[LM24] Le Mans Trap Speeds for 2003?

[Tim Northcutt]

Last year thee were postings of Le Mans trap speeds for various classes and cars...

I thought Mulsanne Mike had posted some last year as an example...

Has anyone seen any kind of trap speed chart for this year??

Could you steer us to whatever sites, or post them for us here???

Thanks!

[MulsanneMike]

It seems to be that the ACO may not release the trap speeds this year.

[Dauntless]

Well, releasing that data would sort of put the lie to denials that they slowed down the R8s to let the Bently win, now wouldn't it...?

[RacingManiac]

Well wasn't the R8 slower than Bentley on the straights regardless though? From the trap speed chart over the last 3 years the R8 was not a strong straight line car anyway....

[MulsanneMike]

Actually it has alot to do with the ACO and the FIA, how this year's change (10% restrictor reduction) was supposed to slow the cars down. Apparently it didn't.

[Garrett]

Why wouldn't the ACO post the trap speeds for the 2003 race MulsanneMike?

[Tim Northcutt]

If they were relatively the same, it confirms two things that many of us have discussed at length in this forum:

1. If a governing body attempts to cut only the horsepower to reduce speeds, give an aero engineer enough time in the wind tunnel, and he'll overcome that reduction to get the same speeds, if not faster speeds, through aero changes within the rules, and,

2. Going back to the 2002 restrictor sizes, but less downforce in the aero package that has been the general approach for 2004 may not necessarily make the 2004 cars faster than what is on the track right now....unless they revise rules for the "Grandfather Clause" cars (with curretn 2003 settings) for next year to attempt to slow them down....

There...that ought to stir up the pot a little...your thoughts???

[pirenzo]

Well, to #1:
Well, they didn't have that much time, and clearly they were taking wing off to go fast on the straights, and it was hurting their lap times (3m36's vs 3m29's in quali last year for the R8). It begs the question: What would have happened if they'd kept the same amount of wing, and suffered going slower on the straights, would the aero advantage through the rest of the lap and the chicanes have made them quicker?

As for #2:
Not quite sure i'm reading it right, but is what you are saying that theoretically, if they allow them the 02 restrictors, then they ought to go faster again, but given the rules are leaning towards less aero grip, then they may be slower still, even with more power?
If that turns out to be the case, then it makes me wonder even more that had they concentrated on aero grip this year, and gone slower on the straights, then they would have gone almost as fast as last year, and leads me to think that perhaps a decrease in aero grip will hurt them much more than 10% less power, and that these days, aero grip is more important than absolute power, and a good aero package can more than make up for a deficiency in power.
I suppose a good example would be the Courages. They're supposedly down on power, but were still able to lap relatively fast, and also maybe it accounts for the speed of the MG's, them being almost as fast a couple of years ago in the wet as the 900's

[Tim Northcutt]

Good points...

I hate to use Indy as an example, but the cars this year were within 3 m.p.h. of the track record with nearly 200 less horsepower when the records were set there...on a day when track condictions and wind were horrible...

That tells me that aero is a huge factor....

I think aero grip with less drag can make a big difference....

It will be interesting to see how it does ultimaely shake out next year...

[JAG]

Didn't Jan Lammers and Wallace say they reduced the wing on the car quite a bit in order to keep the straight line speed up.

So in effect the cars were just as quick on the straights in 2003 but with even less downforce, and therefore less stable/safe, totally the opposite to what the 10% restrictor cut was supposed to achieve.

In 2004 the cars will have 10% power back and as the new regs cut overall downforce, the cars will presumably be running as much downforce as possible/maybe even more than in 2003, in order to be quick on the twisty sections. The 10% more power would mean no top speed problems on the straights.

With the new 2004 tunnels under the car it dosen't really matter how quick the cars are on the straight as the tunnels will keep the cars glued to the track. In the Group C days it was only when cars reached the 230MPH mark that they became unstable and liable to flip, even with tunnels.

With the chicnaes max speeds will only be around 205-210mph and the cars will be more concerned with generating as much downforce as possible to be quick throught the corners,as the extra power will overcome the extra drag created.

It could be argued the 2003 cars were the most dangerous in recent years will even less downforece/stability, yet the same straightline speed.

Thank God the ACO/FIA hae now realised cutting power is not the answer to slower and safer cars.

[MulsanneMike]

There's lots of talk about the '04 tunnels and understand, they are written into the rules to be pretty inefficient. Hence even with the tunnels the ACO was shooting for a downforce reduction compared to current.

[Tim Northcutt]

That's the way I understood it as well....

I think that grip will come from other aero elements that will compensate....

[pirenzo]

Presumably the long tunnels don't grip much, but what grip they do provide is spread over a wider area, making the cars more stable.

[Dauntless]

Actually, pirenzo, long tunnels (full length) work very well - better in practice than any flat-bottomed configuration as they have fewer air migration issues to contend with. Furthermore, tunnels are inherently insensitive to pitch variations, and lose overall grip linearly as ride height increases. That makes them very predictable and tunable.

[MulsanneMike]

But the '04 tunnels aren't what one would describe as 'long' as they begin forward of the rear wheel centerline (not much forward--current diffuser kicks up at wheel centerline). They aren't the full length type seen on past GTP/Group C.

[Dauntless]

You're absolutely right, Mike. And that's why I specified full length tunnels in my post above. The semi-tunnels allowed by ACO's 2004 rules are probably an improvement over the flat bottoms, but not a whole lot, IMO.

I know from engineering my Ralt RT-41, vs flat bottomed cars I am familiar with, that full length tunnels are just a marvelous technology.

Which reminds me...I recently bought a digital camera, so am now in a position to take some photos for you. A while back you said you were interested in looking at flow patterns within the tunnels. I will have the car at Sears Point this weekend for the National, and could do some preliminary work for you. If you're still interested, fire me an email with some ideas...