Mulsanne's Corner

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Le Mans 2013

All news content copyright Michael J. Fuller, unless otherwise noted

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Race day has finally arrived.  Will this be a classic?  I hate that type of hyperbole, and frankly I think we'll know in the first 2-4 hours.  But there's an interesting undercurrent.  Consider, Toyota's qualifying pace was slower than last year.  Why?  The regulations changes from 2013 were minimal for Toyota.  From recollection they amounted to the addition of 15 kgs of weight.  An easily surmountable amount.  Thus Toyota, in theory of course, should arrive at LM 2013 with a more efficient and faster car than last year given the usual year to year gains.  But as for qualifying they didn't.  They qualified about 2 seconds slower than last year.  Their top speed is down too.  Yes, top speed isn't everything of course.  So what to make of all this?  It will make an interesting book, say in 20 years time, one that describes the amount of dickage that goes on in qualifying for this race, assuming everyone is willing to come clean.  Personally I feel Toyota has held a bit back, knowing full well where they are relative to Audi, and only concentrated on race pace.  

But there's quiet confidence over at Audi's camp too.  Yes, it is pretty clear Toyota will have an advantage in fuel economy.  This was the trend this season up until this race; Audi turning economy into power (opposite of last year's strategy) and Toyota having slightly improved their economy over last year.  So the numbers people say to expect possibly up to 12 lap stints for Toyota, 10 for Audi (though could they turn it up to 11?).  Thus Audi will have to run a quicker average lap time in order to keep up with and stay ahead of the Toyota given they have to make more stops.  I've heard Audi will need to lap between 1.5 & 2.0 seconds a lap quicker than Toyota.  Seems pretty easy given the apparent speed advantage that they have, using qualifying as the bench mark.  But then again, I don't think we know where the leading edge of Toyota's ultimate pace actually is.

Morning warm up showed a much closer field with the top guys all in the 3:26-3:27 range.  Top speed was also a relatively symmetrical 320-322 km/h across Audi and Toyota, although the "ideal" lap timing showed a slight edge to Audi, into the 3:25s for the top car.  But let's not make too much of warm up, its roughly 10 laps, after all, so not enough data.

So like I said, 2-4 hours into this race and the trend will emerge.  Yes, leading up to this it looks like an Audi white-wash given their dominance in qualifying.  But I think there's a subtext that needs acknowledgment, so keep that in mind in those first 2 hours.  After that and all bets are off of course!

Oh, and it looks like rain...

Toyota TS030 engine inlet design #1, Le Mans Test DayToyota TS030 engine inlet design #2, Le Mans Test Day6.20.13

First day of practice is down and a bit of idle time while waiting on RCE's Sam Collins' report (computer problems I'm told).  A lot of talk surrounds the not exactly identical specification that the Toyotas are running.  Now, everything on the cars appears to be the same between the #s 7 & 8 but for the engine inlet.  One inlet design is wider and shorter at the inlet than the other (#7 is running the wide design, the #8 the narrow).

This was actually first noticed at the Test last week, so it's further confusing why this carries through to the Race weekend (you could make the supposition that they were using one last track test to hammer that detail, even though there are plenty of arguments against them doing even that). But it looks pretty clear that they are deliberately running this small difference and that they intend to race in that manner.  

So, what's this small difference related to?  I initially considered single vs double inlet restrictors, but the area difference is a mere 1.7 mm^2.  But without further information I'm unsure for the time being.
>>A brief comparison of data from the first Qualifying session and last year shows Toyota 2 seconds down on their qualifying time and roughly 10 km/h down in top speed (323 vs. 332 km/h).  Toyota PR speaks to working towards race setups.  In the mean time the fastest Audi is 1.5 second quicker than their ultimate speed last year but about 6 km/h down in top speed (325 vs 331 km/h).  It should be telling that the #12 Rebellion Lola split the two TS030s in Qualifying.  It's pretty evident that we haven't seen Toyota's ultimate speed yet.

BMW IP, June 2013...6.17.13

OK, so I'll bite: BMW, why are you all hitting my site so hard?  And I've gone back as far as February (so far)...same behavior February, March, April, May, June...540 MBs bandwidth so far for 2013.  1.05 Gigs in 2012.

TMG, let's talk about the1.1 Gigs of bandwidth you all have used so far this year.  So when are you going to give something back in return?  You're welcome, ;0).

Rebellion Lola-Toyota LMP1, Le Mans Test 2013, image copyright Sam Collins, www.racecar-engineering.com6.9.13

I'll continue working my way through these images.

The Rebellion's low-drag kit contains two pretty large vertical turning vanes at the very leading edge of the outboard splitter (1).  These work to condition the airflow, presumably by mitigating the size of the front fender wake.  

The Rebellion Lola also utilizes the nearly vertical leading edge fender shape which helps reducing drag by reducing the stagnation pressure created ahead of the fender by routing air around, rather that up against, the fender.
Rebellion Lola-Toyota LMP1, Le Mans Test 2013, image copyright Sam Collins, www.racecar-engineering.comNeat little strake in the splitter footplate, with a curved trailing edge.  Airflow management around the front tires is critical and devices like the splitter feet help in that process.    
HPD ARX-03c, Le Mans Test 2013, image copyright Sam Collins, www.racecar-engineering.comARX-03c's low drag kit.  Again, a vertical endplate (1) for the splitter footplate.  The open top LMPs are inherently "draggier" than the closed top cars, so naturally drag mitigation is even more important for these cars.  The ARX series has also  featured a secondary vertical element tucking in close to the very outboard face of the front fender (2).  It too helps manage that outboard wake.  See the LMP2 HPD execution below.
HPD ARX-03c, Le Mans Test 2013, image copyright Sam Collins, www.racecar-engineering.comThe fender shape on the LMP2 ARX-03b HPD is different (primarily because of the homologation limitations within LMP2; only one extra aero kit allowed and it's price capped), but the aero elements (1, 2) mirror what's used on the ARX-03c.  

Toyota TS030, Le Mans Test 2013, image copyright Sam Collins, www.racecar-engineering.com6.8.13

Teams have been setting up the past couple of days for tomorrows Test Day running and Race Car Engineering's Sam Collins just hit me with a nearly 2GB photo bomb of photos taken across the last 24 hours or so.  Lots of good details, Sam's outdone himself this time and I'll be adding images throughout the next couple of days.

A nice shot of the front end of the Toyota TS030 reveals, well, not much, but I want to point out the male "chocolate fingers" (1) that locate into female receptacles on the splitter/diffuser assembly.  Not ground braking by far, but the devil is in the details.  Also note the somewhat swoopy bottom shape of the front diffuser (2).  The bodywork assembly below the front of the monocoque is non-structural and is purely for aerodynamic functions (continuation of the forward diffuser shape);
in this area the bottom of the tub is not air-licked.  Note the apparent distance between the bottom of the tub (3a) and the bottom of the diffuser proper (3b).  
Obviously we can also see the array of brake cooling intakes for disc and caliper (4), torsion bar pickups (5), etc.
Toyota TS030, Le Mans Test 2013, image copyright Sam Collins, www.racecar-engineering.comThe exhausting of the front diffuser is so important that a lot of work goes into making the air's path through the car as painless as possible.  The various turning vanes and covering panels, while having a regulatory secondary function, primarily work to help and enhance pressure recovery.
Toyota TS030, Le Mans Test 2013, image copyright Sam Collins, www.racecar-engineering.comThis feature first appeared on the TS030 ahead of Spa.  It draws air flowing down the side of the car into the base area, reducing drag.
Toyota TS030, Le Mans Test 2013, image copyright Sam Collins, www.racecar-engineering.comThe small "undefined" space (1) above the main exit duct is rather odd.
Toyota TS030, Le Mans Test 2013, image copyright Sam Collins, www.racecar-engineering.comSam spotted this strange little, seemingly very deliberate, tab.
Caterham LMP2, Le Mans Test 2013, image copyright Sam Collins, www.racecar-engineering.comThe "Caterham" LMP2; a rebadging of the Zytek.  For LM 2013 the Zytek/Caterham features redesigned front fenders (fender du-jour: tall leading edge), presumably as a drag-reduction program.
Zytek LMP2, Le Mans Test 2013, image copyright Sam Collins, www.racecar-engineering.comThe Zytek LMP2.  Same front fenders as the Caterham.  I loves me some ham.

ęCopyright 2013, Michael J. Fuller