Audi LMP1 Discussion

[cokata]

Originally Posted by Chuliandred

Interesting note from the new edition of German motorsport magazine Pitwalk. They state that Audi increased the engine power by 21 hp while significantly reducing the weight.

Additionally, the write that the flywheel-hybridsystem has its limits at 3,4 megajoule. Sadly it is not clear if that per lap (which would be quite bad from my point of view) or if its the maximum capacity they can store in one point of time (which would be quite good). I think it should be the latter variant as I can't see them stepping up to the 4Mj class without being able recuperate the maximum amount of energy.

Third they magazine states that all three manufactures have some kind of connected suspension similar to Porsches last year version. Especially, for Audi it allows them to use a much harder suspension setup which in combination with their high downforce level results in the extraordinarily good tire wear like we saw in Spa. I guess we will see quadruple and penta stints quite commonly this year. More stints is sadly capped by the drive time limits ^^

Can't be done with a single flywheel.

[MyNameIsNigel]

Audi's flywheel storage capacity is reported to have been improved to about 700kJ for 2015 compared to about 600kJ in 2014. That should be sufficient to recover at least 4MJ at LM considering multiple charge-discharge cycles. I doubt that Audi would have made the jump to 4MJ had they not been able to recover as much.

[Chuliandred]

Originally Posted by MyNameIsNigel

Audi's flywheel storage capacity is reported to have been improved to about 700kJ for 2015 compared to about 600kJ in 2014. That should be sufficient to recover at least 4MJ at LM considering multiple charge-discharge cycles. I doubt that Audi would have made the jump to 4MJ had they not been able to recover as much.

Than the reported 3,4 Mj seems quite strange to me. I will ask the editor directly how he came up with this number and how he explains Audi stepping up 2Mj without beeing able to fully utilize them.
Tanks for the capacity numbers Nigel.

[MyNameIsNigel]

Originally Posted by Chuliandred

Than the reported 3,4 Mj seems quite strange to me. I will ask the editor directly how he came up with this number and how he explains Audi stepping up 2Mj without beeing able to fully utilize them.
Tanks for the capacity numbers Nigel.

That quoted figure may potentially be the maximum that Audi could achieve last year. That's about what Audi were supposed to harvest/release back in 2012-2013 when energy release was limited to 500kJ for each of the seven hybrid zones that were defined at LM (i.e. max 3.5MJ per lap).

[Chuliandred]

Originally Posted by MyNameIsNigel

That quoted figure may potentially be the maximum that Audi could achieve last year. That's about what Audi were supposed to harvest/release back in 2012-2013 when energy release was limited to 500kJ for each of the seven hybrid zones that were defined at LM (i.e. max 3.5MJ per lap).

Yes, I had the same thoughts. I asked the editor on their facebook page. Maybe he clarifies the numbers. But if he really writes numbers of past years as todays maximum capabilities it is the last time I bought the magazine

[MyNameIsNigel]

Originally Posted by Chuliandred

Yes, I had the same thoughts. I asked the editor on their facebook page. Maybe he clarifies the numbers. But if he really writes numbers of past years as todays maximum capabilities it is the last time I bought the magazine

[hcl123]

Originally Posted by MyNameIsNigel

That quoted figure may potentially be the maximum that Audi could achieve last year. That's about what Audi were supposed to harvest/release back in 2012-2013 when energy release was limited to 500kJ for each of the seven hybrid zones that were defined at LM (i.e. max 3.5MJ per lap).

For the 8MJ class, to play it safe, they need >=1000kJ... even for the 6MJ they need >= 800kJ(per event capability).

I think its time to ditch the flywheel, since rules for next year will go probably for 900kg cars and less fuel allocation, weight wont be such an heavy concern, and Porsche's A123Nano have improved quite a bit, perhaps able of >10 KW/kg now ( in 2014 it has ~9KW/kg). Meaning around 50Kg it will give them ~700hp for level of Porsche at the 8MJ class, and ~40kg for the 6MJ class(present flywheel is around 36Kg IIRC).

Else definitely a larger flywheel(which is more difficult to control)... large enough to have the levels of instantaneous power able to save some fuel in very strong accelerations by the ICE side (if not 8 or even 6MJ will be difficult to achieve...they need to cut fuel somewhere).

[chernaudi]

If Audi run 13 laps stints, then quintuple stinting probably won't happen. 5x11 lap stints = 55 laps. 4x13 laps stints = 52 laps. They can't really do a 5th 13 lapper or a 5th period because the 4 consecutive hour/4 out of 6 hour stint time limits doesn't allow for it/make sense to do so.

Audi will probably easily do quadruple stints, and will probably be the factory team who will do so most reliably aside from possibly Toyota. Data from the test will clear up that picture. But we know that Porsche probably won't quadruple stint: their tire wear is too great based on pre-LM races and they'd have to slow down too much to stretch their tires that long.

[hcl123]

I think the max we can expect is triple stinting, quadruple requires an easier pace, and i don't see 'competition' allowing this... it will be *new fashion* endurance racing, not 100% some of the time, it will be 100% almost all of the time, at least high up in the morning, when material fatigue and failures dictates the good fortune of the more resistant(and in this i think diesel has an edge).

Besides i think Audi will go much faster in the straights, not only because of quite lower downforce compared to Spa, but also at Spa (perhaps in a strategy to keep momentum and so safe some fuel) Audi run with only 6 speed gearbox (or the gearbox was 7 ratios, but the last ratio was never used). Higher speed has an heavier toll on tyre wear.

[chernaudi]

I noticed that in the rain that Audi were often slower than Porsche throughout both sessions when it was wet. Were they not pushing, or was the stiff suspension that they're running (they're able to because of the interconnected suspension system) causing them issues a la Peugeot in the past?

I'd almost have to say not pushing, because it seemed like everyone would do a couple of laps, pit, then go out again for a couple of laps and that was the cycle for the LMP1s during the wet parts of the session.

[MyNameIsNigel]

A few interesting shots thanks to Laurent Chauveau of Endurance-Info.com:

[hcl123]

Originally Posted by chernaudi

I noticed that in the rain that Audi were often slower than Porsche throughout both sessions when it was wet. Were they not pushing, or was the stiff suspension that they're running (they're able to because of the interconnected suspension system) causing them issues a la Peugeot in the past?

I'd almost have to say not pushing, because it seemed like everyone would do a couple of laps, pit, then go out again for a couple of laps and that was the cycle for the LMP1s during the wet parts of the session.

Brutal torque engines and downforce bias were never good for wet conditions... matter of fact Audi was never the best in rain, the 2012 and 2013 versions were good (its relative), but Audi was never the best in rain conditions since the R10 TDI.

[Damian Baldi]

In the rain Toyota was as fast as Audi.

[hcl123]

Not quite exactly the same front fenders of Monza test, and nostril patched for closed... and no lateral inside openings, like in Spa (visible in video http://www.youtube.com/watch?v=920KpqOiX0E )

i think that is the final configuration... yet it can have some tweaks... this feeling they are not done yet. At least for an aesthetics reason they could have a 'solid' version without visible patches (would look awful in a museum lol)

Also in that video if you count gear changes, from La Source (more than obvious 1th gear) into the end of Kemmel there is only 5 passages... Audi used a 6 speed gearbox at Spa... or if the rules don't allow it, it was the same 7 gear ratio but the last ratio(7th) was never used, which if the 6th is good for 300kmh at Kemmel, i think only 332 at Mulsanne comes short of possibilities!.... (again the feeling they found more engine efficiency than let it know by now...)

[Lagunaseca_4life]

Man this new audi is awesome,as a toyota fan im being torn between audi and porsche.two amazing powerful and fast machines,this years Le mans is going to be insane.with three cars each between the two it might go down to the last minute.

[joeb]

Racecar-Engineering has a nice piece on the wing endplates of the Audi and Porsche being possible not quite exactly legal:

http://www.racecar-engineering.com/n...ar-wing-trick/

[MyNameIsNigel]

Originally Posted by joeb

Racecar-Engineering has a nice piece on the wing endplates of the Audi and Porsche being possible not quite exactly legal:

http://www.racecar-engineering.com/n...ar-wing-trick/

Interesting. So, if I understand correctly, those shaped extensions on the leading edge of the rear wing end plates are actually part of the bodywork and not of the end plates as such. Weren't Toyota using more or less similar extensions on the TS030 back in 2013 (or even 2012) ?

[TF110]

They disallowed them in '13, but the double endplates stood since they were 'fender extensions'.

[MyNameIsNigel]

Originally Posted by TF110

They disallowed them in '13, but the double endplates stood since they were 'fender extensions'.

The "rear fender extensions" is a different matter and not the issue in the present instance. The issue revolves around bodywork extensions that sit immediatley upstream of the rear wing endplates. The rear fender extensions were mainly aimed at artificially widening the rear wing by providing downforce-generating bodywork extensions on both sides of the rear wing.

The rear wing endplate extensions now used by Porsche and Audi do seem to be functionally similar to what Toyota were using on the TS030 back in 2013 (I am not sure about 2012) as pictured below:

[TzeiTzei]

The Great Rear Wing Controversy of 2014 makes a return, with new ingredients. Yay!

[TF110]

Originally Posted by MyNameIsNigel

The "rear fender extensions" is a different matter and not the issue in the present instance. The issue revolves around bodywork extensions that sit immediatley upstream of the rear wing endplates. The rear fender extensions were mainly aimed at artificially widening the rear wing by providing downforce-generating bodywork extensions on both sides of the rear wing.

The rear wing endplate extensions now used by Porsche and Audi do seem to be functionally similar to what Toyota were using on the TS030 back in 2013 (I am not sure about 2012) as pictured below:

You said 2012 or 13. I only replied saying the fender extensions remained in '13, but the other part- forward of the normal position was not allowed. The 2012 car had the additional bodywork but not the '13

[MyNameIsNigel]

Originally Posted by TF110

You said 2012 or 13. I only replied saying the fender extensions remained in '13, but the other part- forward of the normal position was not allowed. The 2012 car had the additional bodywork but not the '13

Are you sure about this ?

LM 2012:


Paul Ricard Launch, 2013:


Spa version 2013:


(source: Mulsanne's Corner)

LM 2013:


All versions actually had bodywork extensions immediately upstream of the rear wing end plates.

[TF110]

True, but theyre not the same. The 2012 curves outward and isnt uniform. But in '13 they were flat. I thought that was the change in rule. They had to be rigidly attached?

[chernaudi]

I don't know if this is from Spa or when they unloaded for the test day (car is in Spa configuration and this photo is included in the Audi Sport test day photos), but you can get a shot of the front diffuser flap--shape is different than on the sprint version.

"LM" front diffuser:



Vs sprint version:



Also, Audi may want to consider working on their decaling for race week--the wrap was getting peeled back on the #7 during the test:



What is that yellow-brown stuff? Kevlar or adhesive?

[hcl123]

The last picture is in LM test day isn't it ? (it seems LM)

Well... none of those versions is Spa. Spa version is identical to the first picture but had some openings in the lateral inside of the front fenders(visible in video https://www.youtube.com/watch?v=920K...gUiIMQRyDhguP2 )... while the *real* LM version has no such lateral openings neither front nostrils and the shape of the fenders is a little different.