[Rodan]

Originally Posted by oldman

Yes, so I'm now of the opinion that these ultra-high end cars should be setup for their track spec suspension and all on the same brand and type of tire for a true head to head, as this is the way the consumer actually uses the product.

Most of the manufacturers work directly with a tire manufacturer to develop a spec tire for the vehicle. This is the case for the ZLE, and Porsches, not sure about the GT500.

I agree on the 'track alignment', but tests should be run on the OEM tires. Comparison tests should be about what you get off the showroom floor, not the car's ultimate potential...

[TheRealJA105]

Originally Posted by Rodan

Most of the manufacturers work directly with a tire manufacturer to develop a spec tire for the vehicle. This is the case for the ZLE, and Porsches, not sure about the GT500.

I agree on the 'track alignment', but tests should be run on the OEM tires. Comparison tests should be about what you get off the showroom floor, not the car's ultimate potential...

Correct, I was about to edit my post, but I'll follow it up on this. Isn't the MPSC2 on the GT3RS a special spec tire just for that car? Making it a different tire than the CFTP is running?

Edit: But a same tire same day test after the OEM configuration test should happen

[NW-99SS]

Ford had Michelin spec Cup 2's specifically for the CFTP, all while claiming not to be chasing lap times...

"He uses a program that fairly accurately predicts lap times at Virginia International Raceway as the team programs in a vehicle's hard points and tunes for factors such as differential torque bias, tire characteristics, aerodynamics, etc. Early computer twiddling resulted in the team assigning Michelin a fresh set of tire-performance targets (the front tires are especially critical at VIR)"

https://www.motortrend.com/news/2020...rmance-wisdom/

[Lafourche1]

I just had a random thought. Why not run the cars with track alignment. Most people will get the suggested track alignment before taking their car to the track. Run the cars with the OEM tires. Likely there has been engineering around that configuration. Run a 20 minute session with 1 warm up lap. You can get lap by lap times, so you can see who runs a faster Hero lap and how the cars hold up over a full session. -- Later thought -- you might need to change brake fluids. No one wants to face a corner, after a straight when your brake fluid has boiled (4 wheelin' times).

I get it that smaller budgets (Throttle House) may not be able to accomplish all of this testing. I think some manufacturers may balk. That should be clearly called out. I also understand that this will require a longer possession time for the car by the testing group.

They can then move on to the measurement testing of 0-60 / quarter mile / cornering, etc. This would almost certainly call for a tire change and a reset to street specifications. I would do the road course first as that puts the most strain on components.

[Martinjlm]

Originally Posted by Rodan

Most of the manufacturers work directly with a tire manufacturer to develop a spec tire for the vehicle. This is the case for the ZLE, and Porsches, not sure about the GT500.

I agree on the 'track alignment', but tests should be run on the OEM tires. Comparison tests should be about what you get off the showroom floor, not the car's ultimate potential...

Originally Posted by TheRealJA105

Correct, I was about to edit my post, but I'll follow it up on this. Isn't the MPSC2 on the GT3RS a special spec tire just for that car? Making it a different tire than the CFTP is running?

Edit: But a same tire same day test after the OEM configuration test should happen

Originally Posted by NW-99SS

Ford had Michelin spec Cup 2's specifically for the CFTP, all while claiming not to be chasing lap times...

"He uses a program that fairly accurately predicts lap times at Virginia International Raceway as the team programs in a vehicle's hard points and tunes for factors such as differential torque bias, tire characteristics, aerodynamics, etc. Early computer twiddling resulted in the team assigning Michelin a fresh set of tire-performance targets (the front tires are especially critical at VIR)"

https://www.motortrend.com/news/2020...rmance-wisdom/

I do seem to recall a Carl Widmann interview where he stated that Ford had worked directly with Michelin to develop a spec for the GT500 SC2 application. Can't recall if he stated it specifically in the GT500 launch at the Detroit Auto Show or in the Q&A that followed.

I'm not sure how this was done in the '60s, but I am aware that for the past few decades performance car manufacturers have been working with tire manufacturers to spec a tire for "optimal performance". The first one I can remember is the C4 Corvette in 1984. First time I had ever seen tires with specific corner placement. GM made a huge deal out of working with Goodyear to specifically design the tires to work with the new chassis. Could be that others were doing that before the C4 tires and I just wasn't paying attention.


As for GT500 vs GT3RS laps... my opinion is that it's a bit of both car and tire. The stresses on the tires are distributed differently between the two cars.

The GT500 front tires have to bear the stresses of directional and momentum changes as the car barrels through the curves. They have to do that with much of the vehicle's weight bearing down on them. The rear tires have an easier job because they are focused on propulsion and traction.

On the Porsche, the duty is split differently amongst the four tires. The front tires will of course have to manage all the stress input from steering through corners that the GT500 front tires have to manage, but without the additional stress of supporting a heavy engine. The rear tires have to manage the same propulsion and traction duties that the GT500 rear tires have to manage, but also have to manage additional weight. The additional weight aids the traction for the car but probably also induces more wear on the rears than we would likely see on the GT500. Personally, I like that tradeoff.

[ZRacerLE]

Originally Posted by NW-99SS

Ford had Michelin spec Cup 2's specifically for the CFTP, all while claiming not to be chasing lap times...

"He uses a program that fairly accurately predicts lap times at Virginia International Raceway as the team programs in a vehicle's hard points and tunes for factors such as differential torque bias, tire characteristics, aerodynamics, etc. Early computer twiddling resulted in the team assigning Michelin a fresh set of tire-performance targets (the front tires are especially critical at VIR)"

https://www.motortrend.com/news/2020...rmance-wisdom/

Wish Ford would openly go to war with GM on laptimes. They'd both end up with $70K sub 7 minute Ring cars.

[ZRacerLE]

Originally Posted by Lafourche1

I just had a random thought. Why not run the cars with track alignment. Most people will get the suggested track alignment before taking their car to the track. Run the cars with the OEM tires. Likely there has been engineering around that configuration. Run a 20 minute session with 1 warm up lap. You can get lap by lap times, so you can see who runs a faster Hero lap and how the cars hold up over a full session. -- Later thought -- you might need to change brake fluids. No one wants to face a corner, after a straight when your brake fluid has boiled (4 wheelin' times).

I get it that smaller budgets (Throttle House) may not be able to accomplish all of this testing. I think some manufacturers may balk. That should be clearly called out. I also understand that this will require a longer possession time for the car by the testing group.

They can then move on to the measurement testing of 0-60 / quarter mile / cornering, etc. This would almost certainly call for a tire change and a reset to street specifications. I would do the road course first as that puts the most strain on components.

Love this idea. How do the stock cars do in an HPDE scenario?

[TheRealJA105]

Originally Posted by NW-99SS

Ford had Michelin spec Cup 2's specifically for the CFTP, all while claiming not to be chasing lap times...

"He uses a program that fairly accurately predicts lap times at Virginia International Raceway as the team programs in a vehicle's hard points and tunes for factors such as differential torque bias, tire characteristics, aerodynamics, etc. Early computer twiddling resulted in the team assigning Michelin a fresh set of tire-performance targets (the front tires are especially critical at VIR)"

https://www.motortrend.com/news/2020...rmance-wisdom/

Good to know, I was totally unaware that Ford did the same to their MPSC2s.

Originally Posted by Martinjlm

I do seem to recall a Carl Widmann interview where he stated that Ford had worked directly with Michelin to develop a spec for the GT500 SC2 application. Can't recall if he stated it specifically in the GT500 launch at the Detroit Auto Show or in the Q&A that followed.

I'm not sure how this was done in the '60s, but I am aware that for the past few decades performance car manufacturers have been working with tire manufacturers to spec a tire for "optimal performance". The first one I can remember is the C4 Corvette in 1984. First time I had ever seen tires with specific corner placement. GM made a huge deal out of working with Goodyear to specifically design the tires to work with the new chassis. Could be that others were doing that before the C4 tires and I just wasn't paying attention.


As for GT500 vs GT3RS laps... my opinion is that it's a bit of both car and tire. The stresses on the tires are distributed differently between the two cars.

The GT500 front tires have to bear the stresses of directional and momentum changes as the car barrels through the curves. They have to do that with much of the vehicle's weight bearing down on them. The rear tires have an easier job because they are focused on propulsion and traction.

On the Porsche, the duty is split differently amongst the four tires. The front tires will of course have to manage all the stress input from steering through corners that the GT500 front tires have to manage, but without the additional stress of supporting a heavy engine. The rear tires have to manage the same propulsion and traction duties that the GT500 rear tires have to manage, but also have to manage additional weight. The additional weight aids the traction for the car but probably also induces more wear on the rears than we would likely see on the GT500. Personally, I like that tradeoff.

Spot on Martin!

[ZRacerLE]

Originally Posted by Martinjlm

I do seem to recall a Carl Widmann interview where he stated that Ford had worked directly with Michelin to develop a spec for the GT500 SC2 application. Can't recall if he stated it specifically in the GT500 launch at the Detroit Auto Show or in the Q&A that followed.

I'm not sure how this was done in the '60s, but I am aware that for the past few decades performance car manufacturers have been working with tire manufacturers to spec a tire for "optimal performance". The first one I can remember is the C4 Corvette in 1984. First time I had ever seen tires with specific corner placement. GM made a huge deal out of working with Goodyear to specifically design the tires to work with the new chassis. Could be that others were doing that before the C4 tires and I just wasn't paying attention.


As for GT500 vs GT3RS laps... my opinion is that it's a bit of both car and tire. The stresses on the tires are distributed differently between the two cars.

The GT500 front tires have to bear the stresses of directional and momentum changes as the car barrels through the curves. They have to do that with much of the vehicle's weight bearing down on them. The rear tires have an easier job because they are focused on propulsion and traction.

On the Porsche, the duty is split differently amongst the four tires. The front tires will of course have to manage all the stress input from steering through corners that the GT500 front tires have to manage, but without the additional stress of supporting a heavy engine. The rear tires have to manage the same propulsion and traction duties that the GT500 rear tires have to manage, but also have to manage additional weight. The additional weight aids the traction for the car but probably also induces more wear on the rears than we would likely see on the GT500. Personally, I like that tradeoff.

Ford should have done 325s on all four corners with a wide body. I know, that would be crazy forces through the front suspension and even more brake heat, but it seems it would make the front tires much less of a bottleneck.

[ZRacerLE]

Since this is the thread for everything:
https://www.corvetteforum.com/articl...-track-weapon/

Speedphenom, has been to a few racing schools. I thought that kid could drive..

[NW-99SS]

Originally Posted by Lafourche1

I just had a random thought. Why not run the cars with track alignment. Most people will get the suggested track alignment before taking their car to the track. Run the cars with the OEM tires. Likely there has been engineering around that configuration. Run a 20 minute session with 1 warm up lap. You can get lap by lap times, so you can see who runs a faster Hero lap and how the cars hold up over a full session. -- Later thought -- you might need to change brake fluids. No one wants to face a corner, after a straight when your brake fluid has boiled (4 wheelin' times).

I get it that smaller budgets (Throttle House) may not be able to accomplish all of this testing. I think some manufacturers may balk. That should be clearly called out. I also understand that this will require a longer possession time for the car by the testing group.

They can then move on to the measurement testing of 0-60 / quarter mile / cornering, etc. This would almost certainly call for a tire change and a reset to street specifications. I would do the road course first as that puts the most strain on components.

With the current capability of these modern cars - and been "track purposed", this is truly how it should be done. Most owners will participate in HPDE sessions, throughout an entire day and care more about not having to replace items mid-day or in between sessions.

I fully agree with this type of test.

Originally Posted by Martinjlm

I do seem to recall a Carl Widmann interview where he stated that Ford had worked directly with Michelin to develop a spec for the GT500 SC2 application. Can't recall if he stated it specifically in the GT500 launch at the Detroit Auto Show or in the Q&A that followed.

I'm not sure how this was done in the '60s, but I am aware that for the past few decades performance car manufacturers have been working with tire manufacturers to spec a tire for "optimal performance". The first one I can remember is the C4 Corvette in 1984. First time I had ever seen tires with specific corner placement. GM made a huge deal out of working with Goodyear to specifically design the tires to work with the new chassis. Could be that others were doing that before the C4 tires and I just wasn't paying attention.


As for GT500 vs GT3RS laps... my opinion is that it's a bit of both car and tire. The stresses on the tires are distributed differently between the two cars.

The GT500 front tires have to bear the stresses of directional and momentum changes as the car barrels through the curves. They have to do that with much of the vehicle's weight bearing down on them. The rear tires have an easier job because they are focused on propulsion and traction.

On the Porsche, the duty is split differently amongst the four tires. The front tires will of course have to manage all the stress input from steering through corners that the GT500 front tires have to manage, but without the additional stress of supporting a heavy engine. The rear tires have to manage the same propulsion and traction duties that the GT500 rear tires have to manage, but also have to manage additional weight. The additional weight aids the traction for the car but probably also induces more wear on the rears than we would likely see on the GT500. Personally, I like that tradeoff.

On point as usual Jim, thanks

Originally Posted by ZRacerLE

Wish Ford would openly go to war with GM on laptimes. They'd both end up with $70K sub 7 minute Ring cars.

Would love to see more of this as well. As with Ring times, the manufacturers definitely work "outside the box" on certain things, and often are caught not running factory or owner's manual settings.

Case in point - GTR N attack time (you can't even buy these parts on a North American Nissan dealer, you have to spend $80K + at Stillen, then get the tune and correct fuel).

Porsche has also been caught with higher octane fuel than factory spec'd...

This is where they start seeing less value in attacking lap records.

[oldman]

I see few guys on the autoX with "OEM designed tires". I have my doubt on how much collaboration / cooperation are done between the tire guys and the OEM car mfg. Sure there is some, for example the Nexen on the Challenger 1320 has a specific compound on that specific size 275/40R20. Maybe the average GT500 owner will stick to the already sticky spec Cup2s, I highly doubt the Vette, Hellcat and for sure guys like me with a SS stick with the OEM tire. So that is ONE car, maybe 2 if you toss in the GT PP2 setup...

[TheRealJA105]

Originally Posted by oldman

Maybe the average GT500 owner will stick to the already sticky spec Cup2s, I highly doubt the Vette, Hellcat and for sure guys like me with a SS stick with the OEM tire. So that is ONE car, maybe 2 if you toss in the GT PP2 setup...

Yep, and this is why the OEM setup with OEM tires configuration is only good for magazine articles. After that and real world the cars should be tested on the same tire. Tires are the best performance mod for track or strip bar none.

Ex. Put MPSC2s on the ZLE and watch its 2nd and 3rd laptimes fall off a little bit
-Put G3Rs on the CFTP and see how many sessions before they cord and don't mention it got faster, because we don't want that.
-Put MPSC2s on the C8 and watch it close the gap on the CFTP even at VIR Full
-Put DRs on any car that spins on launch

[NW-99SS]

Originally Posted by TheRealJA105

Yep, and this is why the OEM setup with OEM tires configuration is only good for magazine articles. After that and real world the cars should be tested on the same tire. Tires are the best performance mod for track or strip bar none.

Ex. Put MPSC2s on the ZLE and watch its 2nd and 3rd laptimes fall off a little bit
-Put G3Rs on the CFTP and see how many sessions before they cord and don't mention it got faster, because we don't want that.
-Put MPSC2s on the C8 and watch it close the gap on the CFTP even at VIR Full
-Put DRs on any car that spins on launch

No argument with this. I prefer the same tire as it really shows which chassis works better on a road course, can put the power down better/earlier, later braking points, etc.

I have no problem with the CFTP going faster on a different tire, and expect most who track them will likely use a road course tire over the Cup2s or the G3Rs, no different than I have for my GS.

Edit: Speaking of same tire, same day comparisons on "equally" equipped cars - Throttle House did this with the SS 1LE and GT PP2 both on Cup2s...