[LM24] Le Mans Trap Speeds

[PascaLM]

Originally Posted by GT2-R

In the formula used for calculating the drag you can find v². Because of this factor, the drag will increase strongly when the speed increases. Therefor I think the difference in top speed is not very big. But it seems to me that the R10 should have a better top speed because of it's smaller frontal area.

That's true, and the drag depends on V² and also on V (tires, transmission depending on the weight). So an Aston martin cannot be faster than a lighter prototype in high speeds.

[chernaudi]

The DBR9s were reportedly going almost 200mph down the straights at Le Mans in 2005-the handicapped Audi R8s could barely hold them off, and the Pescarolos could only really pass them on accelleration out of chicanes/early down the straights-and the Pescas topped out at about 205 mph(not that the Audi R8s ever were much faster-one went 210 mph in 2002 during a practice session, but went only 200-205 during the race).

[JAG]

To be fair, there is a big performance difference between current P1's and those from 2003-05, which were bang in the middle of the grandfather regs, with little development and significantly smaller restrictors.

[chernaudi]

But the R8 only did 205 in 2000, with what are the 2006-'07 ACO restictors.

[Dario911]

Audi R10 is noticeably faster than Aston. Less front area, more powerful engine, different gear ratios... It's just another story! The fastest GT1 was the Lamb Murcilago R-GT, with 304 km/h, while in GT2 class the fastes car was the Porsche 997 GT3 RSR, with 297 km/h.
Audi R10 achieved 339 km/h (official top speed), while unofficial performance is quite 350 km/h.
There's a little difference with all the others classes...

[AU N EGL]

Isn't this is partly why the ACO mandated certain size air restrictors? to keep things "relatively" safe, speeds down, and a distinction between classes?

We could all guess that without the mandated air restrictors and without those chicanes, that many cars would top 200 mph (322 kph) without much problem

[sssssssss]

Originally Posted by Zytek_Fan

Aston Martin DBR9's are said to be as fast or faster than the Audi R10

The Aston Martin DBR9 had a top speed of around 300 km/h at Le Mans in 2007. The Audi R10 TDi was around 340 km/h.
There was a moment in 2005, when the R8 was so hardly reduced as compared to its original performance, that some said the Astons were as fast as the Audis on the straights. Still, as far as I can remember, the R8 hit 318 km/h even in 2005 at Le Mans. The GT1s always have speeds lower than 310 km/h, from 1999 on.

[JAG]

Originally Posted by chernaudi

But the R8 only did 205 in 2000, with what are the 2006-'07 ACO restictors.

Audi never set their cars up for top speed, but with that extra power, they could accelerate and sweep past the GT1 cars with ease, before leveling off at 200 mph+.

These days you see P1 car's blast past even the Corvettes with pure acceleration, that wasn't the case a few years back with grandfathered LMP900's and LMP675's.

[dj4monie]

Its interesting as well that in 2006 then new F430 ran 289km/h or 179.5mph when the out going 996 GT3 RSR could only muster 286 which explains if they didn't have problems with the lock nuts on those cars that year (Risi as well at Sebring) they would have won the race with ease. Speed kills, especially at track like La Sarthe.

I think unlike the LMP cars which can go through corners faster of course, that the GT2 cars get to up top speed at the first section of the Mulsanne straight I believe because they come out of Tertre Rouge in 3rd gear I believe. They might be coming out of the chicanes faster but slowing down from 170+mph would have an effect to great to make up and they go the slowest through the Mulsanne hairpin of all the cars, which again effects top speed since the LMP cars are turbocharged or geared to turn more RPM with an N/A motor and the GT1 just have them beat on displacement.

Rocky Agusta's Callaway Corvette isn't much faster than current GT2 cars even with the over 10 year span between the cars. Though the original GT2 Viper easily crest mid 190mph, that car was a freight train....and yes LMP's had trouble getting around it, I saw that for all the power LMP's make none of them could match the Viper's torque output in those days.

Diesels are another matter....

[sssssssss]

Originally Posted by Zytek_Fan

Aston Martin DBR9's are said to be as fast or faster than the Audi R10

That one's definitely not true. The Audi R10 tops around 340 km/h on the Mulsanne Straight (and at around 330 km/h before the 2007 Tetre Rouge change), while the Aston numbers actually are around 310 km/h (and 300 km/h before 2007). And that's mostly because the prototypes indeed have much more powerful acceleration and get to higher speeds much quicker. Nobody really has much of a clue about Le Mans sporscars' theoretical top speeds, and they're really not relevant at all, but for sure, in terms of relevant top speeds (that is, the ones achieved on the circuit), the LMPs are exactly what they're called: another category.
Actually, the rumor you're talking about is, I guess, the one in 2005, when the privateer Audi R8s (not the R10s) were slowed down by regulations to such a degree that they were having some problems getting by the Astons on the straights at Le Mans, which was dramatized by some into the Astons being quicker than the Audis on the straights that year (the actual facts are that the 2005 R8 only did 318 km/h on the Mulsanne, which is anyway roughly 15 km/h faster than the Astons of the time, but also over 10 km/h slower than what the R8 did the previous years). And, again, the R10 is doing 340 km/h these days.

[arakis]

a Little correction, Ferrari holds the gt2 top speed a 299 km/h

source: forza Mag
link: http://www.forza-mag.com/art1/art1p1.html

extract:
If any car should have had the ability to set the top-speed mark on the straight from Tertre Rouge to the first chicane on Les Hunadieres, or the long curving run from Mulsanne down to Indianapolis, it should have been the current 997-generation 911 GT3 RSR—but it wasn’t. On the first night of qualifying, five Ferraris held the official top speed at an identical 299 km/h (just a hair under 186 mph), this despite the F430’s larger frontal area and slightly higher drag compared to the 911.

[sssssssss]

Yes, the GTs really had their moment of glory at Le Mans 2008 as far as top speeds are concerned. All the previous years, the trap speeds of the GT1s had the values that the GT2s realised in 2008! GT1s hardly got over 300 km/h the previous years, and now the GT2s did 299 km/h (Ferrari) and 298 km/h (Porsche), while the GT1 Lamborghini did 315 km/h, the Corvette 313 km/h, and the Aston and the Saleen 309 km/h (these are all the first ACO official qualifying trap speeds, where the Peugeot 908 HDI is the fastest with 345 km/h, while the Audi R10 TDIs only did 336 km/h, the equal of the Dome S101 - which for sure didn't do 358 km/h, as the inital rumors told us).

[sssssssss]

Did anyone notice that the official Le Mans 24 Hours site now claims different statistics for the 2007 race than what it did before? The PDFs at the time of the 2007 race claimed 339 km/h being the maximum speed achieved that year both by the Audi R10 and the Peugeot 908, and now the official records page claims 344 km/h in qualifying for the Audi R10 and 351 km/h for both the Audi R10 and the Peugeot 908 in the race!
If those are true, for sure 345 km/h wasn't the highest speed the Peugeot hit in 2008, and it goes the same for the 336 km/h of the Audi R10.

[davehenrie]

I have always wondered about top speeds, a-lot depends from where you take the reading AND other factors like wind and the possibility of a draft. The faster the tops speeds, the longer the draft wake trails out behind. So a car could be getting a tow even without a nearby lead car breaking the wind for the trailing car.(note the near Spinal Tap reference)
Also one might assume the manufactuers might have a small input to the final numbers. Do they want the competition to know they can do 340kph? A few advertising dollars spread around the circuit might incline the ACO to fudge the numbers alittle.
Back in the heyday of the Audi R8, I remember some article about the Audi drivers. They story was they would come back to the pits from a practice session and laugh at the poor Dome pilots. The Dome would rocket by the Audi on the two straights but be so unstable under braking that the Audis easily repassed the shuddering-skating Domes. (my foggy brain may be making up this next part) I think they also stated you could spot a Dome driver just by the haunted look on his face after a practice session.
As others have posted above, it would appear that Audi rarely setup the car for top speeds. But they may have been forced to make some adjustments chasing the Pescarolos in 05 and the Pugs these last few years. also. as Corvette proved against the DBR9s,(or rather vice-versa) there is no substitute at Le Mans for final max speeds.

dh

[ss_collins]

Well as usual we will be doing trap speeds - Speedtv.com will have the headline and analysis - racecar-engineering.com as usual will have the full geeky stat fest as normal.

The ACO trap speeds are nonsense, our ones are checked against the data loggers of a number of teams and are +/- 2kph (consistent error)

For now

Sebring 2009 trap speeds

http://www.racecar-engineering.com/a...r-preview.html

Le Mans 2008 trap speeds

http://www.racecar-engineering.com/a...ner-times.html

[sssssssss]

Yup, so the ACO trap speeds again seem to be nonsense, this year too. It looked like they only had a radar at the end of the pit straight in the qualifying sessions, where the fastest cars hardly reach 300 km/h. I suppose those speeds posted on the Le Mans site (which are mostly under 300 km/h) are not taken before the first Mulsanne chicane, but rather before the Dunlop chicane (where they showed them on TV, too).

[gwyllion]

Trap speed recorded by Racecar Engineering during qualifying: http://www.racecar-engineering.com/a...eed-traps.html

The Peugeot is more than 10 km/h faster than the Audi, but they still do comparable lap times. The coupe cars clearly produce less drag.

[sssssssss]

So the R15 clearly is quicker than the 908 in the corners. In fact, I was absolutely amazed to see how late the Audi drivers were braking for the Mulsanne corner.
The Peugeot had a great qualifying session, however they clearly went out for the glory of having set pole position in the last laps of the session. Audi really didn't seem to go too much for the best time (as McNish stated too).
Nice to see the Astons quick enough on the Mulsanne straight, although definitely not quick enough on an entire lap.
I'm really surprised to see how slow the Kolles R10s were on the straight, I was expecting the R10 to be among the quickest in top speed. 317 km/h on the new Tetre Rouge config means around 308 km/h on the circuit as we knew it from '90 up to '06, namely the one where Toyota GT-One did 352 km/h in '99 and the Nissan R90CP hit 366 km/h in '90.

[gwyllion]

Originally Posted by sssssssss

Nice to see the Astons quick enough on the Mulsanne straight, although definitely not quick enough on an entire lap.

The diesels have a power advantage so they can run with more downforce. Hence, the much faster lap times.

Originally Posted by sssssssss

I'm really surprised to see how slow the Kolles R10s were on the straight, I was expecting the R10 to be among the quickest in top speed.

I think they are taking it safe for their rookie drivers by running more downforce.

[skycafe]

I wish we could see a graph of the cars attaining the top speed recorded, which would show the diesels charging too and holding the top speed long before the petrol cars--I believe.

I think the RaceCar Engineering chart showing the Pesca is mis-labeled, that wasn't the AER/Mazda...

robt

edited 'cause I kern't spell good

[ss_collins]

Yes it is mis labelled - its being corrected now. The culprit is known and chastised!

[Acid09]

Impressive that the RS Spyders manage to post such quick times with that kind of low top speed. Imagine them having a little more power, they would be right up with the top guys.

[LinkF1]

The Speed TV commentators just mentioned something about someone hitting 250 mph in some practice but I didn't catch the whole comment about who it was and where.

[jab]

Originally Posted by LinkF1

The Speed TV commentators just mentioned something about someone hitting 250 mph in some practice but I didn't catch the whole comment about who it was and where.

Probably talking about the WM in 1988 before the chicanes

[Splatz the Cow]

Originally Posted by ss_collins

Well as usual we will be doing trap speeds - Speedtv.com will have the headline and analysis - racecar-engineering.com as usual will have the full geeky stat fest as normal.

The ACO trap speeds are nonsense, our ones are checked against the data loggers of a number of teams and are +/- 2kph (consistent error)

For now

Sebring 2009 trap speeds

http://www.racecar-engineering.com/a...r-preview.html

Le Mans 2008 trap speeds

http://www.racecar-engineering.com/a...ner-times.html

The LM Annuals' 1995 and 1996 speeds were posted earlier in this thread, but how do the racecar-engineering.com speeds compare to them? It would be interesting to see some accurate data on those years, as so much is left to mythology already about the GT1 speeds of that time.

If you have the time would you mind posting a link or the times?

Thanks.