推 Scape: 今天刚出来一则影片,Model 3P换了Cup2胎、改了刹车,在 06/08 00:34
→ Scape: 北京金港赛道跑1:13.789,侧向最大1.8G 06/08 00:35
→ Scape: 这应该不算正式记录,不过可以看到换胎之后差很多 06/08 00:36
→ Scape: 2018年时Giulia Quadrifoglio在同一赛道跑出1:15.841 06/08 00:37
推 Scape: Model 3金港赛道影片:(微博) 06/08 09:33
→ Scape: https://www.weibo.com/2124878297/J5zrF70X3?type=comment 06/08 09:33
呃~基本上市售车不太可能有过弯侧向1.8g的表现
https://i.imgur.com/NTrmReu.jpg
主要由四颗轮子的侧向力提供车辆过弯时所需的向心力
当然会因为轮胎侧滑角(tire slip angle)
所以实际提供的向心力会是四颗轮子乘上该轮侧滑角的分量总和
1.8g过弯,代表向心力是车重的1.8倍
假设以最理想的四轮重量平均分配的条件,那轮胎的侧向摩擦系数要有1.8
一般市售车配胎,侧向摩擦系数约略0.8~0.9左右
就算是顶级街胎,侧向摩擦系数了不起就是1.2~1.4左右(也许我还有些高估了)
https://i.imgur.com/Xd0wLY2.jpg
https://i.imgur.com/egWpcvt.jpg
轮胎载重增加,虽然能提供的侧向力会增加
但最大摩擦系数会越来越小
也就是若同轮胎下若车重增加,也会不利于过弯表现
https://i.imgur.com/WOsOPjZ.jpg
那为啥像方程式或有些单舱赛车的侧向G值可以到2以上
因为除了车重外,还依赖空力提供的下压力
轮胎vertical load增加,能提供的侧向力自然增加
量测到过弯1.8g
很大可能是仪器安装时并没有固定稳
最后附上Focus RS从PSS换成Cup2的表现
Ford Focus RS with Michelin Pilot Sport Cup 2 Tires
https://reurl.cc/oDWoM5
The Focus RS comes from the factory on capable Michelin Pilot Super Sport
radials. Like our Lightning Lap car, this example came with a $1990
wheel-and-tire package consisting of a specific 19-inch forged-aluminum wheel
and as racy a tire as you can put on a street car, the Michelin Pilot Sport
Cup 2
Stopping from 70 mph takes 154 feet, which is only four feet shorter than a
Super Sport–shod RS, but lateral acceleration jumps from just below 1.00 g
to 1.04 g
This RS’s accelerative performance—zero to 60 mph in 4.6 seconds and a
13.4-second quarter-mile—is unchanged
70mph下煞停距离:158 feet -> 154 feet
侧向加速度: 1.00 g -> 1.04 g
加速性能:不变
从PSS换成Cup2,侧向加速度只提升0.04g唷