We re going to nurburgring

[timberwolf]

My loins hurt a bit from all this. But I'm proud of what this skunkworks-like group pulled off. With extra time, we all know they would have done 6s.

I wonder if Chevrolet has been holding out on posting the ZR1 times based on the results here....

[RedTanRT/10]

But 111 F is not hot for an asphalt track. Outside of a cool cloudy day it will be hard to find one lower without rain. Even at this time of the year. Seems like the Kumhos are too sensitive to temperature, pressure, etc.

The ideal day is around 50 degrees outside and partly cloudy with no wind to set records. Cooler temps help the car make more HP and the track is warm but not hot. Look at the time of the year the ACR set all the US track records

Lots of club racers here complain about those Kuhmo's not lasting long, especially the fronts. When FCA set all their US records most of the times were 2:00 or less. Seems like a pro running balls out, on a 7 minute run, is killing those tires in less than 1 lap.

There is more in that ACR but sounds like they need help in the form of a late August cool front

[Scott_in_fl]

As I've mentioned previously, and as others have pointed out, the tires become the limiting factor at some point.

So, let's throw on some slicks for next week and see what she's got!!!

Or maybe throw on the Michelins that the 918 had (or the Trofeo R's that the Huracan has). I hate to see the Kumho tire being the limiting factor here.

[13COBRA]

As I've mentioned previously, and as others have pointed out, the tires become the limiting factor at some point.

So, let's throw on some slicks for next week and see what she's got!!!

Or maybe throw on the Michelins that the 918 had (or the Trofeo R's that the Huracan has). I hate to see the Kumho tire being the limiting factor here.

Won't happen since Kumho has donated to the attempt while no other tire companies have.

[Shooter]

Pretty well about the same as the ACRX, which was about what I expected. Bad ass that a street legal car set that time. Good job by the team. Probably does have another couple seconds in it with cooler track temps.

[Bruce H.]

As I've mentioned previously, and as others have pointed out, the tires become the limiting factor at some point.

So, let's throw on some slicks for next week and see what she's got!!!

Or maybe throw on the Michelins that the 918 had (or the Trofeo R's that the Huracan has). I hate to see the Kumho tire being the limiting factor here.

This is along the lines of what I was going to ask those in the know regarding Ring times. Are the tires used on cars in this time range using ones that are known to hold up to heat better? And is it more a case of the ACR having the fastest tires for the much shorter North American tracks that it was designed for and not so surprising that they aren't optimal for the Ring?

[SSGNRDZ_28]

I wouldn't fixate too much on just the tires or a silver bullet solution. A setup can be good in cool temps and not as good in hot temps or vice versa. In IndyCar you can run the same setup morning to afternoon and be top of the pack to back of the pack when everyone is on the same tires. Hot air will be less dense and produce less downforce so top speed should have been slightly better. Track temp ambient temp shadows air density all play a part.

I'm sure they made setup improvements and the drivers made line improvements from the last runs. The car may be faster but the track is slower. Or the setup is no longer ideal for the conditions. This goes to show how varied tracks can be day to day. Again I think each run should have a +/- 5 second window attached to it. This is why comparing lap times down to the tenth is crazy across days or years.

To understand how he car will react to all of these variables with very limited time is next to impossible. This is why manufacturers spend so much time and money on these efforts. Gaining a database of information that they can use to adjust to the conditions etc.

Anyway sounds like they have a slot sometime next week so we can hope the stars align and some more time is found. Either way they've still done a lot with what they've had and the Viper is still near the top all things considered. Imagine if the field was leveled and Viper had $1,000,000 to spend or others had only $200,000.

[Ghazdall]

I wonder what their theoretical best lap is right now if they string together their best sectors.

[commandomatt]

All this talk about running different tires is BS

The whole idea is to see what the 'factory delivered' car will do. It comes with Kumho's, and that's what it needs to run on....end of story

If you changed up the tires, you are entering a non factory set up and may as well do H&C, exhaust and a bunch more to see what it can do. This however, this is not the goal.

They did amazing up to this point. If they have a chance to run next week, trust Doms prediction that the car has more in it as he probably understands this cars capabilities better than most at this time

[Scott_in_fl]

I believe a lot has to do with the profile of the front tire. Almost no sidewall means not enough air volume to keep the front tires from quickly overheating and destroying themselves.

If you are going to be running this car at the track regularly, you should be doing it with an 18 inch front wheel and a taller profile tire.

Formula One race cars have giant sidewalls on their tires for a reason.... lots of air volume to keep the tire at a safe operating temperature.

[ellowviper]

I believe a lot has to do with the profile of the front tire. Almost no sidewall means not enough air volume to keep the front tires from quickly overheating and destroying themselves.

If you are going to be running this car at the track regularly, you should be doing it with an 18 inch front wheel and a taller profile tire.

Formula One race cars have giant sidewalls on their tires for a reason.... lots of air volume to keep the tire at a safe operating temperature.

Makes alot of sense. Charles Law regarding pressure, temp and volume.

[Vypr Phil]

Formula One race cars have giant sidewalls on their tires for a reason.... lots of air volume to keep the tire at a safe operating temperature.

Absolutely correct, Formula 1 wheels have a rather puny 13" diameter. Front tires are 305/670-13 and rear are 405/670-13. The 670 number is the overall tire dimension (26.38") which is the standard designation for true racing tires as opposed to aspect ratio for street tires.

There was talk of changing to 18" wheels in F1 a few years ago, which was vehemently opposed by F1 engineers.

[Heysie]

https://www.youtube.com/watch?v=72Luk8fjvWc

[Fatboy 18]

Lucky son of a Bitch! Unreal!

[Red Snake]

Awesome vid. I think he liked it lol.

[Fatboy 18]

Awesome vid. I think he liked it lol.

I would have found the nearest exit and driven it home

[Dr.Ron]

Nice! Lucky!
What were the warning lights? I couldn't see on my cell phone.

[ACRucrazy]

IMG_1562.jpg

Nice! Lucky!
What were the warning lights? I couldn't see on my cell phone.

Here ya go.

[Dr.Ron]

Thanks. What's the one next to the seat belt light, and check brake pad wear? Nice! I wonder if that tripped the check engine light?

[Scott_in_fl]

I see the problem in the first 10 seconds of the video. "You wreck it you buy it". Sorry, but that is not how professional race car drivers operate. And neither was that the mandate given to the Porsche 918 or Lamborghini Huracan driver before their runs

These guys had to drive the cars like a moto journalist, and not as professional drivers, letting it all hang out. Go watch the old videos of GM engineer Jim Mero running the Corvette ZO6 around the ring and you'll see what I am talking about. That guy was definitely not told you break it you buy it.

[SSGNRDZ_28]

I see the problem in the first 10 seconds of the video. "You wreck it you buy it". Sorry, but that is not how professional race car drivers operate. And neither was that the mandate given to the Porsche 918 or Lamborghini Huracan driver before their runs

These guys had to drive the cars like a moto journalist, and not as professional drivers, letting it all hang out.

That was a journalist not the driver.

[Scott_in_fl]

That was a journalist not the driver.

Okay, that makes sense. I take back what I said.

[Fatboy 18]

I see the problem in the first 10 seconds of the video. "You wreck it you buy it". Sorry, but that is not how professional race car drivers operate. And neither was that the mandate given to the Porsche 918 or Lamborghini Huracan driver before their runs

These guys had to drive the cars like a moto journalist, and not as professional drivers, letting it all hang out. Go watch the old videos of GM engineer Jim Mero running the Corvette ZO6 around the ring and you'll see what I am talking about. That guy was definitely not told you break it you buy it.

I think that comment was aimed Directly at Dale, NOT Dominic or Mario

[genVer]

Very cool video; thanks for sharing!

[ek1]

The ideal day is around 50 degrees outside and partly cloudy with no wind to set records. Cooler temps help the car make more HP and the track is warm but not hot. Look at the time of the year the ACR set all the US track records

Lots of club racers here complain about those Kuhmo's not lasting long, especially the fronts. When FCA set all their US records most of the times were 2:00 or less. Seems like a pro running balls out, on a 7 minute run, is killing those tires in less than 1 lap.

There is more in that ACR but sounds like they need help in the form of a late August cool front

By now it's a well-known fact that front Kumhos on a Gen V ACR are what's called a "qualifying tire". You use them to qualify (in a race) and throw them out. Shitty for people that track their ACRs, but completely irrelevant for a record attempt where Kumho is supplying unlimited fresh tires. I am pretty sure they have an ability to throw a fresh set of tires on for every lap if they want. I am also pretty sure front Kumhos can survive a single Nurburgring lap, no matter how hard the car is driven.