say your current product really sucks? Either that or your new one gives hand jobs as you use it.

 

The frame is 900% stiffer torsionally. This is because it's the F-150's first year of using a fully boxed in fully hydroformed frame. The hydroforming is what makes all the difference.

The current Silverado has a hydroformed frame, but only the front section. Even so, it saw a 280-350% increase in torsional rigidity when it made the switch in 99.

The Ram went to a fully hydroformed frame for the new 02 body style, and saw around a 400-450% increase in torsional rigidity.

It doesn't necessarily mean that all of their truck's frames sucked before, it just goes to show that hydroforming is quite a leap forward in terms of body-on-frame technology.

 

Ok, you're going to have to bear with me here, Im a programmer I do not know much about physics nor do I aspire to learn about it.

What exactly does making it 900% stiffer torsionally do for the truck?

 

Without going into too great of detail (and I will if you want me to, but some of our engineers here would probably do better than I), torsional stiffness is the end effect of subframe connecters and strut tower braces.

So it's kind of like saying the F150 has rediculously effective subframe connecters from the factory, albeit it's body-on-frame so that wouldn't be possible. But you get the point.

It basically makes it behave better over bumps, keeps it from 'loosening' up as much over time, and let's the suspension do it's job better (with the exception of some extreme off-roading situations like rock crawling where frame flex is needed for that last little bit of extension).

 

That was something our f-bodies have been short on for a long time. The 4th gens got reinforced rails below the doors and a brace (believe it's up forward on the drive shaft tunnel?)....It still wasn't enough IMO. It's also why SFC's and STB's make such a difference.

 

K, follow along here...

Torsional stiffness is resistance to twisting of the frame.

Picture this way:

You're REALLY big and you strip the body off your truck. Grab the frontmost crossmember in one hand and the rearmost in the other.

Now, rotate them in OPPOSITE directions like you're trying to twist the frame into a pretzle from the ends.

That's torsional stiffness.

Want to test it on your vehicle? Jack the thing up from one of the corners. The weight of the vehicle will act in the opposite direction at the other corners and cause the structure to twist.



Now... what's it good for?

Well, here's the idea:

For a vehicle with greater torsional stiffness, a lower spring rate can be used to give a specified amount of suspension compliance. Furthermore, compared to spring rate calculations, calculating the torsional resistance of a structure is more difficult - so lots of complexity is added if the structure in question is relatively compliant (like a vehicle body and frame).

If all things are held equal, then the vehicle with the greater torsional resistance can have lower spring rates and a softer ride.

How do you give a vehicle with a full frame added torsional resistance? Well, the best way so far is to use hydroformed crossmembers with CLOSED SECTIONS (no "U" or "C" channels - a tube) that are perimeter welded at their interface to the fore and aft frame members. Closed sections have exponentially more torsional stiffness than open ones, and perimeter welded joints are exponentially stiffer than riveted or partially welded joints. Closing the fore and aft runners of the frame doesn't help much for torsional resistance (but does help for bending).

If you look at a GMT-800 frame, the crossmembers are closed section hydroformed pieces that are perimeter welded to the fore and aft frame members.



Threxx's following quote is point-blank wrong:

"The current Silverado has a hydroformed frame, but only the front section. Even so, it saw a 280-350% increase in torsional rigidity when it made the switch in 99."

The CROSSMEMBERS are the major contributors to torsional stiffness, NOT THE FORE AND AFT RUNNERS OF THE FRAME. Fore and aft runners are the major items to consider in BENDING.



Nissan doesn't understand this entire concept (which, I will gently add ***NOT A FLAME***, neither does Threxx). They're making the Titan with closed section fore and aft frame members, but OPEN SECTION, RIVETED crossmembers. Technically, it's as advanced as the old C/K truck or the old Dodge Ram. Neither of which were all that stiff.



Now, here's where Ford screws up historically (U222 - Expedition and Navigator are good examples)...

They've got good torsional stiffness in the frame, but the vehicles are too heavy for their purpose.

Spring rates are also defined by the WEIGHT OF THE VEHICLE. If the vehicle is heavy, you still have to have HIGH SPRING RATES to provide adequate suspension characteristics.

As the vehicle gets heavier, the ride gets harsher - and harsh riding,even with the benefit of an independent rear suspension on the U222, is a universal criticism of the U222 platform.

How did GM avoid the weight issues?

Well, first, they used high strength steels all over the place. Hydroforming allows the use of high strength steels (thereby saving weight) that are very difficult and expensive to stamp and weld.

Second, they saved weight where it really counts - the powertrain. OHV engines are as a rule lighter and physically smaller than OHC engines for a given power output at "normal" operating conditions. They make torque lower in the rev range, where you actually use it - especially in a truck.

Third, they only used a CLOSED FORE AND AFT FRAME SECTION where it was NEEDED. Less steel = less weight.

The proof? 1/2 ton, extended cab V8 Silverados are SIX HUNDRED POUNDS LIGHTER than the new F-150.

 

Weight matters, but I don't think it matters as much as you are trying to make it out to in terms of the effectiveness of a frame.

As a general rule of thumb, every time you double the weight of a car, the natural resonant frequency (effectiveness of the frame) is cut in half.

So I could see your point if the F-150 weighed twice as much as the Silverado and it's frame were twice as stiff... Ford would have basically defeated its own efforts.

However 600 pounds, which is only a 10-15% increase in weight, can be more than easily offset by an even slightly more effective frame design.

It is true that the extra weight hurts the truck in other categories such as handling, acceleration, and economy (which all seem to not be that much of a priority with trucks and rightfully so)... but I'm talking strictly frame design here.

I'm glad you know more than Nissan's entire design team. I'd bet they might have a bit better explanation than "oh, wow, you mean we did a bad job designing our frame? $hit, why didn't anybody tell us hydroforming exists!?" More than likely its the fact that they didn't have time when rushing this product to market. I'd bet, like the Tundra, it's something that you'll see come around for the second generation. Cost may have also been an issue, as the Q45-derived V8 that is standard issue on every Titan probably isn't saving Nissan a whole lot of money.

 

"Weight matters, but I don't think it matters as much as you are trying to make it out to in terms of the effectiveness of a frame."

Then you're wrong.

Weight = cost. More steel means more money. You've never done an automovite costs analysis, but on many components in a vehicle the cost of material is far greater than the cost of labor. EVERYTHING my company produces (and we make millions and millions of parts for pretty much every manufacturer) falls into this category.

More weight = bigger brakes = more money.

More weight = worse fuel economy = lots of trouble.

More weight = bigger motors to haul around a given payload = more money.

More weight = more robust transmissions to maintain acceptable reliability = more money.

More weight = higher spring rates, stiffer anti-roll bars, beefier bushings = worse ride.

More weight = more impact energy = higher impact accelerations = even more weight and money spent on keeping the occupants alive.



"As a general rule of thumb, every time you double the weight of a car, the natural resonant frequency (effectiveness of the frame) is cut in half."

Welcome to Mechanical Engineering 101... wait a second, this isn't even that complicated...

The WHOLE IDEA is to achieve the desired natural frequency with the LOWEST MASS. I can hang lead weights all over the car and effect natural frequency, but that isn't exactly elegant.



"So I could see your point if the F-150 weighed twice as much as the Silverado and it's frame were twice as stiff... Ford would have basically defeated its own efforts.

However 600 pounds, which is only a 10-15% increase in weight, can be more than easily offset by an even slightly more effective frame design."

1) You have no clue WHATSOEVER what the words "slightly more effective frame design" mean or the trade offs associated. Your knowledge of even the most elementary of loading conditions was lacking as evidenced by your post concerning torsional rigidity.

2) See the points above concerning weight.

3) 600 lbs. is roughly the weight of a fully dressed Chevrolet Big Block. 12% on 5000 lbs. is HUGE. You can make a solid case that the production costs of the vehicle increase 12% for that very reason alone. Shipbuilding costs, for example, can be fairly accurately estimated for cost by their weight alone - so can vehicle structures and components.



"It is true that the extra weight hurts the truck in other categories such as handling, acceleration, and economy (which all seem to not be that much of a priority with trucks and rightfully so)... but I'm talking strictly frame design here."

Rule #2 of vehicle engineering:

EVERYTHING is a system. The frame is only a component within a system. Natural frequeuncy is not a factor whose considerations is limited only to the frame. The cab structure has a direct effect on it also at the SYSTEM LEVEL - where it counts. COMPONENT level specifications (like torsional rigidity or natural frequency) are the means to an end that exists on the VEHICLE level - they ARE NOT ends unto themselves.


Rule #1 of vehicle engineering:

The least expensive, least complicated and lowest mass solution that meets the requirements is the ideal solution.

Right there, in black and white, is the engineer's job described to a "T". You, and many others like you, are simply not mentally tuned into that concept. Don't feel bad - lots of engineers don't get it either.


Making a stunningly rigid frame and then bolting a cab made of Jello on top is a WASTE and violates rule #2 and rule #1. Did Ford do this? Probably not. But, it can be safely said that to accomplish a given set of conditions of acceptability in a given market, it required them to bolt on 600 lbs. more than GM did to meet their set of conditions.



"I'm glad you know more than Nissan's entire design team."

Actually, it's kind of sad that they're already a over a decade behind.


"I'd bet they might have a bit better explanation than "oh, wow, you mean we did a bad job designing our frame? $hit, why didn't anybody tell us hydroforming exists!?" More than likely its the fact that they didn't have time when rushing this product to market."

WHY ARE YOU MAKING EXCUSES FOR POOR ENGINEERING? Because it's Nissan? WHY is it so difficult to just admit that this vehicle has a pretty good chance of being sub-standard?



"I'd bet, like the Tundra, it's something that you'll see come around for the second generation. Cost may have also been an issue, as the Q45-derived V8 that is standard issue on every Titan probably isn't saving Nissan a whole lot of money."

Reference Rule #1.

BTW - Toyota has managed to screw it up TWICE now.