Discussion
Yellow491 said:
These older cars are just going to get more sought after all the time,for the 991 anv model to be 2secs slower,and the 918 only 3 secs faster,technology has not come that far .He does admit the 918 is a lot faster over the whole lap,but corner speeds,you cant beat physics,even with nanny aids like auto boxes,rear wheel steer,traction control etc etc
You're not really serious surely by implying the older cars can corner faster due to being lighter (unless I have misunderstood you)... cornering speeds of modern cars with modern tyres and loads more mechanical/aero grip is going to be far higher.Yellow491 said:
These older cars are just going to get more sought after all the time,for the 991 anv model to be 2secs slower,and the 918 only 3 secs faster,technology has not come that far .He does admit the 918 is a lot faster over the whole lap,but corner speeds,you cant beat physics,even with nanny aids like auto boxes,rear wheel steer,traction control etc etc
The old 911 is on slicks, and significant aero. look at the cornering speeds. massive difference. Either of the modern porsches with slicks would be significantly faster. The cornering speeds are nothing to do with weight. Just tyres!Come on,40 years of development.
Tyres have also come on massively,slicks dont have as much of a advantage that they used to have.
From memory even the 993 rs had 1.2 g on corners.
Weight has a major part in corner speeds,more weight more grip required and more load on all components.
I thought the article written provoked some interesting questions.
Tyres have also come on massively,slicks dont have as much of a advantage that they used to have.
From memory even the 993 rs had 1.2 g on corners.
Weight has a major part in corner speeds,more weight more grip required and more load on all components.
I thought the article written provoked some interesting questions.
wilkos said:
The old 911 is on slicks, and significant aero. look at the cornering speeds. massive difference. Either of the modern porsches with slicks would be significantly faster. The cornering speeds are nothing to do with weight. Just tyres!
Weight and mass have a huge impact on cornering speed! Then its down to grip and handling.For speed, add lightness.
Yellow491 said:
Come on,40 years of development.
Tyres have also come on massively,slicks dont have as much of a advantage that they used to have.
From memory even the 993 rs had 1.2 g on corners.
Weight has a major part in corner speeds,more weight more grip required and more load on all components.
I thought the article written provoked some interesting questions.
997 gen2 turbo can't pull 1g on sticky tarmac. Only the 991 finally broke the 1g barrier. Tyres have also come on massively,slicks dont have as much of a advantage that they used to have.
From memory even the 993 rs had 1.2 g on corners.
Weight has a major part in corner speeds,more weight more grip required and more load on all components.
I thought the article written provoked some interesting questions.
Weight has a minimal effect on cornering grip. Downforce makes a car heavier and improves grip.
Grip goes up with weight on the tyre, unfortunately the lateral loads go up inline with the weight and the grip.
If the suspension is set up properly and thee tyre is kept in contact with the road (weight shift to the outer tyre is controlled),mthen weight has no bearing.
It's about tyres and downforce (lack of lift)
Look at the slalom test that road and track do in the states. The variance in lateral g achieved is minimal between all cars. Most basic cars archive close to 1g, with sticky tyres gt3's and their ilk making 1.2-1.3.
A slick with no downforce can make 1.5, and once you chuck in downforce, it's just tyre g multiplied by the downforce as a percentage of the cars weight.
The only advantage lightweight cars have is that they tend to exhibit less weight shift to the outer tyres, but this can be counteracted with wider track, stiffer springs, roll bars and damping.
I don't know how many people remember evo chucking a cayenne turbo around Bedford at the same pace as an evo 8.
Grip goes up with weight on the tyre, unfortunately the lateral loads go up inline with the weight and the grip.
If the suspension is set up properly and thee tyre is kept in contact with the road (weight shift to the outer tyre is controlled),mthen weight has no bearing.
It's about tyres and downforce (lack of lift)
Look at the slalom test that road and track do in the states. The variance in lateral g achieved is minimal between all cars. Most basic cars archive close to 1g, with sticky tyres gt3's and their ilk making 1.2-1.3.
A slick with no downforce can make 1.5, and once you chuck in downforce, it's just tyre g multiplied by the downforce as a percentage of the cars weight.
The only advantage lightweight cars have is that they tend to exhibit less weight shift to the outer tyres, but this can be counteracted with wider track, stiffer springs, roll bars and damping.
I don't know how many people remember evo chucking a cayenne turbo around Bedford at the same pace as an evo 8.
wilkos said:
Weight has a minimal effect on cornering grip. Downforce makes a car heavier and improves grip.
Grip goes up with weight on the tyre, unfortunately the lateral loads go up inline with the weight and the grip.
But it is not a linear relationship between tyre load and tyre grip. Doubling the load on a tyre will not double its grip, but the force required to accelerate double the mass around a corner is doubled. Two otherwise identical cars on the same tyres, but of different weights, will not corner at the same speed; the heavier car will be slower.Grip goes up with weight on the tyre, unfortunately the lateral loads go up inline with the weight and the grip.
thegreenhell said:
But it is not a linear relationship between tyre load and tyre grip. Doubling the load on a tyre will not double its grip, but the force required to accelerate double the mass around a corner is doubled. Two otherwise identical cars on the same tyres, but of different weights, will not corner at the same speed; the heavier car will be slower.
Nope. Depends which car is closest to the weight for which the suspension setup and tyres were designed/set up forGo significantly overlight or over heavy for a specific set up and it will corner slower.
In the posted article the 918 is marginally quicker through corners (heavier car) but it's running pilot sport cups over the pirellis on the 911 50th, plus in the faster corners it's aero starts to work.
Tyres and aero make massively more difference than weight. Go checkout lateral g's achieved in American mag slalom tests. Very little variance between all cars, from the lightest to the heaviest.
wilkos said:
Nope. Depends which car is closest to the weight for which the suspension setup and tyres were designed/set up for
Go significantly overlight or over heavy for a specific set up and it will corner slower.
In the posted article the 918 is marginally quicker through corners (heavier car) but it's running pilot sport cups over the pirellis on the 911 50th, plus in the faster corners it's aero starts to work.
Tyres and aero make massively more difference than weight. Go checkout lateral g's achieved in American mag slalom tests. Very little variance between all cars, from the lightest to the heaviest.
If you read the thread below which has a bunch of postings from a F1 engineer, I think you will discover you are wrong.Go significantly overlight or over heavy for a specific set up and it will corner slower.
In the posted article the 918 is marginally quicker through corners (heavier car) but it's running pilot sport cups over the pirellis on the 911 50th, plus in the faster corners it's aero starts to work.
Tyres and aero make massively more difference than weight. Go checkout lateral g's achieved in American mag slalom tests. Very little variance between all cars, from the lightest to the heaviest.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
If you understood what either I or he had written, you would understand that I'm not.
I am not arguing that ultimately weight doesn't make some difference to ultimate cornering speed, but distribution, and weight shift are more important, and ultimately the tyre and aero has much more effect on corner speed than weight.
Almost all cars can be set up to pull 1g lateral loads (sustained not peak) on a road tyre, no matter what they weigh. The difference between a very light and very heavy car.may be 0.05g.
Chuck a track compound tyre on, and instantly add 0.1-0.2g. Chuck a slick on and add 0.4-0.5g (when hot)
Much bigger differences than weight can make.
I am not arguing that ultimately weight doesn't make some difference to ultimate cornering speed, but distribution, and weight shift are more important, and ultimately the tyre and aero has much more effect on corner speed than weight.
Almost all cars can be set up to pull 1g lateral loads (sustained not peak) on a road tyre, no matter what they weigh. The difference between a very light and very heavy car.may be 0.05g.
Chuck a track compound tyre on, and instantly add 0.1-0.2g. Chuck a slick on and add 0.4-0.5g (when hot)
Much bigger differences than weight can make.
911dullard said:
APOLO in your experience of fast cars would you say the 991 TT is a 'supercar'?
no, super car performance yes, but that's only half the picture, it has to be fun to drive, its a bit like the 12C, you need to be doing the far side of 190, before it gets interesting.The GT3 is a is an absolute bundle of fun, even at 30-50 mph, the engine sounds more like a Flat plane crank V8, than a 6...
APOLO1 said:
911dullard said:
APOLO in your experience of fast cars would you say the 991 TT is a 'supercar'?
no, super car performance yes, but that's only half the picture, it has to be fun to drive, its a bit like the 12C, you need to be doing the far side of 190, before it gets interesting.The GT3 is a is an absolute bundle of fun, even at 30-50 mph, the engine sounds more like a Flat plane crank V8, than a 6...
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