... plus a light-duty Cummins diesel V8.
I think that it was about time - full size SUVs based on 1/2-ton chasses have had rear coil suspension for a while now. I predict IRS by the next generation of 1/2-ton trucks (2012-2015 or there abouts).
http://www.leftlanenews.com/dodge-ram-prototype.html (http://www.leftlanenews.com/dodge-ram-prototype.html)
I'd rather see them go to airbags.
"While the coil sprung setup means the next Ram won't be able to haul 10,000 pounds ? as the leaf spring setup is more heavy-duty by nature ? it should offer a better ride and handling, with reduced axle hop."
WTF. If I wanted a better riding and handling vehicle with reduced axle hop that couldn't haul 10,000 pounds, I'd buy something other than a full size truck. Why are the domestics engineering the truck out of their full size trucks? If an import maker did this, all the domestic fan boys will be laughing their asses off saying how the Japanese don't know the first thing about trucks. But I'm willing to be tons of domestic fan boys will crawl out of the woodwork and applaud this move by Dodge as a sensible decision :rolleyes:.
Pretty soon the Tundra and Titan will be the only real full size pickup trucks left. :banghead:
Quote from: 565 on December 03, 2007, 07:45:03 PM
"While the coil sprung setup means the next Ram won't be able to haul 10,000 pounds ? as the leaf spring setup is more heavy-duty by nature ? it should offer a better ride and handling, with reduced axle hop."
WTF. If I wanted a better riding and handling vehicle with reduced axle hop that couldn't haul 10,000 pounds, I'd buy something other than a full size truck. Why are the domestics engineering the truck out of their full size trucks? If an import maker did this, all the domestic fan boys will be laughing their asses off saying how the Japanese don't know the first thing about trucks. But I'm willing to be tons of domestic fan boys will crawl out of the woodwork and applaud this move by Dodge as a sensible decision :rolleyes:.
Pretty soon the Tundra and Titan will be the only real full size pickup trucks left. :banghead:
I agree. This isn't progress. It's the dismantling of the American truck.
Quote from: 565 on December 03, 2007, 07:45:03 PM
"While the coil sprung setup means the next Ram won't be able to haul 10,000 pounds ? as the leaf spring setup is more heavy-duty by nature ? it should offer a better ride and handling, with reduced axle hop."
WTF. If I wanted a better riding and handling vehicle with reduced axle hop that couldn't haul 10,000 pounds, I'd buy something other than a full size truck. Why are the domestics engineering the truck out of their full size trucks? If an import maker did this, all the domestic fan boys will be laughing their asses off saying how the Japanese don't know the first thing about trucks. But I'm willing to be tons of domestic fan boys will crawl out of the woodwork and applaud this move by Dodge as a sensible decision :rolleyes:.
I'm not one of them. This is stupid. Although if you are towing 10,000 lbs with a 1/2 ton then you're an idiot anyway.
So the Ram is soon going to have a more advanced suspension than a Mustang?
:lol:
Quote from: HEMI666 on December 03, 2007, 10:01:36 PM
I'm not one of them. This is stupid. Although if you are towing 10,000 lbs with a 1/2 ton then you're an idiot anyway.
Actually this brings up an interesting question I've had.
Everyone tells me "you shouldn't tow 10,000 pounds with a 1/2 ton." It seems like some unwritten rule that people only tow 75% or 60% of that rating. But I have to ask, do the trucks really break if you tow at the limit? Obviously half ton owners aren't going to be towing 10,000 pounds all the time. But if Toyota and GM rate their trucks to tow 10,000 pounds then I sure as hell expect to be able to tow something close to that at least part of the time without damage to my truck. I've exceeded the gross weight rating of all my cars plently of times (4 people in the Z06, 7 people in the Supra, 8 in the pathfinder) and I've never even considered anything breaking because I know the engineers put down rather conservative estimates. Did manufacturer's urge to one-up each other do away with those safety margins? I mean I'd expect a 10,000 pound tow rating to mean that I can safely tow 10,000 pounds with confidence that my truck isn't going to split in half. If I have no confidence in that, than all these tow ratings are useless because you never know what the true safe amount to tow is.
The more I think about it, the more it makes sense that things like tow rating should have some kind of standardized system like SAE horsepower or crash ratings.
I'm surprised a few have stated that this isn't progress, or otherwise isn't a good move. Leafs' advantage, just as with pushrod engines, drum brakes, recirc balls steering, torsion beam axles, etc., is cost. Air bags would be even cooler, however.
No 1/2-ton comes close to "hauling" 10,000 lbs. Perhaps they meant towing. Either way, the blurb stated that the Ram will lose neither payload nor towing capacity versus the current model.
Towing capacities will be greatly revisited once the new SAE towing spec comes into effect. 1/2-tons are overbuilt (relative to how the vast majority are used) as it is anywho.
I say it again: the truck market will eventually go the way of the van market: Traditional trucks in the 1/2-ton and compact markets will be taken over by Ridgeline-type "trucks," with the traditional BoF/live axle throw-backs relegated to commerical use.
Most 1/2 ton buyers probably barely haul more than what a station wagon could.
Quote from: GoCougs on December 03, 2007, 10:18:49 PM
I say it again: the truck market will eventually go the way of the van market: Traditional trucks in the 1/2-ton and compact markets will be taken over by Ridgeline-type "trucks," with the traditional BoF/live axle throw-backs relegated to commerical use.
That's what I am afraid of. The Van market used to be domestic dominated, now Ford and GM have basically pulled out and only the Chrysler product is left in a market overrun by imports. When full size pickups lose their huge consumer popularity and imports dominate with their Ridgeline type things, it'll be apocalypse for the domestic automakers.
Quote from: Secret Chimp on December 03, 2007, 10:32:49 PM
Most 1/2 ton buyers probably barely haul more than what a station wagon could.
If you took a look at a real station wagon: like a '71 Vista Cruiser, or a Country Squire: you'd know that most of those station wagons could probably outhaul most 1/2 ton pick-ups.
Quote from: GoCougs on December 03, 2007, 10:18:49 PM
I say it again: the truck market will eventually go the way of the van market: Traditional trucks in the 1/2-ton and compact markets will be taken over by Ridgeline-type "trucks," with the traditional BoF/live axle throw-backs relegated to commerical use.
I hope not. There's still a big demand for private work-trucks. And I want to own a vehicle one day that I can cruise dirt in. Jeep'll be around awhile, so at least I got that.
Since this is my first post in some time in the Big Guy forum, I'll break out the good news:
My Uncle just bought a Wrangler. Black on Black, stick shift, two-door, removable hard top, satellite radio, cd, and factory soundsystem (including a sub). I want to buy it after he's done with it.
Quote from: Soup DeVille on December 03, 2007, 10:53:20 PM
If you took a look at a real station wagon: like a '71 Vista Cruiser, or a Country Squire: you'd know that most of those station wagons could probably outhaul most 1/2 ton pick-ups.
You could get some Chevy or Olds wagons with 454s, couldn't you? hoooo boy
Quote from: Secret Chimp on December 03, 2007, 10:59:51 PM
You could get some Chevy or Olds wagons with 454s, couldn't you? hoooo boy
The Olds and Buicks could come with 455s.
Light duty Cummins V8 FTW.
Coil springs FTW.
1/2 ton trucks don't need leafs.
Quote from: NACar on December 03, 2007, 11:06:09 PM
Light duty Cummins V8 FTW.
Coil springs FTW.
1/2 ton trucks don't need leafs.
Railroad cars ride on coil springs.
Quote from: Soup DeVille on December 03, 2007, 11:07:23 PM
Railroad cars ride on coil springs.
They also ride on rails. :lol:
(http://i19.ebayimg.com/02/i/000/c8/c0/5675_3.JPG)
:rockon:
:wub:
Quote from: NACar on December 03, 2007, 11:14:35 PM
:wub:
(http://www.stationwagon.com/gallery/pictures/1972_Ford_Country_Squire.jpg)
:wub:
Can someone explain to me why a coil spring is worse than a leaf spring. If the rates are the same, why would the coil spring be worse?
Quote from: 280Z Turbo on December 03, 2007, 11:52:36 PM
Can someone explain to me why a coil spring is worse than a leaf spring. If the rates are the same, why would the coil spring be worse?
Umm, duh- don't you get it "Real Amurikin trucks" use leaf springs by-golly. Coil springs are something those dad-gummed furriners dreamed up hold up their sissy mobiles because they don't want to curdle their goat milk.
Why everybody knows you cain't haul didly squat wth them silly things, anything heavier than a goat and a french whore will twist 'em up like pretzels!
(http://www1.istockphoto.com/file_thumbview_approve/2155976/2/istockphoto_2155976_springs_on_the_truck_of_a_freight_car.jpg)
Quote from: Soup DeVille on December 04, 2007, 12:04:04 AM
Umm, duh- don't you get it "Real Amurikin trucks" use leaf springs by-golly. Coil springs are something those dad-gummed furriners dreamed up hold up their sissy mobiles because they don't want to curdle their goat milk.
Why everybody knows you cain't haul didly squat wth them silly things, anything heavier than a goat and a french whore will twist 'em up like pretzels!
(http://www1.istockphoto.com/file_thumbview_approve/2155976/2/istockphoto_2155976_springs_on_the_truck_of_a_freight_car.jpg)
Then again some people
do use the trucks, and max payload means something different when you're bouncin over the tops of two-tracks...
I just don't like how low and girly these trucks are all becoming. I remember in 1999 when I had to jump to get into a Ram 2500 at the auto show and subsequently climb into it. My mom with two bad hips could get in and drive that Ram.
At least they won't be able to drive over your Subaru. :thumbsup:
Quote from: 280Z Turbo on December 04, 2007, 01:31:36 AM
At least they won't be able to drive over your Subaru. :thumbsup:
Very good point, but they're no longer badass enough to make me almost want a truck.
The Humvee, HMTT, and Abrams M1A1 main battle tank also use coil springs.
Quote from: the Teuton on December 04, 2007, 01:09:46 AM
I just don't like how low and girly these trucks are all becoming. I remember in 1999 when I had to jump to get into a Ram 2500 at the auto show and subsequently climb into it. My mom with two bad hips could get in and drive that Ram.
Weren't you a lot shorter then?
Quote from: GoCougs on December 04, 2007, 06:23:04 AM
The Humvee, HMTT, and Abrams M1A1 main battle tank also use coil springs.
I'll remember that the next time I have a million dollars to burn.
Quote from: NACar on December 03, 2007, 11:06:09 PM
Light duty Cummins V8 FTW.
Coil springs FTW.
1/2 ton trucks don't need leafs.
I guess that's why we always break our front coils at work, but the rear suspension never has a problem. :ohyeah: :huh:
Quote from: GoCougs on December 04, 2007, 06:23:04 AM
The Humvee, HMTT, and Abrams M1A1 main battle tank also use coil springs.
And they all weigh much more then a 1/2 ton pickup.
Quote from: 565 on December 03, 2007, 10:15:01 PM
Actually this brings up an interesting question I've had.
Everyone tells me "you shouldn't tow 10,000 pounds with a 1/2 ton." It seems like some unwritten rule that people only tow 75% or 60% of that rating. But I have to ask, do the trucks really break if you tow at the limit? Obviously half ton owners aren't going to be towing 10,000 pounds all the time. But if Toyota and GM rate their trucks to tow 10,000 pounds then I sure as hell expect to be able to tow something close to that at least part of the time without damage to my truck. I've exceeded the gross weight rating of all my cars plently of times (4 people in the Z06, 7 people in the Supra, 8 in the pathfinder) and I've never even considered anything breaking because I know the engineers put down rather conservative estimates. Did manufacturer's urge to one-up each other do away with those safety margins? I mean I'd expect a 10,000 pound tow rating to mean that I can safely tow 10,000 pounds with confidence that my truck isn't going to split in half. If I have no confidence in that, than all these tow ratings are useless because you never know what the true safe amount to tow is.
The more I think about it, the more it makes sense that things like tow rating should have some kind of standardized system like SAE horsepower or crash ratings.
It's not breakage that I'm worried about, it's staying in control. My neighbour has a small 5th wheel that weighs in the vicinity of about 5000 lbs. He tows it with a 1/2 ton Dodge and he says the trailer dictates where the truck goes. He has towed the same trialer with a 3/4 ton Dodge and he says it's like night and day. The 3/4 ton tows much better. When I towed my car through the rockies on a trailer that weighed more then 1500 lbs without the car, I was towing about 4000+ lbs and I barely knew the car was there, but in certain situations I could see that if you added 2000 lbs to that trailer it would have been a handful.
The problem is that the manufacturer sets the tow rating and they can set it to whatever they are comfortable with on the liability side of things. When Toyota came out with their new Tundra and it had a tow rating of 10,000 lbs, Ford increased their tow rating on the F-150 overnight with no changes to the truck itself just to stay ahead of Toyota.
Quote from: Tave on December 04, 2007, 08:24:32 AM
I guess that's why we always break our front coils at work, but the rear suspension never has a problem. :ohyeah: :huh:
Sounds like you need something more than a 1/2 ton.
Quote from: Tave on December 04, 2007, 08:20:34 AM
I'll remember that the next time I have a million dollars to burn.
I bet they can tow a lot, too.
I also have a good feeling they get 5 stars or better, in government crash tests.
Quote from: JYODER240 on December 04, 2007, 07:29:13 AM
Weren't you a lot shorter then?
Maybe 6-8 inches, to be honest.
Quote from: Tave on December 04, 2007, 08:24:32 AM
I guess that's why we always break our front coils at work, but the rear suspension never has a problem. :ohyeah: :huh:
I still have yet to see a material technical criticism of rear coils.
Maybe Oshkosh Truck Corporation (uses coils on many, many of its heavy duty trucks) is all wet:
(http://img411.imageshack.us/img411/9814/brains9btmex9.jpg)
Quote from: HEMI666 on December 04, 2007, 08:46:17 AM
And they all weigh much more then a 1/2 ton pickup.
Yes, exactly.
Quote from: Tave on December 04, 2007, 12:42:18 AM
Then again some people do use the trucks, and max payload means something different when you're bouncin over the tops of two-tracks...
What do you think the picture I postd is off of, a Subaru Brat?
Or do you know many people who regularly haul more than the 250,000 pounds or so a typical freight boxcar can weigh?
Quote from: Submariner on December 04, 2007, 09:11:55 AM
I bet they can tow a lot, too.
I also have a good feeling they get 5 stars or better, in government crash tests.
Actually, M1s are damned dangerous vehicles to be in an accident in.
Of course, the tank itself is just fine, but the occupants can be beaten up pretty severely real easily.
Quote from: the Teuton on December 04, 2007, 01:09:46 AM
I just don't like how low and girly these trucks are all becoming. I remember in 1999 when I had to jump to get into a Ram 2500 at the auto show and subsequently climb into it. My mom with two bad hips could get in and drive that Ram.
I disagree bro. I would much rather my car's crash structure absorb a crash with these monsters rather than my freakin' A-pillars (and my upper torso).
Quote from: GoCougs on December 04, 2007, 11:18:58 AM
I still have yet to see a material technical criticism of rear coils.
Maybe Oshkosh Truck Corporation (uses coils on many, many of its heavy duty trucks) is all wet:
(http://img411.imageshack.us/img411/9814/brains9btmex9.jpg)
Burned! :lol: (Sorry Tave, but he's right.)
Quote from: R-inge on December 04, 2007, 11:55:15 AM
Burned! :lol: (Sorry Tave, but he's right.)
:rolleyes: Because that's the same coil they're going to put into the Ram :rolleyes:
Quote from: GoCougs on December 04, 2007, 11:18:58 AM
I still have yet to see a material technical criticism of rear coils.
Maybe Oshkosh Truck Corporation (uses coils on many, many of its heavy duty trucks) is all wet:
(http://img411.imageshack.us/img411/9814/brains9btmex9.jpg)
I thought I've made it clear I'm talking about private-duty light pickup trucks.
Maybe you'd care to mention some more irrelevant machinery that no small buisness owner in the country can afford?
Quote from: NACar on December 04, 2007, 09:05:11 AM
Sounds like you need something more than a 1/2 ton.
We use 3/4. The front shocks and springs are prone to break down after heavy use, but it's not a huge deal -- we fix the truck and keep working -- while the rear suspension lasts the life of truck.
Quote from: Tave on December 04, 2007, 12:24:49 PM
:rolleyes: Because that's the same coil they're going to put into the Ram :rolleyes:
What it proves is that there is no inherent load limitation on a coil spring that's relevant to your argument. Because you know of coils springs breaking, that does not mean that the concept is flawed.
Should I also point out that for years hardcore offroaders have been scrapping their stock leafs springs and replacing them with coils?
Quote from: Soup DeVille on December 04, 2007, 11:49:59 AM
What do you think the picture I postd is off of, a Subaru Brat?
Or do you know many people who regularly haul more than the 250,000 pounds or so a typical freight boxcar can weigh?
Oh, I guess you're right. If a railroad coil is good that means the Ram's will be too.
Quote from: Soup DeVille on December 04, 2007, 12:28:49 PM
What it proves is that there is no inherent load limitation on a coil spring that's relevant to your argument.
Huh? I'm talking about coil springs Dodge uses, and you're talking about industrial machinery.
QuoteBecause you know of coils springs breaking, that does not mean that the concept is flawed.
Someone could probably design a fucking coil that would hold up the world, but that's not what I'm talking about. I'm talking about the real world, not a physics blackboard.
Quote from: GoCougs on December 04, 2007, 11:18:58 AM
I still have yet to see a material technical criticism of rear coils.
I mentioned that your list of vehicles cost a lot, but I guess that was easy to ignore.
Quote from: Tave on December 04, 2007, 12:31:02 PM
Oh, I guess you're right. If a railroad coil is good that means the Ram's will be too.
Are you intentionally being difficult?
What it means is that the Ram's suspension is not automatically bad simply because it has coil springs. It may or may not be well engineered. That has nothing to do with it being coil springs or not.
I remember having exactly this same argument with many Jeepers in 1997.
Then when the TJ proved itself more capable than any previous Jeep: they shut up.
Quote from: Soup DeVille on December 04, 2007, 12:28:49 PM
Should I also point out that for years hardcore offroaders have been scrapping their stock leafs springs and replacing them with coils?
Hmm, sounds a little expensive.
Most hardcore offroaders also aren't interested if their hobby makes sense financially. They do it because they like it.
Quote from: Tave on December 04, 2007, 12:41:22 PM
Hmm, sounds a little expensive.
Most hardcore offroaders also aren't interested if their hobby makes sense financially. They do it because they like it.
I'm done with this argument.
Save this page and re-read in five years.
Quote from: Soup DeVille on December 04, 2007, 12:40:18 PM
Are you intentionally being difficult?
What it means is that the Ram's suspension is not automatically bad simply because it has coil springs. It may or may not be well engineered. That has nothing to do with it being coil springs or not.
I'm not saying it's going to be bad, I just mentioned some concerns, based off my own experience with Dodge suspensions. It could be a great set-up for all I know. Good for Dodge if it is.
QuoteI remember having exactly this same argument with many Jeepers in 1997.
Then when the TJ proved itself more capable than any previous Jeep: they shut up.
As a clarification, I'm talking about durability, not performance. The front end of our work trucks are very capable untill a shock blows.
Quote from: Soup DeVille on December 04, 2007, 12:45:05 PM
Save this page and re-read in five years.
HA! Yeah, it's going to be eating at me the entire time.
Quote from: Tave on December 04, 2007, 12:41:22 PM
Hmm, sounds a little expensive.
Most hardcore offroaders also aren't interested if their hobby makes sense financially. They do it because they like it.
I doubt a coil spring setup is really more expensive than an equivalent leaf setup, as long as you're not talking about conversions. Coils just have more potential, which might lead to higher prices.
Quote from: Tave on December 04, 2007, 12:46:13 PM
As a clarification, I'm talking about durability, not performance. The front end of our work trucks are very capable untill a shock blows.
For durability's sake, there are multiple leafs to back each other up if one fails, but generally only one or two coil springs. A 40-year old rusted out leaf spring can still function with cracks in it, but not a coil.
But, if the suspension is built and maintained properly, it won't be a problem in either case.
Quote from: Tave on December 04, 2007, 12:26:11 PM
I thought I've made it clear I'm talking about private-duty light pickup trucks.
Maybe you'd care to mention some more irrelevant machinery that no small buisness owner in the country can afford?
Literally tens of thousands of small business owners every year buy $100k - $150k class 6 and class 8 trucks.
For whatever reason, you're on a tear using anectodatal data - Which brings up another point: If you're breaking front coil springs on Dodge Ram you are simply abusing the truck well beyond its designed intent. Way WAY beyond. It's quite hard to break a coil spring.
Quote from: Tave on December 04, 2007, 12:40:00 PM
I mentioned that your list of vehicles cost a lot, but I guess that was easy to ignore.
Quite the opposite - that they cost a lot lends credence to coil suspensions, in that those vehicles are specifically very heavy and/or harsh duty. Coil spring design is about as basic as it gets - most domestic cars up until the '80s were rear-leaf sprung, including the performance variety (Mustang, Camaro, Challenger, etc.) - now none of them are.
If Dodge can can use rear coils without sacrificing hauling and towing capability, and it doesn't cost material any more $$, there is virtually zero detriment to the consumer.
I also note the just recently the 4X4 F-250/350 went from leafs to coils in the front, and I also note that the Avalanche has always used rear coils, as have recent iterations of the Expedition, Tahoe, Durango, Armada, and other 1/2-ton based SUVs.
(EDIT - I was mistaken - the Abrams uses torsion bars, not coils.)
Quote from: Tave on December 04, 2007, 12:24:49 PM
:rolleyes: Because that's the same coil they're going to put into the Ram :rolleyes:
Fine. Let's put it this way: I used to replace rear leaf springs on a regular basis on the 1st Gen Nissan Frontier, but NEVER replaced a broken front coil on one. Now which is more durable?
None of the coil spring naysayers have given a good reason why they're bad.
Do leaf springs have some kind of magical spring rate?
Quote from: 280Z Turbo on December 04, 2007, 01:53:43 PM
None of the coil spring naysayers have given a good reason why they're bad.
Do leaf springs have some kind of magical spring rate?
It would seem that, as with all things, you could make either strong enough to suit your needs, however I suppose there is a correlation between beefiness and spring rate.
Quote from: GoCougs on December 04, 2007, 01:28:10 PM
For whatever reason, you're on a tear using anectodatal data
And I never claimed otherwise. For whatever reason, you can't see that you're using anectodal evidence, too.
Quote from: Soup DeVille on December 04, 2007, 12:40:18 PM
Are you intentionally being difficult?
Bingo.
Quote from: R-inge on December 04, 2007, 02:02:42 PM
It would seem that, as with all things, you could make either strong enough to suit your needs, however I suppose there is a correlation between beefiness and spring rate.
To me the issue seems to be which is better for heavy duty performance at a given price? If you have $100 to spend on procuring the heaviest duty suspension component, would you choose leaf-spring or coil springs?
I don't know that much about heavy duty suspensions,but I doubt its as simple as you and gocougs are making it sounds.
Given the price, coils may very well be better at extremely high levels of performance relative to cost, but at more plebian levels leaf-springs may be the better option relative to cost. I don't know the answer, just explaining why the examples given do not really "prove" anything one way or the other.
Quote from: GoCougs on December 04, 2007, 01:28:10 PM
Which brings up another point: If you're breaking front coil springs on Dodge Ram you are simply abusing the truck well beyond its designed intent. Way WAY beyond. It's quite hard to break a coil spring.
I'm sorry to mislead you. We break a lot of front shocks on the trucks. I believe I said that earlier. If I said we break coils coils I apologize.
QuoteIf Dodge can can use rear coils without sacrificing hauling and towing capability, and it doesn't cost material any more $$, there is virtually zero detriment to the consumer.
Correct.
QuoteI also note the just recently the 4X4 F-250/350 went from leafs to coils in the front, and I also note that the Avalanche has always used rear coils, as have recent iterations of the Expedition, Tahoe, Durango, Armada, and other 1/2-ton based SUVs.
Right, the trend to civilize the ride quality of the truck market isn't new.
Quote from: SJ_GTI on December 04, 2007, 02:19:27 PM
To me the issue seems to be which is better for heavy duty performance at a given price? If you have $100 to spend on procuring the heaviest duty suspension component, would you choose leaf-spring or coil springs?
I don't know that much about heavy duty suspensions,but I doubt its as simple as you and gocougs are making it sounds.
Given the price, coils may very well be better at extremely high levels of performance relative to cost, but at more plebian levels leaf-springs may be the better option relative to cost. I don't know the answer, just explaining why the examples given do not really "prove" anything one way or the other.
Exactly, that's all I was wondering too, and the point I tried to make to GoCougs about the Hummer, which also has an independent rear-suspension that performs just as well as a solid axle, but costs more.
Quote from: Tave on December 04, 2007, 02:28:54 PM
Exactly, that's all I was wondering too, and the point I tried to make to GoCougs about the Hummer, which also has an independent rear-suspension that performs just as well as a solid axle, but costs more.
Coils can be used on solid axles, too.
Quote from: SJ_GTI on December 04, 2007, 02:19:27 PM
To me the issue seems to be which is better for heavy duty performance at a given price? If you have $100 to spend on procuring the heaviest duty suspension component, would you choose leaf-spring or coil springs?
I don't know that much about heavy duty suspensions,but I doubt its as simple as you and gocougs are making it sounds.
Given the price, coils may very well be better at extremely high levels of performance relative to cost, but at more plebian levels leaf-springs may be the better option relative to cost. I don't know the answer, just explaining why the examples given do not really "prove" anything one way or the other.
I wasn't trying to simplify it. I think it's proven that for the price leaf springs are more effective, and I'm not arguing that. What I am arguing (see my post on previous page for reference) is that there isn't necessarily a direct correlation between cost-effectiveness and durability, since as I pointed out I used to replace leaf springs on a regular basis on Frontier pickups. I don't remember having that issue with coils. Both can be engineered to a certain point to accomplish a goal. As the article points out it does limit the ultimate load (or was it tow?) rating of the vehicle, but not to the point that it would impact a 1/2 ton truck.
Quote from: SJ_GTI on December 04, 2007, 02:19:27 PM
To me the issue seems to be which is better for heavy duty performance at a given price? If you have $100 to spend on procuring the heaviest duty suspension component, would you choose leaf-spring or coil springs?
I don't know that much about heavy duty suspensions,but I doubt its as simple as you and gocougs are making it sounds.
Given the price, coils may very well be better at extremely high levels of performance relative to cost, but at more plebian levels leaf-springs may be the better option relative to cost. I don't know the answer, just explaining why the examples given do not really "prove" anything one way or the other.
Part of the leaf spring advantage is that the leafs also locate the axle- the traditional hotchkiss drive only uses leaf springs an nothing else, while coil springs need trailing arms or other components to physically locate the axle and hold it in place.
The downsides of this are:
If you really do break a main leaf spring, your axle falls off; if you break a coil, the suspension slumps and may even ride on the stops, but the axle remains more or less in place.
On a leaf spring, it also means the suspension "toughness" is directly related to how strong the leaf spring pack is; and therefore leaf springs simply need to be stronger; and therefore stiffer in many cases than you really want for the suspension to work properly just in order to due their other job of holding things together.
Conversely, on a coil spring suspension you can have a relatively soft progressive rate spring attached to a completely solid, bullet proof suspension.
Quote from: Tave on December 04, 2007, 02:28:54 PM
Exactly, that's all I was wondering too, and the point I tried to make to GoCougs about the Hummer, which also has an independent rear-suspension that performs just as well as a solid axle, but costs more.
The new versions of the Expedition, Armada/QX56, Sequoia, and probably other 1/2-ton based SUVs also use IRS. They don't cost appreciably more than their previous generation live-axle predessors. They tend to weigh a bit more than their truck cousins, so they don't have quite the towing/hauling performance, but it's at about 80%.
Each design can be as reliable/durable/strong as it is designed to be. One can design wimpy leafs (think a '74 Pinto) or beefy coils (think a 50,000 lb HMTT).
When it's all said and done however, coils are better all around than leafs - less unsprung weight, no sliding leafs to bind or catch, better variable rate range, and probably some other stuff.
This is a very good move by Dodge. Will it be a game changer? A bit. I surmise however that other truck makers all ready have coils and/or IRS on the drawing board for future generations - especially considering that many already have coils/IRS under 1/2-ton based SUVs already in production.
Quote from: GoCougs on December 04, 2007, 06:09:51 PM
When it's all said and done however, coils are better all around than leafs - less unsprung weight, no sliding leafs to bind or catch, better variable rate range, and probably some other stuff.
That's an excellent and well-supported qualitative argument there Cougs.
Quote from: sandertheshark on December 04, 2007, 08:28:33 PM
That's an excellent and well-supported qualitative argument there Cougs.
Rather than a personal attack, howzabout a technical counter argument to both mine (and SdV's posts)?
Quote from: Soup DeVille on December 04, 2007, 11:52:12 AM
Actually, M1s are damned dangerous vehicles to be in an accident in.
Of course, the tank itself is just fine, but the occupants can be beaten up pretty severely real easily.
Would you prefer to be the man in the pancaked Aveo?
Quote from: Submariner on December 05, 2007, 08:37:08 PM
Would you prefer to be the man in the pancaked Aveo?
If I'm taking an Aveo up against an M1, I'm screwed from the get-go.
Quote from: GoCougs on December 04, 2007, 01:28:10 PM
Quite the opposite - that they cost a lot lends credence to coil suspensions, in that those vehicles are specifically very heavy and/or harsh duty. Coil spring design is about as basic as it gets - most domestic cars up until the '80s were rear-leaf sprung, including the performance variety (Mustang, Camaro, Challenger, etc.) - now none of them are.
What!!! The Corvette isn't using a rear leaf spring anymore?
Quote from: etypejohn on December 06, 2007, 10:43:40 AM
What!!! The Corvette isn't using a rear leaf spring anymore?
It is, but the Corvette uses a transverse leaf spring (think Model T front axle)
Quote from: Secret Chimp on December 06, 2007, 10:53:12 AM
It is, but the Corvette uses a transverse leaf spring (think Model T front axle)
Of course it does, but it's still a leaf spring.
Quote from: etypejohn on December 06, 2007, 12:22:15 PM
Of course it does, but it's still a leaf spring.
Fiberglass, not steel. Maybe even carbon fiber, but definately not steel.
Fiberglass leaf springs are superior to steel ones since they don't fatique over time.
More importantly the leaf springs in the Corvette are not used to locate the axles as they are in a traditional Hotchkiss drive: they're used in almost exactly the same way as a comparable double A-arm coil spring suspension.
Quote from: etypejohn on December 06, 2007, 10:43:40 AM
What!!! The Corvette isn't using a rear leaf spring anymore?
That's why I like etypeJohn - he keeps me on my toes.
Quote from: 93JC on December 06, 2007, 03:58:47 PM
More importantly the leaf springs in the Corvette are not used to locate the axles as they are in a traditional Hotchkiss drive: they're used in almost exactly the same way as a comparable double A-arm coil spring suspension.
Not exactly. It does do double duty as an anti-roll bar, which is quite problematic when it comes to handling (that is, simultaneously enduring two disparate stresses - torsion and bending - from two disparate actions - body roll and wheel movement).
Well... sort of, I guess. Hypothetically the same 'problem' presents itself in a different way in any car with an 'indepedent' suspension with an anti-roll bar: the movement of one wheel will affect the movement of the other, through the anti-roll bar.
I mean, really, when you get down to it an anti-roll bar is essentially a torsion spring deliberately set up to connect one wheel to the other for the sake of resisting the roll moment in a turn while sacrificing a small amount of suspension independence. The only specific 'problem' with the Corvette's suspension that I can think of is that the monoleaf is used in such a way that it must be stiffer.
But then again that's basically what you just said, isn't it.
*sigh*
Nevermind.
Quote from: 93JC on December 06, 2007, 10:10:43 PM
Well... sort of, I guess. Hypothetically the same 'problem' presents itself in a different way in any car with an 'indepedent' suspension with an anti-roll bar: the movement of one wheel will affect the movement of the other, through the anti-roll bar.
I mean, really, when you get down to it an anti-roll bar is essentially a torsion spring deliberately set up to connect one wheel to the other for the sake of resisting the roll moment in a turn while sacrificing a small amount of suspension independence. The only specific 'problem' with the Corvette's suspension that I can think of is that the monoleaf is used in such a way that it must be stiffer.
But then again that's basically what you just said, isn't it.
*sigh*
Nevermind.
The issue I see isn't necessary one side affecting the other - I'm making the assumption that the transverse leaf is bolted stiff enough in the center such that there is a stress discontinuity (no "cross talk"), and hence it acts as two separate springs. If this is not the case, the Corvette suspension is a
real mess.
The issue is that on the same side, half the spring is being asked simultaneously to counteract the affects from body motion (torsion) and wheel motion (bending). I will also add however the Corvettes still have sway bars, but they are smaller than you'd expect.
Two different stresses with two different consequences on suspension performance. It's too much compromise IMO.
Quote from: GoCougs on December 06, 2007, 10:34:23 PM
The issue I see isn't necessary one side affecting the other - I'm making the assumption that the transverse leaf is bolted stiff enough in the center such that there is a stress discontinuity (no "cross talk"), and hence it acts as two separate springs.
It's bolted at
two points, as far as possible from each other (while still equidistant from the centreline).
QuoteIf this is not the case, the Corvette suspension is a real mess.
I think the idea is that it's essentially fixed in the lateral direction while allowing for
some movement in the vertical.
If you do that, the outside wheel in a turn should push the centre section of spring between the two mounting points down, which bends back up to meet the bracket at the inner wheel mounting, which pushes the inner wheel down, which aids in cornering, right?
I think I confused myself.
QuoteThe issue is that on the same side, half the spring is being asked simultaneously to counteract the affects from body motion (torsion) and wheel motion (bending).
With two mounting points the torsional effects due to the body motion would be minimzed.
QuoteI will also add however the Corvettes still have sway bars, but they are smaller than you'd expect.
I would expect them to be smaller, as the spring acts as its own sway bar. I thought you just said the spring is being asked to be a spring (resist wheel movement) and a sway bar (resist body roll)?
QuoteTwo different stresses with two different consequences on suspension performance. It's too much compromise IMO.
I don't think it's as much of a problem as you think.
But for the sake of shutting up critics they might as well switch to coils in the C7. Not because they're better, but because people think they're better, which is what really matters.
Our trees have green leaves.
Our trees don't have leaves... :mask:
Quote from: GoCougs on December 04, 2007, 11:18:58 AM
I still have yet to see a material technical criticism of rear coils.
Maybe Oshkosh Truck Corporation (uses coils on many, many of its heavy duty trucks) is all wet:
(http://img411.imageshack.us/img411/9814/brains9btmex9.jpg)
Coil springs cost less, are lighter, have almost no internal friction, and even take up less space.
However, they do not locate the axle and require a three or four link system to do the same job leaf springs can do without any assistance, often making the entire leaf spring suspension SYSTEM lighter. They also allow more body drop than do leaf springs in heavy terrain, and under static load.
Leaf springs are modular, want more height? Add a couple more leaves. Want it lower? Remove a couple leaves.
Leaf springs also help to reduce sway.
Quote from: JYODER240 on December 03, 2007, 10:06:32 PM
So the Ram is soon going to have a more advanced suspension than a Mustang?
:lol:
That's not saying much, but yes, I guess...
Early 1960s GM pickup trucks, both 1/2 ton and 3/4 ton, used coil springs at the rear.
I still see these trucks in use as daily drivers.
I won't be a detractor of either system, but the "R" racing 'vettes use coil springs on all four corners. Does anyone know why?
Quote from: Pancor on December 19, 2007, 01:43:58 PM
I won't be a detractor of either system, but the "R" racing 'vettes use coil springs on all four corners. Does anyone know why?
Adjustability.
Serious race teams may want to swap their springs out for different tracks and coilover shocks allow adjustable ride height.
Quote from: 280Z Turbo on December 19, 2007, 02:09:59 PM
Adjustability.
Serious race teams may want to swap their springs out for different tracks and coilover shocks allow adjustable ride height.
As well as corner weighting.
Quote from: GoCougs on December 06, 2007, 10:34:23 PM
The issue I see isn't necessary one side affecting the other - I'm making the assumption that the transverse leaf is bolted stiff enough in the center such that there is a stress discontinuity (no "cross talk"), and hence it acts as two separate springs. If this is not the case, the Corvette suspension is a real mess.
The issue is that on the same side, half the spring is being asked simultaneously to counteract the affects from body motion (torsion) and wheel motion (bending). I will also add however the Corvettes still have sway bars, but they are smaller than you'd expect.
Two different stresses with two different consequences on suspension performance. It's too much compromise IMO.
You've completely misunderstood how the transverse leaf springs on the Corvette work. The springs only bend along one axis of motion, there is no seperate bending or torsion axis. The problem you speak of doesn't exist.
There are no two seperate motion tracks under the control of the leaf spring. The double A arm suspension only allows one track of motion for the assembly. Put in a coil spring and it still follows that same track of motion as it articulates. Remove any sort of spring all together and a double wishbone setup will still follow that same track of articulation. All motion of the double wishbone suspension occurs along this single track of motion, it doesn't matter what kind of spring is attached. The transverse leaf spring is arranged so that motion along this track carved by the double wishbone suspension is translated into a single bending axis in the leaf spring. As there is only one motion axis in the double wishbone suspension, the leaf spring only bends in one axis under any circumstance. To suggest that somehow the up and down motion of the double wishbone suspension due to cornering and the up and down motion of the suspension due to bumps results in a different track of motion carved by the double wishbone suspension setup is false.
The effect of transverse leaf springs acting as antiroll bars is a completely seperate effect. For anything to act as an antiroll bar it obviously has to somehow link the two sides of the suspension together, it's obviously silly to suggest that it wouldn't. What antiroll bar works by not linking the two seperate sides of the independent suspension together? That's right, none. The anti-roll bar inherently sacrfices suspension independence for roll stiffness, it's a balance that every manufacture must strike.
The single transverse leaf spring of the Corvette does indeed transfer motion between the two sides of the IRS. If you look closely at the Corvette's transverse leaf spring, you'll see that it's not held flat but actually arched. This is also why the Corvette uses a large single transverse leaf spring instead of two smaller seperate leaf springs. The single transverse leaf spring transmits motion from one side of the suspension to the other via changes to degree of arch. When the wheel goes up on one side, the arch is reduced and the wheel goes up on the other side as well. When the wheel goes down on one side, the arch is increased and the wheel goes down on the other side as well. Now I'm sure all you transverse leaf spring haters will gasp and point and say this is terrible. But it is exactly the same case as with an antiroll bar. When the wheel goes up on one side the antiroll bar transmitts that upward motion to the other side of the suspension.
So which is better, using an antiroll bar or having the transverse leaf spring do the motion transfer? Well lets think of it this way. GM could have saved quite a lot of leaf spring material if it made two seperate leaf springs without the long linker in the middle. And it's not like they saved money by eliminating a roll bar all together because they still had to include a softer roll bar. And since the diameter of a stiffer roll bar only adds tiny amounts to the sum, I'm sure GM's setup wasn't to save money. In fact it would have been trivial for GM to make a totally independent leaf spring setup and relied totally on the antiroll bar.
But the antiroll bar isn't exactly sophisticated. In fact the torsion bar is probably one of the oldest and most primitive forms of motion absorption ever imployed. It's just a large rod of metal that twists. There is no control or sophistication in it's motion, which is why few cars still use a torsion bar as the main spring of their suspension. However the torsion bar remains in the antiroll bar setup because it's one of the few motion absorption setups that can be used in across such a long distance in such a tight space with low weight, and low cost (it's just a rod of metal). It's evident that GM tried to take as much work away from the antiroll bar as possible onto a motion absorption device that was designed to give far more control (the composite leaf spring). Only because getting enough roll stiffness would have required leaf springs that were too stiff did GM also add an anti-roll bar.
The take home messege is this. If GM wanted to make the antiroll bar the sole source of antiroll stiffness, it would have been the simplest thing in the world, just mount seperate leaf springs and use thicker rods Hell I could do it right now by going downstairs and sawing the leaf spring in half. Obviously they spent extra money and effort to keep as much roll resistance off the antiroll bar as they could.
Edit: So apparently older generations of Corvettes had their leaf springs mounted tight, which did not allow it to act as an antiroll bar.
http://en.wikipedia.org/wiki/Corvette_leaf_springs
"A single, perfectly tight center mount that held a small center section of the spring flat against the frame would isolate one side of the spring from the other. No roll or anti-roll effect would appear. The rear spring of the C2, C3, and C4 has this type of mount, which effectively divides the spring in two. It becomes a quarter-elliptic spring.
Since the C4, the Corvette has had widely-spaced double mounts on the front. The rear spring has had double mounts since the C5. The spring is allowed to pivot about these two points. When the suspension compresses and the end of the leaf is pulled up, the center of the leaf spring between the two mounts moves down. This in turn reduces the spring force on the wheel on the opposite side of the car. In this way, the leaf acts like an anti-roll bar."
So basically GM could easily have a totally independent leaf spring setup and relied completely on the antiroll bars, as they'd been doing it for decades on older cars. GM especially developed mounts that allowed the leaf spring to pivot because they wanted to take as much antiroll duty off the antiroll bar as possible. I'm sure they didn't do this for shits and giggles.
Perhaps I am wrong as the torsion due to body sway, however A-arms (and I'd bet the spring) are not rigidly mounted in the vertical axis (bushings) - granted, movement isn't signficant, but there will be a bit of torsion.
Now as to data regarding side-to-side interaction - wow. At least with a more conventional setup, there are three different springs with signicant damping between each - here it's still one spring doing the work typically handled by three - and to me that still speaks of harmonics issues.
I still see massive compromises in an effort to hold onto a legacy.
Quote from: 565 on December 19, 2007, 11:53:59 PM
Edit: So apparently older generations of Corvettes had their leaf springs mounted tight, which did not allow it to act as an antiroll bar.
http://en.wikipedia.org/wiki/Corvette_leaf_springs
"A single, perfectly tight center mount that held a small center section of the spring flat against the frame would isolate one side of the spring from the other. No roll or anti-roll effect would appear. The rear spring of the C2, C3, and C4 has this type of mount, which effectively divides the spring in two. It becomes a quarter-elliptic spring.
Since the C4, the Corvette has had widely-spaced double mounts on the front. The rear spring has had double mounts since the C5. The spring is allowed to pivot about these two points. When the suspension compresses and the end of the leaf is pulled up, the center of the leaf spring between the two mounts moves down. This in turn reduces the spring force on the wheel on the opposite side of the car. In this way, the leaf acts like an anti-roll bar."
So basically GM could easily have a totally independent leaf spring setup and relied completely on the antiroll bars, as they'd been doing it for decades on older cars. GM especially developed mounts that allowed the leaf spring to pivot because they wanted to take as much antiroll duty off the antiroll bar as possible. I'm sure they didn't do this for shits and giggles.
First, excellent post. I would add however that corvette suspension prior to the C4 used the rear CV axles effectively as the upper control arms. You can imagine the traction issues created by that. So while it might seem that the suspension took a step back with the revised spring mounting, on the whole it moved forward exponentially.
Would it still benefit from the original, isolated leaf spring mounting? Probably.