Audi LMP1 Discussion

[TF110]

I bet all these cars have a decent amount of ballast to achieve a good weight balance. I have no clue how much though.

[mclarenf1papa]

And I might have done some bad math....Which year did the 915 kg weight for manufacturers take effect? If it was 2012, then the Ultra's would have had to have a 165 kg ballast. I'm guessing the KERS + the front motor is roughly 55 kilos. So that brings the weight down to 860 kg from the 2013 E-tron. So that'd be, going by the 750 kg weight above, 90 kg of ballast. Which still seems like a lot. I remember someone from Audi saying that they didn't have a lot of ballast options for the E-tron. 90 kg seems like it would come with a lot of options.

Final weight guess: I think that the 2013 car (stripped out) would weight somewhere around 810 kg. But again, that may be way off.

[JoestForEver]

Originally Posted by mclarenf1papa

And I might have done some bad math....Which year did the 915 kg weight for manufacturers take effect? If it was 2012, then the Ultra's would have had to have a 165 kg ballast. I'm guessing the KERS + the front motor is roughly 55 kilos. So that brings the weight down to 860 kg from the 2013 E-tron. So that'd be, going by the 750 kg weight above, 90 kg of ballast. Which still seems like a lot. I remember someone from Audi saying that they didn't have a lot of ballast options for the E-tron. 90 kg seems like it would come with a lot of options.

Final weight guess: I think that the 2013 car (stripped out) would weight somewhere around 810 kg. But again, that may be way off.

I think the LMP1 minimum weight of 915 was enforced in 2006, to allow climate control for coupe prototypes (or to please Audi as R10 is 935kg according to conspiracies). And the flywheel system is about 70kg, but the number of 840 or so for a Ultra is possible.

[TF110]

It was 900kg in 2012; 915kg in 2013 (factory hybrids); 870kg 2014.

[mclarenf1papa]

Okay, so my guess would be 800 then.

[chernaudi]

I know that I read somewhere that Audi got the unloaded R18 Ultra down to around 750kgs. I though that I found it at Racecar Engineering, but info there on the Ultra is almost non-existant now aside from how it related to the e-tron.

[Bandicoot17]

Thought the ultra was the weight of the e-tron without the hybrid systems

[chernaudi]

Ultra and e-tron shared the same tub. Meaning that the Ultra was just an e-tron quattro without the hybrid system and a two liter larger fuel tank.

The weight figure that I saw for the Ultra without driver, fuel, ballast and hybrid system was about 750kgs. At least that was the goal that Audi set, though it might have been closer to 800kgs.

I still can't figure out where I saw the 750kgs figure, though.

[joeb]

Originally Posted by chernaudi

I still can't figure out where I saw the 750kgs figure, though.

Turns out the link to the appropriate article was earlier in this thread, but here it is again:

http://www.auto-motor-und-sport.de/m...a-5034325.html

2012 car was 750kg with the hybrid bits weight around 100kg leaving room for ballast.

[CyberMotor]

Here's a photo I took of the Ultra back in 2011 at PLM. Just after I took this photo and the crewman had gotten out of the car, the Ultra started rolling backwards toward me. My first thought was of the Audi TV commercial touting the lightweight materials. In the commercial, the car starts rolling backwards after someone blows on it.

It was a bit surreal for me seeing the Ultra rolling towards me since the experience was so similar to the commercial. My next thought was, "Is it really that light and can I put my hand out and stop it from rolling towards me?" I wasn't sure so I whistled to get the crew's attention and they came running back to catch their runaway Ultra.

What was also a bit funny was that they were all distracted and hurrying up to see the new Peugeot going through inspection.

[MihokS5]

Originally Posted by CyberMotor

Here's a photo I took of the Ultra back in 2011 at PLM. Just after I took this photo and the crewman had gotten out of the car, the Ultra started rolling backwards toward me. My first thought was of the Audi TV commercial touting the lightweight materials. In the commercial, the car starts rolling backwards after someone blows on it.

It was a bit surreal for me seeing the Ultra rolling towards me since the experience was so similar to the commercial. My next thought was, "Is it really that light and can I put my hand out and stop it from rolling towards me?" I wasn't sure so I whistled to get the crew's attention and they came running back to catch their runaway Ultra.

What was also a bit funny was that they were all distracted and hurrying up to see the new Peugeot going through inspection.

Thats not the "Ultra" being discussed. I believe they are talking about the 2 Ultra's that ran alongside the 2 E-Tron's at 2012 LM24. They featured even more weight reduction to compensate for the hybrid drivetrain that had to be added to the sister E-Tron cars...

[mclarenf1papa]

Originally Posted by MihokS5

Thats not the "Ultra" being discussed. I believe they are talking about the 2 Ultra's that ran alongside the 2 E-Tron's at 2012 LM24. They featured even more weight reduction to compensate for the hybrid drivetrain that had to be added to the sister E-Tron cars...

Correct.

[carbon_titanium]

In that pic there is the 2011 R18 TDI, the 2012 ultra and e-tron models used an updated and redesigned monocoque because audi engineers were struggling a lot to obtain an optimal weight destribution because of the new hybrid hardware inside the car (the not hybrid "ultra" had kilos of ballast inserted in the same area where the hybrid system was placed in the e-tron). The aim was to give to the r18 ultra the same handling and weigth destribution of the r18 e-tron. Anyway if memory helps me, it was the 2011 R18 TDI that was 750kg without ballast, 2 years ago I saw a pic where during spa tech. scrutenering the #1 and #2 r18 e-tron min. weight was a bit over 900kg, 903 or 905. Indeed the race winner was the r18 ultra #3.

[chernaudi]

Old RCE article said that the R18 from 2011 was well below 850kg unladen. Audi's goal for the later ('12/'13) R18 variant was reduced weight, make the car more suited for a hybrid system, increase durability of the body panels and improve driver visibility.

And according to the article that was just relinked, the previous R18 from the past couple of seasons did weigh around 750kgs without driver, ballast, fuel or hybrid system.

[MyNameIsNigel]

Originally Posted by joeb

Turns out the link to the appropriate article was earlier in this thread, but here it is again:

http://www.auto-motor-und-sport.de/m...a-5034325.html

2012 car was 750kg with the hybrid bits weight around 100kg leaving room for ballast.

Dr. Ullrich claims in this video interview that the new R18 weighs only 760 kg. It is unclear if this figure is being mistakenly quoted by Dr. Ullrich and whether this figure takes into account the weight of the whole hybrid system (flywheel + MGU + electronics), which is now likely to be below the 100-kg figure quoted by Auto Motor und Sport in respect of the 2012-spec car.

In Audi's recent press release, it is claimed that the mandatory wheel tethers, rear crash structure, side intrusion protection panels and seventh gear amount to a total additional weight of 20 kg.

Based on the above, one could assume that Audi have been able to save between 10 kg to as much as 100 kg compared to the 2012-spec car. The 760-kg figure quoted by Dr. Ullrich does not appear to be unrealistic and it could well be that the new car, without the hybrid system, weighs less than 700 kg.

Take the wheels off, remove the engine, and the entire chassis could possibly be lifted by a few team crew members...

[CyberMotor]

Originally Posted by MihokS5

Thats not the "Ultra" being discussed. I believe they are talking about the 2 Ultra's that ran alongside the 2 E-Tron's at 2012 LM24. They featured even more weight reduction to compensate for the hybrid drivetrain that had to be added to the sister E-Tron cars...

Excuse me, but the car in the photograph is an "Ultra", in fact, it is one of the first. It may be a precursor to the R18 with the same name and the Ultra with the same name but, it was the first prototype that Audi presented as the Ultra with advanced lightweight materials.

Audi, the next year, introduced the R18 Ultra of which you speak.

I acknowledge your identification of the specific R18 Ultra (version 2, 3, 4 etc.) but this is the problem when prototypes of obviously different designs and technologies have the same name.

But, as far as your comment about me talking about a different car, you are mistaken. If you have a problem with the naming, etc., that may have caused this miscommunication, please contact Audi.

[mclarenf1papa]

Originally Posted by CyberMotor

Excuse me, but the car in the photograph is an "Ultra", in fact, it is one of the first. It may be a precursor to the R18 with the same name and the Ultra with the same name but, it was the first prototype that Audi presented as the Ultra with advanced lightweight materials.

Audi, the next year, introduced the R18 Ultra of which you speak.

I acknowledge your identification of the specific R18 Ultra (version 2, 3, 4 etc.) but this is the problem when prototypes of obviously different designs and technologies have the same name.

But, as far as your comment about me talking about a different car, you are mistaken. If you have a problem with the naming, etc., that may have caused this miscommunication, please contact Audi.

Yep, you're right.

For everyone that still thinks it's the original R18:
Compare the rear bodywork (especially under the rear wing endplates) to the original R18.

[chernaudi]

Actually, the deal in 2011 is that Audi ran the "Audi Ultra" branding on their cars that year. It was when Audi started the Audi Ultra ad campaign.

Also, the symmetrical color scheme gives it away as being taken of one of the 2011 cars. In 2012, Audi ran a highly asymmetrical color scheme on the Ultra and e-tron. And the rear deck is the sprint variant from 2011. In both '12 and '13, Audi ran the LM-style rear deck with the trailing edge turning down from the fin, and in '13, they ran the endplate extensions.

Also, in the details, it should be noted that Audi haven't run yellow highlights on their cars since 2011.

[MihokS5]

Originally Posted by CyberMotor

Excuse me, but the car in the photograph is an "Ultra", in fact, it is one of the first. It may be a precursor to the R18 with the same name and the Ultra with the same name but, it was the first prototype that Audi presented as the Ultra with advanced lightweight materials.

Audi, the next year, introduced the R18 Ultra of which you speak.

I acknowledge your identification of the specific R18 Ultra (version 2, 3, 4 etc.) but this is the problem when prototypes of obviously different designs and technologies have the same name.

But, as far as your comment about me talking about a different car, you are mistaken. If you have a problem with the naming, etc., that may have caused this miscommunication, please contact Audi.

Wow, someone's a bit sensitive. I don't need to contact Audi for anything because I've worked for them for 13 years now and know my facts. I was also with the team that race at PLM thanks to my relationship with Timo and have been fortunate enough to be around these cars a lot.

You are getting way too defensive because I was simply implying that the car being discussed was the lightest "Ultra" that was put on an extreme diet to compensate for the design/weight of the hybrid system.

The 2011 cars did use lightweight construction and started the Audi Ultra campaign that has since migrated to DTM, Customer Racing, and road cars, but
it was the 2012 cars that went through a complete overhaul to shed as much weight as possible and up until now, were the lightest prototypes Audi Sport had built.

Now, back to the new R18 please-

[TF110]

They're Audi's! They all look alike! At least you can't mistake it for anything else.

[chernaudi]

Maybe this will settle the arguments.

2011 Audi R18 TDI: http://www.ultimatecarpage.com/car/4...i-R18-TDI.html

2012 Audi R18 Ultra: http://www.ultimatecarpage.com/car/5...R18-ultra.html

2012-13 Audi R18 e-tron quattro: http://www.ultimatecarpage.com/car/5...n-quattro.html

Now for the 2014 car (though it applies also to the older cars from the past couple of seasons), how does the colored light strips in the headlights work? I know that it's something to do with LEDs, but how does it work as far as when the light up colored vs white light?

And I also wonder why the double dive planes returned. I don't think that the cars being 4 inches narrower would take away that much drag. However, if you look at the shape of the dive planes (like on the older R18s), they're functioning more as vortex generators/flow conditioners than as downforce producers. This is a principal that can be traced back at least to the Nissan IMSA GTP cars (if not further), where the dive planes made 400+lbs of downforce for less than 30 lbs of drag. The dive planes themselves only made about 60lbs of downforce, but it was the vortex interaction with other parts of the car that made the downforce.

Only way we'd have seen the twin dive planes on the older R18s or the TS030 was probably if there was more than one street race or race at a tighter, twister track in the WEC, of which there were no street courses and no especially tight and twisty tracks. It was either Tilke-designed tracks, or faster circuits like Spa, Interlogos and Silverstone.

Or, maybe Audi have slid back a bit to the theme of "dirtying up" their car with dive planes and such to cut down on making different bodywork for sprint vs LM trim. But then again, I still expect the LM R18s to look quite a bit different than the current sprint oriented package. You don't throwaway know-how if you can apply to it the new generation cars.

[deltawing]

Originally Posted by chernaudi

......And I also wonder why the double dive planes returned. I don't think that the cars being 4 inches narrower would take away that much drag. However, if you look at the shape of the dive planes (like on the older R18s), they're functioning more as vortex generators/flow conditioners than as downforce producers. This is a principal that can be traced back at least to the Nissan IMSA GTP cars (if not further), where the dive planes made 400+lbs of downforce for less than 30 lbs of drag. The dive planes themselves only made about 60lbs of downforce, but it was the vortex interaction with other parts of the car that made the downforce.

Only way we'd have seen the twin dive planes on the older R18s or the TS030 was probably if there was more than one street race or race at a tighter, twister track in the WEC, of which there were no street courses and no especially tight and twisty tracks. It was either Tilke-designed tracks, or faster circuits like Spa, Interlogos and Silverstone.

Or, maybe Audi have slid back a bit to the theme of "dirtying up" their car with dive planes and such to cut down on making different bodywork for sprint vs LM trim. But then again, I still expect the LM R18s to look quite a bit different than the current sprint oriented package. You don't throwaway know-how if you can apply to it the new generation cars.

Very interesting points!

This year the rear floor is spec and to get decent numbers you need to throw a lot of air under it. Air that you don't have coming from the front as it is almost all taken and evacuated on the side of the car by the front wing and side exits. As you point out, the dive planes are actually vortex generators and what they do is create a vortex on the side of the car, which works like a charm in taking the flow from the side exists (behind the front wheels) spin it at 180 degree and stuff it right under the floor in front of the rear wheels, just perfectly on the diffusers' entrance.

Notice also the giant plate/fence/gurney that the car has on the lower side of the side exit - this way you feed the side vortex, "riding it", energizing it, without disturbing it.

If you notice from the test photos from here and there, Audi is setting the car with quite high front and low rear. The new spec floor is so sensitive on ride height and they are riding it as low as they can and perhaps as stiff as they can so it stays low all the time to get higher DF numbers.

[chernaudi]

The rear diffusers have been essentially spec on LMP1 and LMP2 cars for a while, since the tunnel type diffusers were allowed back in 2004. This year, with the cars being narrower, the tunnels are narrower correspondingly with the narrowed track width.

As mentioned, either Audi are exploiting the dive planes as vortex generators/flow conditioners, or they're using them more as tuning tools than they did the past couple of years.

And we do also have to consider that the front diffusers are adjustable wing elements now, too, and they also need favorable air flow to work as designed.

[chernaudi]

New video from the Paul Ricard test weekend:

https://www.youtube.com/watch?v=4j7yfx0laa0

[MyNameIsNigel]

Latest info released by Audi confirms that the new 4.0l V6 TDI makes use of one Garrett VTG turbo. That's not a surprise as such in view of Audi's decision to drop the ERS-H. It is furthermore officially claimed that the engine produces a power output in excess of 395 kW (537 PS).
(source: "Audi sports prototypes 2014" booklet)