High Perf Driving Manual

8/10/2019 High Perf Driving Manual

1/32

2005 Update $12.95

High PerformanceDrivers Manual

ind! "it! "hapter

#M "ar "lu of %merica

& 19'() 199*) 199') 2005 %llen +. Huener

"over and ,llustrations ! -. . /chettel

1


2/32

Copyright 1986, 1994,1996, 1997 & 2005 Allen G. Huebner

Illustrations by Larry R. Schettel

"-%// 1

,. /ecrets of High Performance Driving

,,. Preparing to Drive

%. "ar ,nterior -oose ects3#. 4ire Pressure". /itting ,n the /eatD. Mirrors. /eat #elts

6. Holding and 4urning the /teering heel) Part 1+. arm7UpH. "ool7Do8n

,,,. -ine77,nitial Discussion

,. "ornering

%. #ra:ing#. 4urning the /teering heel) Part 2". %cceleratingD. Do8n /hifting. 4rac: -a!out

. %ttitude

2


3/32

1. /ecrets of /uccessful High Performance Driving

4he three secrets of high performance driving are;

1. /moothness)2. /moothness and)

s suspension.4he steering 8heel is turned onl! as ?uic:l! and onl! as far as is asolutel!necessar! to place the vehicle on the desired path. #ra:es are not applied)released and reapplied causing the car to ounce ac: and forth on its

suspension. ather) the ra:es are applied once) progressivel! and s8iftl! untilthe vehicle attains the desired speed) then smoothl! released. Do8nshifts areimperceptile e=cept for the change in the pitch of the sound from the engine.4here is no lurching) s?uatting) or ouncing of the vehicle as the lo8er gear isengaged. %pplication of the throttle is smooth and progressive) unaccompanied! throttle7on throttle7off antics 8hich 8ould also upset the vehicle>s delicatealance.

+ood driving consists of proper use of the steering 8heel and foot8or:.

4he rest of this manual contains the information !ou need to help !ou ecomesmooth) smooth) and smooth. @ou) ho8ever) must suppl! the discipline anddetermination necessar! to put the information to 8or: for !ou.

,,. Preparing to Drive

%. "lean ,nterior,t is imperative that all loose oects) and an! oects 8hich might ecomeloose) are removed from the interior of !our car efore venturing out ontothe trac:. "H"A UBD 4H 6B4 /%477oects tend to gravitateto this area and are forgotten until the first time the ra:es are appliedvigorousl! 8hereupon the! roll) slide) or roc:et out to ta:e up residence inor aout !our feet.

,t>s ad enough carr!ing loose oects in !our car on the street) ut on a

racetrac:) the haCards are magnified. %side from getting in the 8a! at the8rong time) these items can ecome lethal proectiles) particularl! in anaccident. B "%@ %B@4H,B+ B 4H /H-6 UBD 4H% ,BD on or off the trac:3.

e also recommend that !ou remove the floor mats to avoid the possiilit!of getting tangled up in them or their moving and interfering 8ith thepedals.


4/32

#. 4ire PressurePeople 8ho have auto7crossing e=perience tend to inflate their tires tover! high pressures ,>ve heard conversations of as high as *0 psi3.4hese high pressures might e fine for auto7crossing onl! a tirep!rometer 8ill guide !ou to the optimum pressure3 8here the car is on the

course for onl! aout a minute ut it>s too high for a race trac: or thestreet3.

Due to cornering) ra:ing) and accelerating forces on the tire) heattransfer from the ra:es and the length of time spent on the trac:) the tires8ill get hot. %s the! heat up) the air in the tire e=pands resulting in anincrease in tire pressure.

,f !ou start 8ith *0 psi cold pressure) !ou ma! end up 8ith e!e poppinginflation during a trac: session. /tart 8ith around s 8here the8arm up comes in discussed later3. %s the tires heat up and the pressurerises the tires should egin to feel ver! good.

B4; /ome ne8er high performance tires call for ver! high coldinflations pressures. ,f !ou have such tires) follo8 the tire manufacturesrecommendations. ,n all cases) ho8ever) , recommend that !ou note=ceed the ma:ers recommended inflation pressures 8hen the tires arecold.

". /itting in the Drivers /eat

Performance driving does not permit the driver to e a loose oect in thecar. 4o control the car !ou must e firml! installed ehind the steering8heel in a manner 8hich permits !our legs and arms the ma=imum rangeof motion and leverage. 4o achieve this) !ou must first sit in rather thanon the seat. Use !our feet to push !ourself into the seat. iggle !ourehind to urro8 do8n into the seat.

%fter !ou are sitting in the drivers seat) 8ith !our ac: against the seatac:) chec: to ma:e sure !ou can reach all the pedals77if not) adust theseat for8ard until !ou can) and urro8 ac: do8n into the seat.Bo8) :eeping !our ac: against the seat ac:) reach for8ard and place!our hands on the steering 8heel at the < and 9 o>cloc: positions) see6,+U 1.

*


5/32

6,+ 1

-oo: at !our arms. 4he! should e slightl! ent. ,f !our arms are full!e=tended) !ou>re too far from the steering 8heel e=cept) perhaps) if !ou>re

driving an ,talian car3. /itting too far ac: 8ill cause !ou to lean for8ardand out of the seat ac: in order to steer or shift) 8hich in turn 8ill cause atendenc! to use the 8heel as a race during hard cornering. %dust theseat closer to the steering 8heel or) if !ou need the leg room) tilt the seatac:) for8ard.

Be=t) remove !our right hand from the < o>cloc: position and place it ontop of !our left hand at the 9 o>cloc: position. ,f !ou are ale to do this8ithout !our ac: moving a8a! from the seat ac:) and) assuming oth of!our arms are the same length) !ou>re on the right trac:) ut !ou still mustma:e certain that !ou are not sitting too close to the steering 8heel.

Place !our hands ac: on the steering 8heel at the < and 9 o>cloc:

positions. ememer) !our arms should e ent slightl!. 4urn thesteering 8heel to the right and then to the left 8ithout moving !our handsfrom the < and 9 o>cloc: positions. ,f 8hen !ou do this) !our elo8s hit theseat ac: or !our od!) !ou are too close to the steering 8heel. 4ilt theseat ac:) ac: until !our arms are ust slightl! ent. /hort people ma!never e ale to otain the proper seating position 8ithout modif!ing thecar) i.e.) e=tending the pedals 8ith loc:s. ,f !ou>re short) ust tr! to findthe est compromise et8een reaching the pedals) slightl! ent arms) andeing ale to see over the dashoard or) modif! !our car.

D. Mirrors and +auges

#efore attaching !our seat elt) adust !our rear vie8 mirror and sidemirrors. H,- D,,B+ B 4H 4%"A) @U MU/4 "B/4%B4-@MB,4 @U M,/. 4his should e !our regular practice8henever and 8herever !ou>re driving. @ou must constantl! e a8are of8hat>s going on around !ou77to accomplish this) !ou must use thosemirrors. n the trac:) !ou need to e a8are of traffic that ma! 8ish topass !ou. /ince !ou>ll e prett! us! in the corners) !ou 8on>t have time to

5


6/32

chec: the mirrors) ut chec: them several times on each straight a8a!. ,naddition) 8hile on a straight a8a!) chec: the engine function gauges or8arning lights77engine temperature) oil pressure) and charging s!stem amalfunctioning charging s!stem ma! mean that the fan elt has ro:en3.6orget aout the speedometer.

. /eat #elts

e stated earlier that !ou must e firml! installed ehind the steering8heel. ,f !our car is e?uipped 8ith a competition harness) it>s noprolem77ust cinch do8n the lap elt and tighten the shoulder elts untilthe! hurt a little pain 8ill :eep !ou alert3. ,f !ou>re considering installing acompetition harness in !our car) a five point s!stem t8o lap) t8o shoulderand an antisumarine elt3 is the est s!stem and the one !ou shoulddefinitel! install if !ou are planning on going racing. 4he anti sumarineelt mounts on the car floor) runs up et8een !our legs and connects up8ith the other four elts. ,n addition to preventing !ou from sliding underthe lap elt) it 8ill hold the lap elt in the correct position do8n around!our pelvic one and hips3 8hen !ou cinch up the shoulder elts.

% four elt s!stem t8o lap and t8o shoulder3 is the ne=t est andpreferale to the ..M. s!stem. #e a8are ho8ever that the shoulderelts ma! pull the lap elt out of its correct position do8n around !ourpelvic region. 4o minimiCe this prolem) first sung up the lap elts tightl!then adust the shoulder elts.

,f !ou don>t have a competition harness ma!e all is not lost. %ttach theM eltEshoulder harness and cran: the seat ac: do8n. hile !ou>restaring at the roof of !our car) gra the shoulder elt and give it a violent

er: to fool it into thin:ing !ou>ve ust een in an accident. 4he inertias!stem 8ill loc:. nce it>s loc:ed) lean !our od! for8ard against it tohold it in the loc:ed position and at the same time cran: the seat ac:)ac: up to !our driving position. @ou are no8 installed ehind the 8heel.Unfortunatel!) at least for us go fast fol:s3 auto manufactures havechanged the s!stem that causes the elts to loc: so this little tric: 8on>t8or: in some ne8er vehicles.

riginal e?uipment manufacturer.

6. Holding and 4urning the /teering heel77Part ,

#oth hands please. ne hand ma! e removed to change gears or signalanother to pass) ut once accomplished) it is to e returned to the 8heel.B B H%BD D,,B+. ,t is ver! difficult to otain the smooth)

accurate movements of the steering 8heel re?uired in high performancedriving using onl! one hand.

4he car is to e driven 8ith !our hands at the < and 9 o>cloc: positions. ,f!our steering 8heel permits) hoo: !our thums over the spo:es. 4hesteering 8heel) li:e a golf clu is held lightl! ut firml! 8ith the fingers.@our fingers are more sensitive than the palms of !our hands.3 ,f !ouhold the 8heel 8ith a death grip) !ou>ll cut off !our circulation and !ou

(


7/32

8on>t feel an!thing. ,n addition) gripping the 8heel too tightl! 8ill inhiitsmooth precise movements of the 8heel. 4o turn the 8heel) pull do8nrather than pushing up i.e.) for a right turn) pull do8n 8ith !our right handrather than pushing up 8ith !our left3.

4he < and 9 o>cloc: positions should permit !ou to ma:e most turns on

most trac:s 8ithout getting !our arms full! crossed. @our arms shouldnever ecome full! crossed ecause if !ou discover that more loc: isre?uired) !ou 8on>t e ale to do it. -oc: is an! change in steering 8heelrotation. ,t does not necessaril! mean turning the 8heel as far as it 8illgo.3

,f a turn is so sharp that it cannot e navigated 8ith hands at < and 9o>cloc:) t8o acceptale solutions e=ist. Beither of 8hich re?uiresremoving !our hands from the steering 8heel.3

6irst) !ou can change the position of !our hands on the steering 8heelefore !ou reach the turn. 6or e=ample) if !ou>re approaching a sharpright turn) slide !our right hand up the steering 8heel to one o>cloc:) !our

left hand to F o>cloc: and pull do8n 8ith !our right hand to ma:e the turn.%fter the turn) slide !our hands ac: to < and 9.

%lternativel!) !ou can slide !our right hand to one o>cloc: as !ou approachthe turn and leave !our left hand at 9 o>cloc:. %s !ou turn the 8heel) letthe 8heel slip through !our left hand until the part of the steering 8heeldirectl! opposite !our right hand is ! !our left hand. Bo8 close the gripof the left hand and complete the turn using oth hands. hen !ouun8ind the 8heel) again let the 8heel slide through !our left hand until the9 o>cloc: position comes around and close !our grip. @ou can) ! moving!our right hand all the 8a! over to !our left hand) get one full rightrevolution of the steering 8heel. ,t is not unli:el! that !ou 8ill feeluncomfortale holding and using the steering 8heel correctl!. %fter doingit incorrectl! for man! !ears) it>s ound to feel uncomfortale ut stic: 8ithit and unlearn !our ad haits. ,f !ou reall! 8ant to ecome a competenthigh performance driver) the correct use of the steering 8heel is important.

+. arm 7Up

1. Bovice Drivers. Drive the first several at least t8o3 laps of each of!our trac: session at a conservative pace to allo8 !our car) its tires) and!ou time to 8arm up.

2. ,ntermediate and %dvanced Drivers. Beed to 8arm7up also.During !our 8arm7up lap or laps) drive at a conservative pace ut) use the

ra:es ver! hard) enter the turns at a relativel! slo8 pace ut turn in hardand accelerate hard out of the turn. ,n addition) pinch the car in a little atthe e=it of the turn i.e.) don>t un8ind the steering 8heel as much as !ounormall! 8ould coming out of the turn3.

H. "ool Do8n

F


8/32

%t the conclusion of each trac: session) !ou 8ill e given a cool do8n lap.U/ ,4 4 "- DB77!ourself and !our car. /lo8 do8n) use thera:es as little as possile to assist in their cooling off. D B44UB 766 @U #%,B . 4he cool do8n lap can e e=tremel!dangerous ecause) compared to !our speed on the previous lap) it 8illfeel li:e !ou>re traveling ver! slo8l!. @U> B4G @ou>re still traveling

?uite fast so P%@ %44B4,B.

hen !ou finall! stop !our car in the pit lane or paddoc:) D B4 /44H M+B"@ #%A. D B4 H-D 4H #%A PD%- DBH,- 4H "% ,/ /4PPD. %t this point) !our ra:e rotors are hotand getting hotter. Doing either of the aove ma! 8arp the ra:erotors77or 8orse.

,,,. 4he -ine 77Preliminar! Discussion

4he line is the path descried ! a vehicle as it travels on a road.

4he correct line through a corner 8ill al8a!s involve using all7 of the availale

road8a!. 4his) and the other information in this manual) is applicale no matter8here !ou>re driving. 6or e=ample) the correct line doesn>t change) onl! theamount of road8a! availale to !ou changes. n a race trac:) the entireroad8a! from one shoulder to the other is availale 8hereas) on a pulic road)onl! a single lane ma! e availale to !ou. Aeep this in mind so that 8hen !oucomplete this performance driving school !ou can appl! the principles !ou>velearned to !our ever!da! driving.

4he Icorrect lineI 8ill al8a!s 8ell) almost al8a!s77ut for no8 al8a!s3 involvestarting an! turn from the e=treme outside edge of the road8a!) then touchingthe e=treme inside edge of the road8a! and finall! touching the e=treme outsideedge of the road8a! as !ou e=it the corner. /ince a picture is 8orth a thousand8ords) refer to 6igure 2. 4he point on the inside edge of the road8a! touched !the car as it travels through the turn is called the %pe=.

'


9/32

6,+ 2

6or this school) 8e have identified these important points on the trac: for !ou !placing p!lons at the correct turn7in point) the %pe=) and in some cases) atouching point on the outside of the road8a! at the e=it of the turn.

,. "ornering

-ater 8e 8ill discuss %pe=es) the "orrect -ine) and the 8h!s and 8herefores adnauseam) ut during !our first trac: session all !ou need to do is drive on thee=treme outside of the trac: surface as !ou approach a turn the outside is theside opposite the direction of the upcoming turn) i.e.) if the turn !ou>reapproaching is a right7hander) then the left hand side of the road8a! is theoutside and vice versa3) turn into the turn at the turn7in p!lon it 8ill e the firstp!lon !ou encounter as !ou approach the corner3) touch the edge of the road8a!

at the p!lon mar:ing the %pe= the second p!lon3) and touch the outside edge ofthe road8a! at the e=it p!lon. ,f !ou do this correctl!) the line !ou 8ill e driving8ill e the safest route) and usuall! the fastest) through the corner. ,t is called a-ate %pe= line.

4o drive the line that 8e have laid out for !ou) !ou must not;

9


10/32

1. 4urn in too soon) i.e.) efore !ou reach the turn7in p!lon2. Move a8a! from the outside edge of the road8a! efore !ou reach the

turn7in p!lon. ,n other 8ords) don>t even thin: aout starting the turn until!ou reach the turn7in p!lon

t8orr! if !ou hit the %pe= cone.3

*. Drop a tire or tires off the road8a!.

%. #ra:ing

%s !ou approach the turn in p!lon) !ou 8ill) in most cases) need toget the car slo8ed do8n. nl! the ra:es should e used to slo8the car. Do8nshifting) 8hile it might seem neat) should not e usedto slo8 the car. #ra:es are cheaper and more effective for thepurpose than transmissions and clutches.

4he proper use of the ra:es re?uires that the! e used as hard aspossile over the shortest possile distance. Hard means that thera:es must e applied hard enough for the 8heels to reach a point

ust short of loc:ing up i.e.) stopped3. 4his is called thresholdra:ing. 4he ra:es must e applied smoothl! and progressivel!s?ueeCe the pedal do8n3 to a point ust short of loc: up. 4heslo8er the speed of the vehicle) the more pressure can e appliedto the pedal 8ithout loc:ing up the 8heels. 4herefore) al8a!ss?ueeCe do8n on the pedal. Bever) never slam !our foot do8n onit. @ou don>t 8ant to loc: up the 8heels) ecause) at an!thing overre perfect) the! 8ill also smo:e.

D B4 /-%M B 4H #%A/ this 8ill cause the 8heels toloc:3. D B4 PUMP 4H #%A/ unless !ou find !ou havenone. Pumping 8ill sometimes ring ac: enough pedal to get !ouslo8ed do8n enough to avoid disaster. nce !ou have pedal)ho8ever) use them as discussed aove3.

6,B,/H %-- #%A,B+ H,- 4H "% ,/ 4%-,B+ ,B %/4%,+H4 -,B.

4he ra:es should e used ver! hard earl! on as !ou approach theturn in p!lon) less ust efore reaching the p!lon and even less ornot at all right at the p!lon. 4he idea here is that !ou 8ant thetransition from full ra:ing to no ra:ing to e gradual. ememer)

10


11/32

as !ou ra:e) 8eight is transferred to the front tires and 8hen thera:e is released) 8eight is transferred to the rear tires.

@ou should e a8are that sometimes the ra:es are continued ver!slightl! as the car is turned into the corner. 4his is called 4rail#ra:ing or 4railing the #ra:es. Bo8 forget it for the present and

finish all of !our ra:ing in a straight line.

@ou ma! find that at first !ou have difficult! ra:ing ver! hard andreleasing the ra:es ust efore the turn in point and also drivingthe correct line. ,f so) since it is more important at this point3 that!ou drive the correct line) slo8 do8n until !ou can do it correctl!.

#. 4UB,B+ 4H /4,B+ H- 77P%4 ,,

4o turn the 8heel al8a!s pull do8n rather than pushing up. 6ore=ample) in a right turn) pull do8n 8ith !our right hand rather thanpushing up 8ith !our left. hen !our car reaches the turn in p!lon)the steering 8heel motion re?uired to get pointed to8ard the %pe=

must e one continuous) smooth motion. %void turning the 8heeltoo little or too much so that corrections 8ill not e re?uired in orderto hit the %pe=. 4his 8ill ta:e some practice. %t the %pe=) !oumust egin to un8ind the steering 8heel in one continuous) smoothmotion so that the car touches the edge of the road8a! at the e=itp!lon. ,n high speed performance driving) the steering 8heelshould e moved as infre?uentl! as possile and no more than isnecessar! to put the car 8here !ou 8ant it. 4he less the steering8heel is moved) the faster the car 8ill go. Bo sudden her:!7er:!steering inputs. hen !ou>re driving slo8l!) !ou can ma:e thesemista:es 8ithout getting into troule) ut 8hen !ou>re driving nearthe limits) mista:es can e costl! or 8orse3. -%B 4 D ,4""4-@ B.

". %""-%4,B

%s soon as !ou have turned and the car is pointing to8ard the%pe=) egin to accelerate. Do not coast through the turn. Ho8much !ou can accelerate 8ill depend on a numer of things) utthe general rule of thum is that !ou should have the acceleratorpedal do8n on the floor as !ou clip the %pe= point. @our instructor8ill assist !ou in ma:ing this determination.3 D B4 /UDDB-@-,64 @U 64 66 4H %""-%4 H,- 4H "% ,/4UB,B+. ,t transfers 8eight and could cause the car to spinout.3

#! the end of !our first trac: session) !ou should e ale toconsistentl! drive the correct line e=actl!3 in each turn) and !oushould e recording a mental picture of ho8 ever!thing loo:s 8hen!ou>re driving the correct line) particularl!) the picture of the %pe=and its setting ust after !ou>ve turned in. 4his information 8ill ee=tremel! important to !ou as !ou egin to drive faster. ,f !ouma:e a mista:e in eginning !our turn) the earlier !ou recogniCe

11


12/32

!our error) the easier it 8ill e to ta:e corrective action slo8 do8n3to avoid a potentiall! serious prolem later in the turn.

During this first trac: session) !ou do not need to and shouldn>tdrive fast. /peed 8ill not impress !our instructor. Ho8ever) drivingsmoothl!) on the correct line) using the ra:es properl! and

accelerating at the proper time 8ill. Drive at 8hatever speed 8ithinreason3 8ill allo8 !ou to consistentl! drive the correct line. /peedis not important right no8. Driving the correct line is. ,f !ou cannotdrive the correct line) !ou 8ill not e ale to drive fast. 6re?uentl!)the slo8 drivers in the first session are among the ?uic:est driversat the end of the da!.

D. DB/H,64,B+

,f !ou do not alread! :no8 ho8 to heel and toe 8e 8ill discuss thistechni?ue later3) 8e suggest that !ou don>t tr! do8nshifting duringthe first trac: session. Just stic: the thing in third gear) andconcentrate on 8hat 8e have discussed so far.

,f !ou do :no8 ho8 to heel and toe and can do it proficientl!) thecorrect procedure is to finish shifting 8hile the car is still traveling ina straight line. 4he clutch should e released 8ith the transmissionin the proper gear ust efore !ou turn in. 4he longer !ou 8aitefore engaging the lo8er gear) the less li:el! 8ill e the chance ofan overrev. i.e.) spinning the engine faster than it 8as designedfor77over the red mar: on the tachometer. Damage from overrevinggenerall! occurs during do8nshifting.3

. 4%"A -%@U4

MemoriCe the trac: so that !ou 8ill :no8 e=actl! 8hat>s comingne=t. @ou cannot drive fast if the ne=t turn comes as a surprise and!ou merel! react to it. Ano8 8hat>s coming ne=t and 8hat !ou aregoing to do 8hen !ou get there. hen !ou 8or: corners) stud! theterrain near the e=it from the turn. K,s there room to go off the roadthere 8ithout serious conse?uencesL 4he information ma! come inhand! efore the end of the da!.

Use some of !our rest period time to go off ! !ourself and thin:aout the trac: and !our driving. Mentall! drive the trac: severaltimes77tal: !our 8a! through it. 4he great thing aout this is that!ou 8ill do it perfectl! ever! lap. During !our ne=t trac: session)!ou>ll e surprised ho8 much !ou>ve improved since the previous

session.,. %44,4UD

/ta! alert) this is serious usiness) ut don>t tense up. ela= and drive 8ith anair of calm. -isten to !our instructor and follo8 hisEher directions. 4H,BA.

12


13/32

"lass ,,

,. Ph!sics of High Performance Driving

%. 6riction "ircle#. /peed in a turn

". elationship to Performance DrivingD. /lip %ngles. versteer and Understeer

,,. /:id "ontrol

%. 4otal -oss#. -ess than a 4otal -oss

,,,. %gricultural Driving

,. #ra:e Points

. Driving in the ain

1


14/32

"lass 2

,. Ph!sics of High Performance Driving

4here are several ph!sical concepts that are important to high speed driving.4hese concepts are interrelated and 8hile !ou ma! find the follo8ing discussions

to e some8hat dr!) it is important for !ou to understand 8hat is happening to!our vehicle during spirited driving.

%. 6riction "ircle

%n automoile contacts the road surface through its tires at least that isthe position !ou should strive to maintain3. % tire>s contact patch is aoutthe siCe of a post card) or aout the siCe of this page for all four tirescomined. 4he contact patch area for an! given 8eight automoileremains constant regardless of the siCe of the tire. hen !ou hearsomeone sa! that the! put 8ider tires on their car to get more ruer onthe road) the! don>t :no8 8hat the!>re tal:ing aout. ider tires 8illchange the shape of the tire patch) ma:ing it 8ider ut shorter and

perhaps increasing cornering traction ut the total area of the contactpatch remains the same.

4hese four contact patches and their ailit! to grip the road surfaceultimatel! determine the car>s limits for accelerating) ra:ing) andcornering. 4he tire>s ailit! to grip the road surface depends on a numerof factors including the road surface) tire compound) siCe and shape of thecontact patch) 8eight on the tire) inflation pressure) age of the tire) theamount of tread on the tire) etc.

ver! tire has a ma=imum limit of adhesion77its traction limit ta:ing intoconsideration all of the aove factors3. ,f this limit is e=ceeded) the tire 8illlose its grip on the road surface and 8ill spin or s:id.

% tire>s traction limit is e?ual in all directions77for8ard) ac:8ards) orside8a!s. /tated another 8a! the traction limit is the same for ra:ing)accelerating) or cornering.

-oo: at 6igure < page 153. 4he thing in the center represents a tire. 4hecircle represents the traction limit of that tire. I%I therefore is theacceleration traction limit) I#I the ra:ing traction limit) and I"I the lateraltraction limit. Bote that the limit is the same in all directions.

1*


15/32

6,+ t do that if 8e>re usingma=imum cornering traction.I

"orrect) ut !ou forgot aout 15g N MPH3O. -oo: at 6igure 2 againpage 83. Botice that the initial turn7in is ?uite sharp. %t this point) 8e areneither ra:ing nor accelerating. Botice also) ho8ever) that thereafter) theradius of the line increases dramaticall!. %fter the initial turn7in) 8e areusing no 8here near the tires> lateral limit of adhesion ecause the radius

15


16/32

is so large. e no8 have reserve traction for more acceleration77so let>sdo it.

ne more point aout traction adhesion3. % tire>s traction limit is affected! the amount of 8eight on the tire. 4he more 8eight there is on a tiredo8nforce3 the greater its traction limit. hen an automoile is

accelerated) 8eight is transferred via the cars> suspension3 to the reartires. 4herefore) 8hen !ou accelerate after the initial turn7in) !ou areactuall! increasing the limit of adhesion of the rear tires. 4he lesson ofcourse is don>t coast through a turn. see page 2m approaching the limit of adhesion of m! tiresLII/lip angles.I Ihat the hec: are slip anglesLI

% tire is elastic. % force applied to it in an! direction 8ill distort the tire>sasic shape. % cornering force distorts it side8a!s at the point of contact

8ith the road. 4his side8a!s distortion ma:es the car follo8 a path at anangle to the direction the 8heel is pointed. 4his angle is called the I/lip%ngle.I /ee 6igure *3

6,+ *

4he higher the cornering force on the tire the larger the slip angle.

%t the instant a tire loses traction) the slip angle is Cero ut as long as hedirection of the car can e influenced ! the steering 8heel) there is a slip

angle. hen cornering) the slip angle of a tire can range from ver! smallver! little cornering force3 to ver! large ver! high cornering force3 to Cerono cornering force) the tire has lost all adhesion3.

hen the slip angle is relativel! small) !ou ma! hear a faint s?ueal fromthe tires. %s the slip angles ecome larger) the s?ueal 8ill ecome louder.hen the slip angles ecome Cero) the tires 8ill screech loudl! and !ou8ill not e in control of the vehicle. @ou 8ill e) as 8e sa!) a passenger.

1(


17/32

-oud s?ueals are good) loud screeches are to e avoided. Bote; Modernhigh performance tires don>t ma:e much noise.3

Just efore screeching loudl!) the slip angles ecome ver! large. 4hetires have lost some of their traction and are sliding side8a!s some8hatut the! still have some traction and the tires are still e=ercising control

over the direction the car is traveling. 4his condition is called I% Drift.I I%DriftI through a turn is desirale.

I% DriftI is the reason !ou should e driving the correct line precisel!. ,f!ou turn in too soon earl! I%pe=I3 or don>t get to the I%pe=I !ou ma! driftright off the e=it side of the turn. ,f !ou>re a foot a8a! from the I%pe=)I !ou8ill have a foot less road8a! on the e=it side of the turn. ,f !ou miss it !four feet) the e=it side of the turn ecomes at least four feet narro8er.4a:e an earl! I%pe=I and !ou>ll have a lot less road8a! on the 8a! out. ,tis er! ,mportant to Drive the "orrect -ine.

Understeer and versteer ,f the I/lip %nglesI at the front tires are muchgreater than those of the rear tires) the car is said to understeer) push or

plo8. 4o the driver) it feels as if the car 8on>t get itself turned in and thedriver must continue to add steering loc: or slo8 do8n or oth3 to get thecar pointed into the %pe=. %n understeering car is a safe car for anine=perienced driver ecause to correct it) the driver need onl! ac: offthe throttle and add more steering loc: in the direction he 8ants the car totravel. Most drivers 8ill do this instinctivel!. %n understeering car is)ho8ever) not a ver! satisf!ing car to drive ?uic:l! and it>s generall! not a?uic: car around a race trac:.

hen the /lip %ngles of the rear tires are greater than those of the fronttires) the car is said to oversteer or to e loose. 4he front of the car turnsin real 8ell) in fact) it egins to descrie an arc 8hich is tighter than thedriver had intended. 4his happens ecause the rear of the car is tr!ing toget through the turn efore the front of the car.

%n oversteering car is more fun for the e=perienced driver to drive ?uic:l!than an understeering car) ho8ever it is more difficult for theine=perienced driver. /uddenl! lifting off the throttle the naturaltendenc!3 8ill transfer 8eight off the rear tires) reducing their traction)increasing the slip angles and the oversteer. 4his little e=ercise in futilit! iscalled I4railing 4hrottle versteerI or merel! 44. 44 can e induced! lifting off the throttle 8hile turning. 4his might e useful forautocrossing ut don>t do it on the trac:.

% vehicle ma! understeer in some turns and oversteer in others. ,t ma!

also do oth in the same turn. Most cars 8ill understeer if the turn isentered at too high a speed. ,t ma! then transition to oversteer 8hen thethrottle is released. ,f !ou detect understeer) !ou are proal! enteringthe turn at too high a speed.

,deall!) 8e 8ant a neutral handling car) one 8hich neither oversteers norundersteers. e 8ant to have the same slip angles at oth the front and

1F


18/32

the rear so that 8e can drift through the turn 8ith the rear tires follo8ingthe front tires.

,,. /:id "ontrol

@ou) the driver must e :eenl! alert to 8hat the car is doing so that !ou are ale

to detect the first signs of the rear of the car coming unglued oversteer3. 4hee=perienced driver 8ill detect the condition ver! earl! and 8ill merel! maintain aconstant throttle position or ac: off the throttle slightl! and ver! ver! gentl!3and add a small amount of opposite loc: turn the steering 8heel in the directionhe 8ants the front of the car to go3. Don>t> overreact. Don>t attempt to correct aprolem efore it happens. ait for it to happen and correct simultaneousl!.

%. 4otal -oss77,f !ou don>t tr! to drive over !our head) this 8ill not happen to!ou.

,f corrective action is not ta:en soon enough) !ou 8ill not e ale tocorrect it. ,f !ou lose it that adl! this evaluation must also e maderather ?uic:l!3) PU4 #4H 64 ,B. -eft foot do8n on the clutch) right

foot do8n on the ra:es. 4he car>s ra:es 8ill loc: and 8ith an! luc:) thecar 8ill spin violentl!) dissipate its speed on the trac: surface and stop onthe inside of the turn>s trac: surface facing appro=imatel! in the originall!intended direction of travel. Don>t release the ra:e until the car has cometo a complete stop. #e a8are that the car ma! roll ac: on to the trac:8hen !ou finall! release the ra:e. ,f !ou engaged the clutch earl! on) thecar>s engine 8ill still e running 8hen the car comes to a halt and !ou canslip the gear selector into first) chec: for traffic and motor off li:e a stuntdriver. ,t ma! also e a good idea to no8 motor into the pit area and stopthere until !our heart rate returns to normal.

#. -ess than a 4otal -oss

/ome8here et8een catching the s:id ver! earl! and losing it completel!is an area 8here the car can still e rought under control. 4he dilemma;if !ou suddenl! ump off the accelerator) !ou 8ill lighten up the rear endand reduce the traction availale at the rear of the car. /ta!ing on thethrottle) ho8ever) 8ill ma:e matters 8orse ecause !ou>ve alread! lost thelateral traction of the rear tires and in persisting on the throttle !ou>reas:ing the tires to do t8o things at once rememer the 6riction "ircletheor!3.

4he trade off favors ac:ing slo8l! out of the accelerator) disengaging theclutch and counter7steering. I"ounter7steeringLI

/ome8here in our meager drivers training 8e have all heard aoutcontrolling a s:id on ice or sno8 and some of us have actuall! done it.e 8ere al8a!s told to turn the 8heels in the direction of the s:id. /omeof us figured out 8hat this meant77some of us didn>t. %ll it means is that!ou turn the 8heels in the direction !ou 8ant the front of the car to go.

"ontrolling a s:id at high speed on a dr! surface is ust li:e controlling as:id on ice or sno8. ell) almost. ,f !ou cran: the steering 8heel a lot on

1'


19/32

ice or sno8) the rear end 8ill s8ing out of the s:id and continue s8inginginto a s:id in the opposite direction 8hereupon !ou cran: the steering8heel the other 8a! and the rear end no8 s8ings around in the oppositedirection and so on and so on. %ll the 8hile) the car is slo8ing do8n andthe s8ings from side to side ecome smaller and smaller until eventuall!!ou gain control of the car.

,f !ou cran: the 8heel a lot in the direction !ou 8ant the front end to go ondr! pavement at high speed) that 8ill li:el! e the last time !ou are incontrol of the vehicle. 4hat gentle counter s:id !ou e=perienced on the ic!street ecomes a violent counter s:id on dr! pavement at speed. 4hecounter s:id 8ill occur so violentl! and so ?uic:l! !ou 8ill li:el! not eale to catch it. ,f !ou cran:ed the 8heel far enough) !ou proal! 8on>teven :no8 8hat happened.

"ounter /teer nl! nough to "orrect the riginal /:id. 4oo little ispreferale to too much. Don>t overreact.

19


20/32

,,,. %gricultural Driving or ff7oading3

-,/4B UP. 4H,/ ,/ ,MP4%B4. ver the !ears) fear of agriculturaldriving has caused almost all the serious damage suffered ! cars at cluschools. 4he damage results from going off the trac: surface follo8ed !an ill7advised attempt to ?uic:l! regain the trac: surface out of some elief

that a motor vehicle can>t e operated off the pavement.

Bot true. atch most an! race) and !ou>ll proal! see cars driving off thetrac: surface. ,>m not tal:ing aout loosing control of the car on the trac:surface and spinning off the trac:. ,n that case) it doesn>t matter 8hat !oudo ecause) ! definition) the car is not under !our control) !ou are merel!a passenger.

hat , am tal:ing aout is running out of trac: surface 8hile !ou>re stille=ercising some control over the car. /hould this happen to !ou) D B4%44MP4 4 U,"A-@ +%,B) %,D UBB,B+ 66 4HP%MB4 #@;

1. %dding more steering loc:) andEor2. Jumping off the throttle.

4he comination of 1 and 2 aove 8ill generall! result in a total loss ofcontrol and !ou 8ill most li:el! spin and go off the trac: on the inside ofthe turn 8hen !ou thought !ou 8ere going to go off on the outside3. ,t 8illoccur ?uite ?uic:l!.

f course) driving around on the unpaved part of the trac: could involvecertain haCards) and is not recommended ho8ever) if !ou>re in control ofthe vehicle 8hen !ou go off the paved surface) !ou>ll e in a etterposition to avoid those haCards than if !ou>re merel! a passenger.

4he agricultural form of high performance driving) at least the potentiall!dangerous t!pe) 8ill occur at the e=it of a turn. @ou>re full on the throttle)past the ape=) drifting to8ard the outside of the trac:) and 77777 Ih no) ,>mgoing to run out of trac: on the outsideI. 4he untutored) normal responseLJump off the throttle and add steering loc: i.e.) turn the steering 8heelmore3.

/UPP// @U BM%- /PB/ M"H%B,/M.D B4 JUMP 66 4H 4H44-.D B4 %DD /4,B+ -"A.h! notL

1. @ou>re proal! not going to run off the road) it ust loo:s and

feels li:e !ou 8ill. ,f) ho8ever) !ou no8 do either or oth of theaove) !ou 8ill definitel! e going off the road.

2. 44 /ee page 1'3.

s at its limit ofadhesion. ,f !ou no8 re?uest more rudder) !ou>ll loosetraction see friction circle discussion on page 1*3.

20


21/32

/o 8hat should !ou doL

,f onl! the outside tires drop off the road8a!) nothing much 8ill happen.4he car 8ill proal! ehave ust as if all four tires 8ere on the pavement.Ho8ever) don>t attempt to ring those tires ac: on the trac: until !ou>re

sure the car is under !our control. hen !ou are read! to get ac: on thetrac: surface) do it graduall! i.e.) opposite of cran:ing in a lot of steeringloc: to get it ac: on the trac: in a hurr!3.

,f all four 8heels go off) !ou 8ill e=perience a change in road surface that!ou>ll need to adust to.

4H "% "%B # D,B B 4H +%//) +%-) H%4 H%@U.

4he potential danger lies in attempting to get ac: on the trac: too ?uic:l!.@ou must :eep the car under !our control.

DB>4 JUMP 66 4H 4H44- %BDDB>4 %DD /4,B+ -"A.

@ou ma! come off the throttle ver! graduall! reathe out of the throttle3. ,tma! also help to reduce steering loc:. 4hat is) increase the radius of thearc in order to gain or retain traction i.e.) drive further off the road3. nce!ou have the car slo8ed do8n) and !ou are full! under control) !ou ma!re7enter the trac: if there is no traffic in the immediate area. ,f !ou cannotsee enough of the trac: to tell if it>s clear) point at the trac: and 8ait for acorner 8or:er to signal that it>s alright to re7enter the trac:.

,. #ra:e Points

IHo8 close should , get to the turn efore , start to ra:eLI , don>t :no8. @ourra:e point is personal to !ou and !our car. , can onl! tell !ou ho8 to go aoutfinding it.

Pic: out a mar:er of some sort near the turn preferal! a permanent one. Don>tuse a la8n chair that someone ma! move3. hen !ou get to that point) eginthreshold ra:ing. ,f !ou come to a stop 8ell efore the turn7in point) oviousl!!our ra:e point is too soon. Move !our ra:e point closer to the turn7in point.Aeep moving it until !ou have the desired entr! speed at the turn7in point.

ememer) !ou 8ant to e ale to egin accelerating as soon as possile afterturning in. 4herefore) each time !ou move !our ra:e point closer to the turn in

point) note 8here !ou are ale to egin acceleration. ,f !ou are unale to eginaccelerating as earl! as !ou could 8ith the previous ra:e point) !our ra:e pointis no8 too late. Move it ac:.

4he ideal ra:e point is one 8hich) using threshold ra:ing) slo8s the carenough to negotiate the turn on the proper line and permits the earliestapplication of throttle.

21


22/32

48o factors ma! have an effect on the ra:e points that !ou estalish for !ourselfearl! in the da!. %s !our driving improves) !ou>ll e going faster 8hen !ou reach!our ra:e point than !ou 8ere earlier. @ou ma! find that !our ra:e point isno8 too late. n the other hand) as !our driving improves) !ou ma! e ale tohandle higher cornering speeds. @ou ma! find that !our earlier ra:e points aretoo earl!. JU/4 AP 4H,/ ,B M,BD.

@ou should also :eep in mind that the trac: surface 8ill have an effect onra:ing;

Be8 asphalt77generall! slipper!+ravel or dirtil or coolant#ra:ing going do8nhill

%ll increase ra:ing distances77# %-4 6 4H/ "BD,4,B/.

er! fe8 things decrease ra:ing distances. #ra:ing going uphill is one. Hittingthe car in front of !ou is another. %4"H @U ,B4%-.

Ihat if , can>t get slo8ed do8n enough to ma:e the turnLI 4hen don>t ma:e theturn) ut congratulations on recogniCing that !ou>re going too fast. 4he generalrule is if !ou>re going too fast to turn in) don>t. "ontinue threshold ra:ing anddrive straight off the turn. @ou 8ill e ale to steer the car 8hen it leaves thetrac: and !ou 8ill hopefull! e ale to ring it to a stop efore coming intocontact 8ith something hard or) at least !ou might e ale to steer around thehard oect.

,f !ou>re going too fast to ma:e the turn and turn an!8a!) !ou>re still going to gooff the trac: ut !ou 8on>t e in control of the car. @ou 8ill e unale to steer)ra:e) or e=ercise an! control 8hatsoever over the car.

4he e=ception to the rule of course is 8hen the conse?uences of driving straightoff the trac: are potentiall! 8orse than spinning off of it. 6or e=ample) a concrete8all on the outside of the turn77ver! unforgiving.

. Driving in the ain

Driving on 8et surfaces re?uires smoothness to the Bth. degree. @our vehicle8ill have consideral! less acceleration and ra:ing traction and a 8hole unchless cornering traction. n a 8et surface) !ou 8ill have onl! aout F0 percent ofdr! acceleration traction) aout 50 percent of dr! ra:ing traction) and a mere 20percent of dr! cornering traction. ,t should e clear to !ou from this that a 8etsurface re?uires a considerale reduction of speed. ,f the surface is e=tremel!slipper!) coast through the turns and don>t appl! throttle until the car is traveling

in a straight line.%t some race trac:s) !ou ma! find that the -ine ecomes e=tremel! slipper!."ars running on the trac: deposit ruer from their tires on the -ine. ,n addition)if a car lea:s an! fluids) it 8ill generall! e deposited on the line. hen it rains)the oil and ruer float to the surface and ride on top of the 8ater. ,f the lineecomes unreasonal! slipper!) tr! avoiding the line. Drive around the outsideedges of the turns. 4his part of the turn is seldom used and !ou>ll find that !ou

22


23/32

have reasonal! good traction there. #e8are) ho8ever) that even if !ou drive theoutside edges of the turns) !ou 8ill still e ra:ing on the same slipper! line andat some point in the turn !ou 8ill again meet and cross the -ine. @ou ma! gofrom reasonale traction to Ih m! +od.I

Driving in the rain or on ice or sno83 is great for 8or:ing on !our smoothness.

2


24/32

"-%// ,,,

,. Do8n /hifting

%. Heel74oe#. Doule "lutching

,,. 4rail #ra:ing

,,,. -ine7Detailed Discussion

%. -argest Possile adius#. -ate %pe=". arl! %pe=D. 6inding the "orrect -ine. ntr! /peed

2*


25/32

,. Do8n /hifting

% shift do8n to a lo8er gear is done to otain the gear that 8ill permit thema=imum acceleration out of the turn. ,4 /HU-D B4 # DB 4 /-4H "%.

/hifting) li:e ra:ing is completed 8hile the car is traveling in a straight line. ,f!ou are threshold ra:ing and simultaneousl! shift to a lo8er gear) the engine>sPMs 8ill drop to idle speed. hen the clutch pedal is released) the car 8ill er:caused ! the rear 8heels stopping momentaril!3. 4his is the e?uivalent ofsuddenl! adding more ra:ing to the rear 8heels. 4his ma! cause a loss oftraction at the rear tires and 8ill definitel! transfer 8eight fore and aft) upsettingthe car>s alance ust efore it enters the turn. ,t is unsmooth.

%. Heel74oe

4o avoid upsetting the car>s alance) 8e must raise the engine>s PMsust efore releasing the clutch pedal.

/ince most of us have onl! t8o feet and the car has three pedals tooperate the ra:e) clutch) and throttle) one foot must do doule dut!.@our right foot must operate the ra:e and) at the same time) lip thethrottle.

4he easiest 8a! to do this is to place the all of !our right foot on the rightside of the ra:e pedal. 48ist !our right leg around slightl! so that !our:nee is pointing slightl! in8ard. Bo8 !ou can operate the ra:e and 8hen!ou need to lip the throttle) roll !our foot to the right and contact thethrottle 8ith the right side of !our right foot. 4his is done 8ithout releasingthe pressure on the ra:e pedal.

,f !our foot is too small or !our car>s pedals are too far apart) !ou can lipthe throttle 8ith the heel of !our right foot 8hile maintaining ra:e pedalpressure 8ith the all of !our foot.

4his is :no8n as heel and toe. 4he correct procedure is as follo8s;

1. 4hreshold ra:ing continue ra:ing through 2)


26/32

(. %s the PMs egin to come do8n) release the clutch pedal. Don>trelease the clutch until the PMs egin to come do8n) ut releaseit efore the engine returns to idle PMs.

ith practice) !ou>ll learn ust ho8 much to lip the throttle and the properPM at 8hich to release the clutch. ,f !ou>ve lipped the throttle too much

or let the clutch out too soon3) the car 8ill lunge for8ard underacceleration3. ,f the PMs are too lo8 or !ou release the clutch too late3)the rear 8heels 8ill gra77it 8ill feel li:e additional ra:ing. ,f !ou do itcorrectl!) the car>s attitude 8ill not change and e=cept for the change inthe sound of the engine the gear change 8ill not e perceptile.

"aution77Heel and toeing ta:es practice. hile !ou are learning to do it)ra:ing distances 8ill increase.

#. Doule "lutching is emplo!ed to minimiCe 8ear and tear on thevehicle>s drive train. ,t is used along 8ith heel and toeing. ,f !ou8ant to ecome a reall! accomplished driver) !ou should learn todoule clutch) ut it is not essential to high performance driving.

Heel and toe shifting ,/ //B4,%- to ecoming a highperformance driver.

4he correct procedure for doule clutching is;

1. 4hreshold ra:ing 8hich continues through /teps 2 through '3.

2. Depress the clutch pedal.


27/32

6ormer orld "hampion Jac:ie /te8art) among others holds to the vie8 thatra:ing should e completed efore turning in. Mr. /te8art) 8hen as:ed aouttrail ra:ing as advocated ! #arer) #ondurant) et al.) responded 8ith a?uestion of his o8n) IHo8 man! 8orld championships have the! 8onLI

, don>t :no8 8ho is correct) ho8ever) , thin: a ver! good driver should :no8 ho8

to do oth. , have found that trail ra:ing 8or:s ver! 8ell in some turns in allcars and perhaps for all corners in some cars.

Here>s ho8 it 8or:s. 4hreshold ra:ing is used ust as 8e>ve instructed. Just as!ou reach the turn7in point) ho8ever) the ra:es are not full! released ut arecontinued slightl! as the car is turned in. ,f !ou use too much ra:e) the car ma!spin.

4o get the proper amount of ra:ing) imagine a left turn and that !our hands onthe 8heel and !our foot on the ra:e pedal are connected ! a solid rod. ,norder to turn the 8heel) !ou must also raise !our foot off the ra:e pedal. 4hemore !ou turn the 8heel) the more !our foot must raise off the ra:e pedal.

4railing the ra:e 8ill :eep more of the vehicle>s 8eight on the front tires) !ieldingmore traction there and the car 8ill turn in ver! 8ell. 4he rear tires) ho8ever) 8illhave less 8eight and therefore less traction. %s the vehicle is turned in) the rearof the vehicle 8ill egin to slo8l! come around rotate to8ard the outside of theturn3 and point the front7end to8ard the %pe=. %s soon as the car is pointedto8ard the %pe=) the throttle is s?ueeCed on) transferring 8eight and traction3 tothe rear tires. 4he rear tires 8ill gain traction) stop sliding and the car 8illaccelerate to8ard the %pe=. ,f throttle is not applied at the proper instant) therear ma! continue to slide 8hich ma! result in a spin.

6or corners that trail ra:ing 8or:s 8ell on) it 8or:s ver!) ver! 8ell.

"%U4,B) the transitions et8een threshold ra:ing) trailing the ra:es) turningin and application of throttle must e performed e=tremel! smoothl!. ,n addition)8hen trail ra:ing is used) the steering 8heel is turned less than it 8ould eturned 8ithout trail ra:ing. ithout trail ra:ing) onl! the front steering is usedto get the car turned into the %pe=. hen trail ra:ing is used) ho8ever) the rearend rotating out has the effect of adding some steering.

e recommend that novices do not attempt trail ra:ing. ,f !ou 8ant to learn it)8ait until !ou have more high performance driving e=perience or go to /:ip#arer>s school and learn trail ra:ing in his cars.

,,,. -ine 77Detailed Discussion

%pe=%n %pe= is an imaginar! point at the edge of the road8a! on the inside of a turnthat the car touches as it travels through a turn.

%. 4heoretical %pe= Q -argest Possile adius

2F


28/32

%n %pe= at the geometric center of a turn>s arc is called the 4heoretical%pe=. ,f a vehicle is driven from the e=treme outside edge of the road8a!)then touches the 4heoretical %pe= and then touches the e=treme outsideedge of the road8a!) the vehicle 8ill have descried a line through theturn 8hich 8ill e the largest possile radius through that turn 6igure 5)page 293.

6,+ 5

e :no8 from our e?uation 15gr N mph3O that the larger the radius of aturn) the faster a car can travel through that turn. 4he largest possileradius 8ill give !ou the highest speed around a turn. ,t is generall! not)ho8ever) the fastest 8a! around a race course. ,f 8e 8ere to add up thetime spent on turns and the time spent on the straights on one lap of thetrac:) 8e 8ould find that 8e spend consideral! more time on thestraights than in the turns. e can go ver! fast on the straights ut not sofast in the turns.

4he largest possile radius 8ould e the line to use if our courseconsisted onl! of corners that could e driven at our car>s top speed andit is the line to use 8hen negotiating such a turn3. ,n realit!) most cornerson a trac: cannot e negotiated at our car>s top speed. e must reduceour straight a8a! speed ! using the ra:es3 in order to go around thecorner. ,f) ho8ever) after ra:ing and turning into the %pe=) 8e couldegin to accelerate efore the car 8as totall! finished turning)

2'


29/32

8e 8ould) in effect) e ma:ing the follo8ing straight longer.,f the straights 8ere longer) our terminal speed at the end ofthe straight 8ould e higher. ,t follo8s that if 8e go faster onthe parts of the trac: 8here 8e spend most of our time) 8e8ill get around the 8hole course in less time.

ecall our friction circle. ,f 8e are driving the largest possile radius asfast as ph!sicall! possile at the tire>s limit of adhesion3) 8e cannotaccelerate until the car is once again traveling in a straight line. /o) 8hatdo 8e doL Use a -ate %pe= line.

#. -ate %pe= -ine

% late %pe= line is the line descried ! a vehicle 8hich touches an %pe=occurring after later than3 the 4heoretical %pe=. 4his is the line !ou haveshould haveL3 een driving all da! and the line !ou should use all of thetime on a race trac: B 4H /44 unless !ou have a goodreason for doing other8ise. #rain fade is not a good reason.3

h! it>s the 6astest

-oo: again at figure 2 page '3. ,t illustrates a late %pe=. Bote that theeginning of the turn is much sharper than it 8ould e if the largestpossile radius 8ere used. #ecause of that initial sharp turn) 8e 8ill needto slo8 do8n more than if 8e used the largest possile radius.ememer our friction circle.3 Botice also) ho8ever) that after thatsharper turn) the alance of the line has a much larger radius than eventhe largest possile radius. 4herefore) 8e can) and should egin toaccelerate almost immediatel! after ma:ing that sharp turn. Ho8 much!ou can accelerate 8ill depend on a numer of factors) the radius of theturn) 8hether the road8a! is an:ed) flat or off7camer the opposite ofan:ed3) the po8er of the car) 8hether or not !ou 8ish to induceoversteer) etc. 4he rule of thum) ho8ever) is that stead! throttle is usedto the %pe= to maintain the ma=imum cornering speed for the givenradius3 and full throttle at the %pe= as the radius increases3 !ourinstructor 8ill help !ou on this point.

%ssuming that !ou have driven the correct line) have not entered the turntoo fast) and the road is not slipper!) !ou should not coast through a turn.%l8a!s appl! po8er after the car is turned to8ard the %pe=. 4hisapplication of throttle transfers 8eight to the rear tires) increasing theirtraction for acceleration.

29


30/32

". arl! %pe=

-oo: at 6igure (. ,t illustrates an arl! %pe= -ine. 4he %pe= occursefore the 4heoretical %pe=3.

6,+ (

,f !ou ta:e this line) !ou 8ill not onl! e a IsleaCe all earl! ape=er)I ut if!ou persist 8ith full throttle at the %pe=) !ou 8ill fall off the road8a!) thecar 8ill li:el! then accelerate side8a!s) !ou 8ill ecome a passengerinstead of the driver and !ou 8ill not li:e it) or 8orse. ,f !ou use an earl!ape= line in !our street driving !ou 8ill run the ris: of a head7on collision8ith an! car traveling in the opposite direction ecause !our car 8ill e inthe 8rong lane.

Botice that 8ith an arl! %pe=) the sharpest part of the turn occurs afterthe %pe=. ,t cannot e negotiated at the same speed as the earl! part ofthe turn. ,t re?uires slo8ing do8n efore the sharp part of the turn.

4he most common error made ! drivers is turning in too soon resulting inan arl! %pe= -ine. Most li:el!) !ou 8ill also ma:e this mista:e) and !ourinstructor 8ill scold !ou. ,f !ou persist in this all da! long) !ou 8ill e:no8n as a /-%R #%-- %-@ %PS.


31/32

4he arl! %pe= -ine is not totall! 8ithout sociall! redeeming value. ,tmight e the est line to ta:e if a long straight is follo8ed ! a ver! slo8section of trac:) sa! several slo8 turns in ?uic: succession 8here the onl!line !ou>re concerned 8ith is the line through the last turn in thesuccession of turns. % -ate %pe= in this situation permits !ou to carr!!our straight a8a! speed longer. @ou 8ould threshold ra:e up to the

turn7in point) ut ecause the earl! part of the turn has a relativel! largeradius) !ou could continue some ra:ing all the 8a! to the point 8here theradius ecomes smaller.

,f !ou>re thin:ing) !ou have proal! alread! figured out that it might alsoe useful if !ou>re approaching a turn too fast and can>t get slo8ed do8nenough to ta:e the proper line. 4he arl! %pe= -ine 8ill give !ou morera:ing distance to 8or: 8ith. @ou can forget aout a good lap time) ut itmight prevent an off road e=cursion. hen !ou are traveling on anunfamiliar road) B) B %pe= earl!. ,n fact) don>t even thin: ofape=ing until !ou can see 8here the road is going. /ta! out 8ide until !oucan see 8hat>s on the other side) then ape=.

D. 6inding the "orrect -ine

/tart ! using a ver! late %pe= usuall! later than !ou thin: it is3. ,f the%pe= is too earl!) !ou 8ill find that !ou are unale to un8ind the steering8heel as !ou clip the %pe= falling off the road is also a clue3. ,f !ou can>tget to !our %pe=) it means that !ou turned in too late.

nce !ou have found an %pe= and a turn7in point that 8or:s reasonal!8ell) start refining it. hat !ou 8ant is e=it speed. =it speed translatesinto PMs 8hich translates into speed at the end of the follo8ing straight.Pic: out a spot or convenient mar: on the straight some distance after thecorner. 4he distance doesn>t matter as long as !ou use the same mar:ever! time.

ach time !ou pass !our mar:er) chec: the PMs and note 8hether or not!ou>ve used up all the road8a! on the e=it side. ,f !ou still have someroom on the e=it side) tr! a slightl! earlier %pe= and chec: the PMs at!our mar:er. %re !our PMs higher or lo8erL Aeep e=perimenting until!ou find the line that consistentl! !ields the highest PMs at !our mar:er.

4his e=ercise can also e used to determine the correct gear for aparticular turn.

Don>t trust the seat of !our pants. -ots of noise and 8heel spin does notgenerall! e?uate 8ith the fastest 8a! through the turn. Bote) !our mar:er

must e far enough do8n the straight so that regardless of the gear usedfor the turn) !ou are al8a!s in the same gear 8hen !ou pass !our mar:er.4he gear that results in the highest PMs at !our mar:er is the gear touse for that turn.

@ou 8ill fre?uentl! find that !ou can use a higher gear than !ou originall!thought.


32/32

. ntr! /peed

4he speed at 8hich !ou should enter a turn is more or less a seat of thepants proposition. 4he tendenc! is to go too fast in slo8 corners and tooslo8 in fast corners. e recommend that) at first) !ou concentrate on e=itspeed. +o in slo8er that !ou thin: !ou need to so that !ou can get full

throttle at the %pe=. %s !ou ecome more e=perienced) !ou can egin topic: up !our entr! speed. ememer) the underl!ing principle is toaccelerate as soon as possile so that !ou go faster on the straights. ,f!ou enter too fast) !ou 8on>t get to !our %pe= and !ou>ll e fighting tocontrol the car at the point 8here !ou should e accelerating.

,n high performance driving) no one is a natural) ever!one must learn.4hose 8ho concentrate on smoothness and consistenc! learn faster.4hose 8ho thin: charging do8n the trac: is the ans8er) ra:ing atdifferent spots each time) reacting rather than anticipating) learn nothing.

Bo matter ho8 long !ou>ve een driving on the street) or ho8 fast !our caris) or ho8 e=pensive !our tires are) until !ou are 8illing to rethin: an!

driving hait77!ou aren>t read! to learn to e a trul! fast driver. @ou havethe opportunit! to vastl! improve !our driving s:ills77and 8ith an openmind) and a lot of concentration) !ou>ll do it. +o for it.

High Perf Driving Manual

Documents

Transcript of High Perf Driving Manual