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Why isn’t the orange and the blue line being compared? They threw in the green line to show that they handle heat well and a driver who isn’t pushing for 10/10s is going to still run consistently fast in a 25 minute track session. Like doing a HPDE vs a TT, the blue being the latter.
Originally Posted by CPhelps
So green vs. blue is same compound but just driver pace? I wasn't sure if it was a comparison to the existing Porsche/Mercedes compounds, suggesting they were designed for hero lap and the Corvette flavor is steady pace. The way the graph highlights that first data point as hero lap, is part of it, since if the tire was the same I'd expect that to be the same for green and blue, however obviously how they are driven would factor into that.
If green and blue are the same compound, I agree they should be compared.
The X-Axis label was also not visible so I wasn't sure if those were laps at a specific course, or purely time based, so thanks for the clarification there. Certainly in a real use case like a full session, that delta highlighted by LS6 starts to add up, but I think JVP's point was that the Lightning Lap results are more like the initial grip hero lap, so that first few data points would be the comparison. Of course again if the green vs. blue is use case of driver and not compound differences, then the PSC2R's are still significantly faster for hero lap situations.
you guys missed the point. The blue line is the standard cup2R. The green line is the GM spec cup2R ZP. They went for a longer lasting compound. The little paragraph explains how gm worked on their own version. Essentially they wanted a tire that wouldn’t deteriorate immediately like the cup2zp and standard cup2R. It’s a win win but it makes the tire slightly slower. The GM cup2R ZP is apparently slower than the standard cup2R and old cup2ZP on first hero lap. But then those two tires overheat fast and lose 5 seconds pace by 10 laps in while the new gm cup2R ZP can stay consistently fast.
you guys missed the point. The blue line is the standard cup2R. The green line is the GM spec cup2R ZP. They went for a longer lasting compound. The little paragraph explains how gm worked on their own version. Essentially they wanted a tire that wouldn’t deteriorate immediately like the cup2zp and standard cup2R. It’s a win win but it makes the tire slightly slower. The GM cup2R ZP is apparently slower than the standard cup2R and old cup2ZP on first hero lap. But then those two tires overheat fast and lose 5 seconds pace by 10 laps in while the new gm cup2R ZP can stay consistently fast.
Got a source for that? The chart says its the same tire at a different pace
you guys missed the point. The blue line is the standard cup2R. The green line is the GM spec cup2R ZP. They went for a longer lasting compound. The little paragraph explains how gm worked on their own version. Essentially they wanted a tire that wouldn’t deteriorate immediately like the cup2zp and standard cup2R. It’s a win win but it makes the tire slightly slower. The GM cup2R ZP is apparently slower than the standard cup2R and old cup2ZP on first hero lap. But then those two tires overheat fast and lose 5 seconds pace by 10 laps in while the new gm cup2R ZP can stay consistently fast.
It would be nice to know if your interpretation is definitely correct, but it does seem reasonable based on the wording of that slide. It is interesting that the C&D driver set his best lap at what sounds like was his second lap, although he said there were tire warmers on so that may compensate for having a very fast early lap. This all means there is no specific gain in tire advantage between the Zr1 and new Z06 for a single hot lap.
Having raced mid-engined formula cars and noting that every F1 and lower formula car has been mid-engined for so many years - where in many cases you can choose whatever configuration you want - there very much is a handling and racing advantage with the mid-engined configuration.
you guys missed the point. The blue line is the standard cup2R. The green line is the GM spec cup2R ZP. They went for a longer lasting compound. The little paragraph explains how gm worked on their own version. Essentially they wanted a tire that wouldn’t deteriorate immediately like the cup2zp and standard cup2R. It’s a win win but it makes the tire slightly slower. The GM cup2R ZP is apparently slower than the standard cup2R and old cup2ZP on first hero lap. But then those two tires overheat fast and lose 5 seconds pace by 10 laps in while the new gm cup2R ZP can stay consistently fast.
That’s not the way I understood it based on the legend of the colored lines in the top right corner. Obviously every tire compound has it’s optimum temp range and how hard/how long you drive around a track determines how much heat is generated, so that plays a factor on when it performs best as I know you know.
In terms of all the claims about PSC2R track performance vs PSC2's one has to read GM's info and chart on the specially designed PSC2R for the C8Z06, and perhaps forget about every claim of faster this, faster that.
From GM's presentation on the bespoke PSC2R for the C8Z06
GM Tire tech Talk Slide PSC2R vs PSC2
Text in the box says: "Interestingly, MacDonald says that the Z06 breaks from the recent norm of having track tires that are at their best in the first couple of laps. For the Z06, the Corvette team worked with Michelin to create a new version of its Pilot Sport Cup 2 R's. MacDonald reports that development drivers are seeing their quickest times 10 laps in."
Zoom into the chart.
On the lap 1 hero lap, there is no more than 1 second between the 3 laptimes of the PSC2, PSC2R driven hard for a hero lap, and PSC2R driven for longevity for a 1-1/2 minute lap.
For lap 2, lap time varies from about 1:23.3 to 1:24.7 to 1:25,8, or about a variation of 2.5 seconds.
At lap 5, the green and blue curve match on terms of laptime, and then at lap 9, there is a 2 second difference in laptime between the blue and green curve.
Without knowing how hard a fresh set of tires were pushed on the first lap, everyone is just making wild guesses about the performance difference between tires. GM's development drivers would be hard to match in terms of consistency as they are the ones working with Michelin to custom design the specific version of the PSC2R for the Z06.
Maybe some of the misunderstanding is the result of the following. The actual text box in the slide says: "Interestingly, MacDonald says that the Z06 breaks from the recent norm of having track tires that are at their best in the first couple of laps. For the Z06, the Corvette team worked with Michelin to create a new version of its Pilot Sport Cup 2 R's. MacDonald reports that development drivers are seeing their quickest times 10 laps in."
But the original poster of this slide said: "On the lap 1 hero lap, there is no more than 1 second between the 3 laptimes of the PSC2, PSC2R driven hard for a hero lap, and PSC2R driven for longevity for a 1-1/2 minute lap."
So the OP leads one to believe its about how it is driven, but this is conjecture on behalf of the CF poster, the actual GM slide would indicate the new tires are different than other PSC 2R tires and are fastest on laps 9 or 10.
This is entirely possible as my R60A racing slicks definitely require some hard laps to get fully up to temp for a qualifying lap and are not fastest on lap 1 or 2 like my previous Goodyears.
GM drove test mules at the 'ring, not full production cars. And they were in traffic, with other cars to navigate around, not on a clean, empty track. There is no "time" for GM to publish.
For Porsche, getting to the ring and posting times is easy. GM has to air freight the cars and spares and equipment there, rent space to store and prep them, and if they happen to hit a bad weather streak all that money is down the drain. Why spend all that money for a car that's already in such demand people are willing to pay $50K, $100K, and even more over sticker? Breaking 7 minutes isn't going to sell one more Z07.
The Nurburgring is a pretty long haul from Stuttgart. Probably quite a bit farther than from Frankfurt, which is where I imagine GM would fly their cars and equipment into, so I'm not sure that location is a huge advantage for Porsche.
The legend is in the top right, who says you can’t start a hot lap at optimal tire temp for optimum results?
I saw the legend, I didn't see the X-Axis.
Either way, all I was saying is that it's a little ambiguous with the legend, if it's referring to two different tire compounds (we know there are different versions for different manufacturers) or if it's the same compound, just different paces. Since as you say, whose to say you couldn't do a hero lap then back off the pace to conserve them for longer, it seems plausible that the blue and green lines are different compounds Team Corvette and Michelin were trading. That, coupled with JVP's assertion that the Rs were worse in a hero lap, is where my confusion is coming from.
Originally Posted by BrunoTheMellow
you guys missed the point. The blue line is the standard cup2R. The green line is the GM spec cup2R ZP. They went for a longer lasting compound. The little paragraph explains how gm worked on their own version. Essentially they wanted a tire that wouldn’t deteriorate immediately like the cup2zp and standard cup2R. It’s a win win but it makes the tire slightly slower. The GM cup2R ZP is apparently slower than the standard cup2R and old cup2ZP on first hero lap. But then those two tires overheat fast and lose 5 seconds pace by 10 laps in while the new gm cup2R ZP can stay consistently fast.
That's what I was getting at, my impression from when those charts originally were presented/circulated, was that they were two different compounds.
Originally Posted by FF2000
Maybe some of the misunderstanding is the result of the following. The actual text box in the slide says: "Interestingly, MacDonald says that the Z06 breaks from the recent norm of having track tires that are at their best in the first couple of laps. For the Z06, the Corvette team worked with Michelin to create a new version of its Pilot Sport Cup 2 R's. MacDonald reports that development drivers are seeing their quickest times 10 laps in."
But the original poster of this slide said: "On the lap 1 hero lap, there is no more than 1 second between the 3 laptimes of the PSC2, PSC2R driven hard for a hero lap, and PSC2R driven for longevity for a 1-1/2 minute lap."
So the OP leads one to believe its about how it is driven, but this is conjecture on behalf of the CF poster, the actual GM slide would indicate the new tires are different than other PSC 2R tires and are fastest on laps 9 or 10.
This is entirely possible as my R60A racing slicks definitely require some hard laps to get fully up to temp for a qualifying lap and are not fastest on lap 1 or 2 like my previous Goodyears.
My original interpretation of the graph was as you say, GM and Michelin went for a different compound for the C8 Z06 and the blue and green graph line are comparing the different PSC 2R compounds.
Actually looking at that chart again, you will see the orange line for PSC 2 is faster on that first hero lap, than the green "consistent" PSC 2R line that presumably reflects the C8Z06/Z07 tires, just like JVP says. So I stand corrected on my earlier post of thinking it was all relative to PSC2Rs.
What we all agree on is that the Cup 2R tire is much better than the Cup 2 tire once they have several laps in them.
The LL times are NOT calculated on cold tires. They are averaged by 3 different drivers which tells me the tires have heat in them.
What we all agree on is that the Cup 2R tire is much better than the Cup 2 tire once they have several laps in them.
The LL times are NOT calculated on cold tires. They are averaged by 3 different drivers which tells me the tires have heat in them.
I dont think this is correct. The reported time for the Z06, a 2:38:06, was exactly the same as the best lap from the guy chasing the Lambo. His second best lap was like 1 second down, and i cant imagine anyone else got the exact same lap times.
In the discussion along with the video, the driver said something about tire warmers and being able to go fast on his early laps, and not wanting to do another sighting lap because of the tire warmers.
That’s not the way I understood it based on the legend of the colored lines in the top right corner. Obviously every tire compound has it’s optimum temp range and how hard/how long you drive around a track determines how much heat is generated, so that plays a factor on when it performs best as I know you know.
@PRE-Z06 I read this the same way you, @RedLS6, @ZRacerLE@range96 all do. The reason I think we all read this graph the same is that there are multiple Cup2Rs compounds that other Manufacturers have developed (And have been noted in this thread) - Thus there is no "Standard Cup2R". Which is also why @LowcountryVette also posted "The chart says its the same tire at a different pace" - Which is what the chart actually says (Consistent pace vs ultimate lap).
I would think that the chart would have noted the "Standard Cup2R" tire from another manufacturer in the legend if they were comparing (3) tires and not (2) tires total (Along with the title of the chart.
Last edited by JG853; 02-09-2023 at 06:43 PM.
Reason: Spelling
Maybe some of the misunderstanding is the result of the following. The actual text box in the slide says: "Interestingly, MacDonald says that the Z06 breaks from the recent norm of having track tires that are at their best in the first couple of laps. For the Z06, the Corvette team worked with Michelin to create a new version of its Pilot Sport Cup 2 R's. MacDonald reports that development drivers are seeing their quickest times 10 laps in."
But the original poster of this slide said: "On the lap 1 hero lap, there is no more than 1 second between the 3 laptimes of the PSC2, PSC2R driven hard for a hero lap, and PSC2R driven for longevity for a 1-1/2 minute lap."
So the OP leads one to believe its about how it is driven, but this is conjecture on behalf of the CF poster, the actual GM slide would indicate the new tires are different than other PSC 2R tires and are fastest on laps 9 or 10.
This is entirely possible as my R60A racing slicks definitely require some hard laps to get fully up to temp for a qualifying lap and are not fastest on lap 1 or 2 like my previous Goodyears.
Except it specifically states the blue and green line are 2 different paces. Anyone who’s competed realize a tire is fastest not when it’s cold and not when it’s too hot, but when it’s just right. You can run hard and create more heat for a max effort lap or you can back off a notch to make a tire last and be faster over a period of time.
The Nurburgring is a pretty long haul from Stuttgart. Probably quite a bit farther than from Frankfurt, which is where I imagine GM would fly their cars and equipment into, so I'm not sure that location is a huge advantage for Porsche.
Porsche partially owns Manthey Racing...Manthey Racing is in Meuspath, right next to Nurburg. An MR prepared GT2 or 3 RS is the ultimate Porsche.....The synergy created between these two companies has helped Porsche get to the track times we see today......GM finally starting a customer racing program will hopefully create the same type of synergy and improve the product.
BTW: Different days with different ambient temperatures (15 degC for the Cup2 and 18 degC for the Cup2R), so possibly different track conditions as well. There are also some insightful comments as well: There is a delta in time, but hard to tell
Hello Spychciu, Very interesting video ! Can you remind me the type of car 991.1 or 991.2 ? How many track days do you do with the R...can they be used at the depth limit ? Thanks in advance for your return, Best regards, Patrick
1
· spychciu 1 year ago
It's a 991.2, as specified in the video description. So far used the R only once, and judging by the wear it's a 2 day tire maximum. Mind you, I'm pretty gentle on the tires, (I frequently managed 5 days on regular Cup2s and Dunlops), so if someone is pushing very hard and doing a lot of laps it can be worn out in a day of track driving. I've seen them on other cars after a single day and they did not have another full day in them. It's at the sharp end of the grip/durability spectrum.
1 year ago
Thanks a lot for your reply. Michelin says that the performance of their R tyre is very constant after a slight initial drop...can you confirm ? Patrick
1 spychciu 1 year ago @Patrick CAMBIER on my first day on the R I beat my previous personal best on a 4 km track by almost 2 seconds on lap 40 on the tire, so that sounds about right. Didn't have the opportunity to try them out fresh having warmed myself up on a different set.
BTW: Different days with different ambient temperatures (15 degC for the Cup2 and 18 degC for the Cup2R), so possibly different track conditions as well. There are also some insightful comments as well: There is a delta in time, but hard to tell
Sure, but definitely seeing a pattern. Here’s another 2 second difference that I’ve referenced before, hadn’t seen the other video I posted though have seen the one you had.
It’s an average? Not outright best lap by any 1 person?
Originally Posted by FF2000
I dont think this is correct. The reported time for the Z06, a 2:38:06, was exactly the same as the best lap from the guy chasing the Lambo. His second best lap was like 1 second down, and i cant imagine anyone else got the exact same lap times.
In the discussion along with the video, the driver said something about tire warmers and being able to go fast on his early laps, and not wanting to do another sighting lap because of the tire warmers.
Average of 3 or best of three, in my argument it doesn't matter. The point was that LL times published are NOT done on cold tires. Once the tires have heat in them, the Cup 2R tires (on dry surfaces) outpace the Cup 2 tires. And that was my point. Nothing disputes that. Thanks for pointing out the best of 3 part.
I did notice the published time for the Z07 was the same as shown in the video, chasing the Lambo. Most of us do better in that situation.
None of my comments are to make the Z07 look bad. I'm thrilled Car and Driver was able to achieve those times. They are amazing!
Interesting notes about the track camber settings that GM recommends as maximum. Also very interesting about his comments at 3:49... "I think they are the fastest tires... For sure, they are like Hot Lap Tires". (But hey, like others have mentioned in this thread, it has nothing to do with the tires. At All).
There are several advantages of the C8 Platform over the C7 Platform as has been mentioned before - And yes, Cup2R is one of them.
02-09-2023, 11:57 AM
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