If Mulsanne didn't have chicanes

[Welshbeef]

Going back through the fastest speeds hit by prototypes in Le Mana it seems that the Jags hit 248mph down the Mulsanne.

Today with two chicanes the prototypes hit 200mph three times on the straight.


So... You can see where this is going IF the Mulsane was straight what would the Prototypes hit as a Macimum speed ? Clearly they would have to change the gearing but it's 25yeaes since that speed was hit a lot of advancements have been made so what would we be up to?? 280mph -300mph?

[kambites]

Has the power output of the LMP engines actually risen over the years, or has it just been more and more strangled by the regulations?

[mrmr96]

Do you mean the current cars as they are, JUST different gearing and no chicanes?

OR

Do you mean the current RULES as they car, JUST no chicanes?

Because I reckon you could attain a higher top speed within the rules, but they choose not to.

[Dusty964]

Didn't the 917 hit 254.6 or something equally absurd (number plucked from memory from- Porsche the racing legend).

Surely given the length of track though there is still a trade between downforce and top end (although again given the average speed, the downforce is lower than most circuits)

[kiteless]

IIRC, the highest top speed on the Mulsanne (pre-chicane) was a modified Peugeot 905 with added slippery bits which broached the 250mph barrier.

I suspect that the older Group C cars would be faster, top-end, due to less aero. Also their engines were plenty more powerful than the current R18's and such like (didn't the Sauber C9 have something like 800bhp?)

[rumple]

I'm sure the 917 did 267mph in 1971, this holds the record, which is unlikely to be beaten because of the chicane, could be wrong though as that's off the top of my head as well

[Welshbeef]

I'd say within the regs as is but then of they didn't have regs. Surely for the track there is a max top speed you would want to hit ie balance between downforce and less aero

[mrmr96]

Welshbeef said:

I'd say within the regs as is but then of they didn't have regs. Surely for the track there is a max top speed you would want to hit ie balance between downforce and less aero

Agree there's a balance.

But my point is that the current cars are setup not to have much more speed after each of the 4 short straights. But if re-building a car to existing regs for a non-chicane circuit then I reckon they would go for a lower downforce setup than current.

As such I think that using the existing cars would yeild a sub-optimal top speed within the regs, and you'd need to build a differnt car with less drag to get teh best no chicane laptime.

[Mastodon2]

I don't think the cars make as much power now, I don't really keep up with modern LM because it's so dull with the coal burners on the track now, but in the days of the Porsche 962 and the Mazda 787b, they were making 700+bhp, with aero leaning more towards speed.

Now that the track has those chicanes cut in, and less ground can be won on the Mulsanne road, I'd imagine the cars are more optimised for maximum downforce for high cornering speeds, as opposed to top speed. If you don't have to make a car good for 230mph or more, I suppose you can afford to really stick the car to the track in the corners.

[rumple]

Reference my earlier post, I can't verify it so probably bks, however I did discover that a 917 longtail at one time put out 1580bhp, and the 917 chasis weighed 42 kg, that would be quite nippy then

[Ozzie Osmond]

Theoretically with good aerodynamics and, say, a 10 speed gearbox the speeds would be very high indeed. But even with good aerodynamiocs fuel consumption goes through the roof as speed increases so there would be a balance to be achieved between (a) max speed and (b) frequency of pit stops. Brake heat would get pretty exciting as well.

It seems every form of motorsport has decided that things shouldn't go much over 200 mph. I think part of the reason is the amount of energy which needs to be dissipated in the event of a crash. See, for instance, the German ICE high speed train accident which was at least as devastating as a plane crash.

[pwrc]

kiteless said:

IIRC, the highest top speed on the Mulsanne (pre-chicane) was a modified Peugeot 905 with added slippery bits which broached the 250mph barrier.

and, it's for sale at the moment! sans engine though, which grenaded that weekend (unsurprisingly)

http://www.artcurial.com/en/asp/fullCatalogue.asp?...


253mph.
I think the 917s topped out at 225. However the can-am 917/30 was capable of 260+ but it never raced at Le Mans.

[LaurasOtherHalf]

rumple said:

Reference my earlier post, I can't verify it so probably bks, however I did discover that a 917 longtail at one time put out 1580bhp, and the 917 chasis weighed 42 kg, that would be quite nippy then

Not at Le mans it didn't

Heading to the classic this week & I'm determined to witness a 917 on the mulsanne at night :cloud9.

[NotNormal]

I think the Group C Sauber Merc during the 2010 support race at LeMans was hitting faster speeds than the LMP1 down the "chicane'd" Mulsaine.

[Ozzie Osmond]

This is what you need to see, about 30 seconds into the clip,

http://www.youtube.com/watch?v=Ow3rxq7U1mA

[Dusty964]

Just tried looking for the info I mentioned earlier- can't find it of course, but sure it mentioned Norbert Singer calculating top speed at 8000 odd revs and accounting for tyre expansion.
Will continue looking.........

[pwrc]

NotNormal said:

I think the Group C Sauber Merc during the 2010 support race at LeMans was hitting faster speeds than the LMP1 down the "chicane'd" Mulsaine.

fastest car to lap the sarthe this year? Sauber C9, 340 km/h. modern prototypes have nothing!

[Mastodon2]

Ozzie Osmond said:

This is what you need to see, about 30 seconds into the clip,

http://www.youtube.com/watch?v=Ow3rxq7U1mA

The legendary flying Mercedes!

I remember reading in "TURBO" issue of EVO last year that, I believe it was the Toyota team at Le Mans in the 1980s, were running a ridiculous power figure on their car, did an incredible qualifying lap (I think it might have been the fastest single lap of the whole meeting) and then could not race because the temperatures under the clamshell melted the gearbox or something like that. If I still had that issue I'd dig it out and check it, it was an interview with the driver who did it I believe, great piece.

[Tango13]

Mastodon2 said:

I don't think the cars make as much power now, I don't really keep up with modern LM because it's so dull with the coal burners on the track now, but in the days of the Porsche 962 and the Mazda 787b, they were making 700+bhp, with aero leaning more towards speed.

Now that the track has those chicanes cut in, and less ground can be won on the Mulsanne road, I'd imagine the cars are more optimised for maximum downforce for high cornering speeds, as opposed to top speed. If you don't have to make a car good for 230mph or more, I suppose you can afford to really stick the car to the track in the corners.

I think you've hit the nail on the second part. I'd imagine the cars are geared more towards acceleration as they now spend less time at speed and more time accelerating to speed. They also now have extra corners where they need the down force so the extra down force is not a hinderance as less time is spent at speed.

The balance has just moved towards cornering from pure speed.

There was in 1988 a French team whose goal was to hit 400 km/h down the Mulsanne straight which they managed in qualifing. Most works Group C cars had the horsepower to go faster but ran more downforce for higher corner speed and a faster overall lap.

[Tango13]

Ozzie Osmond said:

This is what you need to see, about 30 seconds into the clip,

http://www.youtube.com/watch?v=Ow3rxq7U1mA

Any truth in the rumour that after the crash the driver was breathalised as it had happened on the (albeit closed) public highway?