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November/December 2010
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long with Audi's R18 announcement, it was also mentioned that instead of running the R18 at Sebring they will instead run the R15+.  Now there's been rather rampant speculation about what developments might be peeled off the R18 in order to update the R15 in a effort to utilize the R15 platform as a racing test bed for R18 bits.  Upon further inquiry, we understand that in fact no changes will be allowed to be made at all to the Audi R15 other than changes in order to equalize it's performance to the new 2011 cars; therefore, only changes to the inlet restrictor (smaller), boost (reduced), and fuel cell (reduced).  Don't expect wide tires, R18 front suspension, or any R18 aero bits.  And detailed reading of the newly released regulations makes all of this very evident.  Art 19 states explicitly, "The LMP1s having participated in at least one race organized according to the ACO specifications before 31/12/2010 will be admitted in 2011 under the condition to keep the full specifications of the 2010 season,"  further confirming our inquiry. is an online shop for performance parts & accessories, including headlights and tail lights

he 2011 final regulations have (finally) been released.  Here are the highlights:

The regulations make use of a new term, "SRSE", through out.  This is an acronym based off the French wording, "système rechargeable de stockage d'énergie".  But reading the English text this isn't abundantly clear.  Indeed, for whatever reason the acronym "STSY"  is actually assigned (Art 1.14) to the English wording of, "Rechargeable Energy Storage System."  But note that the English text uses STSY interchangeably with SRSE.

  • Art 1.13 covers all the details of the hybrid systems.  4-wheel drive is now allowed through the use of a hybrid system, assuming the two rear wheels are driven by the engine and the two fronts are driven by the hybrid system.
Recovery and release of energy from the brakes, either on the 2 wheels of the front axle, or on the 2 wheels of the rear axle.
  • Further reading of 1.13 gives the maximum fuel capacity for gas- or diesel-powered LMPs.  It's interesting to note the ACO feels the hybrid system is only worth 2 liters across an entire fuel load (vs. 75 l and 65 l respectively for non-hybrids):
petrol: 73 l.
diesel: 63 l.
  • F-Ducts are illegal:
1.5.4 – Any system operated automatically and/or controlled by the driver to modify the airflow on the rear wing when the car is in motion is forbidden.

  • We understand the additional verbage attached to 3.5.4 is to clarify that the wheels and their assembly (brake ducts, uprights, etc.) are exempt from the wording stating, "all visible parts of bodywork from the underside must form a continuous surface, without openings, slots or cut-outs."  The additonal text states:
The only openings permitted are the minimum gaps necessary for the sensors measuring the ground clearance (LMP1 only). In order to permit wheel and suspension part movements (suspension travel and steering) and the passage of brake scoops, the volume around the front wheels is free. His position and its maximum dimensions are as follows:
• 800 mm length, distributed symmetrically about the front axle centerline,
• 300 mm high, measured from the reference surface,
• 550 mm wide, the inner surface of the volume being at least at 450 mm from the longitudinal centreline of the car,

  • Art 3.6.1 has additional text that makes it illegal to put gurneys on the trailing edge of any non-wing wings:
(no bodywork element is permitted within 25 mm from the trailing edge)
  • Art 3.6.3 removes the wording mandating that both LMP1s and LMP2s run a 20 mm gurney:
a.4 - A rigid trim tab/gurney is mandatory (LMP1 only).

  • B.2 of 3.6.3 allows single rear wing mounts as long as all the parameters of 3.6.3 are met:
b.2 - The supports must be 1250 mm apart as a maximum. If they are assembling in order to make only one support, they must be in compliance with all the points of article 3.6.3. ;

  • The full rear wing deflection regulations are also contained within 3.6.3
  • Art 3.6.4 covers the Big Honking Fin's design and deflection requirements.
  • Art 10.4 is clearly aimed at Audi and their aerodynamically shrouded suspension from 2009:
10.4 - The suspension arms :
a/ Must not be chromium plated ;
b/ Must be made from an homogeneous metal.
c/ The height /width ratio of the profile does not exceed 3.0,
d/ A protection for brake lines or electrical wire can be fixed to the suspension arms provided that:
It has no wing profile;
The height /width ratio of the profile does not exceed 2.5,
• The maximum thickness of the profile is equal to the maximum height of the profile of the suspension arm on which the protection is fixed + 3 mm

  • Art 19 covers Performance Adjustments for both LMP1 and LMP2, as well as the participation of LMP1s and 2s designed to 2010 regulations.

Audi R1812.13.10

ith its short turbo diesel V6 one would expect the Audi R18's wheelbase to be shorter than the Audi R15's mammoth 3080 mm, and indeed it would appear the R18 comes in around 64 mm shorter.  Front and rear overhangs are hedging towards the maximum allowed though appear to be shy.  The rear wing projects beyond the trailing edge of the bodywork by approximately 111 mm
Audi R1812.12.10*

*Continuously being updated, see below

udi R18.  Here's what Audi is telling us:  The car is powered by a 3.7 liter, turbo-diesel, V6, and power is transmitted through a newly developed 6-speed gearbox.  The choice for a closed top coupe, a first for Audi (post LMP2004 rules) since the 1999 Audi R8C, was driven by the need for higher aerodynamics efficiency given that the new-for-2011 engine regulations have slashed nearly 150 horsepower.  Thus the former aerodynamics paradigms are out the window and low(er) drag is the name of the game.

Very few other technical details have been reveled, though interestingly, Audi felt the need to mention that R18's monocoque is a single piece construction rather than the typical two piece, upper and lower glue bonded together, construction.  This ultimately leads to a lighter and stronger structure.  
Audi R18The regulatory mandated Big Honking Fin blends into the single center rear wing mount.  The boundary layer build up as air slides down the fin allows one to look at a single central rear wing mount for two reasons.  The layer build up allows the single mount to be "hidden" easier (think of it being tucked in behind a curtain).  And secondly, it allows you to get away with a much thicker mount then you would want to typically use (to make up for there only being one mount).  The endplates bear a good portion of the wing load helping everything out.  

The height of the rear wing is very low given the amount of endplate left above it.

The leading edge of the rear fender is very far forward and unusually shaped.  There's little reason to think its shape is driven by anything other than aerodynamic considerations.  It's reasonable to assume that the lower intake is as it was on the R15; brake cooling.
Audi R18There's absolutely no missing the wide front fenders which lead us to wide front tires. Yes, Audi's pulled an Acura and are running rears on the fronts.  According to their press release this is all about weight distribution.  This indeed may be the case, but recalling back to the issues Audi had with the R15, we also believe it's also about front aerodynamic balance.  The Audi R15 was running so much front load that the Michelins simply couldn't handle it and thus Audi ran with a compromised set up at Le Mans in 2009.  Subsequent development on the R15 "plus" eliminated or reduced this problem, but the desire remained to want to run higher front weight distribution and front downforce.  And therefore rears came into the picture.

We saw this coming back in March (3.25.20 entry) when the R15 plus was seen with removable front inner fender bulges; ultimately there was no other reason for
bolt-on tire clearance bulges from a manufacturing stand point (not to mention a CAD standpoint) as it would be vastly easier to make, one less mold, if integrated into the fender mold.  The assumption was that it was bolted on to allow for larger bulges should one want to test wider fronts.

There has been no mention if Michelin will develop a bespoke rear-front tire compound for the R18.
Audi R18It's been said elsewhere that Audi began using aluminum front diffusers on the R15 and that this practice had been continued on the R18.  The reasoning was given that as a race wore on, the carbon diffusers were deteriorating, getting damaged, and front aero performance subsequently dropped off.  Supposedly the car was very front aero sensitive.  At first this didn't pass the sniff test at all.  But with the R18 in all carbon, it is easy to differentiate between differing materials without a layer of paint covering it all up and indeed something is going on there.  Posing a question, we get an answer.  Yes, the front diffusers are made from a combination of machined aluminum with carbon skins (we can see at very least the top has a carbon skin, but the leading edge clearly appears to be aluminum and so too the mid section connecting joint).  But the reason is actually quite simple and nothing to do with the durability of carbon, aluminum is particularly soft after all, especially in thin sections.  With the diffuser's leading edge clearly aluminum, one can imagine the material is actually less than ideal from a durability standpoint; carbon at least has some elasticity.

Instead it's done because of very short lead times for aluminum and little tooling investment.  In the end, Audi found that the cost of a carbon front diffuser was no different than the cost of an aluminum one.  Weight or weight distribution wasn't an issue.  That seems a little counterintuitive at first when everything on a race car appears to be scrutinized heavily for strength to weight and indeed it typically is.  And one can imagine an aluminum front diffuser being heavier than an all-carbon version.  But it's added weight in an area where Audi was already looking to put ballast (indeed, on most F1 cars the front wing is used as an area to place ballast--it's the lowest/furthest forward part of the car after all).  But the big benefit was the ability to generate multiple variations and have them made very quickly for testing.  To make a carbon part first requires a pattern to be machined.  A mold is then laid up off that pattern, and then the part is laid up out of the mold.  The process is labor intensive and time consuming and all your tooling is worthless if you decide to try another diffuser shape.  Thus Audi saw aluminum as a way to actually reduce costs and decrease turnaround times.
Audi R18There's also been some discussion that the R18's turbos (some even say 'turbo' singular) might be packaged into into the 'V' of the 6-cylinder engine and there is some proof that that could be the case, namely the roof mounted intakes (clearly engine intakes given the lack of periscope ducts elsewhere--also note the small inlet volume, not cooling much of anything with that small inlet x-section) and the single centerline mounted engine exhaust.  

*And we now have it confirmed that the roof inlet is for engine induction, the slot on the nose is simply for driver cooling.
Audi R18
Audi R18The bodywork immediately behind each tire appears a very close facsimile of the Audi R15's.  However, the bodywork between the rear fenders is very different and much lower and culminates on centerline in a nice peak intersecting the single triangular-section engine exhaust.
Audi R18
Audi R18
Audi R18Looking down on the rear fenders and you get the impression they've been designed to encourage flow towards the rear wing.  But we're told on very good authority that the leading edge shape is actually designed with reduced drag in mind and not rear wing performance.
Audi R18We understand the wind tunnel used for the scale development of the R18 was none other than the Sauber F1 team's BMW tunnel.  This would signal a break with Fondtech, Audi's traditional aerodynamics development partner.  Allegedly some within Audi felt there were issues with the Fondtech wind tunnel that culminated in concerns about its accuracy over the course of the development of the Audi R15.  As a result, we understand that the R15 relied more heavily on CFD as it's development progressed given the emerging lack of confidence in the Fondtech facility.  That the Fondtech facility had been used to develop the highly successful Audi R8 and R10 should be noted.
Audi R18Speaking of wind tunnels, Audi included this shot of the R18 undergoing full scale testing at Ingolstadt's Audi Wind Tunnel Center.  What was interesting was not what was going on through the window, but what was behind the screens.  At full resolution, you can clearly read the data off the computer monitors.

*Update 12.15.10:  It's with some interest that I note that this image (right, click on image for original resolution) has been removed from Audi's PR portal.  All industry persons whom I've inquired with said the data would be of little no to relevance to a rival outfit, particularly because of the method of ground plane simiulation being used in the Audi wind tunnel.
Audi R18The data shows the drag coefficient, front coefficient of lift (.cl), and rear coefficient of lift.  This would be .8486, -1.7965, and -1.5873 respectively.   Initially we thought these were raw coefficients, but in hindsight it appears they are CdX figures:  that's the coefficient of drag (or lift, replace the 'd' with 'l') multiplied by the reference area.  Thus the data needs solving for the raw coefficients to make better sense for us (well, for me really).  Therefore we get a coefficient of drag (.cd) of .471 and a total coefficient of lift (.cl) of -1.8798.  Assuming a frontal area of 1.8 m^2, that translates to 934 lbs drag and 3727 lbs. downforce for a L/D of 3.99:1.  The balance is a very front biased 53% front.  But let's also mention that given the nature of the Audi tunnel, spinning wheels, partial rolling belt, it doesn't have the ingredients to produce an accurate ground simulation and the numbers need to be taken with a grain of salt in that respect.  Especially the balance.
Audi R18Obviously this is one of two things:  either a complete PR gaff or a deliberate release of information.  If deliberate, then clearly designed for misinformation.  It's hard enough to inquire about aerodynamics data from decades old race cars that have no relevance to current regulations or trends, thus there's little reason for Audi to release this information willingly at this time.
>>Craig Scarborough has been doing some sketching.  Check out his Audi R18 interpretations.



e have independent verification that on December 10th (4 days from now) Audi will unveil their new R18 LMP.  And while no other details are forthcoming for the moment, we are told that the car will be diesel powered.

>>We've also received a copy of the latest regulations (Version 5).  Note that the ACO has still not released rules for 2011.  We understand there's much hand wringing occurring over the specifics of the hybrid rules.  Also at issue are some of the details concerning the wing deflection testing.  

hanks to Google translate we have this headline from the ACO, "Toyota Returns to Endurance as an Engine!"  Well then...The ACO are announcing that Toyota Motorsports has joined forces with Rebellion Racing for 2011 and will be supplying the team with engines.  Speculation is that the effort will use Toyota's Lexus Super GT 3.4 liter normally aspirated V8.  This would seem to be the first toe-in-the-water for an all out effort aimed at 2012 and confirmation of the raging rumors we've been hearing.  Machine translation is here.  

ecall that back in August of this year Dome announced that they were shuttering their LMP program.  So it's with interest that we note the recent publication in the Japanese car magazine "Motor Fan Illustrated" of aero figures for Dome's S101.5, S102, and unraced S102i.  Now this isn't without precedent; back in March of 2008 (3.21.08 entry) Dome released similar data for the S101.5 and S102.  But when the original information was released Dome didn't cite at what speed regime the data was collected
(or even the units used though Newtons made a lot of sense).  Thus the data was interesting, but of little use.  But this time around they have.

It's a pretty straight forward matter of converting the data into pounds force and extrapolating to 200 mph once you know the original units and speed regime:

This gives us really good insight into what a contemporary, post LMP2004 regulations, LMP can achieve aerodynamically.  But looking at the above chart, on first glance it would appear the various Domes were rather draggy.  And calculating for top speed, using the given drag and assumed frontal area and power (and drive train efficiency), seems to bear that out:

But we know from recent Le Mans history that the Dome has traditionally been one of the fastest LMPs on the straights and most certainly the fastest non-factory backed car.  Indeed, in 2008 the S102 was timed at 207.2 mph.  So what was going on?  Was the data quoted at some unrealistically high 
(and unknown to us) ride height?  We have it on good authority that one could expect drag to drop upwards of 5% at lower ride heights, those ride heights typically seen at speed.  Thus it would be fair to assume the inverse was true:  high(er) ride heights would produce higher drag.  But an inquiry to Dome's Hiroshi Yuchi shook out the answer; the data as presented was simply the ride height map average.  Yuchi further confirmed we were looking at Le Mans setups.  And based on that, calculating an assumed 5% reduction in drag at lower ride heights we get the following:

To which Mr. Yuchi's response was, "
I can not tell you the actual figure for drag of the RH at top speed, as this figure quite important for Le Mans.  However, I can tell you that I think your above calculation is not far from the actual figure."


otalSim will be hosting the
Motorsports Aerodynamics
conference this coming Monday (November 29, 2010) in Indianpolis in conjunction with the Indianapolis Motorsports Industry Show.  Register here, conference details here.

ore round-about news regarding Toyota's plans for the future (or, at least what they're not doing next year).  Today it was announced that the technical partnership between the Hispania Racing Team Formula One team and Toyota Motorsports, which would have seen Toyota act as consultant and more for the HRT organization, has fallen through (1, 2).  This would seem to answer the concern about the technical capacity of the Cologne, Germany based operation, i.e., if Toyota had been tied down with HRT then they certainly couldn't have pursued an LMP. is an online shop for performance parts & accessories, including headlights and tail lights
2011 Riley LMP2 Coupe11.12.10

iley Technologies has released images of their 2011 LMP2 in coupe form.
2011 Riley LMP2 Coupe
2011 Riley LMP2 Coupe
2011 Riley LMP2 Coupe

e're hearing interesting things out of Cologne, Germany, specifically out of the Toyota Ex-F1 facility.  Based on what we've heard, if one had to guess, it would appear an advanced design study is in the works for an LMP.  Toyota's name gets discussed every off season it seems.  It certainly has been discussed a lot recently, even with little to no tangible evidence (though supposedly Toyota sent reps to most of the 2009 ALMS events to reconnoiter).  But it would seem this is the real deal though highly dependent on getting the go-ahead from up top.
Peugeot 90X11.4.10

umors, and we'll stress they are rumors, keep trickling out about the technical specification of the Peugeot 90X.  We're hearing 3.7 liter, diesel, V8, hybrid (remember the 908 HY?).  Is the 90X on display in recent days merely a mule/technology demonstrator?  If yes, then that would run counter to the discussion that the Peugeot program isn't exactly flush with cash.  

This is the rumor season.  Don't get your panties in a bunch.  Have fun with it.  Don't worry, be happy.

In the same breath, we've further "confirmed" the Audi is to be a "compact" 3.7 liter diesel V6.  Of course this was the rumor back in February (2.17.10), so could this simply be reverberations of that item from 9 months ago?


2011 Peugeot 90811.2.10

quick look in AutoCAD appears to show that the Peugeot 90X has about a 50 mm reduction in the wheel base (compared to the 908), making it around 2900 mm in total.  The rear overhang appears to be around the maximum allowed (750 mm) though we can't really vouch for the front overhang given that the image Peugeot provided cuts the splitter short.

We're hearing from other sources that the Peugeot 90X is a reflection of current budgetary struggles within the Peugeot Motorsports department at the moment.  Earlier this year we were told that Peugeot had designed swan neck rear wing mounts but that they never were implemented given the costs associated.  This would seem to be a continuing trend even as the 90X breaks covers.  It is our understanding that the 90X is effectively what would have been the 2010 908 bodywork but reworked in the relvant areas for the new engine package. 
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©Copyright 2010, Michael J. Fuller