Mercedes-Benz CLR

[BSchneiderFan]

I am, as some of you will well be aware, a great Mercedes-Benz fan (and yet I feel no warmth for McLaren - but then I'm contrary...), so my question is this: how good, potentially or actually, was the Mercedes-Benz CLR?

Yes, yes, yes, I know they flipped horribly and that Mark Webber and Peter Dumbreck had very lucky escapes. But bear in mind that, prior to the 1999 Le Mans, there was a worry among the other competitors that Mercedes would be very strong. One driver said he was sure that Mercedes was sandbagging, as the CLRs just blew by him on the straights. Remember, also, Bernd Schneider's fantastic and intense drive in the opening stages of the race - I've never seen a sportscar driven so determinedly, and you had to wonder if anyone had told Bernd it was a 24 hour race...

A final question: to what extent were the CLR's aerodynamic instabilities a result of the FIA cancelling the International Prototype Cup for 1999? The CLR, like the Porsche 917, was designed simply to win Le Mans. Would Mercedes-Benz have designed a different car if they had been intending to run a full series?

[Mopar]

I would argue that having failing so miserbly in 98 with the clk at le mans (and paradoxically dominating the FIA champinship), Mercedes' prime goal for the 99 season was to win le mans it would be easy for the firm to adapt the car to suit and win in whatever sportscar championship it competed in proof can be found in the fact it didnt compete at Sebring. Mercedes were rumoured to have considered building an open top car as well as running the CLRs they were that dedicated to winning lemans!

[BSchneiderFan]

Perhaps so. The point is, however, that in building a car specifically to win Le Mans - and it is, as you suggest, instructive that, unlike BMW and Audi, they did not compete at Sebring - Mercedes produced a low-drag, low-downforce, fuel-efficient car, which may have contributed to its aerodynamic instability.

[Es Nes]

and indeed it did, do you remember the r8c? the rear window was sucked off at least 2 times.

[Mopar]

as weer the doors!

[Rick]

Slightly OT - Spark models had a CLR listed a year or so ago for production - anyone know anything?

[The Badger]

I reckon as a car it failed dismally ..... not only did it flip 4 times , it reminded Mercedes-Benz of that terrible accident that killed 80 odd people at LeMans in the 50's . It also has kept them away from LeMans , scared of bad publicity . And it was instrumental in removing the hump in the Mulsanne . Well done Mercedes-Benz .

But it was a beast to watch especially with a certain Mr.Schneider doing the driving . All in all not a car that Mercedes-Benz want to remember I think !

[The Badger]

Originally posted by Rick
Slightly OT - Spark models had a CLR listed a year or so ago for production - anyone know anything?

Are you sure that wasnt "airfix" ..... they are more into Airplanes !!! I would suggest that if spark dont have it out by now , it might not be coming out from them . Maybe something to do with lisenceing agreements . There is one available from "Provance Moulage" in 1/43 scale though , built and unbuilt but there is a bit of a price differance in the built one though . The PM kit should be simple enough as there was minimal decals on the car . Just a big can of silver paint and off you go !!

[EliseGT1]

Originally posted by Rick
Slightly OT - Spark models had a CLR listed a year or so ago for production - anyone know anything?

Yep, I'm waiting for that model as well. I contacted Hugo (Sparkmodel) and he told me that this model (just like the CLK GTR) would possibly come out early this year. Thought indeed that it was some licensing issue, just like the (expensive) Red Line Ferrari models they just issued.....

Nice car, the CLR...shame they didn't use it more often.

[The Badger]

Originally posted by EliseGT1
Nice car, the CLR...shame they didn't use it more often.

They do ..... Lufthansa use it on their long haul flights to Tokyo cleverly disguised as an Airbus . They even changed the color to white cuz Airbus wouldnt give them a corossion waranty !!!

[JAG]

I heard the CLR was ran too soft at the rear, and was suspect to bottoming out, which combined with the plat bottom caused severe problems.

[Try Hard]

Originally posted by JAG
I heard the CLR was ran too soft at the rear, and was suspect to bottoming out, which combined with the plat bottom caused severe problems.

IIRC they ran the rear end soft (or with progressive springs) so that at high speed, any rake in the car was removed (ie front and rear run at same ride height), so to reduce drag.
They tried to solve the flipping problem by running dive planes at the front, but i think these broke off on the dumbreck car.

Would have thought stiffer rear springs would have been the better fix....

[JAG]

Apparently they did not identify this problem earlier because they only tested on very smooth fast circuits, which did not simulate the bumps and elevation changes found at Le Mans.

[PascaLM]

Originally posted by The Badger
Are you sure that wasnt "airfix"...

The CLR was, as the GTOne (i don't forget Ayse), a kind of ultimate LMGTP car. Very long and thin, with a 6l V8 more reliable than the V12, splendid.
It took off because :
1 - the front part of its shape generated less downforce than the GTOne did (just compare the front views of both beasts) ;
2 - the efficiency of the venturi tunnels which are under the front part were balanced by the force of the front suspension springs. This generated a kind of pumping, as a movement of second order in physics (check this on your video recorder, the GTOne is stable, the CLR is pumping). And as it was high, a bump caused the taking off before Mulsanne and down to Indianapolis.

I think that the global wing profil shape of the car didn't participate to this accident: on TV, I already saw a Nascar car turn over like a pancake at Talladega or something.
Just blow air under the car at 300km/h and..."fly Mercedes !"
The same happened to Dalmas at Petit LM 1998, he was driving a Porsche GT1.

This is my own analysis of the problem. If someone has another opinion, I'd like to share it.

[jhansen]

If you want some insight into the "flying" phenomena, check this link out.

http://www.mulsannescorner.com/techarticle1.htm

[Mopar]

I remember hearing that the Mercedes Sportscar team rang up Adrian Newey (who was at the Canadian GP) for a cure for the flipping problems on the friday night, they were so concerned about it.

[JAG]

Originally posted by Mopar
I remember hearing that the Mercedes Sportscar team rang up Adrian Newey (who was at the Canadian GP) for a cure for the flipping problems on the friday night, they were so concerned about it.

Bit late in the day to discover such a serious flaw.

Particulalry when you consider it was probably the most tested Mercedes race car ever!

[Aysedasi]

I well remember the interview with Haug on RLM only a short while before the start of the race. His assurances that they had solved their problems sounded very hollow just a few hours later......

[Chofar]

I remember some drivers saying after the race that Schneider was the only one that was listened by the Benz staff. Others had to follow his advice. Lagorce and Bouchut were not on his side but he was the man...for the team. I didn' t hear about sandbagging for the CLR. Rather heard of going through kerbs and gravels to keep with the Toyotas on test day. 30000 kms of tests on rovals : kudos to Mercedes !!

[The Badger]

Originally posted by Try Hard
IIRC they ran the rear end soft (or with progressive springs) so that at high speed, any rake in the car was removed (ie front and rear run at same ride height), so to reduce drag.
They tried to solve the flipping problem by running dive planes at the front, but i think these broke off on the dumbreck car.

Would have thought stiffer rear springs would have been the better fix....

Those guerneys were supposed to increase the downforce by 25% !!

[BSchneiderFan]

I too remember reading that, after speaking to Adrian Newey in Montreal, the AMG team added dive planes or similar to the front of the car, but that Dumbreck nosed another car prior to his accident and these were broken off or rendered useless.

As I recall, Mercedes had pledged four cars for an invitational race at the Norisring in July 1999 - shame it never happened.

[The Badger]

Originally posted by JAG
Apparently they did not identify this problem earlier because they only tested on very smooth fast circuits, which did not simulate the bumps and elevation changes found at Le Mans.

IMO I think LeMans should not except any chassis that has not completed some race distancees . You cannot prepare for LeMans because of the characteristics of the track , and then expect the track to modify itself because of an aerodynamic screw up . Nice one Mr.Benz

[avsfan733]

A lot of cars have flipped...I see it as not so much a design flaw (granted there were several of them) but as a combination of bad circumstances. the car was designed to behave one way, and a certain portion of the track just happened to be dangerous when the car performed the way it was set up. It's really not that hard to do, air getting under most things at 240 mph tends to cause lift...look at a jet fighter, or stunt planes ability to fly upside down.

As an aside to the soft suspension point, with just soft rear setings, i would think that the car would rotate up more over the bumps because it can compress the rear suspension as well as kicking up the nose when you hit the bump. This basically sets the car in a way that seems perfectly prepared for takeoff.

[The Badger]

Originally posted by avsfan733
A lot of cars have flipped...I see it as not so much a design flaw (granted there were several of them) but as a combination of bad circumstances. the car was designed to behave one way, and a certain portion of the track just happened to be dangerous when the car performed the way it was set up. It's really not that hard to do, air getting under most things at 240 mph tends to cause lift...look at a jet fighter, or stunt planes ability to fly upside down.

As an aside to the soft suspension point, with just soft rear setings, i would think that the car would rotate up more over the bumps because it can compress the rear suspension as well as kicking up the nose when you hit the bump. This basically sets the car in a way that seems perfectly prepared for takeoff.

I understand that but then so should Mercedes-Benz instead of blameing the track !!! Nobody elses car did the same that year and in previous years nobody elses car (except funnily another Benz) was to blame for getting rid of the hump on the Mulsanne . When credit is due but also when addmiting who is at fault is equally important . And it happened four times !!!

[simon c]

didn't Palmer's Joest 962 flip in practice in 1990?