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- From: welty@cabot.balltown.cma.COM (richard welty)
- Newsgroups: rec.autos,rec.autos.tech,rec.autos.sport,rec.autos.driving,rec.autos.vw,alt.autos.antique,news.answers
- Subject: rec.autos: Frequently Asked Questions
- Keywords: Monthly Posting
- Message-ID: <1992Dec20.050303.28470@cabot.balltown.cma.COM>
- Date: 20 Dec 92 05:03:03 GMT
- Reply-To: welty@balltown.cma.com
- Followup-To: rec.autos
- Organization: New York State Institute for Sebastian Cabot Studies
- Lines: 215
- Approved: news-answers-request@MIT.Edu
-
- Archive-name: rec-autos/part4
-
- [this article is one of a pair of articles containing commonly
- asked automotive questions; the other article contains questions
- of general consumer interest, and is broken out to facilitate
- crossposting to misc.consumers -- rpw]
-
- [last change: 30 september 1992; fix typo in one answer -- rpw]
-
- Commonly Asked Questions
-
- Radar Questions:
-
- Q: Where are radar detectors illegal?
-
- A: In the US, currently Virgina, Connecticut, and the District of
- Columbia prohibit all usage of radar detectors. The Connecticut
- law has been changed, and detectors will be legal in that state
- beginning in October of 1992. New York prohibits their use in
- large trucks. In Canada, they are illegal in Manitoba, Ontario,
- Quebec, Newfoundland and PEI (Prince Edward Island). They
- are apparently are illegal through most, if not all, of Europe.
- Legislation which would make them illegal is pending in many other
- jurisdictions; chances of such legislation passing varies a great deal.
-
- Q: Where are Radar Detector Detectors used? Do they really work?
-
- A: Usage is spreading rapidly; initially they were used only in Canada,
- but now they are appearing in New York and Virginia. It is unsafe
- to assume that they are not in use in Connecticut and D.C.
- They work by detecting a certain frequency radiated by many currently
- available super Het radar detectors; some brands of detector radiate
- more strongly than others, and are thus more likely to be spotted.
- New radar detectors are becoming available which may not be detected
- by the current generation of detector detectors. Note that a
- detector may only be spotted by one of these devices if it is turned
- on.
-
- Q: What is VASCAR? Is it some kind of Radar?
-
- A: VASCAR is nothing more than a fancy stopwatch and time-speed-distance
- computer. It depends on the operator pressing buttons as the target
- vehicle passes landmarks. No radar signals are emitted by a VASCAR
- system.
-
- Q: What is Ka band radar? Where is it used? Should a radar detector be
- able to handle it?
-
- A: Ka band has recently been made available by the FCC for use in the US
- in so-called photo-radar installations. In these installations, a
- low-powered beam is aimed across the road at a 45 degree angle to the
- direction of traffic, and a picture is taken of vehicles which the
- radar unit determines to have been in violation of the speed limit.
- Tickets are mailed to the owner of the vehicle. Because of the low
- power and the 45 degree angle, many people believe that a radar
- detector cannot give reasonable warning of a Ka band radar unit,
- although some manufacturers of radar detectors have added such
- capability anyway. The number of locales where photo-radar is in use
- is limited, and some question the legality of such units. Best advice:
- learn what photo radar units look like, and keep track of where they
- are used (or else, don't speed.)
-
- Q: Do radar jammers work? Are they legal?
-
- A: Quick answer: No, and Not in the USA.
- Detailed answer: Cheap radar jammers do not work well at all.
- Jammers that work are expensive and usually the property of the
- military. Jammers are a major violation of the regulations of the
- Federal Communications Commission of the USA.
-
- Driving technique and Vehicle Dynamics Questions:
-
- Q: What are understeer and oversteer?
-
- A: Understeer and oversteer are terms describing the behaviour of a
- car while cornering near the `limit' (limit of adhesion, that is.)
- Most drivers do not normally drive hard enough for these terms to
- be descriptive of the situations they encounter. Simply put, they
- tell whether the car wants to go straight in a corner (steer `less',
- or `understeer') or it wants to turn more in a corner (`oversteer'.)
- Understeer is commonly designed into most production cars so that
- untrained drivers, inadvertantly traveling too fast, won't get into
- trouble. Understeer may also be induced by using too much throttle
- in a corner. Oversteer is designed into some more performance
- oriented cars; it may be induced by lifting on the throttle (Trailing
- throttle oversteer, or TTO). In extreme cases, lifting on the throttle
- may induce so much oversteer that the car reacts by fishtailing or
- spinning.
-
- Some technical details: in a corner at speed, the tires on the car
- will develop what are called `slip angles'; the slip angle is the
- angular difference between the direction that the car is traveling
- and the direction that the steering wheel is directing the car to
- travel. In understeer, the front wheels have a greater slip angle
- than the rear wheels. In oversteer, the rear wheels have a greater
- slip angle than the front wheels.
-
- Q: What is a rev-matched downshift?
-
- A: When downshifting, the engine must be rotating faster in the lower gear
- than it was in the higher gear. However, during a downshift, normally
- you declutch and lift your foot from the throttle, so the revs drop
- rather than increase. In rev-matched downshift, you blip the throttle
- before re-engaging the clutch so that the engine will already be up to
- the new speed. This results in a much smoother and faster downshift.
-
- Q: What does heel-and-toe mean?
-
- A: Heel-and-toe is a technique used to do a rev-matched downshift while
- braking. This is normally challenging, because you need the right foot
- for both the brake and throttle. It is called heel-and-toe because you
- use one end of the foot on the brake, and the other on the throttle to
- match revs for the downshift. In many modern cars this is a misnomer;
- often you must use the ball of the foot on the brake and the right side
- on the throttle.
-
- Note that some race car drivers will skip the clutch, and just use the
- left foot on the brake and the right foot on the throttle, accomplishing
- the same thing.
-
- Q: What is double-clutch downshifting?
-
- A: While your right foot is doing the above, your left foot can do one of
- three things: nothing, declutch once, or declutch twice. The reason for
- declutching twice is to match the speeds of the two shafts in the
- transmission to the speed of the engine. This is usually coupled with
- rev-matching, so that while the engine is in neutral and the clutch
- engaged, the throttle is blipped and both shafts of the transmission
- speed up.
-
- The procedure is as follows:
- (0) declutch
- (1) move gearshift lever to neutral
- (2) engage clutch
- (3) match revs
- (4) declutch
- (5) move gearshift lever to next lower gear
- (6) engage clutch
-
- This sounds like a lot of work, but with practice it becomes natural.
- The problem that double-clutching solves is normally the function of the
- synchronizers within the gearbox. In transmissions without synchros or
- with very worn synchros, double-clutching makes it much easier to shift.
- Basically, if you double-clutch well, you are not using the synchros at
- all. This is generally unnecessary on street cars with synchros in good
- condition.
-
- Q: What do the numbers for acceleration from 0-60, 1/4 mile, skidpad, and
- slalom times in the Auto Magazines really mean? May they be compared?
-
- A: In short, 1) not as much as the magazines want you to believe, and
- 2) almost never.
-
- In more detail: the acceleration numbers (0-60mph and 1/4 mile times
- in the US) may be vaguely compared as long as they all come from the
- same source. Testing procedures vary so much from magazine to magazine
- that comparing a Road & Track number to a Car & Driver number is quite
- pointless. Keep in mind, too, that the same variation applies from
- driver to driver on the street; the driver is a major (often *the*
- major) part of the equation.
-
- Skidpads vary, and even if they didn't, skidpad figures are really
- only tests of the stickiness of the stock tires; they change radically
- when tire compounds change. DO NOT make any assumptions about the
- comparative handling of, say, two sports sedans based on skidpad numbers.
- This is not to suggest that skidpads are without value, however. Skidpads
- are an excellent educational tool at driving schools. They are simply
- of limited value in the comparison of anything except tires.
-
- Slalom times are slightly more useful; they test some small parts of the
- automobile's transient response. However, they are also heavily influenced
- by the stock rubber on the car, and they do not test many corners of the
- car's envelope. They DO NOT tell you all you need to know before making
- a buying decision. For example, they don't tell you what the rear end
- of the car will do on a road which suddenly goes off-camber. When a car
- has an adjustable suspension, these tests are usually done in the `sport'
- setting, which may be quite unsuitable for daily driving. The list of
- caveats could go on for page after page.
-
- Misc. Questions:
-
- Q: What does <name or acronym> stand for?
-
- A: Here is a list of some of the names which are commonly asked
- about; be careful in soliciting the meanings of other names
- as misinformation abounds on the net. In particular, NEVER
- ask in rec.humor if you want a useful result.
-
- Saab: Svenska Aeroplan A. B.,
- or The Swedish Airplane Corporation
-
- Alfa: Societa Anonima Lombarda Fabbrica Automobili,
- or The Lombardy Automobile Manufacturing Company
-
- Fiat: Fabbrica Italiana di Automobili Torino,
- or The Italian Automobile Manufacturers of Turin
-
- BMW: Bayerische Motoren Werke,
- or Bavarian Motor Works
-
- MG: Morris Garage
-
-
- Q: Does VW own Porsche?
-
- A: No. Porsche is a publicly held company, controlled by the Porsche and
- Piech families. Porsche has extensive business dealings with VW/Audi,
- which causes some confusion. Since currently Porsche is in some
- financial difficulty, there is a possibility that Mercedes or VW may
- be interested in purchasing the company in the near future, but this
- is only speculation at this time.
- --
- richard welty 518-393-7228 welty@cabot.balltown.cma.com
- ``Nothing good has ever been reported about the full rotation of
- a race car about either its pitch or roll axis'' -- Carroll Smith
-