Comments on: The Friction Circle http://www.pansypatrol.com/the-friction-circle/ News, technical articles, and lessons for those who own, fix, race, modify, or beat their 3000GT or Stealth. Sat, 31 Jul 2010 05:13:01 +0000 http://wordpress.org/?v=2.7 hourly 1 By: Noah http://www.pansypatrol.com/the-friction-circle/comment-page-1/#comment-35072 Noah Mon, 29 Mar 2010 17:18:38 +0000 http://www.pansypatrol.com/the-friction-circle/#comment-35072 While I don't understand why you would split hairs between the definition of "grip" and "traction" in the first place, I cannot accept your definition of "grip" as the "size, shape and compound of the tire's contact patch." By any definition, "grip" can be boiled down to the ability of entity A to hold on to entity B. For cars, entity A would be the tire, and entity B would be the road. Whether you call this "grip," "traction," or any other such synonym is completely irrelevant. The amount of grip is the end result from the COMBINATION of adhesion, tire compound, and contact patch. The friction circle is simply a means depicting how much ultimate grip is available for any given tire. Nor is your assertion that trailbraking will invariably be beneficial correct. Some corners, with some cars, with some lines benefit from trailbraking, but this technique cannot simply be applied across the board with expectations that it will yield faster times. It may, but not always. While I don’t understand why you would split hairs between the definition of “grip” and “traction” in the first place, I cannot accept your definition of “grip” as the “size, shape and compound of the tire’s contact patch.” By any definition, “grip” can be boiled down to the ability of entity A to hold on to entity B. For cars, entity A would be the tire, and entity B would be the road. Whether you call this “grip,” “traction,” or any other such synonym is completely irrelevant. The amount of grip is the end result from the COMBINATION of adhesion, tire compound, and contact patch. The friction circle is simply a means depicting how much ultimate grip is available for any given tire.

Nor is your assertion that trailbraking will invariably be beneficial correct. Some corners, with some cars, with some lines benefit from trailbraking, but this technique cannot simply be applied across the board with expectations that it will yield faster times. It may, but not always.

]]> By: Astraist http://www.pansypatrol.com/the-friction-circle/comment-page-1/#comment-34851 Astraist Sun, 28 Mar 2010 11:22:26 +0000 http://www.pansypatrol.com/the-friction-circle/#comment-34851 Friction circles refer to adhesion and traction, not grip. Grip is the size, shape and compound of the tire's contact patch, which generates the force known as adhesion. Grip is effected by mechanical and aerodynamic downforce. By trailbraking even so slightly into a corner, you shift the weight of the car slightly forward, resulting in more grip to the front tires, which carry much greater loads than the rear tires coming into a corner. This can be advantagous at the track. Friction circles refer to adhesion and traction, not grip. Grip is the size, shape and compound of the tire’s contact patch, which generates the force known as adhesion. Grip is effected by mechanical and aerodynamic downforce.

By trailbraking even so slightly into a corner, you shift the weight of the car slightly forward, resulting in more grip to the front tires, which carry much greater loads than the rear tires coming into a corner. This can be advantagous at the track.

]]> By: The Pansy Patrol - Info for the 3000GT / Stealth Community http://www.pansypatrol.com/the-friction-circle/comment-page-1/#comment-838 The Pansy Patrol - Info for the 3000GT / Stealth Community Mon, 24 Sep 2007 16:42:04 +0000 http://www.pansypatrol.com/the-friction-circle/#comment-838 [...] This will slowly transfer the rear tires from cornering grip to braking grip, as we discussed in The Friction Circle. I have this down to a reflex now. Whenever I hit the brakes in a corner, I unwind the wheel a [...] [...] This will slowly transfer the rear tires from cornering grip to braking grip, as we discussed in The Friction Circle. I have this down to a reflex now. Whenever I hit the brakes in a corner, I unwind the wheel a [...]

]]> By: The Pansy Patrol - Info for the 3000GT / Stealth Community http://www.pansypatrol.com/the-friction-circle/comment-page-1/#comment-396 The Pansy Patrol - Info for the 3000GT / Stealth Community Mon, 02 Apr 2007 03:48:42 +0000 http://www.pansypatrol.com/the-friction-circle/#comment-396 [...] But on a track, you want to be on the gas as much as possible. If you brake completely before a corner, then the entirety of your braking zone is on the previous straightaway. Since straightaways are where we can go fastest, the more time we can spend accelerating on them, the faster we will get around the track. The way to gain more gas time on a straightaway is to extend the braking zone into the corner itself. This is where trailbraking comes into play. Trailbraking and the Friction Circle If you read The Friction Circle you should be saying to yourself, “I can’t brake at threshold and begin turning or I will exceed my tires’ grip.” You’re right! You cannot. What you can do is brake almost at the limit and begin to turn. When you trailbrake, you transition your braking traction into turning traction. [...] [...] But on a track, you want to be on the gas as much as possible. If you brake completely before a corner, then the entirety of your braking zone is on the previous straightaway. Since straightaways are where we can go fastest, the more time we can spend accelerating on them, the faster we will get around the track. The way to gain more gas time on a straightaway is to extend the braking zone into the corner itself. This is where trailbraking comes into play. Trailbraking and the Friction Circle If you read The Friction Circle you should be saying to yourself, “I can’t brake at threshold and begin turning or I will exceed my tires’ grip.” You’re right! You cannot. What you can do is brake almost at the limit and begin to turn. When you trailbrake, you transition your braking traction into turning traction. [...]

]]> By: The Pansy Patrol - Info for the 3000GT / Stealth Community http://www.pansypatrol.com/the-friction-circle/comment-page-1/#comment-30 The Pansy Patrol - Info for the 3000GT / Stealth Community Thu, 01 Mar 2007 04:26:43 +0000 http://www.pansypatrol.com/the-friction-circle/#comment-30 [...] Understeer Imagine that you when you are cornering, your rear wheels have plenty of traction but your front wheels lose traction. Since your front wheels don’t have any more traction to make the car turn, your car will continue to move in a straight line regardless of whether you turn the steering wheel more. This condition is known as Understeer. Alternatively, you might hear it referred to as “pushing” or “plowing.” Correcting Understeer The best way to fix understeer is slow the car down. To do so, you should straighten the steering wheel and get on the brakes. As described in The Friction Circle, there is a limit to the amount of grip of your tires. If you are understeering, you have exceeded your tires’ limit of traction. For the same reason that turning the steering wheel more will not make the car turn, hitting the brakes will not make the car slow down appreciably. To regain braking traction, you need to unwind the steering wheel, transitioning the gripping force from a sideways cornering force to a straight braking force. When you have bled of some speed, you can then finish turning through the corner. Though this is not the best Line to take through a corner, it is the safest and most effective way to deal with Understeer. If you are understeering, you are already off of the best Line, so just slow down as quick as possible so that you can quickly get back on the Line. [...] [...] Understeer Imagine that you when you are cornering, your rear wheels have plenty of traction but your front wheels lose traction. Since your front wheels don’t have any more traction to make the car turn, your car will continue to move in a straight line regardless of whether you turn the steering wheel more. This condition is known as Understeer. Alternatively, you might hear it referred to as “pushing” or “plowing.” Correcting Understeer The best way to fix understeer is slow the car down. To do so, you should straighten the steering wheel and get on the brakes. As described in The Friction Circle, there is a limit to the amount of grip of your tires. If you are understeering, you have exceeded your tires’ limit of traction. For the same reason that turning the steering wheel more will not make the car turn, hitting the brakes will not make the car slow down appreciably. To regain braking traction, you need to unwind the steering wheel, transitioning the gripping force from a sideways cornering force to a straight braking force. When you have bled of some speed, you can then finish turning through the corner. Though this is not the best Line to take through a corner, it is the safest and most effective way to deal with Understeer. If you are understeering, you are already off of the best Line, so just slow down as quick as possible so that you can quickly get back on the Line. [...]

]]> By: The Pansy Patrol - Info for the 3000GT / Stealth Community http://www.pansypatrol.com/the-friction-circle/comment-page-1/#comment-28 The Pansy Patrol - Info for the 3000GT / Stealth Community Sun, 25 Feb 2007 20:37:59 +0000 http://www.pansypatrol.com/the-friction-circle/#comment-28 [...] However, you can’t just get on the throttle earlier and expect everything to turn out fine. If you read The Friction Circle, you’ll see that if you try to accelerate too hard while at maximum cornering grip, your driving wheels will lose traction and slip. In a front wheel drive car, you will understeer, and in a rear wheel drive car, you will oversteer. Both conditions are undesirable, and will make you slower through the corner. [...] [...] However, you can’t just get on the throttle earlier and expect everything to turn out fine. If you read The Friction Circle, you’ll see that if you try to accelerate too hard while at maximum cornering grip, your driving wheels will lose traction and slip. In a front wheel drive car, you will understeer, and in a rear wheel drive car, you will oversteer. Both conditions are undesirable, and will make you slower through the corner. [...]

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