Mulsanne's Corner

In partnership with Race Car Engineering Magazine

Le Mans 2016

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

Useful links:

Le Mans Weather<<
>>Le Mans Live<<
>>2016 24 Hours of Le Mans entry list<<
>>Andy Blackmore's Le Mans 2016 Spotter's Guide<<
>>Radio Le Mans<<
>>Jayson Fong's 24 pieces of artwork in 24 Hours<<


Audi R18, Le Mans Test 20166.17.16

>>Das Biest.  With looks that can only be described as brutally efficient, the Audi R18 is without a doubt the most interesting car aerodynamically this year.

Check the link below for Sam Collins' take on the R18:

>>Audi R18
Audi R18, Spa WEC 2016The R18's core aero concept at the front is the raised nose (1); the highest in the LMP1 field.  This allows a much larger volume of air (2) to be blown past and over the front aero devices.  Also evident in this view is the undercut nature of the front fender leading edge (3).  The vertical shape of the Le Mans front fender leading edge (4), not to mention, how far forward they are on the splitter, is apparent.  Rising outboard on each fender is a strake (5) that reduces airflow migration outboard, corrals it, and directs it downstream.  To where?  Well the raised nature of the Big Honking Hole trailing edge (6) has never been more evident, and suspect, than in this image.  I imagine the strake-directed airflow is aimed there, where it gets partially ingested into the front fender, and directed various places inboard and outboard.  Air management anyone?
Audi R18, Le Mans Test 2016Again the raised nose (1).  But it's also important to point out how very narrow the nose box is (2) where it attaches to the tub.  This can only be achieved by pushing the driver rearwards as there are minimum regulatory volumes to be considered in the area of the driver's feet.  Contrast this with the Kolles LMP1 that makes use of a narrow crash box but has not shifted the driver rearwards (understandably they don't have the budget to design a new tub every year), and thus the interface between the tub and the crashbox is much, much wider.  A wide crash box is an impediment to exit airflow from the front wing and flap, and the R18's narrow box allows much wider top exits (3).

Interestingly, the movement of the footbox volume has had some impact on the overall tub shape as the various internal regulatory volumes are interconnected.  So one's movement affects another's position, etc.  And this is apparently why the current Audi tub has a more square appearance at the top, in frontal elevation, than the 2015 tub.

Concave legality panels (4) head the exit slot.  These are bi plane, one below the other, and Audi has different panels for different downforce configurations.  The ones here are as run at Le Mans, the Silverstone/high DF configuration are different (as are the front fenders in that config).  

Audi R18, Le Mans Test 2016A portion of the airflow exiting out of the wheel well is directed inboard (1).  The side view mirror is mounted to a constant height continuation of the outboard strake.
Audi R18, Silverstone WEC 2016A splitter change allows a sneaky peak at the front of the crash box (1) and further emphasizes how absolutely narrow it is.  Strakes still abound (2).  This was their configuration at Silverstone.  Panullo has a nice image contrasting the Silverstone and LM Test VG sets.

Audi R18, Silverstone WEC 2016Audi's issue at Silverstone afforded an opportunity to have a look at its strakes from the bottom.  Here we can see the small outboard strake (1) and the cluster of inboard strakes (3).  What's interesting is the small airdam in between the strakes (2).  Seen from the side, it's the inside face of the wheel well projected below the floor, offset from the radius of the tire, though concentric to, and forms and angled vertical that would seem to peel off a layer of airflow ejected off the front tire's trailing edge.  Clearly an area of complicated, but profitable, airflow.
Audi R18, Le Mans Race 2016As Le Mans race weekend progressed Sam was able to get the definitive shot of the LM-spec strake package.
Audi R18, Le Mans Test 2016At the rear, the brake duct (1) heads the elongated rear fender leading edge (2).  The intent of the elongated leading edge is similar to the concept regarding the front fenders; drive air around, instead of over, the fender in order to avoid as best as possible the mandatory Big Honking Hole.

The bodywork just ahead of the rear wheel is inset in order to accommodate a series of three vortex generators (3) and still stay within the max width regulations.  These VGs are designed to route air around the influence of the rear wheel, shooting the subsequent vorticies into the region of the rear cheese wedge (4) so that the air can be better managed inboard and into the base area of the car.
Audi R18, Spa WEC 2016An outboard vertical return (1) has been a feature on Audi LMP1s for years.

Note the turning vanes on the floor ahead of the rear tire leading edge (2).  I suspect they've been there since 2014, but this is the first time I've seen a shot revealing such. Note they direct air inboard, around the rear tire.
Kolles CLM P1/01 AER, Silverstone WEC 2016>>The Kolles P1/01 is a curiosity.  And at the lower end of the grid it's always extremely difficult to make leaps forward.  But it's always good seeing teams try, and for 2016 Kolles has updated their P1/01.

Sam dives deep into the convoluted story and evolution of the Kolles LMP1 in the link below.

>>Kolles CLM P1/01 AER
Kolles CLM P1/01, Le Mans Test 2015Here's a reminder of what the 2015 car looked like, with a little compare and contrast to 2016.  The nose is low (1), though interestingly the crash structure is waisted (2).  However, the tub is wide where it connects with the crash structure (3).  The covering panels over the front wings (4) are not vented or slotted but at the very trailing edge (5).  From what I can tell, the 2015 front fender (6) essentially carries over little changed, Kolles are even using the same double dive planes (7).  The 50 mm legality step in the front wing was more abrupt in 2015, and this is cause for one of the few changes to the front fenders given this shape extrudes inboard (and thus required a new interface surface between the bottom of the fender and the top surface of the wing).
Kolles CLM P1/01 AER, Silverstone WEC 2016The 2016 car's nose (1) is effectively twice the height of the 2015 car.  Admittedly the better picture to assess that is the first one at the top of the Kolles section here (two images above).  The crash box waisting (2) is initially much more abrupt, occurring very soon after transitioning forward from the tub.  However I don't think the width at its narrowest is significantly different than the 2015 car.  This nose redesign would have required a new crash test certification and a rehomologation.

The covering panel is obviously much shorter (4), though it still appears to vent out the trailing edge in nearly, if not exactly, the same position (5).  Ahead of the shortened covering panel is a concave legality panel (6), similar in concept to the Audi R18's.  Audi changes the shape of these panels depending on downforce configuration, though it appears Kolles is utilizing only one flavor as these seem identical to the ones seen at Le Mans (these shots are Silverstone).

As mentioned before, the fender and dive planes are carry overs, and the wing's 50 mm step transition is much smoother (6).
Kolles CLM P1/01, Silverstone WEC 2016Underneath the nose, the front wing consists of a long chord mainplane, with a short chord flap notched in the center (shorter chord in the center, longer outboard) to clear the underside of the tub (and reduce tub to wing trailing edge exit flow interactions).
Kolles CLM P1/01 AER, Le Mans Race 2016Race week affords a look at the underside of the Kolles' front aero package.  Note the diveplanes, while still bi-plane, are shorter in length that those run at the test day.

Toyota TS050, Le Mans Test 2016>>Toyota went to great efforts to design a new engine for 2016, a 2.4L, twin-turbo V6 replacing previous years normally aspirated, 3.7 liter, V8.  So it's rather surprising how similar the aero on the TS050 is to the previous TS040.  In some areas it is essentially identical.  

>>Toyota TS050
Toyota TS050, Le Mans Test 2016Having said that, the front end HAS been revised.  The architecture is evolutionary for sure, Toyota is still going with the low nose/inlet mold (Porsche does same, Audi is actually the outlier).  The primary inlet is raised more than last year (1), and aero elements are visible just inside.  This is the reason for the increased inlet height, to provide airflow to those new elements.  Toyota runs a traditional diffuser, one that's continuous past front wheel centerline, and ending near the face of the radiator inlet (2).  The aero/wing elements are on top of the diffuser, covered by the bodywork, and exit out the end of said bodywork (3).  At the very front of the fender is a inlet duct (4), presumably for brakes, however it seems a bit small to provide all the cooling needs for the brakes.  Another image (below) gives us more details.
Toyota TS050, Le Mans Race 2016The aero element above the diffuser is decidedly un-wing like (1).  However, air can blow over the top, and underneath it as it is suspended above the diffuser surface.  However, it looks more like a tube, and it also has a corresponding inlet duct in its wide radius face (2).  Presumably this provides the difference for the brake cooling.  

And on further thought, I now believe the bodywork element covering the front diffuser (3) might instead be wing shaped.  An image shot forward through the valley between the pontoon fender and the top would possibly clear things up about this area of the car.

It's worth noting the lack of diveplanes on the TS050 in LM spec, especially compared to their use by the competition.
Toyota TS040, Le Mans Test 2015Last year's TS040 front fender trailing edge cluster.
Toyota TS050, Le Mans Test 2016I can only spot a handful of differences on the TS050, none significant.  There's  a small ledge feeding out of the front wheel well (1), just above the outboard strake, that carries down about 1/2 the length of the pontoon fender.  And the traling edge of the side view mirror is now notched (2).
Toyota TS040, Le Mans Test 2015Underneath the skin.  Here's the TS040 at the Le Mans Test last year.
Toyota TS050, Spa WEC 2016It's almost stunning how little is changed.  However, there are many detail changes, starting with the brake drum ducting (1).  Interestingly, the outboard strake (2) is identical, as is the "bluff body" airflow reorganizer (3).  The inboard strake (4) isn't new (just isn't visible in the TS040 image above).  Here we can see the crosssectional shape of the Toyota's diffuser (5), it consists of two medium-sized tunnels, one left, one right, going either side of the tub's footbox, as well as the "chocolate fingers" (6) where the front portion indexs together with the rear continuation.  The cross sectional shape of the inner fender (7) has changed, becoming more convex compared to the concave-ish shape in this area on the TS040. 
Toyota TS050, Silverstone WEC 2016Revisions have been made to the rear end as well.  Here is the TS050 at Silverstone.
Toyota TS050, Le Mans Test 2016Overall the changes are again subtle.  The louvers have been removed out of the rear fender trailing edge and instead another "bluff body" aero structure (1), which performs the regulatory act of masking the mechanical components, while reorganizing the air before it leaves the fender well, has been  placed.  The diffuser trailing edge corner has been elongated outboard (2).
Toyota TS050, Le Mans Test 2016A closeup of the aero shape inside the rear fender and note the trailing edge vent (1).  What it vents is anyone's guess.  However, the proximity of the underfloor and obvious wheel well area leads to some interesting possibilities.  Significant?  Not at all, but interesting yes.  

Also note how the inboard vane (2) is angled to direct airflow slightly outboard.  The  diffuser trailing edge return (3) extends into the exit flow of the rear fender and helps to extract.
Audi R18, Le Mans Test 2016>>Endplates.  Back in December of last year, when evaluating the first images of the Audi R18, I had this to say about its rear wing endplates:

Then there's those rear wing endplates.  I suppose I'm a little puzzled by them.  However, one aerodynamicist I contacted cynically suggested they was done for pure aesthetics, "But they look different, no?"

Given Toyota arrived at the Le Mans test  with similarly angular endplates 
(below) I felt the issue deserved a second inquiry. And the bottom line is that this area of the regulations is not productive given the restrictions and any developments tend to produce effectively invisible/not dissimilar results.  Thus the conclusion regarding aesthetics.

A second opinion weighs in a week later and changes the narrative back to performance.  That the design element is of questionable aesthetics means the performance opinion rules the day.  However, I don't think the aero gain is much at all.
Toyota TS050, Le Mans Test 2016

ęCopyright 2016, Michael J. Fuller