Autocross School, 2005 Grenada, MS - PowerPoint PPT Presentation

1 / 44
About This Presentation
Title:

Autocross School, 2005 Grenada, MS

Description:

All events are run by volunteers. In order to compete, you must 'work' the course ... Watch cones and not that beautiful Saleen Mustang that's driving by ... – PowerPoint PPT presentation

Number of Views:130
Avg rating:3.0/5.0
Slides: 45
Provided by: z11
Category:

less

Transcript and Presenter's Notes

Title: Autocross School, 2005 Grenada, MS


1
Autocross School, 2005Grenada, MS
  • By James Lee, Lance Coley, Matthew Anderson,
    Teddy Gibson
  • Special thanks to
  • Roger H. Johnson and Trey Walker

2
Volunteer Organization
  • All events are run by volunteers
  • In order to compete, you must work the course
  • More co-operation means a smoother running event

3
Working the course
  • Obtain work assignments from chief of workers
  • Report to work station on time
  • Station will have some extra cones, fire
    extinguisher, red flag and radio
  • One person holds both the radio and the red flag
  • Everyone else picks up downed cones
  • Watch cones and not that beautiful Saleen Mustang
    thats driving by
  • Face cars at all times never turn your back
  • Watch out for other workers
  • If there is an emergency on course, show the red
    flag and try to get the driver to stop

4
Working the Course
  • Each downed cone is a 2 second penalty which will
    be added to your final time
  • Person calls in the cone(s) mentioning
  • Station number
  • Car and class
  • Number of cones

5
Working the Course
NO DNF
  • 2005 Solo Rule book 7.9.3
  • A DNF, or a time penalty if so specified shall
    be charged for any uncorrected deviation from the
    course, or for unnecessarily delaying the event.
    A course deviation shall not be charged if any
    part of the car hits a marker defining the
    limits of the course. A DNF is charged only if
    part of the course is omitted. In returning to
    the course after an off course excursion, it is
    acceptable to drive a part of the course a second
    time.

SCCA Solo Rules, 2005 Edition by Sports Car Club
of America, Sports Car Club of America, Topeka,
KS, 2005, p. 45
6
Working the course
  • Penalties
  • Directional cones do NOT count!!!

SCCA Solo Rules, 2005 Edition by Sports Car
Club of America, Sports Car Club of America,
Topeka, KS, 2005, p. 46
7
Working the Course
  • No Penalty
  • Directional cones do NOT count!!!

SCCA Solo Rules, 2005 Edition by Sports Car
Club of America, Sports Car Club of America,
Topeka, KS, 2005, p. 46
8
Driver Responsibility
  • Make sure car passes tech inspection
  • Drive quickly and safely
  • Bring out the full potential of the car
  • on a given course
  • Drive car at the limit
  • Choose the optimum racing line
  • Analyze course conditions

9
Tech inspection
  • Seat belts working
  • Roll bar for certain classes
  • Removable tops / panels
  • Brakes / fluids / pedal
  • Battery firmly mounted
  • Fluid leaks
  • Muffler / exhaust
  • Loose items removed from car
  • Front suspension / steering
  • Throttle return / belts / accessories
  • Tires / tread / pressure / treadwear
  • Wheels / hubcaps / lugs
  • Number / class marked on car
  • Helmet

10
Class and Numbers
  • 14 SM2

8 in
4 in
1.25 in
0.75 in
SCCA Solo Rules, 2005 Edition by Sports Car
Club of America, Sports Car Club of America,
Topeka, KS, 2005, p. 30
11
Helmet Requirements
  • Snell foundation standards
  • Current and two immediately preceding standards
    (SA, K, M)
  • Current Standard is 2005, so 95 and 2000
    standards are valid
  • SFI standards
  • 31.1A, 31.2A, 41.1A, 41.2A
  • FIA approved helmets which are acceptable for use
    in Rally events.

SCCA Solo Rules, 2005 Edition by Sports Car
Club of America, Sports Car Club of America,
Topeka, KS, 2005, p. 46
12
Helmet
http//www.smf.org http//www.motorsportbayern.de/
verschiedenes/reglement/slalom-tipps-helme.htm
13
Tires
14
Tires
  • Uniform Tire Quality Grading
  • System (U.T.Q.G.)
  • Treadwear
  • 100 30,000 miles
  • 200 60,000 miles
  • 140 Street Tire
  • Traction (AA, A, B, C)
  • Testing on wet surface
  • Compound not tread design
  • Temperature (A, B, C)
  • Ability to dissipate heat
  • Based on tires ability to operate at high speed
    w/o failure

http//www.hankooktireusa.com
15
Tire Pressures
Tread Wear Indicators (TWI)
Tread wear
  • If suspension settings cannot be changed or if
    suspension settings are optimal, adjust tire
    pressures until tire wear barely touches the TWI
    markings

16
Contact Patch and Weight Transfer
Front
Front
Front
Rest Equal contact patches on all tires
Accelerating Weight transferred to rear tires
Braking Weight transferred to front tires
Front
Front
Front
Right turn Weight transferred to left hand tires
Left Turn Weight transferred to right hand tires
Brake Turning (Trail-braking) Weight concentrated
on the front outside tire
17
Slip Angles
Direction tire is pointed
Direction vehicle is traveling
Slip angle
Race Tire
Street Tire
18
Slip Angles
  • Slip angle and self aligning torque (steering
    centering force)
  • Sensitive drivers feel the steering effort
    fall off letting him/her know that they are out
    of the optimum slip angle range

Self Aligning Torque
Drive to win by Caroll Smith, Carroll Smith
Consulting, Inc., Palos Verdes Estates, CA, 1996,
p. 2-7
19
Slip Angles
Overdriving/ Drifter
Optimum (Genius Level)
Novice
Advanced Driver/Talented Novice
20
Neutral Steer
  • Front tire slip angle the same as rear tire slip
    angle
  • Ideal
  • 4 wheel drift!
  • Might feel like a substantial slide to a novice
  • Satisfaction guaranteed!

5o
5o
Front tire slip angle the same as rear tire slip
angle
21
Understeer
  • Front tire slip angle larger than rear tire slip
    angle
  • Causes
  • Front tires have less traction than rear tires
  • Improper car setup
  • Natural handling characteristic of car (FWD, AWD)
  • Insufficient weight transfer to the front tires
    before turning
  • Entering a turn to fast (Overcooking)
  • Remedies
  • Unwind wheel
  • If front tires over optimum slip angle range
  • If front tires lose rotational speed
  • Slow down the car gently by lightly letting off
    the gas pedal or by light left-foot braking
  • Transfers weight to front tires
  • Reduces centripetal force
  • Trail braking
  • Curse wont do anything but will make you feel
    better, look cool

15o
5o
22
Oversteer
  • Rear tire slip angle greater than front tire slip
    angle
  • Causes
  • Rear tires have less traction than front tires
  • Improper car setup
  • Natural handling characteristics of car (RWD)
  • Excessive trail-braking
  • Abrupt/jerky steering inputs
  • Trailing throttle oversteer (TTO)
  • Power oversteer
  • Remedies
  • Countersteer
  • TTO - keep constant throttle or possibly
    increasing throttle input gradually to transfer
    weight to the rear
  • Power oversteer - decrease throttle input to
    reduce tire slippage
  • Stop watching dvds like drift society,
    dorifuto tengoku, option, etc.

5o
30o
23
Traction circle
  • Represents the grip capability of a car
  • Can only use 100 of any one action at a time
  • Or split duty between two actions
  • To maximize the use the traction circle, you need
    to drive smoothly

24
Corner sequence
  • Threshold braking zone
  • Brake turning zone/trail-braking
  • Constant throttle zone
  • Gradual increase in acceleration while unwinding
    wheel
  • Always use smooth steering inputs and smooth
    transitions

Acceleration
Braking
Turning
25
Basic racing lines
  • The traditional racing line is the widest
    constant arc through a corner
  • Maintains momentum throughout corner
  • Excellent line for low horsepower cars or for
    large radius corners

26
Racing line Early Apex
Wheee!_at_
  • Premature turn-in severely chokes corner exit.
  • Corner exit speed suffers
  • May result in an agricultural excursion

27
Racing LinesLate Apex
  • Gives up a little speed at entry to gain a
    longer straightaway on exit
  • Ideal for straight-line traction limited cars
    (ie. high horsepower) or for tighter corners
  • Safer than early apex

28
Sacrifice Corners
  • Line you would take if corner leads to a straight
  • But you need to place car here if you want to
    take the next turn with the widest arc

29
Sacrifice Corners
  • Cars with lower HP cant accelerate as fast so
    they need to maintain as high a speed as possible
    therefore the fast line for them is a little
    different. Typically they need to maintain a
    higher average speed.
  • The sacrificial line taken by a high HP car if
    the second turn leads into a significantly long
    straight

Miata
Miata
Miata
30
Advanced TechniquesTrail-braking/Heel and
Toe/Left foot braking
These techniques smoothes out braking-turning/acce
leration-braking transitions
  • Trail-Braking
  • Instead of completing braking before turn-in,
    braking is initiated slightly later and continued
    through turn-in to take advantage of the traction
    circle
  • Once turn-in begins, braking must be decreased to
    prevent wheel lock-up
  • Can be used to help rotate car at turn-in
  • Left Foot Braking
  • Can be used in conjunction with trail-braking
  • Allows better mid-corner balancing of cars
    steady-state attitude
  • Allows quicker transition from brakes to gas
    after turn-in
  • Normally only done when a downshift is not
    required to take the corner
  • Excellent autocross technique, but some great
    drivers dont use it
  • Heel/Toe Downshift
  • Utilized when a downshift is required in the
    braking zone
  • Match revs without lifting off brakes,
    maintaining control of cars attitude.
  • Rarely needed on an autocross course

31
Seating Position
  • Seat should be upright to slightly reclined.
  • Arms should have slight bend at elbow so that the
    steering wheel can be turned about 180 degrees
    without completely straightening arms
  • Hands should not hit legs at severe steering
    angles
  • Always use both hands to control the steering
    wheel
  • Legs should be slightly bent at the knee

32
Course Walking
  • Objective
  • Familiarize yourself with general course lay-out
  • Identify key cones
  • Define driving lines
  • Find places to gain an edge on competition
  • Course should be walked twice at a minimum
  • Once with experienced person or group to discuss
    lines
  • Again by yourself to define your own line and
    memorize course.
  • Should have a good enough visual image of course
    to mind drive it

33
Locating Key Cones
Key Cone
  • Locate key cones
  • Key cones dictate the racing line
  • Choose line based on car, key cones and how wide
    the gates are
  • Wider gates allow for sloppier lines which are
    not necessarily faster

Key Cone
Key Cone
Key Cone
Key Cone
Diagram Courtesy of Roger Johnson of the Houston
Region SCCA
34
Choosing a Line Recognizing Visual Deceptions
Diagrams Courtesy of Roger Johnson of the Houston
Region SCCA
35
Slaloms
Diagrams Courtesy of Roger Johnson of the Houston
Region SCCA
36
Slaloms
Examples slaloms in disguise
  • Recognize certain course features as slaloms
  • Focus on key cones when walking/driving the course

Diagrams Courtesy of Roger Johnson of the Houston
Region SCCA
37
SlalomsPacing Slalom cone distances
Slalom cone distances may vary. Therefore its a
good practice to always pace them
Diagrams Courtesy of Roger Johnson of the Houston
Region SCCA
38
Slaloms
The Gap will make a tight maneuver faster
Version "A"

Speeding things up
With an increasing gap, you will be able to drive
faster through the slalom. A small increase
(e.g. one foot) will have a surprisingly large
effect
Diagrams Courtesy of Roger Johnson of the Houston
Region SCCA
39
Slaloms
Diagrams Courtesy of Roger Johnson of the Houston
Region SCCA
40
Other Visual Deceptions
Look painful - but are not
Truly Painful
solutions keeping the same flavor as the original
Narrow, walled in sharp turns
these areas
cause the
All can be driven as one flowing turn
maneuver to be
painful
The problem associated with this narrow walled in
turn is that the placement of the wall forces the
turn to be made up of 2 or more painful turns
instead of a flowing turn
30' gates
18' gates
Diagrams Courtesy of Roger Johnson of the Houston
Region SCCA
41
Looking Ahead
  • When you are here
  • You need to be spotting this key cone
  • When you are here
  • You need to be looking at this key cone
  • When you are here
  • You need to be looking there

Diagrams Courtesy of Roger Johnson of the Houston
Region SCCA
42
Revolving magical gates
Walnut Ridge, AR, National Tour 2005
Watch these cones
Racing Line
43
Revolving magical gates
Walnut Ridge, AR, National Tour 2005
Now they look like a slalom
44
Revolving magical gates
Walnut Ridge, AR, National Tour 2005
But wait, If you take the correct line, they open
up into a short straight!
Write a Comment
User Comments (0)
About PowerShow.com