Audi LMP1 Discussion

[gwyllion]

Wurz explained that the hybrid system was not working to its full potential on his car during the first 3 laps. See http://tentenths.com/forum/showthrea...83#post3095783

[henk4]

Mike Fuller knows a lot about aerodynamics and can be considered an expert in that field. That, however does not make him an expert on every other aspect of long distance racing.

[chernaudi]

Someone has also posted graphs on his page these graphs comparing pit times, average stint speeds, and pit stop times vs in/out laps. The comparison is initially between the #1 Audi and #7 Toyota, and then some graphs compare the #1 and #2 R18s:

http://www.facebook.com/media/set/?s...3615384&type=1

According to those graphs, Audi had a big edge in pit stop times, 1-2 laps per stint over Toyota, but Audi from the fourth stop on hemorrhaged time to the Toyota as far as in/out laps, which could down to the aforementioned issues with tires not coming up to temperature. If Toyota were able, in part to short stints (think Audi quadruple stinting tires in '11 while running 11 lap stints vs Peugeot triple stinting on 12 lap stints), were able to skip a tire change, that's about an other 20 seconds gained, and it seems that Audi once the sun started to lower and temps cooled down, they struggled with tire temps, while Toyota made a better tire compound selection for the conditions, again a-la Peugeot in 2011 during most of the nighttime hours.

[gwyllion]

Your link does not work without a facebook account. Can you try to post direct links to the images?

[Velociraptor]

I suspect Audi was sandbagging primarily so ACO wouldn't restrict diesels any further. Also to deny Toyota any excuse to complain ...
I'm guessing here but I'll bet neither of the 4 R18s was doing 100% laps. There was no visible smoke and Ultras matched or slightly bettered e-trons in fastest laps. According to Toyota their Hybrid drive is worth several seconds a lap... I'm thinking 3:23s was possible for e-trons

[gwyllion]

According to Audi the difference in performance between the e-tron quattro and ultra was around 0.4 sec in Le Mans. This is confirmed by the difference in average lap time (between #2 e-tron quattro and #3 ultra) that I calculated earlier .

[henk4]

Originally Posted by gwyllion

According to Audi the difference in performance between the e-tron quattro and ultra was around 0.4 sec in Le Mans. This is confirmed by the difference in average lap time (between #2 e-tron quattro and #3 ultra) that I calculated earlier .

a splendid case of the economic law of diminishing returns....

[adrs2k]

I think Audi played the cards they were dealt. Race just hard and fast enough to win. It would have been useless to push 100% as there was no real competition. Nobody expected Toyota to finish the race, much less have a chance to win it this year...well at least I never expected it (no disrespect to Toyota).

I think of it this way, next year Audi will use the same cars and only need to do minor tweaks to this years car. Only show enough pace to win to prevent any major rule changes. Keep this years speed to a just enough pace so when Toyota comes back stronger next year, Audi is already ready for them. I think it also can save Audi a lot of money by not showing their cards this year. IF they pushed 100% and we saw even more speed I bet the rules would be changed again for next year, and Audi would have to spend more money to get the speed back.

So I think Audi did what they needed to win and be in a good position for next year. Rule makers, Toyota, and others probably think the formula is not all that far off and no major changes are needed for next year. I think it would be extremely foolish to change the rules for next year based on Toyota vs Audi this year as Toyota has very limited running under their belt and arent even close to unlocking their cars potential.

[gwyllion]

There are five more WEC races on the calendar this year. This will give the ACO and FIA plenty of useful data to better judge the current balance of performance.

Toyota will keep improving the car and with the shorter race reliability should not be an issue. Hence Audi will have to up their game in order to stay ahead. I doubt that Audi can keep hiding their true performance.

[chernaudi]

Well, let's wait until Fuji, where Audi and Toyota will likely run their LM bodywork (Fuji has that mile long front straight and has a lot of slow corners on it now since Tilke worked on it, and Fuji's like Paul Ricard in that way) and lets see if Audi drops the hammer or if they sandbag and only run fast enough to hold Toyota at bay, which is the popular perception at Le Mans, that Audi only ran fast enough to win.

Also, with the ACO's rules on hybrids, it would be interesting to see what the TS030 can do without it's hybrid system--I think that the ACO have tried hard under the pre-2014 regs to not give the hybrid cars much more than a theoretical (very slight) advantage, unlike the diesel regs. I don't think that a TS030 over a flying lap on clear track would be much slower without the hybrid system--yes, acceleration would be better, but power is nothing without control (at least according to the Pirelli ads on TV during F1 races), and I do think that even with the TC that some of the power and torque out of the hybrid system on the Toyota does go to waste though wheelspin and traction issues, not that Audi wouldn't have similar issues with the e-tron in a corner under certain conditions, which is why I favor a limiter for both Audi and Toyota of about 100km/h--at least then out of slow corners the car might be pointing straight when the power kicks in.

I really think that there's not a huge advantage or disadvantage to the hybrid systems right now--Audi and Toyota use it for a power boost, the R18 e-tron was only about half a second a lap on average faster during the race, on a flying lap the cars perform virtually the same, the e-tron and Ultra were capable both of 12 lap stints, and the TS030, for whatever reason, got it seems poor fuel mileage with many of it's 9-10 lap stints, and only ran a few 11 lappers thought out their time at LM (lack of DFI doesn't help, but there has to be another reason, since in reality Rebellion are running a de-tuned version of the TS030's engine and they ran longer stints).

As for the graphs, I don't know how to direct link, because those who don't have a Facebook account will likely have the same issues if I linked to an individual graph, but they did show essentially what I described in my post about it: Audi had faster stops, could run further on fuel than Toyota to the tune of usually 1-2 laps, but got murdered from the forth stop on as far as in/out lap times until the #7 Toyota went out of contention.

[gwyllion]

Originally Posted by chernaudi

the e-tron and Ultra were capable both of 12 lap stints, and the TS030, for whatever reason, got it seems poor fuel mileage with many of it's 9-10 lap stints, and only ran a few 11 lappers thought out their time at LM.

Except for the opening stint, which includes the lap to the grid and the formation lap, both Toyota were consistently doing 11 lap stints

	Driver	Laps	Average lap time
1	Wurz	31 = 9+11+11	3:31.701
2	Lapierre	54 = 11+11+11+11+10	3:30.737
3	Nakajima	28 = 8+5+11+4	3:38.636
4	Wurz	21 = 11+10	3:35.499

On his second stint Sarrazin can in a lap early, such that the two cars would not pit at the same lap.

	Driver	Laps	Average lap time
1	Sarrazin	30 = 9+10+11	3:32.463
2	Buemi	44 = 11+11+11+11	3:31.308
3	Davidson	8 = 8	3:32.576

Furthermore, as I showed earlier the e-tron quattro could only manage 11 lap stints when they were pushing.

Originally Posted by chernaudi

(lack of DFI doesn't help, but there has to be another reason, since in reality Rebellion are running a de-tuned version of the TS030's engine and they ran longer stints)

You already gave the answer. The Toyota engine in the Rebellion produces less power and hence uses less fuel.

You also seem to forget that the factory Toyota has a smaller fuel tank. Rebellion Lola can do 12 laps with 75 liter, so they use 6.25 liter/lap. The TS030 only has 73 liter, so it can do 73 liter / 6.25 = 11.7 laps with a full tank.

[Articus]

The first lap of Le Mans shows that the Toyota is reduced to a lmp class B petrol without its hybrid system. The System had a glitch for the first 3 laps. And McNish blew by like the Toyota was standing still.


Also I dont think theyll have traction issues. Just because they can use the system at any speed doesnt mean they use in the lowest speed stuff. And at a place like Le Mans theyre are not many places where they go slow enough that traction is an issue. Im not sure thye are using first gear wear traction isseus might arise. Also they have a traction control system that is resumable integrated with the hybrid system. The boost is controlled electronically and inteligently. Its not just dumped out to let the wheels spin.

[chernaudi]

The #1 Audi after the first few hours of the race usually ran 11 lap stints, where as the #2 commonly ran 12, and I think that they were trying to use that as a trump card, but it does sort of balance out--the #2 could stay on track longer, but the #1 would have to spend less time in the pits for fuel only stops (less time to fill up the tank). Ben said in his website piece that late in the race that the #1 team reverted back to the strategy they had in '11, which was 11 lap stints and to push hard, while it seemed that the #2 was hoping that the one lap longer that they could manage without much time loss would swing things in their favor, that was until McNish's spin and the fact that they lost a lap due to repairs and basically gave the #1 Audi a free splash of fuel under that yellow at least (I think that the final driver change was done under that yellow, as with the #2 in the garage they had plenty of time to do it and not lose anything), as well as several laps at pace car speed to save fuel.

It still doesn't help Toyota out even if they could go 11 laps because Audi could back off a bit and do 12 if they had to, or they could push and still be on the same 11 lap cycle as Toyota were. And it doesn't seem that the hybrid system was a big help with fuel consumption, especially as the Toyota's engine goes into hibernate (shut down) mode when the pit speed limiter is on, which controls the hybrid system for on/off pit road per rules for RWD hybrids. Audi, with their quattro system, doesn't have to abide by that restriction (they probably could, but it's not required for FWD systems), but the problem is that the pit road is only about the length of the front straight, which at LM isn't very long, and at 8.5 miles and with over 85% of the lap at or near full throttle, it takes longer for the savings to snowball.

We probably won't see any major savings as far as fuel mileage goes until we get to the smaller circuits for both Audi and Toyota, but even then it'll probably be a nickel and dime deal, as it's more stop and go and less constant throttle position, and fewer regeneration/activation zones.

As long as the hybrid systems are as puny as they are and as long as Audi and Toyota use it for a power boost in traffic, etc., we probably won't see any fuel economy gains of note. For instance, almost all of Audi's gains were done in the dyno room with the engine, not the hybrid system.

[gwyllion]

Originally Posted by chernaudi

It still doesn't help Toyota out even if they could go 11 laps because Audi could back off a bit and do 12 if they had to, or they could push and still be on the same 11 lap cycle as Toyota were.

Toyota would still spend less time in the pits, if they could have continued quadruple stinting the tyres: 44 laps between driver changes is better than 36 laps. This strategy helped Audi to its victory last year.

Note that Audi did not manage a quadruple stint this year at all.

Originally Posted by chernaudi

And it doesn't seem that the hybrid system was a big help with fuel consumption, especially as the Toyota's engine goes into hibernate (shut down) mode when the pit speed limiter is on, which controls the hybrid system for on/off pit road per rules for RWD hybrids.

Toyota is not required from the rule book to run on electric power in the pitlane. It is their own choice! According to Toyota this helps them save some fuel, it is more gentle on the clutch and the car accelerates more quickly to pitlane speed limit because the peak torque of the electric motor is available at 0 rpm.

Originally Posted by chernaudi

Audi, with their quattro system, doesn't have to abide by that restriction (they probably could, but it's not required for FWD systems)

Audi is not allowed to run on electric power, because the speed in the pitlane (60 kph) is lower than 120 kph.

[TF110]

I don't see how refiring the engine at the end of the pit lane would consume more fuel than running the engine on the pitlane. So I agree with gwyllion there. We'll see how this plays out at Silverstone, but that is a very high speed track even with the new layout. Average speeds are around 200kph and it's got plenty of straights. I think Toyota will be very strong there, and if they can repeat the tire strategy Audi should have a fierce battle on their hands.

[gwyllion]

Originally Posted by gwyllion

http://www.motorsport-total.com/wec/..._12062210.html reveals that the #1 Audi could not use the hybrid system to its full potential during the complete race. The system stopped working twice and this was solved by a software reset in the subsequent pitstop. On the #2 Audi the hybrid system worked flawlessly.

In http://www.autosport.com/news/report.php/id/100765 Wolfgang Ullrich gives more information regarding the technical issues with the hybrid system on the #1 car.

If someone thinks that the winning car — which was one of the quickest in the race, including the last hours — was running without full power, I am honoured.

The mode we had chosen to be the best for the race was running out of function and we had to reboot the computer system to make it run in the mode we wanted twice during the race.

It did not cost time because it is something you can do in the pitstop. There is also something called a safety mode and we then went into this mode to make sure we could run to the end without a problem.

It is a mode in which the system works but not in the mode that we thought was best for the race. On any electronic system you have a default mode in which it runs safely.

Ullrich would not reveal when they switch the hybrid system to the safety mode, nor how much the system is tuned down in this mode.

[Creep89]

So they had the hybrid boost all the time - but not the preferred mode they have made for the race?

[henk4]

The #7 Toyota is at the Goodwood Festival of Speed. We spoke with somebody from the German Toyota outfit, and he came up with an interesting titbit, namely that Michelin had been unable to prepare tyres specifically for the Toyota. In stead they have been running Peugeot spec tyres sofar.

And the Toyota at the FoS is the real thing, the Audi #1 shown is not the real car but one of the four test cars, dressed up as number one. (There is also no hybrid stuff fitted...)

And talking about budgets...Audi has built four R18/2012 for testing purposes (one is now a write-off, injuring Timo Bernard) and the Spa/Le Mans were four news tubs. Toyota had big trouble completing their third tub in time for LM...

[Articus]

Of course Dallara has a wealth of experience in LMP composites so they have a process and molds for making Audi tubs in a shorter amount of time but toyota makes their own tubs and don't have that much experience with it. The manufacturing process will be optimized in the future if they continue however.

[R4z3rw33n]

Originally Posted by henk4

And talking about budgets...Audi has built four R18/2012 for testing purposes (one is now a write-off, injuring Timo Bernard) and the Spa/Le Mans were four news tubs. Toyota had big trouble completing their third tub in time for LM...

Makes one wonder how (much more) competitive Toyota would/could be, if they were invested to a greater extent.

[chernaudi]

Audi is not allowed to run on electric power, because the speed in the pitlane (60 kph) is lower than 120 kph.

Again, if Toyota's system is controlled by the pit road speed limiter and software in the car's ECU, why can't Audi do the same? The ACO seem to be pretty willing to bend their own rules when Audi or Peugeot or other factory teams came up with stuff in the past, and you can't tell me that there can't be a lock out on such a software item that will only deactivate when the pit road speed limiter is on.

And when did this "hybrid system only on pit road" rule get dropped? Wasn't that supposed to be a feature of hybrid cars that they had to run on pit road only on electrical power and that Hope Racing had major issues with that last year? I basically see the FWD hybrids not having to run on electrical power on pit road as a get out of jail free card to prevent what happened to the #7 Toyota when the engine wouldn't re-fire at pit out when the speed limiter was turned off.

But then again, if Toyota never had to run in the pits with the hybrid system alone providing power, why didn't they put in place a fail safe mode that kept the #7 from stalling at pit out, unless the hybrid system's issues completely shorted out a major electronic bit. After all, as we know now, Audi had a redundancy system built into their system (the safe mode referenced).

I do think that the ACO wavering with the hybrid rules (no more need to use the systems on pit road and letting Audi and Toyota use it purely for power boosting) does smack a bit of F1--only difference is that at least Audi and Toyota, as these are endurance races, don't have to over charge their systems to get power out of them, which isn't green at all, let alone not cheap, as the F1 KERS systems have to rebuilt almost from scratch after each race and the batteries thrown out.

As for Silverstone, if Toyota are gonna be stuck with Peugeot's tires, we have to remember that I don't think that Audi or Peugeot ever did more than double stint in the shorter races, and I don't know if they can get an advantage out of it--they seemed in certain conditions to be struggling with those diesel tires.

And even if TMG get their own tires, that can be a doubled edged sword--the newer tires might be grippier, but would also probably wear out faster as it's built around their car's performance specs, not the Audi or Peugeot diesel cars'.

And for TMG's tub issues, we have to remember that Toyota only signed off on the program about 9 months ago, and TMG have been loaded with customer/sub-contract work. Of course, there's been murmurings about what Toyota's future beyond next year will be, and even what course they'll take for 2013 with TS030 improvements--I can't see them running an all new tub or an all new engine next year. This isn't like F1 where you can sustain things by building newly designed cars every year though, ironically, Audi stopped short of doing that this year, as the 2011 and 2012 R18s only share the basic engine, gearbox internals, and wheel and tire dimensions with each other, everything else it seems has been modified or updated, often times substantially, such as the tub.

[Holt]

Originally Posted by gwyllion

In http://www.autosport.com/news/report.php/id/100765 Wolfgang Ullrich gives more information regarding the technical issues with the hybrid system on the #1 car.

Ullrich would not reveal when they switch the hybrid system to the safety mode, nor how much the system is tuned down in this mode.

Well, the mystery is solved.

It was very odd how fast Toyota caught the Audis and passed them after consistently falling to 60 seconds back after the first few hours.

The #1 Audi's Hybrid system must not have been working allowing the Toyota to catch it. At first everyone was saying this sudden change in speed was because of better tire wear on the Toyotas. But the Toyotas had already changed tires and did not catch the Audis toward the end of the first set of tires.

Watch the #1 and Toyota battle for the lead again. Exiting the 2nd chicane the Toyota is WAY back, but somehow he draws even with the Audi halfway to Mulsanne corner?

And then the Toyota passes the Audi like its standing still out of Mulsanne. And again the Toyota passes the Audi like it's standing still out of Arnage. At first I thought this was just a superior hybrid system by Toyota.

http://www.youtube.com/watch?v=VfvkKRmd2X8

But it's now my belief the #1's hybrid system was not working at that time. I think a careful study of the laptimes can reveal when it was down.

[chernaudi]

Toyota was much faster down the straights at times, too, to th tune of 3-5 mph on average. I still think that Audi tire strategy had an impact more than the hybrid system issues--the Ultra on average was only about .5 or less of a second a lap slower in race trim than the e-tron hybrid.

[gwyllion]

Originally Posted by chernaudi

And when did this "hybrid system only on pit road" rule get dropped? Wasn't that supposed to be a feature of hybrid cars that they had to run on pit road only on electrical power and that Hope Racing had major issues with that last year?

No such rule ever existed. You are probably confused by the pitlane test which is used to homologate a car as a hybrid.

To be considered as hybrid, an LMP1 car must be able to move along the whole length of the pit lane (minimum 400 m) at 60 kph using only the electric motor or the flywheel system.
The test must be carried out for the homologation of the car in the pit lane of the "24 Heures du Mans" circuit. During the test, the energy used will be measured and after the test, the weight of each element of the energy recovery system will be checked and indicated on the Homologation Form of the car. These elements must equip the car permanently and must be at the weight indicated on the Homologation Form. A new test must be carried out for any weight modification of these elements.

In 2011 Hope Racing did not pass this test the first time, so it had to be rescheduled.

This rule does not imply at all that hybrids must always drive on electric power in the pitlane. As I explained, Audi is not allowed to do this because under normal conditions the hybrid system can not active below 120 kph.

[gwyllion]

Originally Posted by gwyllion

It seems that Paul Truswell is preparing his analysis of the 2012 24 hours of Le Mans.

In http://trussers.blogspot.com/2012/06...t-le-mans.html he observes that Audi changed the driver rotation of the #1 and #2 car during the race. It is known that Treluyer had a bad cold and Capello probably preferred not to drive during the night because his eyesight is not that good anymore.

In http://trussers.blogspot.com/2012/06...mparisons.html Paul gives some more statistics. He concludes that Lapierre did the fastest stint during the first 5 hours of the race and McNish of the complete race.