Audi LMP1 Discussion

[TF110]

Maybe a rear driven hybrid would be a better option after hearing these statements? IMO- Now I think so, before I thought the 4wd option would be better. All of this can change though. Audi will get on top of it I'm sure. So was Lotterer speaking truthfully or was it something he felt that wasn't actually happening?

[chernaudi]

Lotterer's stint was the first one when the track was wet, which is where the e-tron had a huge advantage over the Ultra.

Interestingly at Mulsanne's Corner Facebook page, someone found a graph that showed that the Ultras and the #1 e-tron were competitive in terms of laptime once the track dried. Allan also said that the #3 Ultra was fast in the early dry phase and the #4 Ultra was fast in its last stint. This, and the differences between the #1 and #2 e-tron, does suggest that even individual cars were set up slightly differently. It also shows that in the dry right now that the e-tron doesn't have a decisive edge over the Ultra.

It seems that Audi may have to find a way to better modulate the electric power to the front wheels, which may be difficult with the way that the ACO has governed the power release (controlled by the electronic throttle), but it seems that they can adjust it. I do wonder if the current e-tron system has torque vectoring like the 911 GT3H and what Audi plan on using on some of their road cars, which seems to be a plus with their current road car pinion gear quattro system?

As far as the tire deal, Allan suggested that Michelin and Audi tried to develop tires that encompassed enough of the characteristics of both cars that they can be used on the Ultra and the e-tron interchangeably. Problem is, does the 911 GT3H use the same front tires as the RSR and other similiar 911s, or did Michelin develop bespoke tires for it? I do remember that at PLM in 2010 that the GT3H had tire problems early, but they made adjustments in tire pressure that fixed those issues.

[Articus]

On another important note.
Did anyone actually notice the E-Trons to be running in the pitlane on electric power only? Being in effect FWD.

I have seen videos of the Toyota in EV mode in the pitlane but i cant confirm for the E-Trons.

[chernaudi]

I'm not sure, but some Audi TV videos that have shown up on You Tube seem to indicate that the e-trons' engines were idling, but they didn't seem to be driving the rear wheels once the speed limiter is on. Problem is that listening to the videos doesn't help since the R18 doesn't make much noise. Maybe someone watched the onboards on Motors TV or from a good quality Audi TV stream can help.

[Articus]

This is the million dollar question haha. The Toyota engine starts up at pit exit. No one is really sure what the Audi is doing since its so quiet. Isn't Electric drive mandatory in the Pitlane for the Hybrids?

[gwyllion]

Audi runs on the combustion engine in the pit lane. The speed in the pit lane is limited to 60 km/h and a front hybrid system can only be used above 120 km/h. That sort of rules out running on electric motors in the pit lane.

Toyota does not have this limitation because they went for a rear hybrid system.

[gwyllion]

Originally Posted by chernaudi

Interestingly at Mulsanne's Corner Facebook page, someone found a graph that showed that the Ultras and the #1 e-tron were competitive in terms of laptime once the track dried. Allan also said that the #3 Ultra was fast in the early dry phase and the #4 Ultra was fast in its last stint. This, and the differences between the #1 and #2 e-tron, does suggest that even individual cars were set up slightly differently. It also shows that in the dry right now that the e-tron doesn't have a decisive edge over the Ultra.

Can you post an URL to that graph, for the people who are not on facebook?

In http://tentenths.com/forum/showthrea...43#post3070743 I calculated the average of 20% fastest lap times. Those calculations also show that the #2 was almost 1 second of the pace of the other 3 Audis.

[gwyllion]

The picture some of us have been waiting for: the 2012 carbon fibre gearbox.


The press release about Audi's light weight design: https://www.audi-mediaservices.com/p...tlichkeit.html

The ultra car is around 10% lighter than last year.

Evidently Audi is very proud of their gearbox.

Something like this has never existed in an LMP sports car before. What differentiates this design from a formula race car, in which this technology is already used, is that the fully structural transmission has to bear a much higher base load of 900 kilograms. In addition, it holds up to endurance distances of several thousand kilometers straight. And with more than 850 Newton meters the engine torque that acts on the transmission in the R18 clearly exceeds the corresponding torque level in a Formula One car.

A carbon fiber gas pedal is another example for their weight saving program.

[Adam43]

Mmmm.

[chernaudi]

Originally Posted by gwyllion

Can you post an URL to that graph, for the people who are not on facebook?

In http://tentenths.com/forum/showthrea...43#post3070743 I calculated the average of 20% fastest lap times. Those calculations also show that the #2 was almost 1 second of the pace of the other 3 Audis.

The FB post, which more or less confirms your information, and also includes comparisons between the Rebellion Lolas and the Pesca Dome:

http://www.facebook.com/photo.php?fb...type=1&theater

And on the R18 gearbox casing photos, are they using a cassette type gear cluster system, or does everything come out of the back of the gearbox though the differential cover?

Edit: More Spa performance graphs:

http://www.facebook.com/media/set/?s...6549099&type=1

[chernaudi]

Panullo Blog shows that the R18 e-tron's front brakes have swapped the position of the calipers and have a modified cooling shroud that covers the whole brake rotor:

http://lemansprototypes.over-blog.it...104562959.html

Anyone know if the Ultra has a similar set up or do they stick to the '11 R18 configuration?

[joeb]

850Nm of torque? That is some major grunt.

[Articus]

Why don't they put the caliper at the very bottom? for CoG reasons.

[Simmi]

On a bit of a side note - very cool to see the full airborne moment from LM last year on TV in Audi's extended advert. I've seen glimpses of the car in the past on TV but great to see that shot make the cut.

[gwyllion]

Originally Posted by Articus

Why don't they put the caliper at the very bottom? for CoG reasons.

Maybe this makes the brake cooling less efficient?

[Lasse]

From a CoG point that is a good idea, but have anybody ever done that? I don't remember seing such a setup.

[Tim the Grey]

If I recall things right, you want the caliper at 90 degrees to maximise Anti Dive. Top or bottom is mechanically less advantageous.
If it was any good, somebody would have tried it LONG ago...

[gwyllion]

Better late than never. George Achorn finally wrote his report of the Sebring test: http://fourtitude.com/features/Misce...tro-r18-ultra/

[Articus]

It’s known now that Timo Bernhard experienced some sort of equipment failure going into turn 17, that long right-hander that I’m told by the more experienced Mr. Lefebure is done flat out in a prototype like the R18.

There's no way this is actually true right? T17 is effectively a 180 degree turn right? And the radius isn't that big. How can they be doing it flat out even on a qualy lap? After just leaving the longest straight.

[PaulsF1]

Originally Posted by Lasse

From a CoG point that is a good idea, but have anybody ever done that? I don't remember seing such a setup.

In Formula 1 it's common to have such a setup:
http://www.racecar-engineering.com/w...1/UpRb7suz.jpg

[ronnie peterson]

Originally Posted by Articus

There's no way this is actually true right? T17 is effectively a 180 degree turn right? And the radius isn't that big. How can they be doing it flat out even on a qualy lap? After just leaving the longest straight.

It's true. They first brake and then steer the car through the apex flat out.

He probably meant the apex speed..

[gwyllion]

I am not sure if this information is correct, but according to LMR #73 the new monocoque is longer than last year.

source: http://www.vif-argent.fr/lmr73/#/8/

The latest Audi Sport press release confirms that the 2012 monocoque is indeed longer than last year.

Or because the monocoque has been stretched in forward length compared with the predecessor model. This shortens the crash structure in front of it which still has to successfully pass all crash tests, though.

source: https://www.audi-mediaservices.com/p...tlichkeit.html

[gwyllion]

Originally Posted by gwyllion

Jüttner explains that in Spa the hybrid system is activated at three locations on the track, that have been defined by the ACO. This contradicts Tréluyer who said that it is active after every corner. Laurent observes that the rules only state that the hybrid system can be activated when braking exceeds 2G for more than 1 second, and he reasons that these requirements might apply to these three locations.

The latest Audi Sport press release confirms that the FIA defines where the hybrid system can be activated.

At the same time, the number of braking zones is specified by the FIA for each track. The prescribed 58-liter fuel tank capacity of the hybrid vehicle is two liters less than that of the conventional car. Last but not least, the amount of energy that may be recuperated between two braking zones is limited to 500 kJ. “The FIA defines these intervention options for itself in order to create a balance between the hybrid vehicles and the conventional models. The effects vary from track to track and are difficult for us to judge at this point in time,” says Dr. Ullrich.

source: https://www.audi-mediaservices.com/p...tlichkeit.html

[Adam43]

Originally Posted by ronnie peterson

It's true. They first brake and then steer the car through the apex flat out.

He probably meant the apex speed..

That is not my idea of flat out! "I took that corner flat out, after I'd slowed down enough to do so".

[Tim the Grey]

I suspect Flat Out, i.e. Top Wack Speed, and Foot Flat to the Floor are getting lost in translation here?