[WEC] Porsche Prototype Discussion

[Spyderman]

I don't think it is just a tire issue, although there is still room to improve. They were very unlucky at the start of the race, and Spa is good for them, but it is a track that is very traffic sensitive. When Porsche got traffic they lost a lot of time to Audi. Le Mans will be different.

[TF110]

Imo, Audi can afford to load downforce on their car. That diesel torque will get them through. So they load up on downforce. Porsche and Toyota probably would suffer more by putting wing on the car. The petrol doesnt make power enough so they rely on less drag and the hybrid. Porsche at least have that going. They were close today. I think the #17 would have won if it stayed trouble free. Hopefully for Porsche those little issues can be fixed by LM.

[Artur]

Originally Posted by J Jay

Tyres, mate. For all that power the 919 has its tyres have to be able to put it down consistently well throughout the stints. There's also a knock-on effect on lateral grip which doesn't help in the corners.

We're at the point where Michelin make custom tyres for each factory so what else can be done to prolong the tyre life?

I think Porsche will ask Michelin to work on a more resistant tyre for Le Mans. Btw, I heard that Michelin's biggest focus all year is developing tyres specially for the Le Mans tarmac and that this would be the reason for them doing up to 750km on one set, there. We need to keep in mind that, despite the many long straights, Le Sarthe has lots of long medium and high speed corners which puts, lap after lap, up to 3,7Gs(already saw that on Audi live stream) of lateral acceleration(equivalent of 5,5Gs on a 600kg car) on places like Porsche Curves.

With Michelin's resources and efforts being much more focused on the big race(LM), I expect Porsche to be quite fine there. Audi might do an extra stint on a set, but I expect Porsche's times to be consistent over their's,likely, triple stints.

Curiously, Audi's put far more lateral load than Porsche(and Toyota) but that doesn't seem to stress the tyres much. Because Audi is a longer partner, maybe they benefit from Michelin having a bigger know how on lateral load resistance. I have a suspicion that Porsche needs to work/improve their tools that, in theory, controls sliding such as ABS(I think it isn't even allowed because Webber said a light is shown on the steering wheel, when they lock a wheel, because they can't see the smokes) and traction control.

If Porsche tyres weren't sliding either on braking or on the acceleration of their massive powertrain system, they should be way more kind on tyres than Audi, as they corner slower and, therefore, put's less loads on the tyres.

Long story short, maybe the biggest part of the problem is on the Porsche's end

[Spyderman]

OK. A little bit of good news: Eliminating the "in laps" and the "out laps" it is clear that Porsche has caught (and surpassed) Audi in terms of race pace (at least at Spa).
Here are the averages:
#17
02:00.4
#18
02:00.5
#19
02:01.1
#7
02:00.7
#8
02:01.1
#9
02:02.2
#1
02:02.4
#2
02:02.6

[cokata]

Originally Posted by Spyderman

OK. A little bit of good news: Eliminating the "in laps" and the "out laps" it is clear that Porsche has caught (and surpassed) Audi in terms of race pace (at least at Spa).
Here are the averages:
#17
02:00.4
#18
02:00.5
#19
02:01.1
#7
02:00.7
#8
02:01.1
#9
02:02.2
#1
02:02.4
#2
02:02.6

That was clear from the begining of the race. They were pulling away from the Audi's, even after Lotterer got in the #7 the gap grew from ~15 seconds to about 30 before the end of the stints. They do seem to have a slow pit crew though and that has carried over from last year, they really need to work on that.

The other thing is they should have had a stint length advantage compared to the Audis like they did at Silverstone, but for some reason they can only manage the same amount of laps as them.

[Spyderman]

Not really. The #17 had a 15 second drive thru penalty (plus the time lost for missing the breaking zone) and a damper issue that forced them to change it. (not the pit crews fault).
#18 had slower (than #7 Audi) "in laps" and "out laps".
There is work to be done by all. The good news is the cars race pace is up there where it should be. Now the rest of the pieces of the puzzle need to fit into place.

[Articus]

Originally Posted by Spyderman

Not really. The #17 had a 15 second drive thru penalty (plus the time lost for missing the breaking zone) and a damper issue that forced them to change it. (not the pit crews fault).
#18 had slower (than #7 Audi) "in laps" and "out laps".
There is work to be done by all. The good news is the cars race pace is up there where it should be. Now the rest of the pieces of the puzzle need to fit into place.

But on the contrary, at what cost is the "race pace"? Porsche could not double stint. Where they to have run a harder compound they may have been slower but maybe able to double stint. One could imagine Audi on an even softer tire would have went faster but then not been able to double stint. Just some food for thought.

[Spyderman]

Not true. Porsche double stinted their tires (Marc Lieb). The numbers don't lie. Porsche average lap times over the entire race were quicker than Audi's. Double stint or not. Porsche lost time in other areas, and if they had not lost this time, they could have afforded to be slower when double stinting their tires. As they lost this time on other occurrences, the time lost from double stinting only made the situation worse.
Example : #18 spent 8:12.114 in the box. Audi #7 spent only 7:36.918

[carbon_titanium]

Originally Posted by Spyderman

Not true. Porsche double stinted their tires (Marc Lieb). The numbers don't lie. Porsche average lap times over the entire race were quicker than Audi's. Double stint or not. Porsche lost time in other areas, and if they had not lost this time, they could have afforded to be slower when double stinting their tires. As they lost this time on other occurrences, the time lost from double stinting only made the situation worse.
Example : #18 spent 8:12.114 in the box. Audi #7 spent only 7:36.918

beyond the huge pit stop time difference, I noticed this: true is that both 919 and R18 can double stint their tyres, but during the second stint 919 performances considerably drop while R18 more or less keeps the same pace of the first stint. In last 90 minutes, Treluyer with fresh tyres spent less than 10 laps to recover about 25 seconds from lieb (during his second tyres stint) while in the exact reverse situation, Jani (new tyres) spent much more time to recover about 15 seconds from treluyer (second tyres stint).
In the last 20 minutes both #7 and #18 were lapping in 2.02-2.03; porsche was in his second stint, audi in third!
Is clear that, beyond #17 unluck, porsche main problem is tyres wear rate (and lotterer).

Don't know if new tyres were available during porsche last pit stop, but if they were, porsche had to change their tyres at the end. They could gain more than 3 seconds per lap in the last part of the race.

[Spyderman]

Lotter is no doubt fantastic.....but...if one looks at the average lap times by driver (over the entire race and eliminating "in Laps" and "out Laps"), then we get these numbers:
André LOTTERER 02:00.5
Mark WEBBER 02:00.4
Timo BERNHARD 02:00.3
Romain DUMAS 02:00.1

[Articus]

Originally Posted by Spyderman

Not true. Porsche double stinted their tires (Marc Lieb). The numbers don't lie. Porsche average lap times over the entire race were quicker than Audi's. Double stint or not. Porsche lost time in other areas, and if they had not lost this time, they could have afforded to be slower when double stinting their tires. As they lost this time on other occurrences, the time lost from double stinting only made the situation worse.
Example : #18 spent 8:12.114 in the box. Audi #7 spent only 7:36.918

Oh come on you know what I meant. Porsche attempted to double stint and ended the stint 8 laps early because they were losing far too much time....Hence Porsche never even completed a double stint with that lead car.

[carbon_titanium]

about average laps, it's really shamefull to see both toyota's unable to run faster than 2.02... maybe it's a bit too early, but this 2015 reminds me a bit 2008 and 2010...

porsche as peugeot; the fastest car but sometimes unreliable and not great strategy

audi as audi; slower but strategy master

toyota as lola-aston

[Gil Abobeleira]

Originally Posted by Spyderman

Lotter is no doubt fantastic.....but...if one looks at the average lap times by driver (over the entire race and eliminating "in Laps" and "out Laps"), then we get these numbers:
André LOTTERER 02:00.5
Mark WEBBER 02:00.4
Timo BERNHARD 02:00.3
Romain DUMAS 02:00.1

You have to take into account that Lotterer did a double stint with the same tyres, unlike the other Porsche drivers. That should account to some fall-off (which does not seem to be too apparent in that comparison!)

[sssssssss]

Originally Posted by carbon_titanium

about average laps, it's really shamefull to see both toyota's unable to run faster than 2.02... maybe it's a bit too early, but this 2015 reminds me a bit 2008 and 2010...

porsche as peugeot; the fastest car but sometimes unreliable and not great strategy

audi as audi; slower but strategy master

toyota as lola-aston

audi don't look slower to me, just less focused on qualifying (and having less mj for it). they won silverstone on speed and at spa they were just about as fast as the porsches, but with glorious strategy as well. looking at the two races so far, their fastest laps were significantly faster than porsche's at silverstone and equal at spa, which is the track that might suit the porsches the most. and looking at the ideal lap times, which show the true potential of the cars, even at spa the no7 audi has an ideal race lap that is more than a full second quicker than porsche's ideal lap. which, to me, is quite spectacular. audi might not have shown all they've got yet.

[Chuliandred]

Originally Posted by Gil Abobeleira

You have to take into account that Lotterer did a double stint with the same tyres, unlike the other Porsche drivers. That should account to some fall-off (which does not seem to be too apparent in that comparison!)

When I see such insufficient data aggregations I know why I can't wait for Trusser to crunch some numbers for us.

Silverstone report as a little reminder: http://trussers.blogspot.de/2015/04/...six-hours.html

[Spyderman]

Originally Posted by Articus

Oh come on you know what I meant. Porsche attempted to double stint and ended the stint 8 laps early because they were losing far too much time....Hence Porsche never even completed a double stint with that lead car.

They were 8 laps short of a full stint because they were losing too much time.
No one is saying that they are not losing more time than the Audis when they double stint. What I'm trying to point out is that if they had not lost so much time in other off track activities, they could have better afforded to loose the time, As it was, they could not.

[Spyderman]

Originally Posted by Gil Abobeleira

You have to take into account that Lotterer did a double stint with the same tyres, unlike the other Porsche drivers. That should account to some fall-off (which does not seem to be too apparent in that comparison!)

If we take an average from say between laps 49 to 68 (way before anyone was double stinting) we get the following averages:

18 Romain DUMAS 02:00.1

17 Mark WEBBER 02:00.2

7 André LOTTERER 02:00.2


So as you can see, there are others that can keep up with him.

[Spyderman]

Originally Posted by Chuliandred

When I see such insufficient data aggregations I know why I can't wait for Trusser to crunch some numbers for us.

Silverstone report as a little reminder: http://trussers.blogspot.de/2015/04/...six-hours.html

My apologies for my inefficiencies, but we will see what Paul comes up with.

[Chuliandred]

Originally Posted by Spyderman

My apologies for my inefficiencies, but we will see what Paul comes up with.

Sorry. I didn't mean to offend you but to emphazise the point that reading data correctly can be dificult.

It would be nice to have something like a pitstop cam. Because most of the stops of the #17/#18/#19 were quite on par with the Audis. Only stop 2 and 4 of the #18 were to slow and it would nice to know the reason.

[Spyderman]

Originally Posted by Chuliandred

Sorry. I didn't mean to offend you but to emphazise the point that reading data correctly can be dificult.

I agree, but without having to go into to too much detail, the numbers show that the race pace of the Porches has improved and are now as quick (or slightly quicker) than the Audi's. This was certainly not the case before. They still have to improve on their tire-wear and other small (but important) areas. Reliability is still not 100%

Originally Posted by Chuliandred

It would be nice to have something like a pitstop cam. Because most of the stops of the #17/#18/#19 were quite on par with the Audis. Only stop 2 and 4 of the #18 were to slow and it would nice to know the reason.

They lost a lot of time in the pits. Brendan's mistake played a big part in #17's race and that compounded with the broken damper was fatal. A real shame.

[Spyderman]

http://www.porsche.com/uk/motorsport...f021c6&lang=en

[The Badger]

Must admit i am a bit gutted about Porsche not winning this round .

The Joest team i think have a magic hat and can pull anything outta it , fair dues to them .

[Spyderman]

This is what I was trying to get at: “First off, congrats to the #7 guys, that was a great job,” added Webber. “I think they did 60 laps on a set of tyres – you wouldn’t get that in the ‘other formula’! We had too many own goals today, but that’s how it should be – we don’t want to be gifted results if we weren’t performing at the highest level. I’m surprised that we were able to get back as well as we did – our car speed was good and fortunately the races are long enough that you can make it back.” - http://www.dailysportscar.com/2015/0...h-porsche.html

[Articus]

Jani was horrific in traffic and that really cost Porsche

[cokata]

Originally Posted by Articus

Jani was horrific in traffic and that really cost Porsche

I was watching the onboard, and while he was maybe playing it too safe, he always caught the traffic at the worst possible parts of the track, and the opposite could be said for the #7 Audi.