42 replies to this topic

[BRIAN GLOVER]

http://[IMG]http://img85.exs.cx/img85/1407/miaaskoenigseggrearsuspension04.jpg[/IMG]

I saw this car at the Miami Auto Show last week and took this photo of the rear suspension.
The design of the upper A arm at the rear also pushes a horizontal coil/over. The roll is controlled by this Watts link set up, mounted to the gearbox. The Heims are turned all the way in, so there is no more adjustment. The increase in unsprung weight and the couple to the spring on the A arm seems to be offset by not having to damp torque on a normal anti-roll set up. The I beam section on the Watts seems to be mounted 90' out of phaze. How does it feel when one wheel hits a bump or a pot hole? I didn't see the front suspension.
They played a closed loop video with Martin Brundle at the wheel. 700hp and 2200lbs makes it the fastest production car ever(according to the manufacturer) He loved it. They probably slipped him a couple of grand to say that.

Any comments.

[Engineguy]

Maybe you're seeing a shadow... the anti-roll blade seems to have a tapering square or rectangular cross-section in the CAD view below...



Production car, eh? I wonder how many have been built.

[BRIAN GLOVER]

The car shown is the same one that Brundle tested. It looks pretty beat up and the link on the actual car is different from the one that you show. It is longer and has an I section. Maybe the properties of the beam when used like this are more suitable for this application.
They plan to sell 23/year in the states at $500 000 a copy.

Originally posted by Engineguy
Maybe you're seeing a shadow... the anti-roll blade seems to have a tapering square or rectangular cross-section in the CAD view below...

Production car, eh? I wonder how many have been built.

[Greg Locock]

I guess the arms of the central member act as leaf springs, otherwise the whole thing would lock up in roll. I wonder if by driving the front of the wishbone they are trying to get some toe or castor effect in roll?

10/10 for being different, but I'm pretty sure they could have packaged a conventional sta bar in the same space, which I'm sure would have been lighter for a given rate.

[Ben]

Greg's right the bar in the middle acts as a leaf spring to resist roll. It's identical in function to any anti-roll bar in that it's an undamped spring that acts in the roll mode and partially in single-wheel bump. Just happens to be a slightly different spring and mechanism.

Ben

[Engineguy]

This could explain why the one you saw was different...

The integral Z-shaped anti-roll bars are also incorporated in the KACS, and are completely adjustable, suiting each driver and any specific driving conditions. The function of the anti- roll bars can be set anywhere between very hard to ultra soft, just by replacing the cross-link. The ease with which different suspension characters can be accessed is one of the most appealing aspects of racing a Koenigsegg, according to test drivers. Adjustable length pushrods are connected to each top wishbone and transplant force into the cross-link. These progressive anti-roll bars were conceived and developed by Koenigsegg and are unique in the field of motoring. This simple but ingenious device is a key component in achieving the rock-steady road holding and wonderfully obedient handling of these high-speed machines

[McGuire]

"The integral Z-shaped anti-roll bars are also incorporated in the KACS, and are completely adjustable, suiting each driver and any specific driving conditions. The function of the anti- roll bars can be set anywhere between very hard to ultra soft, just by replacing the cross-link."

Ohhhhh, it's "adjustable" ...by replacing it with another one.

[BRIAN GLOVER]

I've seen a similar mechanism in an airplane aileron activator. The bellcank is designed to bend depending on the pressure on the ailerons. This double blade arb which works as a leaf bar as Ben has pointed out, probably has interesting kinematics as the rods go from compression to tension.
I would assume the longer the leaf bar, the more roll resistance and the push rods are adjusted to keep everything at L angles. Has this ever been tried before, Richard ;) ??? Nudge.

I just don't like the heavy upper A arm.

I saw an interesting thing today along the same lines more or less. I will go and take some photos tomorrow. I was looking under a trick '68 Mustang on a lift. A rectangle box tube section was bolted in place of the leaf springs in the same holes and the solid 9" aluminum axle was mounted above it. The axle was attached by links from the axle to two bell cranks mounted on the frame which pushed horizontal coil/overs also mounted to the frame. 3 trailing radius arms were mounted to the box frame. The center one was as long as the drive shaft and is braced to the 3rd member so that only the front universal changed plane. To locate it laterally, a Watts link was mounted under the diff and the push rods were mounted to the box frame. The shaft for the bearing for the Watts doubled as the drain plug bolt. Understand? Obviously a road race set up but it sure was neat.
McGuire, have you heard of such a thing?

Originally posted by Engineguy
This could explain why the one you saw was different...

[McGuire]

Originally posted by BRIAN GLOVER
I saw an interesting thing today along the same lines more or less. I will go and take some photos tomorrow. I was looking under a trick '68 Mustang on a lift. A rectangle box tube section was bolted in place of the leaf springs in the same holes and the solid 9" aluminum axle was mounted above it. The axle was attached by links from the axle to two bell cranks mounted on the frame which pushed horizontal coil/overs also mounted to the frame. 3 trailing radius arms were mounted to the box frame. The center one was as long as the drive shaft and is braced to the 3rd member so that only the front universal changed plane. To locate it laterally, a Watts link was mounted under the diff and the push rods were mounted to the box frame. The shaft for the bearing for the Watts doubled as the drain plug bolt. Understand? Obviously a road race set up but it sure was neat.
McGuire, have you heard of such a thing?

You mean like this?








No, never heard of such a thing.

[BRIAN GLOVER]

I should have known. Who makes it?
One would have to design a pretty darned good IRS to work as well as this set up on smooth road. The Watt's link in this location also lowers the roll centre. I would like to see NASCAR do about 6 road races a year, one at the Brickyard. They would need to get rid of their Panhard rod though and replace it with the Watt's.

Originally posted by McGuire


No, never heard of such a thing.

[RDV]

Brian Glover-I would assume the longer the leaf bar, the more roll resistance

Actualy the shorter the blade, the more roll resistance.... thought experiment (well , practice too...) shows an infinitely short (nice tautology ,huh?) blade would not bend at all (if the same thickness-always an useful caveat), as links would be acting against each other..... mmmm... very muzzy analogy.... lets start again.

A leaf spring of a given section , will deform (bend) a given amount for each unit of lenght... so double the lenght , it will bend twice as much under the same load... as rate is defined by load/deflection rate will be half, so reducing roll resistance when connected to wheels through link.

And keeping link angle to blade as close as possible to 90deg. keeps rate linear over a reasonable amount of travel (which translates in angular position of this particular double-opposed blade arrangement...imagine it at zero or 180 degrees and it will be infinite , as links again will be pulling against each other , thus stopping all movement notwithstanding the force).

Other angle values can be used to have a progressive or regresive roll resistance... quite interesting, but difficult to implement as related to ride height.... I have used it on rear suspension of car with rear fuel tank location to cater for full-empty tank condition. Ultimately a conventional "C" shaped bar the easiest to use, at a pinch "T" bars, but all other versions depending on packaging or space availiable.

Much more interesting is the Kinetic tipe of bar actuation.. as used on WRC Citroens, and subject of article in RCE some months ago... see their site for more details.

And neat Mustang work around... some good lateral thinking there...interesting way of lowering the roll center on a beam axle.

[schuy]

BTW, the Koenigsegg is not yet the fastest production car in the world- They have yet to test it to it's maximum speed.

(Or perhaps they have, and they didn't like the results much)

Many makers claim to have the fastest production car in the world, but don't go through the actual timed trial- why is that???

[McGuire]

Originally posted by BRIAN GLOVER
I should have known. Who makes it?
One would have to design a pretty darned good IRS to work as well as this set up on smooth road. The Watt's link in this location also lowers the roll centre. I would like to see NASCAR do about 6 road races a year, one at the Brickyard. They would need to get rid of their Panhard rod though and replace it with the Watt's.

An outfit called Total Control. I first saw it at SEMA or the PRI show or something I think. Then Shelby picked it up for the 1968 Mustang GT 500E "Eleanor" replicas (copies of the "Gone in 60 Seconds" car) he is currently hustling. (Except the movie people are now suing him or something.) The beauty of it is the entire assembly is modular, and simply bolts to all the original unit-body's hard points plus four weld-on brackets. Plus, when all chromed and polished up it looks real slick and high tech-y. Powder-coated in Fisher-Price colors as in the photos, it's kind of dorky-looking. Looks like it was made out of Kent-Moore shop equipment.

The advantage of the Panhard bar is adjustability. On a pit stop you can go through the back window with a long wrench and adjust the frame mount height of the 'ol "track bar," raising and lowering the roll center in only a second or two. This is a very useful method of on-the-fly chassis tuning, say if you are tight or loose corner out. With a Watts link you would need some kind of crazy mechanism to raise or lower it that quickly. On the NASCAR road courses of course, they will reverse the axle and frame mountings side-to-side so the lateral roll center change in travel is in the opposite (beneficial) direction. (Which you don't need with a Watts link - the pivot of the center link describes perfect linear motion.)

....Which reminds me of a funny story. Years ago one day I was standing off to one side while a Very Well Known Automotive Journalist and Engineer was asking the King why they swap the Panhard bar around like that for the road courses. He looked at him over his sunglasses, paused for a moment, and said "Wellsir, yew want what that bahr n'yhere should always be in tension, see what ah mean?" Totally possumed him, as they will tend to do in those parts. (NEVER tell people what you are doing, especially nosy yankees.) Later as we walked away the guy said to me, "No offense, but I don't think Richard knows very much about chassis engineering." Riiiight.

[MclarenF1]

Is that a rod end in single shear? Boy, that would have pissed Carol Smith off like nothing else

[Greg Locock]

Crazy or not our Taxicab racers adjust their Watts links at pit stops in a couple of seconds or so.

Incidentally our chassis is very similar to Mustang's, derived from a 59 Galaxy I think, and our first IRS picked up the leaf spring mounting points for the front subframe location. Our second IRS was supposed to be used on mustang but that put too much cost and so on into it.

They have recently had to retrofit a beam axle due to cost, sensibly they took our old beam axle (4 bar, watts link). The genius that thought of that got a promotion!

The Koenigssegg sta bar could have been made fully adjustable by using a sliding link along the leaf spring.

Wee Jackie came to drive all our cars around the (very smooth) handling circuit. The car he liked best was a wagon fitted with leaf springs.

[xflow7]

Originally posted by MclarenF1
Is that a rod end in single shear? Boy, that would have pissed Carol Smith off like nothing else

I thought exactly the same thing! Nice one.

[BRIAN GLOVER]

Are you sure about that? What about the larger moment arm and the longer travel? The spring is there just so it doesnt brake.

[QUOTE]Originally posted by RDV
[B]

Actualy the shorter the blade, the more roll resistance....
A leaf spring of a given section , will deform (bend) a given amount for each unit of lenght... so double the lenght , it will bend twice as much under the same load... as rate is defined by load/deflection rate will be half, so reducing roll resistance when connected to wheels through link.

[BRIAN GLOVER]

The Panhard rod or track bar is good for ovals only. The rod adjustment moves the axle left or right to change the thrust line. Move it left for a tight car. There is no need to adjust a Watt's link, it is only there to locate the axle, it is no good for ovals.
The trouble with the track rod is that it goes through a radius which moves the axle left and right over bumps and thru roll which gives it that old '48 Buick wobble.

[QUOTE]Originally posted by McGuire
[B]


The advantage of the Panhard bar is adjustability.
With a Watts link you would need some kind of crazy mechanism to raise or lower it that quickly. On the NASCAR road courses of course, they will reverse the axle and frame mountings side-to-side so the lateral roll center change in travel is in the opposite (beneficial) direction. (Which you don't need with a Watts link - the pivot of the center link describes perfect linear motion.)

[RDV]

BRIAN GLOVER-Are you sure about that? What about the larger moment arm and the longer travel? The spring is there just so it doesnt brake

Yes , definitely sure.
... the longer travel for a same force reduces the rate.... moment arm is immaterial as it is the blade that flexes... imagine turning blade on side, thus increasing its Iz, it will be infinitelly stiff because it doesnt bend, effectively linking both wheels through linkage.

[McGuire]

Originally posted by BRIAN GLOVER
Are you sure about that? What about the larger moment arm and the longer travel? The spring is there just so it doesnt brake.

Absolutely sure: the shorter the bar, the higher the rate.

Cut off a 2" piece of coat hanger and try to bend it. Now try it again with a 10" piece.

[McGuire]

Originally posted by BRIAN GLOVER
The Panhard rod or track bar is good for ovals only. The rod adjustment moves the axle left or right to change the thrust line. Move it left for a tight car. There is no need to adjust a Watt's link, it is only there to locate the axle, it is no good for ovals.
The trouble with the track rod is that it goes through a radius which moves the axle left and right over bumps and thru roll which gives it that old '48 Buick wobble.

With a beam axle, in practice the functional difference between a Panhard bar and a Watts link is not that great. In either case it locates the axle laterally and helps determine the roll center. The Watts link has the advantage of perfect straight motion in travel. However, if the Panhard bar is long enough, the lateral displacement in arc is not all that significant.

Meanwhile, in NASCAR the Panhard bar also permits quick adjustment on pit stops. (They don't adjust it left or right but up and down.) It's not that a Watts link or Panhard bar requires adjustment per se, it's just a very convenient way to raise or lower the rear roll center....and you don't want it too low on a NASCAR taxi if you want decent roll couple distribution. These are big, tall, overweight, overpowered, undertired cars. It's all a moot point in NASCAR anyway, since the Watts link is not permitted. The trailing arm/Panhard bar deal is the only legal setup. NASCAR even specifies the maximum length of the parts.

[McGuire]

Originally posted by Greg Locock
Crazy or not our Taxicab racers adjust their Watts links at pit stops in a couple of seconds or so.

Sounds very intriguing. Where would I find a photo of this clever device?

[McGuire]

Originally posted by Greg Locock
Crazy or not our Taxicab racers adjust their Watts links at pit stops in a couple of seconds or so.

When I think about it I guess it would not be all that difficult....I suppose you could capture the Wats link's center pivot in some kind of vertical sliding block arrangement with a screw on the top, all mounted on the back of the diff.

[BRIAN GLOVER]

Since the rod is not horizontal, any up and down adjustment moves the axle left and right. Got a picture? (Not the picture but a picture )

[QUOTE]Originally posted by McGuire
[B]

if the Panhard bar is long enough, the lateral displacement in arc is not all that significant.

Meanwhile, in NASCAR the Panhard bar also permits quick adjustment on pit stops. (They don't adjust it left or right but up and down.) It's not that a Watts link or Panhard bar requires adjustment per se, it's just a very convenient way to raise or lower the rear roll center....

[BRIAN GLOVER]

I'm a simple southern boy, so type slowly 'cause I can't read fast.
You can't effectively eliminate this couple. The wheels will still be linked no matter what the link material and it's properties. In my photo, it shows a solid I beam structure mounted on it's side. I don't know what the material was, but it looked like forged steel welded to the bearing housing. It could have been a last minute fabrication for the show because maybe the shorter link broke. Supposing this link was solid, which it sure looked like to me and spring rate not withstanding. The geometory alone will increase roll resistance. The larger the radius, the shorter the arc which at larger wheel deflections will have less effect on rate toward max deflection.

This spring actuation method gives a little more flexibility in giving rising rate springing ( but does not have the potential in this respect as pushrud or pullrod actuation ), but I think it was done originally in the GTP/Group C era to get the spring/shock out of the venturi tunnel to help airflow.

Originally posted by RDV


Yes , definitely sure.
... the longer travel for a same force reduces the rate.... moment arm is immaterial as it is the blade that flexes... imagine turning blade on side, thus increasing its Iz, it will be infinitelly stiff because it doesnt bend, effectively linking both wheels through linkage.

[McGuire]

Originally posted by BRIAN GLOVER
Since the rod is not horizontal, any up and down adjustment moves the axle left and right. Got a picture? (Not the picture but a picture )

Sure, and if we know we will be turning mostly right or left we can put it to use by raking the bar in the appropriate direction. On a symmetrical setup we simply get the bar as level as we can at working ride height, and as long as we can. (A 36" bar describes a circle six feet in diameter, eh.)

Or we can use a straight-motion device like a Watts link. Why not? We can all use a little more unsprung weight and a couple more heim joints to look after.

In the immortal words of Carroll Smith [Tune to Win, p. 156]: "I do not think the theoretical advantages of the Watts link over the Panhard Rod are worth the extra structure and complexity -- although the cross structure necessary to mount the pivot is an ideal location for any necessary ballast."

(Carroll wanted the center link on the frame and the motion links on the axle, to reduce unsprung weight. That is another feature of the Mustang setup above he might not like.)

[McGuire]

Originally posted by BRIAN GLOVER
I'm a simple southern boy, so type slowly 'cause I can't read fast.
You can't effectively eliminate this couple. The wheels will still be linked no matter what the link material and it's properties. In my photo, it shows a solid I beam structure mounted on it's side. I don't know what the material was, but it looked like forged steel welded to the bearing housing. It could have been a last minute fabrication for the show because maybe the shorter link broke. Supposing this link was solid, which it sure looked like to me and spring rate not withstanding. The geometory alone will increase roll resistance. The larger the radius, the shorter the arc which at larger wheel deflections will have less effect on rate toward max deflection.

On the Mustang system shown earlier, a Watts link is used in its traditional role: lateral axle location. On the Konigsegg a Watts linkage is used in a different way: as an antiroll bar. However, here it is just another kind of antiroll bar, but employing a more unfamiliar form of spring medium instead of the usual torsion bar or blade. (In fact if we were sticklers we could say this is not a true Watts linkage but simply a 180 degree bell crank: its intended plane of action is through the motion arms, not at right angles to them.)

If the central link is rubber, effectively there will be zero resistance to roll. If the center link is infinitely rigid, we have an elaborate sort of beam axle: 100% of the roll motion on one wheel is then translated to the other. As long as the linkage is symmetrical, its geometry doesn't really matter, except as it affects the effective rate of the spring medium.

[Fortymark]

I think the suspension geometry have been designed by a guy called Dag Bolenius. He´s a computer programmer from the beginning but loves cars. He designed an Lambo Countach replica using some ex F1 suspension. That car had an Porsche 928 V8 engine installed. The chassis was made by a few very thick pipes. It had an very nice finish but looked anything but stiff. I even think the car cracked in two halves after a couple of years, I´m not sure though.
Later he did an Ferrari F40 replica all of his own too. Make no mistake, he did almost everything himself from doing the molds to the chassis design. This guy is an genius.
The ferrari F40 also used an Porsche 928 engine but this time supercharged producing over 550hp IIRC. The car had better finish, was lighter and was more powerfull than the real thing.

The new CCR with 806 hp and lots of torque (920 Nm (678 ftlb) at 5.700 rpm) should be able to claim the highest top speed ever.

Read more here: http://www.koenigsegg.com/index.asp

[McGuire]

Originally posted by Fortymark
He´s a computer programmer from the beginning but loves cars. He designed an Lambo Countach replica using some ex F1 suspension. That car had an Porsche 928 V8 engine installed. The chassis was made by a few very thick pipes. It had an very nice finish but looked anything but stiff. I even think the car cracked in two halves after a couple of years, I´m not sure though.

You're just trying to scare us.

[Lukin]

Originally posted by Greg Locock
Crazy or not our Taxicab racers adjust their Watts links at pit stops in a couple of seconds or so.

Is that the adjustements for rear RC height?

[Greg Locock]

That's what our ever reliable commentators on TV claim!

McGuire I couldn't find a picture, and I've never seen one myself. I assume they screw the central link up and down on the diff.

The cars aren't very technical for the most part, nice engines jammed into fairly unsophisticated chassis (so shoot me). Here's a freebie for any V8 teams: rebound springs /do/ make a difference.

[desmo]

Reliable or not, I'm duly impressed that your commentators even discuss relative tech arcana like roll centers. I'd be totally shocked if I ever heard that mentioned here.

[McGuire]

Originally posted by desmo
Reliable or not, I'm duly impressed that your commentators even discuss relative tech arcana like roll centers. I'd be totally shocked if I ever heard that mentioned here.

In NASCAR the announcers will often point out when teams raise or lower the track bar during pit stops, and may also go into why they do it -- raising the bar induces oversteer, lowering the bar reduces oversteer. However, rarely do they talk about how it works: by raising and lowering the rear roll center.

[Lukin]

Originally posted by Greg Locock
That's what our ever reliable commentators on TV claim!

McGuire I couldn't find a picture, and I've never seen one myself. I assume they screw the central link up and down on the diff.

The cars aren't very technical for the most part, nice engines jammed into fairly unsophisticated chassis (so shoot me). Here's a freebie for any V8 teams: rebound springs /do/ make a difference.

I've asked in another forum to confirm the RC adjustment. 99% of them are VB swilling yokels but one of them is pretty accurate with his information it seems like he works for a team.

How do you mean Rebound Spring?

Clipboard Crompton is a good comentator, beats the hell out of James Allen the eternal ****.

I was lucky enough to spend over an hour in the 888 pits at Waneroo this year talking to Campbell Little, their cheif engineer (he showed me everything in the car) and even though the technology pales in comparison to top level open wheelers, it's still pretty cool. Their hub/uprights looked awesome. Though given the Bathurst failures I guess looks didnt help.

[McGuire]

Originally posted by Greg Locock
That's what our ever reliable commentators on TV claim!

McGuire I couldn't find a picture, and I've never seen one myself. I assume they screw the central link up and down on the diff.

The cars aren't very technical for the most part, nice engines jammed into fairly unsophisticated chassis (so shoot me). Here's a freebie for any V8 teams: rebound springs /do/ make a difference.

I didn't realize you were talking about the V8 Supercars!? I LOVE those things! For the past several years I have been doing the Champ Car race at Surfers Paradise (missed the last one tho) and I always check them out. Very intriguing. I love how all the kit is stuffed into a production floor pan -- makes them much more "stock" than our NASCAR equipment. Um, can't say I remember how the rear axle location is accomplished though.

I love Australia in general, I must say. To me it appears to be a car nut's and car spotter's paradise. Much like America in that you have all these hardy folk of pioneer roots doing a nearly unlimited number of crazy things with automobiles, but different enough from our scene to make everything new and wonderful again. I have a blast just wandering around staring gape-jawed at what is running up and down the roads. I believe there may be a wider variety of automotive vehicles in Australia than anywhere, including the USA and Europe.

[McGuire]

Originally posted by Lukin


I was lucky enough to spend over an hour in the 888 pits at Waneroo this year talking to Campbell Little, their cheif engineer (he showed me everything in the car) and even though the technology pales in comparison to top level open wheelers, it's still pretty cool. Their hub/uprights looked awesome. Though given the Bathurst failures I guess looks didnt help.

If you guys start a V8 Supercar thread, I'm sure all of us non-Australians would find it extremely fascinating and educational. In America we don't have anything quite like it.

[Lukin]

Originally posted by McGuire
I didn't realize you were talking about the V8 Supercars!? I LOVE those things! For the past several years I have been doing the Champ Car race at Surfers Paradise (missed the last one tho) and I always check them out. Very intriguing. I love how all the kit is stuffed into a production floor pan -- makes them much more "stock" than our NASCAR equipment. Um, can't say I remember how the rear axle location is accomplished though.

They are great hey! I love em too. They arent the worlds most technical series, but it sits well with the general attitude of Aussie's I would like to think. I've been going to the V8's here in WA since 2000 and its always great. The racing is so good. The driving is sometimes questionable, but thats not always a bad thing! I'm hoping to work with them in a few years.

I dont know a great deal about them technically though, well not enough for anyone here to learn anything from me. Greg would be the man to talk to, I hear his company might be on the manufacturers involved. There doesnt seem to be much on the net apart from the usual superficial specification crap each team puts on their website.

[Fat Boy]

Originally posted by MclarenF1
Is that a rod end in single shear? Boy, that would have pissed Carroll Smith off like nothing else

I doubt if the old man would've really cared that much. There's a couple places on car that it's tough to get things in double shear. Lower ball joints and Watt's links are some of them. You can go with a high misalignment bearing, but then you've lost strength that way. Damned if you do and damned if you don't.

Incidently, Watt's link placement is an interesting problem. If you put it on the axle, like this example, then the roll center height stays constant w.r.t the ground, but if the car hits bumps in the corner, then as the chassis moves, the distance between the roll center and chassis CG varies as does your roll couple distribution.

If you put the pivot on the chassis, the roll couple stays the same, but when the car hits a bump in the corner the roll center forces are variable. It's interesting to see how different people attack the problem. I'm not convinced there is a 'right' answer.

Oh ya, the CC8S looks like a kluge to me. It's like they went out of their way to make it look clumbsy. Just one guy's opinion.

[McGuire]

Originally posted by Fat Boy
Incidently, Watt's link placement is an interesting problem. If you put it on the axle, like this example, then the roll center height stays constant w.r.t the ground, but if the car hits bumps in the corner, then as the chassis moves, the distance between the roll center and chassis CG varies as does your roll couple distribution.

If you put the pivot on the chassis, the roll couple stays the same, but when the car hits a bump in the corner the roll center forces are variable. It's interesting to see how different people attack the problem. I'm not convinced there is a 'right' answer.

Indeed. Both the Watts link and the Panhard bar have some very subtle and interesting qualities. They don't ordinarily matter so much in the usual applications...but to see some interesting stuff check out the dirt track late model guys. There, forward bite off the corners is everything and they will use every trick they can to get it.

[clSD139]

Donkervoort has beaten the Porsche on the Nurnbergring (www.autoweek.nl). The Dutch prestigecar was by far better on track time. 15s ahead of the GT3. I don't say I understand all this, but the Koenigegg would make a great chance. The suspention and chassis of the dutchman are very good is mentioned in the article. But a real Dutch match for the Porsche should be Spyker. I think the CC8S beats anything in corners.

[McGuire]

Originally posted by clSD139
Donkervoort has beaten the Porsche on the Nurnbergring (www.autoweek.nl). The Dutch prestigecar was by far better on track time. 15s ahead of the GT3. I don't say I understand all this, but the Koenigegg would make a great chance. The suspention and chassis of the dutchman are very good is mentioned in the article. But a real Dutch match for the Porsche should be Spyker. I think the CC8S beats anything in corners.

Lap times on race tracks mean little or nothing in road performance cars. It is very easy for a cottage manufacturer to play that game: they can ignore all the other aspects of proper engineering and design which create a complete car and work on the lap times....usually resulting in a state of tune that is impossible to live with on a daily basis. Meanwhile, a clapped out Formula whatever school car on old tires with a timed-out motor will profoundly embarrass any of these specialty creations on an actual race track. If you want a race car, buy a race car.

[Greg Locock]

One might say the same of any road car whose development engineers spend too much time chasing lateral g. No names! Clue: start with bloody awful suspension, fit rock hard springs and sta bars, and big fat tyres.

As Chapman said "Any suspension will work if you don't let it move."

As John Miles said, "the G analyst was the worst thing Lotus Cars ever bought."

[red300zx99]

http://www.gurneyfla...rces/LOLAT3.jpg

Do I need glasses?

def not here http://www.gurneyfla...llapa20s564.jpg