Audi LMP1 Discussion

[gwyllion]

Williams Hybrid Power has just announced officially that they are the supplier for Audi's hybrid system: http://www.williamshybridpower.com/n...-by-audi-sport

For the Audi R18-H, WHP has designed an entirely new, ultra-lightweight electric flywheel and associated power electronics and the company has worked closely with Audi engineers to fully integrate its unique electric flywheel into the car. The system will provide 150kW of power and have a top rotor speed of 45,000 rpm.

I wonder how "entirely new" the flywheel is. The flywheel can spin up to 45K rpm. In comparison, the 911 flywheel could rev up to 40K rpm, but at the 2010 Nurburgring 24 hours Porsche ran it between 28K-36K for safety reasons (source).

The press release also lists the benefits of their flywheel accumulator compared to other technologies such as batteries, ultra-capacitors or mechanical flywheels.

The main benefits of the WHP system are a high power density and correspondingly low mass, high efficiency energy transfer to and from the e-storage, the ability to continuously deep power cycle and an insusceptibility to performance or life degradation over a wide range of operating temperatures. In short, the technology is perfectly suited to the high performance demands of endurance racing.

[Articus]

Originally Posted by knighty

so despite all the quattro marketing bull........its really not going to help in low speed corners, which is where you need 4wd........the rear based systems can activate at any time, so Toyota may be on the money by developing both options and choosing the best performer.

I dont really think they need help in the low speed corners do they? They already have a torque advantage. So putting a hybrid drive there would just spin the tires and be useless. I suppose it helped that there was this inevitable marketing push....Probably alot easier to ask for money when you start using some of the brands commercial names on the race car, e-tron, ultra, quattro....

[Razgriz8484]

Originally Posted by Articus

I dont really think they need help in the low speed corners do they? They already have a torque advantage. So putting a hybrid drive there would just spin the tires and be useless. I suppose it helped that there was this inevitable marketing push....Probably alot easier to ask for money when you start using some of the brands commercial names on the race car, e-tron, ultra, quattro....

I thought I read somewhere that one area the R18 could have improved was slow corner grip? I can't remember where I read/heard this at. Was probably somewhere in this thread

[Articus]

Maybe, I read about that in the Imola round but putting the hybrid power to the rear wheels would make that even worse correct?

[chernaudi]

That was probably part of the rumored/suspected front suspension redesign--if they were going to use front wheel electric motors, you'd need to have some hefty mechanical grip to harness that power, no matter the speed. And Audi wanted to have improved mechanical grip to make the R18 better in slow corners and maybe go back to the R8 like characteristics where the mechanical grip works more in concert with the areo grip, and not be so aero dependent.

And the R18 e-tron and the R18 Ultra are supposed to be virtually the same aside from the hybrid system.

So Audi may've killed two birds with one stone, at least in theory.

[gwyllion]

A while back I tried to calculate the theoretical benefit from a hybrid system under the current LMP1 rules, by comparing the energy from the fuel with that electric energy from the KERS. In my analysis I assumed 7 charge/discharge cycle for every lap around the Le Mans circuit. See http://tentenths.com/forum/showthrea...40#post3017840

Someone on the EI forum did similar calculations, but he assumed only 5 KERS activations per lap. See http://endurance-info.com/version2/f...202585#p202585
Remark: his numbers for diesel powered cars are wrong because the fuel tank is 58 liter for hybrid diesels and 60 liter for non-hybrid diesels.

It seems that I underestimated the number of braking zone at Le Mans. The Autocar article about the R18 e-tron quattro suggests around 10 cycles per lap. This means that flywheel accumulator has to be "able to cope with 3600 energy 'cycles' (charge/de-charge) per 24-hour race."

[CTD]

Originally Posted by chernaudi

That was probably part of the rumored/suspected front suspension redesign--if they were going to use front wheel electric motors, you'd need to have some hefty mechanical grip to harness that power, no matter the speed. And Audi wanted to have improved mechanical grip to make the R18 better in slow corners and maybe go back to the R8 like characteristics where the mechanical grip works more in concert with the areo grip, and not be so aero dependent.

And the R18 e-tron and the R18 Ultra are supposed to be virtually the same aside from the hybrid system.

So Audi may've killed two birds with one stone, at least in theory.

What will be interesting is if the R18 Ultra has instead of the hybrid system to weight down the front...
The basic front setup (with more mechanical drop of course) weights less than the hybrid one. If the Ultra is virtually the same, it either needs additional weight in the front, or somehow shifted some of the rear weight forward.

In any case, the Ultra will probably have a better weight distribution than the e-tron and therefor better breaking into and through the corners.

[gwyllion]

Audi will just put 80 kg of ballast in the nose of the ultra, where the electric motors are located in the e-tron quattro. This ballast can be moved around to the liking of the drivers.

[gwyllion]

http://www.86400.fr/articles/207-aud...attro-au-mans- has some short comment from Baretzky about the 2012 diesel engine.

According to Ulrich Baretzky, the head of engine department at Audi Sport, it has been widely reviewed and improved to adapt to smaller restrictor. "We redesigned the process of combustion and gas exchange." The diesel engine is now lighter than the 2000 V8 TFSI!

Dr. Ullrich is convinced that the diesel engine now is at a disadvantage, because of the rule changes during the winter. He believes that the ACO and FIA will take the right decision in the future. So Audi is hoping for some BoP breaks after Spa?

[chernaudi]

I don't think that Audi will be at any severe disadvantage at all, since TMG has to run the same size restrictor that Rebellion's Toyota engines do (if Rebellion ran one restrictor like TMG's engine does), and the R18 will still have a sizable torque advantage, being a diesel, and the fact that the diesel engine has so much more torque probably governed the choice to run the power to the front wheels.

That, and Audi at Sebring in '09 when they won was using about 10% less power in the R15 than the R10 a year earlier, and had a draggier car, but were still much faster than the R10 was at Sebring, and Audi was faster with a 6% power drop with the same car in testing in late '09/early '10 with the same basic R15 than they were that March.

Audi and Peugeot showed time and time again that no matter how much the ACO tried to ratchet the diesels or help out the gasoline/privateer contingent, they still went even faster than previously if anything, and I wouldn't expect anything different this time around.

[gwyllion]

Originally Posted by gwyllion

I also noticed this. http://www.akrapovic.com/ promotes that they are an Audi Sport partner and that Audi won the 24 hours of Le Mans in 2010 and 2011 with an Akropovic exhaust system.

Akrapovič just officially announced its partnership with Audi: http://www.akrapovic.com/news/2012/m...l-partnership/. Apparently they have supplied the exhaust for Audi since 2009.

Crafted from a specialised titanium alloy, the high-performance system is 40 percent lighter than a stainless steel equivalent to further enhance the performance and handling of the Audi R18s. The special alloy material also has outstanding heat-resistant properties and durability – both crucial in the punishing field of endurance racing.

[Dead-Eye]

Originally Posted by gwyllion

A while back I tried to calculate the theoretical benefit from a hybrid system under the current LMP1 rules, by comparing the energy from the fuel with that electric energy from the KERS. In my analysis I assumed 7 charge/discharge cycle for every lap around the Le Mans circuit. See http://tentenths.com/forum/showthrea...40#post3017840

Someone on the EI forum did similar calculations, but he assumed only 5 KERS activations per lap. See http://endurance-info.com/version2/f...202585#p202585
Remark: his numbers for diesel powered cars are wrong because the fuel tank is 58 liter for hybrid diesels and 60 liter for non-hybrid diesels.

It seems that I underestimated the number of braking zone at Le Mans. The Autocar article about the R18 e-tron quattro suggests around 10 cycles per lap. This means that flywheel accumulator has to be "able to cope with 3600 energy 'cycles' (charge/de-charge) per 24-hour race."

10 sounds about right. I count the following braking zones:
- Dunlop Chicane
- Esses
- Tertre Rouge (slightly)
- Mulsanne Chicane 1
- Mulsanne Chicane 2
- Mulsanne Corner
- Indianapolis
- Arnage
- Porsche Curves (two braking zones)
- Ford Chicane

I don't know if it makes sense to count the Porsche curves and Indianapolis/Arnage separately, because they aren't on the power for long between the braking zones.

[NelisB]

Ok I tried to layover the 2 audi r18 photos to see where there are any differences. The images don't really match up perfectly but enough to see where the 2 cars differ.
First thing I notice is the lower wing on the Hybrid. I think this is the low downforce setup for le mans and maybe Spa?
The second this is the front fenders on the new car are less round. They have more of a blunt edge to them.

I probably have missed a couple of things so here's the image.

[chernaudi]

#3 Audi is a 2011 spec car that will run Sebring--remember in the release, the only notable difference between the e-Tron and the Ultra is the presence or not of the hybrid system.

[alexkiller8]

Originally Posted by Dead-Eye

10 sounds about right. I count the following braking zones:
- Dunlop Chicane*
- Esses
- Tertre Rouge (slightly)
- Mulsanne Chicane 1*
- Mulsanne Chicane 2
- Mulsanne Corner
- Indianapolis (only second part)
- Arnage
- Porsche Curves (two braking zones)
- Ford Chicane* (only the first chicane)

I don't know if it makes sense to count the Porsche curves and Indianapolis/Arnage separately, because they aren't on the power for long between the braking zones.

i guess that these are the only turns where the r18 (and lmp at all) run under 120km/h in reacelleration, usefull to use the kers (at least for r18, because if hybrid of toyota will be rear powered it may be used wherever). And in my opinion the turns with * in no-traffic condition may be ran over 120km/h.

[Articus]

The Sebring R18's will be get weight penalty...Combine that with the new HPD which is reportedly on point and suddenly you have the makings of an upset.

Also the Toyota isnt using the same engine as the rebellion. So even with the same restrictors the new Toyota engine is supposed to be more powerful, more torque, better driveability...Combine that with cut back to diesel power and suddenly it looks like a very different battle at Le Mans.

[TF110]

If it stays dry for most of LeMans, Toyota's rear drive hybrid might give them the torque to make up for the advantage of a diesel? And the capacitor storage compared to the flywheel, I calculated 67hp for 10seconds from 500kilojoules... between each braking zone. How about the flywheel?

[gwyllion]

Originally Posted by TF110

If it stays dry for most of LeMans, Toyota's rear drive hybrid might give them the torque to make up for the advantage of a diesel?

Maybe, it can match the torque of the R18 ultra, but not of the R18 e-tron quattro.

Originally Posted by TF110

And the capacitor storage compared to the flywheel, I calculated 67hp for 10seconds from 500kilojoules... between each braking zone. How about the flywheel?

Exactly the same. 500 kJ stays 500 kJ respectively of the storage type.

Anyway, the front axle motors of the R18 generate 2 x 75 kW = 150 kW ~= 200 hp. 500 kJ of recovered kinetic energy will be released in 3.33 seconds.

[AGD]

Originally Posted by knighty

perhaps they both might start to lobby the FIA/ACO in order to let the hybrid systems stretch develop, but if the y do I think they should reduce the fuel allowance further, as it should add fuel economy, not performance......hmmmmm

If there is a fuel and performance advantage to be gained, why not allow both? I know this is dangerous free thinking for a Bolshevik racing world. But, hey, innovative thinking....DeltaWang....ohhhhh yeah!

Originally Posted by knighty

so despite all the quattro marketing bull........its really not going to help in low speed corners, which is where you need 4wd........

Marketing bull in racing? Unpossible!

[AGD]

Originally Posted by The Badger

I reckon its the nicest livery Audi have had for ages .

Indeed it is. I would say that it is the best factory livery Audi has put on an LMP. Of course, that's a bit like saying that PBR is the best tasting beer at a hipster bar, isn't it?

[gwyllion]

http://www.dailysportscar.com/viewAr...39A784A2F4EC73 has interviews with Oliver Jarvis, Marcel Fässler, Timo Bernhard, Marco Bonanomi and Romain Dumas. Great stuff!

Some interesting facts:

• the release rate of the hybrid system (short burst vs smoothly over a longer time) can be changed depending on the track characteristics
• they have not yet done a 24 hour endurance test
• the decision to run only one hybrid car after Le Mans can still be changed
• they balance the car better because of the weight reduction
• the side pods are lower
• they have a rear view camera now, but the visibility to the right is still terrible
• Bernhard and Dumas are not in the hybrid version because they are involved in the Porsche 2014 program

[CTD]

Originally Posted by gwyllion

http://www.dailysportscar.com/viewAr...39A784A2F4EC73 has interviews with Oliver Jarvis, Marcel Fässler, Timo Bernhard, Marco Bonanomi and Romain Dumas. Great stuff!

Some interesting facts:

• the release rate of the hybrid system (short burst vs smoothly over a longer time) can be changed depending on the track characteristics
• they have not yet done a 24 hour endurance test
• the decision to run only one hybrid car after Le Mans can still be changed
• they balance the car better because of the weight reduction
• the side pods are lower
• they have a rear view camera now, but the visibility to the right is still terrible
  
• Bernhard and Dumas are not in the hybrid version because they are involved in the Porsche 2014 program

Sounds a bit strange, but makes a lot of sense.
Personally i would have taken in new drivers instead.

[gwyllion]

Originally Posted by CTD

Sounds a bit strange, but makes a lot of sense.
Personally i would have taken in new drivers instead.

That is my interpretation of the conversation with Dumas

And one cheeky question – is he involved in Porsche’s planned LMP1 return in 2014? “I’m at an Audi presentation,” he smiled. “I’m very fortunate to have a contract with both manufacturers, and it’s a nice situation; but perhaps you can understand why I’m not in the hybrid!”

[Dead-Eye]

Originally Posted by alexkiller8

i guess that these are the only turns where the r18 (and lmp at all) run under 120km/h in reacelleration, usefull to use the kers (at least for r18, because if hybrid of toyota will be rear powered it may be used wherever). And in my opinion the turns with * in no-traffic condition may be ran over 120km/h.

They can still use the hybrid drive though, as soon as they get beyond 120. That's still beneficial, just not as massive an advantage as it would be at slower speeds.

[alexkiller8]

Originally Posted by Dead-Eye

They can still use the hybrid drive though, as soon as they get beyond 120. That's still beneficial, just not as massive an advantage as it would be at slower speeds.

sure i used you same logic, but the batteries charge after a brake and i guess huge brake = huge charge, so is more probable that kers will activate after those slow points