s*****8
发帖数: 606 | 1 thanks all for the reply. sorry cannot type the Chinese.
There are tons of the methods to tune the car to understeer/oversteer, but
all start from the slip angle, I was trying to understand the slip angle so
I can tell how to tune the car when im driving it.
I am thinking there are 2 slip angles, one is the slip angle the tire
designed for, the other is the way to create slip angle(SA) by the tire. I
dont know if it is right or wrong.....
For example, front engine rear wheel drive car, if the ti... 阅读全帖 |
|
s*****8
发帖数: 606 | 2 SUV很难很难会有oversteer的情况，第一几乎所有SUV出厂都是understeer，第二，很
少有大马力后驱SUV。
赛道上的oversteer分好多情况，有些是有利，有些有有弊。oversteer造成slide/spin
的时候，反向打轮的时机和角度（调整方向），还有油门的控制（weight transfer）
很重要，刹车只有控制不了的时候才用。 |
|
l*******t
发帖数: 717 | 3 Feb. 8, 2011, 9:45 p.m. EST
U.S. sees Saudi oil reserves as overstated: report
LOS ANGELES (MarketWatch) -- U.S. diplomatic cables from 2007 to 2009 made
public by the website Wikileaks say that Saudi Arabia is unable to pump
enough oil to keep prices from rising, according to a Guardian report
Tuesday. Based on views from a senior Saudi government oil executive, the
cables say Saudi Arabia's reserves may be overstated by nearly 40%,
according to the report. The report cites comments attributed ... 阅读全帖 |
|
t******4
发帖数: 2300 | 4 DETROIT (AP) — Hyundai and Kia overstated the gas mileage on 900,000
vehicles sold in the past three years, a discovery that could bring
sanctions from the U.S. government and millions of dollars in reimbursements
to car owners.
The inflated mileage was uncovered in an audit of test results by the
Environmental Protection Agency, which ordered the Korean automakers to
replace fuel economy stickers on the affected cars. The new window stickers
will have figures that are one-to-six miles per gallo... 阅读全帖 |
|
q**j
发帖数: 10612 | 5 多谢。就是oversteer了猛打方向盘是可以的。但是不能踩刹车？以前没听人提起来
weight transfer这么危险。假设左转弯，而且你oversteer了以后，重心是向
右边边去你这个时候向右边猛打方向盘，前轮不打滑，还是有weight transfer？ |
|
s*****8
发帖数: 606 | 6 有个事一直想不明白，来请教一下。假如车是前置后驱，想减少understeer，所以就要
增加后轮的slip angle，举几个例子
1-重心后移，这个很好理解，增加后面的压力来增加slip angle
2-后悬挂调硬，过弯的时候如果悬挂越软，外侧的轮子的受力就越大，如果将悬挂调硬
，两侧的受力分布会更平均所以外侧轮的受力会减小，因此后轮slip angle就会减小，
那么为什么还会导致oversteer呢？？？
3-降低后轮胎压和用窄胎也可以减少understeer，但减少胎压增大接触面积不是跟用窄
胎相违背么？？而且autox的时候我问过好几个老油条，他们都说是增加后轮胎压来减
少understeer，谁能帮忙解释下这个？？难道induce和cause oversteer不是一个意思
？ |
|
u******w
发帖数: 1882 | 7 可以这么想，重心后移动会增加甩尾的几率，在转弯的时候其实这就是oversteering了
具体可以看汽车动力学最简单的bicycle model，有个公式，质心到后车轴距离b减小，
则转向特征变oversteering
从最理想的胎压开始，增加和减少胎压都会降低traction。增大会减少接地面积，减少
braking
.5 |
|
q**j
发帖数: 10612 | 8 前轮压力不够要under,后轮是Over。所以前轮车一般是under，后驱车会oversteer。感
觉understeer会更危险。转不过弯会飞出去，但是一般都说over危险。请问原理是什
么？ |
|
t******k
发帖数: 5617 | 9 understeering对于普通人来说更好控制，因为大部分人第一反应是踩刹车，
understeering的时候踩刹车不会有很大危险，而oversteering的时候踩刹车就飘了。
。。 |
|
q**j
发帖数: 10612 | 10 多谢回复。understeer是前轮摩擦不够。前驱车前面重，好像更应该oversteer, 但是
这个好像和平常说的不一样。请问怎么回事？ |
|
q**j
发帖数: 10612 | 11 再谢一次。那么如果oversteer发飘了，不能打方向盘应该做什么呢？ |
|
t******k
发帖数: 5617 | 12 这个我就不太清楚了，现在的车都有VTD之类的自稳定系统，应该可以最大程度的对转
向过度和转向不足修正。oversteering情况下并不是不能打方向盘，主要是不能猛踩刹
车，不然就真成漂移了 |
|
a****h
发帖数: 1012 | 13 Oversteer，要拉回来，必须踩油门，然后反打方向盘。。。然后这对操控不熟的新手
来说，作出这样的反应是比较困难的。。。
understeer，要拉回来，只要减速就行了。。。。这比较容易，也比较符合一般人的第
一反应。。
如果要体会的话，去跑一跑场地就明白了。。。就是在停车场里面，摆圆锥桶做赛道那
种。。 |
|
m*********8
发帖数: 1018 | 14 AP1?
Honda tried to neutralize the oversteering on AP2 |
|
|
o******o
发帖数: 1205 | 16 第一个是自己SB，第二个油门控制不当，第三个自己lift，换句话说，都是开的有问题
不是车的问题。HONDA试图每2年减少oversteer的方法是减小sway bar的尺寸，好事坏
事见仁见智了。 |
|
T******g
发帖数: 21328 | 17 第一个是因为brake into corner吗？
第二个看不太清楚
第三个是不是刚出现oversteer，那个driver没有正确修正，反而猛地松油门，造成
spin? |
|
b***i
发帖数: 10018 | 18 嗯，都是人的问题。
不知道ap1 s2000跟mr2比哪个oversteer的趋势更多? |
|
T******g
发帖数: 21328 | 19 那肯定是ap1 s2k啦。
不过其实是因为s2k比较neutral，而一般的车都是tune的understeer多一些，所以很多
刚开的很容易oversteer/spin |
|
o******o
发帖数: 1205 | 20 其实s2000原厂也是understeet，只是车比较灵活，对driver的反应要求比较高。
其实真的开始跑track，是需要根据自己喜好设定一下车的，最好的解决方法就是
alignment，我见到大多的s2000都调的倾向于understeer，走aggresive路线的不多。
上面的几种情况，和车无关，纯粹driver的问题，道理上不能叫oversteer应该叫lose
control，换成AWD也是一样的结果。 |
|
h****y
发帖数: 9234 | 21 ...轿跑和跑车只要不撞,一般很难翻吧...
SUV或者往上的, 一般不会oversteer吧... |
|
h****y
发帖数: 9234 | 22 你这个不是oversteer吧...-_-
就是突然猛变向, 那是挺容易翻车的.... |
|
q**j
发帖数: 10612 | 23 这个和oversteer不是很像么？都是朝反方向猛打方向盘。 |
|
i****x
发帖数: 17565 | 24 毫无关系，oversteer是后轮打滑，你这个是weight transfer
★ 发自iPhone App: ChineseWeb 7.8 |
|
e**n
发帖数: 1326 | 25 2的话其实软硬是相对前后轴的，或者整车侧倾的力在前后悬挂的分配。 举个简单的例
子,假如前后悬挂硬度原来都是5, 然后你把它调节成前4后6。 改前改后，整个车过弯
侧倾是基本一样的,但是改了之后后悬挂承担了更多的侧倾的力，所以会有更多的
oversteer。
当然实际生活中只是后面加硬，前悬不动，最简单的就是后sway bar换粗，效果立竿见
影... |
|
e**n
发帖数: 1326 | 26 "When using the stiffer suspension, the load is decreased on the outside
tire "
关键是前后轮的SA不一样啊。 不考虑悬挂的toe (static/dynamic), 拐弯的时候后轮
的SA要是比前面大的话，就是oversteer了嘛? 后悬调硬的话，cornering weight
transfer 到后面外侧轮比较多（相对前悬）, 自然后轮SA也相对比较大，所以结果就
是后面的SA要比前面的多...
so |
|
e**n
发帖数: 1326 | 27 "很多人的误区就是降低部分性能来提高感觉上的好操控"
我试着解释下：damping设置理论上应该保证最佳的车轮贴地性，车轮吃坑/bump后应该
要最快的回到原位但是不能弹跳（under damped)。如果over damped车轮归位的时间会
变久。两种情况都会导致抓地力的损失。
但是同时也可以调节damping来控制瞬态的weight transfer来改善车子的操控性。比如
说spring/rollbar设成静态的understeer,但是通过调节damping来提供瞬态的neutral/
oversteer来改善turn in. 这样调出来的damping rate和提供最佳车轮贴地性的
damping rate往往就不相等，那个时候就要在两个之间作取舍了。
year
not |
|
s*****8
发帖数: 606 | 28
I did road course, autox and drift, I understand how to use throttle/brake,
tire, camber to setup/induce understeer/oversteer, but i want to find out
theoretically why they happen, which i believe origin from the tire slip
angel, that is the thing confusing me.
Thanks for all your reply, I got some good books, I will read them and see
if I can find out the answer. |
|
|
|
l****z
发帖数: 29846 | 31 Hyundai, Ssangyong Face Fines for Overstating Fuel Efficiency
Transport Ministry Says the Auto Makers Exaggerated Fuel Economy by as Much
as 8%
By In-Soo Nam
June 26, 2014 8:07 a.m. ET
SEOUL—South Korea's transport ministry said on Thursday it would fine
Hyundai Motor Co. 005380.SE +0.44% and Ssangyong Motor Co. 003620.SE
+0.47% for overstating the fuel economy of their sport-utility vehicles.
The decision by the Ministry of Land, Infrastructure and Transport, however,
comes as anoth... 阅读全帖 |
|
A**z
发帖数: 184 | 32
后轮驱动的车因为前轮单纯转向用，所以不会有torque steer, 启动的时候
因为weight transfer, 所以驱动轮摩擦力更强，转弯的时候容易oversteer,
也就是甩尾，对于熟手来说，oversteer不会影响速度而且可以玩的空间比较多，
还有就是weight distribution比FWD的车均衡。
缺点也不少，结构复杂，成本高，多出来个drive shaft, 车内和行李空间
小，对于普通人来说，understeer比较容易修正，oversteer的修正是
跟人的直觉相反的，所以容易出事，而且oversteer在比较滑的地面上
特别容易出现。
基本上RWD的车更加追求performance, 实用性和价钱就都不如FWD了。不过要是
拿车当玩具的话，还是RWD好多了 |
|
t*****0
发帖数: 264 | 33 ☆─────────────────────────────────────☆
fjcruiser (FJ) 于 (Fri Jan 21 01:47:10 2011, 美东) 提到:
四驱是一个很复杂的概念，广大不明真相的群众很容易看一些无良厂商制作的
youtube录像受骗上当。一个四驱车到底怎么样，*至少*要从以下八个方面看：
公路驾驶指标(AWD)
AWD类型: 适时(on-demand) / 全时 (full-time)
中差: 无/ 开放 / 限滑
后差: 开放 / 限滑 / 其它(SH-AWD)
前差: 开放 / 限滑
越野驾驶指标(4WD, 4x4)
低速档: 无/有
中差锁(分动箱锁): 无/有
后差锁: 无/有
前差锁: 无/有
下面，我们以一些本版常讨论的车型为例，分析一下这些四驱车到底都是什么货。
（待续）
☆─────────────────────────────────────☆
fjcruiser (FJ) 于 (Fri Jan 21 01:57:46 2011, 美东) 提到:
四驱系统案例：Gra... 阅读全帖 |
|
y***k
发帖数: 9459 | 34 【 以下文字转载自 USANews 讨论区 】
发信人: lczlcz (lcz), 信区: USANews
标 题: 现代汽车因为谎报油耗数字面临政府罚款
发信站: BBS 未名空间站 (Thu Jun 26 19:25:07 2014, 美东)
Hyundai, Ssangyong Face Fines for Overstating Fuel Efficiency
Transport Ministry Says the Auto Makers Exaggerated Fuel Economy by as Much
as 8%
By In-Soo Nam
June 26, 2014 8:07 a.m. ET
SEOUL—South Korea's transport ministry said on Thursday it would fine
Hyundai Motor Co. 005380.SE +0.44% and Ssangyong Motor Co. 003620.SE
+0.47% for overstating the fuel econom... 阅读全帖 |
|
l**********l
发帖数: 4468 | 35 随便举个例子你不要生气。
比如你说miata山道那个。你说后来发现手刹都拉了，说漂移动作除了反打其他都做了。
这句话太奇怪太奇怪了。首先你当时这车显然是oversteering了，你是应该要救
oversteer，一般人本能都会反打方向盘的。这首先跟漂移没任何关系，因为你是要改
出漂移状态，不是进入。你拉手刹，锁住后轮了，这是initiate oversteer的操作，车
子后部一旦开始kick就要放手刹。你去做这个动作救oversteer，很危险的。你如果要
讲漂移动作的话，包括有kick离合器，油门控制，方向盘操作，降档不补油或者忽然升
档等等等等，加上一个手刹initiate。你拉了手刹就说自己漂移动作做齐了，是不是挺
奇怪的啊？何况你这个反打的最基本操作都没做。
你如果对漂移感兴趣的话可以看看formula D或者D1GP的视频，基本上手刹离合重心转
移这些都是initiate的动作，入弯以后控制角度控制漂移基本完全是在靠方向盘和油门
的控制。 |
|
k*********u
发帖数: 2897 | 36 美国拿粮食收割世界的时间应该快到了。
布局都布了10多年，差不多该收网了。
就等着天灾加把油了，一切具备了。
China to add to squeeze on world corn supply
http://finance.yahoo.com/news/china-add-squeeze-world-corn-0221
BEIJING/SINGAPORE (Reuters) - Beijing and the influential U.S. agriculture
department may have overstated China's corn crop by as much as 14 percent,
pointing to higher imports from the world's second-largest consumer of the
grain that could squeeze already tightening global supplies.
If China plugs the gap between projected and actua... 阅读全帖 |
|
g********d
发帖数: 19244 | 37 ☆─────────────────────────────────────☆
swat518 (GT) 于 (Mon Apr 8 11:50:45 2013, 美东) 提到:
1st of all, cannot type Chinese…
I owned this Nissan 350Z for a year, it is mainly for autox and will be
built for track use as well. Not a daily car because installed supercharge
and tuned for performance, so the MPG is mess, car is loud and need extra
time to warm up.
I’ve been self-studying engine, suspension tuning, tires and driving skill
for less than 2 years, so still too fresh. I did 90% of mai... 阅读全帖 |
|
s*****8
发帖数: 606 | 38 You are "right" about one thing, driver uses 屁股 to feel if the car starts
oversteering.
damper is only one thing can affect understeering or oversteering. and most
important, driver is the key to induce understeering or oversteering.
Be polite, people here is talking about 操控 for fun. If you do know the
answers for what you quesitoned, please write it down (I bet you don't,
because we can tell from your novice questions) |
|
i*******d
发帖数: 1430 | 39 没错，速度快是一方面，这个oversteering也是主要原因。视频上可以看出，总是处在
oversteering和understeering之间，不能守住弯道的弧度。打滑就是出在最后一次
oversteering时。lz开车基本技能，或者说基本习惯有待提进。 |
|
d********8
发帖数: 74 | 40 According to the IRS, 75% of the tax cheating is done by individuals—mostly
middle-income earners. Most of the rest of the cheating is done by
businesses. Cash-intensive businesses and service providers, from self-
employed handypeople to doctors, are the worst offenders.
How People Cheat on Their Taxes
Most cheating is from deliberate—actual or willful—underreporting of
income. This is called tax evasion—the most commonly charged tax crime. A
government study found the most underreporting of in... 阅读全帖 |
|
c**m
发帖数: 1457 | 41 http://www.mitbbs.com/club_bbsdoc/MA_Mortgage_Realestate.html
【 以下文字转载自 MA_Mortgage_Realestate 俱乐部 】
发信人: chem (Mortgage Consultant), 信区: MA_Mortgage_Realestate
标 题: Buyer Information for Closing
发信站: BBS 未名空间站 (Mon Oct 24 23:00:47 2011, 美东)
What responsibilities do I have during the lending process?
To ensure you won't fall victim to loan fraud, be sure to follow all of
these steps as you apply for a loan:
■Be sure to read and understand everything before you sign.
■Refuse to sign any blank do... 阅读全帖 |
|
l**********l
发帖数: 4468 | 42 你没看清我说的,还有我回复那哥们写的内容。他说没有LSD要甩起来很难的意思是他
现在没有办法initiate oversteering。保持oversteering那都是暂时没影的事情了。
我的回复就是说要甩起来要initiate，不需要LSD。而且本来练漂移最早拿没有LSD的车
就没有坏处，保持漂移会很难，因为没有办法锁住两个轮子，你能给的操作要少很多。
你知道了没有LSD你能练习能做到的极限以后。再上LSD，就会对LSD有更深刻的认识。
我就更没说过练drift应该拿没有LSD的车来练这类话了哦。
我也没有提到所谓漂移定义更没有纠结这个字眼了。
楼主本来也就是想体会一下oversteer的感觉而已。
还有你对drift的定义成了必须后轮不断输出动力我觉得不完全对。drift时候不给油的
时候多了，不是要一直给动力的。关键就是要后轮失去抓地力，你给油powerslide让后
轮失去抓地力，你用手刹锁住后轮让后轮失去抓地力，你用clutch，降档不补油，升档
，用flick，踩放油门控制重心等等，或者结合起来用，都是要想办法改变后轮抓地情
况得以保持或者调整你想要的车身角度而已。 |
|
V***b
发帖数: 3419 | 43 是这样，新STI底盘调校貌似非常好，给油过弯是neutral的，松一下就oversteering.
我的观点是这样，轮胎和地面的最大摩擦力基本是一定的，等于traction和grip的矢量
和，高速过弯出现understeering的话就说明grip不够了，松油门前轮traction减小
grip增大，马上就从neutral/understeering过渡到oversteering. 这个叫Lift-off
Oversteer。 |
|
h*****n
发帖数: 90 | 44 我对车本身其实基本不懂，猜他是指86比较容易oversteer，并且是属于predicable和
easily control/handle的那种oversteer，fun oversteer。从他的个人喜好来说，他
更享受86在赛道上漂移的控制感，所以我感觉他并不是很喜欢那种过弯出弯车子强grip
带来的快感。 |
|
H****g
发帖数: 14447 | 45 【 以下文字转载自 Military 讨论区 】
发信人: Herzog (singularity), 信区: Military
标 题: 关注一下这个吧，中国粮食产量数据可能虚报一亿吨之多
发信站: BBS 未名空间站 (Wed Mar 28 17:01:01 2012, 美东)
如果这个说法得到了证实，就可以和“80后90后农民不愿务农 中国恐陷无人种地处境
”的新闻对上号了。
现在看来，让茅于轼出来说“中国不需要守住18亿亩耕地红线，没粮食可以靠进口“，
就是有目的的为以后大批进口美国粮食放口风而已。
“A discrepancy of about 100 million metric tons in the last three years
alone was caused by unreliable statistics, chairman Li Qiang told an
industry conference in Boao, Hainan. Shanghai JC is China’s largest
independent agricultural research... 阅读全帖 |
|
H****g
发帖数: 14447 | 46 如果这个说法得到了证实，就可以和“80后90后农民不愿务农 中国恐陷无人种地处境
”的新闻对上号了。
现在看来，让茅于轼出来说“中国不需要守住18亿亩耕地红线，没粮食可以靠进口“，
就是有目的的为以后大批进口美国粮食放口风而已。
“A discrepancy of about 100 million metric tons in the last three years
alone was caused by unreliable statistics, chairman Li Qiang told an
industry conference in Boao, Hainan. Shanghai JC is China’s largest
independent agricultural researcher by membership. The overstated volume
represents 18 percent of annual output, according Bloomberg News
calculations based on government stati... 阅读全帖 |
|
H****g
发帖数: 14447 | 47 中国粮食产量数据可能虚报一亿吨
如果这个说法得到了证实，就可以和“80后90后农民不愿务农 中国恐陷无人种地处境
”的新闻对上号了。
现在看来，让茅于轼出来说“中国不需要守住18亿亩耕地红线，没粮食可以靠进口“，
就是有目的的为以后大批进口美国粮食放口风而已。
“A discrepancy of about 100 million metric tons in the last three years
alone was caused by unreliable statistics, chairman Li Qiang told an
industry conference in Boao, Hainan. Shanghai JC is China’s largest
independent agricultural researcher by membership. The overstated volume
represents 18 percent of annual output, according Bloomberg News
calculations based on ... 阅读全帖 |
|
s*******t
发帖数: 1743 | 48 The Korean automakers Hyundai Motor and Kia Motors will pay the federal
government a combined $300 million in penalties as part of a settlement for
overstating vehicle fuel-economy standards on 1.2 vehicles, the Justice
Department and the Environmental Protection Agency announced on Monday.
The penalty is the largest ever for a violation of the Clean Air Act,
government officials said.
Under the agreement, the automakers will pay $100 million in fines and
forfeit an estimated $200 million in gre... 阅读全帖 |
|
l****z
发帖数: 29846 | 49 By EVAN RAMSTAD And MIKE RAMSEY
Hyundai Motor Co 005380.SE -0.46% . and Kia Motors Corp. 000270.SE +0.67%
overstated the fuel economy for more than a third of the vehicles they sold
in the U.S. in the last two years, an embarrassing concession by two of the
fastest growing car makers in the U.S.
On Friday, the U.S. Environmental Protection Agency said Hyundai and Kia
issued incorrect mileage estimates on fuel consumption for about 900,000
vehicles sold since late 2010. Such estimates appear on n... 阅读全帖 |
|
l****z
发帖数: 29846 | 50 AP/Gfk调查，已有医疗保险的美国人中，将近半数的保险会变差，其中77%的人认为是
奥巴马医疗法案造成的恶果
Poll: Americans Blame Obamacare for Inferior Coverage, Higher Costs
Note well, Democrats: These complaints are unrelated to Obamacare's failed
roll-out, and are being driven by the vast majority of Americans covered on
the employer-based market -- whom the White House has falsely claimed will
not be affected by the law's changes:
Americans who already have health insurance are blaming President Barack
Obama's health care overhaul for th... 阅读全帖 |
|
