Buttonwillow Raceway Park - Clockwise · PDF fileTIME TRIAL DRIVER HANDBOOK BUTTONWILLOW...

TIME TRIAL DRIVER HANDBOOK BUTTONWILLOW (CLOCKWISE)

PORSCHE CLUB OF AMERICA BW (CW) - 1 GOLDEN GATE REGION

Buttonwillow Raceway Park - Clockwise Direction

DISCLAIMER: The following information is provided by the Golden Gate Region of thePorsche Club of America as a orientation to this track. It is intended to be used only as aguideline and intended only for use by drivers at GGR events. All drivers are responsiblefor determining the safest and best approach for themselves and their cars. Under nocircumstances will the region, its officers, event organizers, instructors or other membersbe responsible for any consequences to any driver as a result of completely or partiallyfollowing the recommendations herein. This exclusion applies to events conducted byGGR as well as other events where drivers may choose to use these guidelines to assistin learning to drive this track.

BUTTONWILLOW (CLOCKWISE) TIME TRIAL DRIVER HANDBOOK

GOLDEN GATE REGION BW (CW) - 2 PORSCHE CLUB OF AMERICA

©2003 by Henry Watts, Brad Maker and the Golden Gate Region, Porsche Club of America. Allrights reserved. Permission for individual use (single copy electronic download and printing) isgranted. This document may not be printed for distribution, either as a single document or includedin any type of publication such as compilation or book.

Buttonwillow Raceway Park is owned and operated by the Southern California SCCA. It is in arelatively arid environment and relatively flat. It has been laid out to facilitate a great number ofpossible configurations. It contains a number of interesting challenges and is marvelously fun todrive. Directions: From the Bay Area, get on I-5 South. You're going almost to Bakersfield. About12 miles south of the Hwy 46 interchange (Paso Robles to the right, Wasco to the left) you'll findthe Lerdo Highway (Shafter to the left). Take this exit, turn right, go one half mile and turn left intoButtonwillow

Due to the number of configuration, official track maps offer turn names rather than numbers. Thisguide will use the numbers as originally assigned by the track. The turns are numbered in theclockwise direction, no matter which way the course is being run.

More than any other California track, Buttonwillow links the various corners together, providing littlemental relaxation space for the driver. Many turns, as will be seen, are not so much completed astaken as far as they can until the necessity for dealing with the next turn takes over. This creates asituation in which the preparation for execution of the next corner routinely must (not the usualshould) take place during the previous corner. It is assumed that all apexes are hit correctly withinabout 3 inches.

The text occasionally indicates likely gear choices as a very general guideline only. The gearchosen will, in many cases, depend not only on the gearing, rev limit and torque curve of the car,but also on driver preference. There are places where higher gears may add smoothness andmay make a high-horsepower or low-available-traction car more controllable but at the expense ofcritical acceleration. Cars with narrow horsepower bands obviously need more careful gearselection; cars with broad torque curves may care less.

The lines described in this document are qualifying or time trial lines. With appropriateadjustments for the specifics of your car, they should produce the fastest laptimes available foryour driving level.



Turn 1 and Turn 2: �Buttonhook�

Turn 1 is a medium left-hander at the end of the front straight. The corner is flat, with reasonablegrip: Speed from the straight will be high, so some braking is needed. The turn can be takenrelatively quickly. For most cars, the appropriate braking is not threshold braking, but a gentledialing-down of the speed, without overloading the front suspension.

Turn-in is 1 to 2 car lengths before theend of the berm on the right. If the rightfront tire rides on the berm duringbraking, anticipate a right pull on thesteering wheel toward the berm. Finishbraking & downshifting to 3rd before youturn in. Trail braking is not suitable herefor most cars. Turn-in is less abruptthan you think, so smooth steeringinputs are preferable.



Take a reasonably late apex, beyondthe mid-point of the apex berm as ashort straight follows and you want tomaintain speed. You should be able toapply power as soon as the car rotatestoward the apex. The inside edge of thetrack will seem to come out to meet youjust after the painted apex berm ends. Itis possible to brush the inside tiresalong this dirt edge.

Past the apex, drift right to a full exit,and keep to the right side of the track toset up for turn 2. You may need toupshift to 4th gear in this short straight.

Turn 2, the �Buttonhook� is anincreasing-radius hairpin U-turn to theright that is preceded by a slight kink tothe left. If turn 1 is done quickly, twoseparate braking zones may berequired for turn 2. First brake brieflyand smoothly along the right edge nearthe end of the straight between turns 1and 2.



At the last possible moment the car isrotated slightly to the left, given a veryshort time to settle, then brakes areapplied very firmly.

This puts car on a line to hit an outsideapex toward the turn 2 entry. Thebrakes are applied firmly as the carpasses the left-side berm. This is theslowest point on the track and thetrickiest braking zone. Most cars need2nd gear here. Cars with greater powerand less stick may prefer to stay in 3rd.The turn-in to the hairpin itself will likelyrequire trail braking.

Be sure to drive deeply enough into thebeginning of the turn to avoid making itinto an early apex. The line for turn 2itself is a late apex, starting wide.



As the car is turned it will move up overa small crest and apex about a yardpast the end of the inside berm. Oncethe car is rotated the throttle can be fedin. Do not unwind the steering tooquickly after the apex. 3rd gear will beneeded before reaching the exit pointand, for most cars, 4th gear some timethereafter.

As the increasing-radius turn keepscurving well beyond the apex, a properexit point is surprisingly far down thetrack.

The straight between 2 and 3 offers anexcellent passing opportunity.Depending upon the passing rules ineffect, let by any cars that have groupedup behind you. It is normally possible tolet 3 or 4 cars pass during this straight.



Turns 3 and 3a: �The Whoops�, and Turn 4

Turn 3, a sharp right, is the first of threetightly-linked turns. Heavy braking isrequired before entering this sequence.3rd gear will be best for most cars. Youare braking for all three corners, not justthe first one, so entry speed is lowerthen you might otherwise expect.



The first turn must be taken with anextremely late apex, or the entiresequence gets quite messy. The apexof the initial right turn is so late that it�sbeyond the apex berm provided.

The car should "exit" this turn to theright of the track centerline to preparefor the left-hander. Done properly theexit and apex are essentially the samepoint, at the right side of the track,preparing for the next turn.

The next (unnamed) turn is a sharp left,the second of the three tightly-linkedturns. This needs a late apex to attemptto get properly set up for 3a. Entry isfrom as far to the right as the exit of 3allowed, basically at the right side of thetrack and somewhat past the end of theright-side berm.

Using the late apex in the un-numberedturn, minimize the exit as much aspossible, drifting out to the middle of thetrack before moving back toward the leftside of the track to prepare for 3a. Giventhe short amount of time available, theamount of movement to the left will notbe very great.



Turn 3a, a cresting right, is the third ofthe three turns. It will not be possible toget more than about two thirds of theway to the left to prepare for 3a. Oncethe point is reached when turning inmust begin, turn toward the apex whichis just beyond the crest at the end of theinside berm, and not visible until you areon the crest. This is a medium lateapex, but still needs to be treated withcaution as the car will be light. Oncethe apex is reached, it may be useful toslightly unwind the steering momentarilywhile the car is light to maximize theavailable grip for acceleration, and thenresume steering to the right (as needed to stay on the pavement) as soon as the car settles. Exitfully to the left.

The exit is about a car-length before theend of the long flat berm on the left.

Turn 4, a gentle right, beginsimmediately upon completing 3a sodon�t unwind the steering. Most carswill require a slight use of the brakes toadjust the speed downward. It is veryimportant to maximize your exit speedfrom this corner because it precedes avery fast section of the course. Use theentire width of the track at both entryand exit. Most cars will still be in 3rd

gear and should stay there.

This turn needs a slightly late apex,near the end of the apex berm. Somecars may want a very little bit of trailbraking. The exit berm becomes visiblefrom the apex, and can be surprisinglyclose if too early a line is taken.



Beware of putting a wheel off the backof the exit berm, which may drop offseveral inches into the dirt beyond.After completing 4 the road will riseslightly, then level out. The shift to 4th

gear will likely be needed in this section,even if maximum revs are not yetreached. Shifting later (during or afterturn 5) will be uncomfortable.



Turn 5 and Turn 6

This is a very fast two-corner sequence.Turn 5 is a gentle right into the infield.Very little braking is needed here. Theturn-in is surprisingly early (since theturn is just a slight dogleg), beginning atabout the middle of the entry berm. Inmost cases little or no braking is neededand a late apex is not required. Enterfrom the extreme left (where you shouldbe already after exiting turn 4). Exceptfor a slight lift some cars like to assistwith turn-in, the turn can normally betaken at full throttle.



A medium apex is reached at about themidpoint of the right-side apex berm. .Unless your car is very stiffly sprung,you may drive over the bottom third ofthis apex berm. This may unsettlelightweight and stiff cars because of thehigh speed achieved here. Clip thisapex as closely as possible within thoselimitations. As you accelerate throughthe exit of this turn, do not unwind thesteering wheel.

Once past the apex you will exit at theleft side of the track and begin to movethe car to the right as firmly as possible;you won't get very far. If your speeddoesn't require you to exit fully to theleft, use that fact to pick up more speedthrough the next turn by getting furtherto the right. One way to do this is tomaintain a nearly constant steeringangle through and after the exit of 5.

The next (unnamed) turn is a gentle leftin the infield. A slight lift will set mostcars to negotiate this turn. Begin fromas far right as you were able to achievecoming out of turn 5, which should bejust to the right of track-center. Rollingthe car�s weight, and therefore grip,from the left tires to the right tires mustbe done smoothly so as not to result ina spin. As speed increases, your carwill have a greater propensity tooversteer, so steering inputs must becorrespondingly softened. Keep youreyes as far ahead of you as possible.



The apex for the un-numbered turnshould be reasonably late. There is noapex berm. The exit is somewhatpinched off. The closer you can get to alate apex the less close you will come torunning out of track before Turn 6. Exitcompletely to the right on the protrudingberm which forms the entry for turn 6.

Turn 6 is a gentle left in the infield. Theexit of the previous turns becomes theentry to 6. Most cars will need to brakesomewhat. This happens right at theberm protrusion on the right. If the rightfront tire rides across the protrudingberm during braking, anticipate a rightpull on the steering wheel toward theberm. Most cars will need to drop backinto 3rd gear. Look ahead to the apexand exit. Turn in once you arealongside the entry berm and re-applythe throttle once the car has rotatedtoward the apex.

A proper apex will be medium to lateand will feel the bump of the ratheraggressive berm. However, climbing toomuch into the berm will unsettle the carmore than necessary. Done properlythe turn will be taken at full throttle.



Exit completely to the right, then beginmoving left to prepare for the next turn.You will make it to roughly the middle ofthe track before needing to move backto the right into the beginnings of turn 7.4th gear will be needed at about thispoint by most cars.



Turn7: �NASCAR�, and Turn 8



Turn 7, �NASCAR�, is a sweeping,banked right-hand turn.

The first key point is to get onto thesweeper by being reasonably close tohitting an apex as you come out of theinfield. This turn is not numbered. Youwill have a moment in which to glancedown at your tach or speedometer.Knowing the proper entry speed for youand your car can be important and laptimes are significantly affected by thespeed you can carry through turn 7.

Once you reach the entry of thesweeper, you may need to lift off thethrottle to get the car to turn insufficiently. Start looking ahead, wayaround the turn, for the apex as soon asthe car is turned in. Let the car drift upthe bank, rising no higher than just pastthe middle of the track and beginfocusing on bringing the car to the lateapex. Add as much throttle as possiblewhile holding the car in the middle of thetrack.



This apex is at the end of the smallinside berm. This is a place wheresmall differences make a big difference.Given the recently-added runoff room,this apex can be neutral. If in doubt, belate. Speeds are high here. Due to thehigh speeds there will be a tendency togive up on the apex if it doesn't appearto be reachable. This leads very quicklyto a trip into the dirt at speeds highenough to make the outcomeunpredictable. Insist on hitting the apex.

If you attain the apex the car shouldstay on the track. The car will exit at theextreme left of the track (once you havefound the right apex). Once the car hasexited on the left, maintain the samesteering angle (or more, if you can do it)for an additional few moments to bringthe car back towards the middle of thetrack to prepare for Turn 8, which is aslight kink to the left.



Turn 8

The straight towards turn 8 willsometimes be an appropriate place tolet cars pass in slower rungroups,especially if the cars behind are muchfaster than you and can get by quickly.Depending upon the passing rules ineffect, if you have cars behind you,move to the right, ease back on thethrottle, and offer them a left pass.

Turn 8 is a gentle left heading up MagicMountain. In preparation for this turn,move the car as far as possible to theright. On a good lap, it won't bepossible to get all the way to the right,you just head there until you have to turn left to make the apex of 8. On a normal lap you will havemade it about two thirds of the way to the right.

Turn at that point to a latish apex whichmust be hit, as an early apex heresends the car into bumps and marbles..Speeds are high and margins are slim.

This will carry the car to an exit on ornear the far right. Not to fear, there istime, just barely, to get ready for turn 9.



Turn 9 and Turn 10



Turn 9 is a gentle right on top of MagicMountain. As you head up themountain, move the car fully to the leftof the track. Strong braking in a straightline and, for most cars, a downshift from4th to 3rd will be required prior to turn-in.The turn-in is tricky; err on being toolate, as long as the apex is actually hit.Once you turn in, you'll be able to seethe concrete berm at the apex. It isimportant to have the car completelyturned-in prior to the apex point, sincecresting the hill will unload thesuspension and reduce the availabletraction.

The proper line is to get the right fronttire fully into the paint and drive it off theend of the berm, which will run itthrough the dirt just a bit before it getsback to the pavement. The car will belight over the top, and any throttle lift islikely to result in a spin. If the apex isdone properly, the car will stay on thetrack. If too early an apex, or not closeenough to the apex, the car will end upin the dirt on the left. If that happens,with care the car may proceed straightto rejoin the track, but this is not ahealthy line. Ideally, you will crest thehill drifting only slightly and find yourselftraveling in a straight path that carries you just to the right of the exit berm.

The proper exit is near the center of theprotruding berm on the left. It is OK tobe up to halfway into this berm. Yournatural path will carry you to the right ofthe track (actually the track is turningslightly left and you're just goingstraight). An up-shift to 4th gear will beneeded, and the car should be broughtover toward the right side of the track inpreparation for Turn 10, a mild left-hander.



Turn 10 is a gentle left onto a shortstraight. In most cars it can be taken atfull throttle in 4th gear. After the exit of 9move to the right to prepare for 10.About the time you reach the right sideof the track it will be time to turn in to 10�

and hit a clean medium-to-late apex(tighter than the photo shown!). Youare unlikely to need all of the very widelane at exit; just let the car float outwherever it wants to and then beginmoving it back to the left to prepare for11.

The straight between 10 and 11 offersan excellent passing opportunity.Depending upon the passing rules ineffect, let by any cars that have groupedup behind you. It is normally possible tolet 2 or 3 cars pass during this straight.



Turn 11 using the �Star Mazda� option

When the Star Mazda turn 11 is used, the straight after turn 10 is longer, allowing plenty of time tolet several cars pass if necessary. The length of track available before entering the esses is also

substantially extended, making the esses faster and more challenging.



The Star Mazda Turn 11 is right-hand sweeper of more than 90degrees, followed by an increasingradius section which leads into theesses. A flag station located onthe right side of the track is clearlyvisible as you approach the turn.The turn uses two apexes, oneimmediately after braking andturning in, and a second apex laterin the long sweeping righthandsection.

Heavy braking is required at the end ofthe long straight, so timing andjudgment of proper entry speed areimportant. Brake very deeply into theturn, resisting the temptation to followthe collection of tire marks deposited bythe wheel-to-wheel racers on earlylines. The turn is slow and sharp, sosome trail braking may be needed torotate the car.

After turning in, if you have been patientenough, slowed enough, and turned inlate enough, you will be able to applypower aggressively and steer for a verylate apex, nearly to the end of thesmooth, relatively flat berm. Do notsettle for a medium or early apex, asyou�ll run out of exit room. If you do findyourself apexing too early, hug the bermand/or lift partially off the throttle torotate the car until the end of the bermfinally comes into view and a late apexcan be made.



After the apex, drift left and exit near theend of the wide, flat exit berm. If anadequately late apex was made, itshould be possible to begin unwindingthe steering wheel and acceleratestrongly down the track. Many cars willneed to upshift at this point.

The turn continues sweeping right in along, lazy arc. Move the car right,across the track to a second apexmidway to the entrance to the esses.Full power can be applied throughoutthis section. Some cars will need tomake a short upshift (before reachingredline) just before entering the esses inorder to avoid shifting or running out ofRPMs in the middle of the fast essessection.



12 & 12A, the EssesTurn 12 is the esses, which aren'texactly turns. A fairly straight line isavailable through the first two apexes,provided substantial parts of each bermare used. The esses are driven muchfaster coming out of the Star Mazdacorner than using the previous turn 11sweeper.

The esses begin at the end of 11 �StarMazda�. They are a series of fiveberms, alternating from left to right,which you must drive the car throughand/or over. This is normally donewhile maintaining full throttle.

Don't be afraid to use up to half of theapex berms. By driving around (insteadof over) the second berm in particular,you will find yourself on a line thatcompletely straightens out the third andfourth berms.



Turn 12A leads onto a small straight.Depending upon the car and thesuccess with the esses, this corner willneed no lift, lift only, or very slightbraking. Otherwise a standard corner, itbegins on top of the last berm of theesses on the right �

� and should be a late apex, slightlypast the berm mid-point

The straight between 12A and 13 offersan excellent passing opportunity.Depending upon the passing rules ineffect, let by any cars that have groupedup behind you. It is normally possible tolet 2 or 3 cars pass during this straight.Most cars will shift to 4th if they haven�talready during or before the esses.

Watch also for cars signaling to exit leftinto the pits.



Turn 13

Turn 13 is a medium left-hand turnleading onto the main straight.Preparation for this turn requiresmoderate to hard braking. Pick out fixedreference points on or beside the tracksurface to locate your braking and turn-in points with consistency. The apex ofthe turn is slightly lower in elevation,leading to slightly less adhesion thanexpected as you approach the apex(the ground is falling away), and slightlymore adhesion just after the apex as theground rises. Great care is needed, asa navigational failure at this point risksputting the car into the pit wall along theleft side of the main straight.



The proper apex is slightly late, about1 foot from the end of the inside berm;with greater experience the apex canbe moved closer to neutral, but willstill be somewhat late.

On the front straight, in addition tostaying on the throttle and shiftinggears let any cars behind you get past.If you need to lift out of the throttle tomake this happen, do so. Once thecars that need to pass are safely ontheir way, turn your attention to yourcar. Check the gauges (temp, oilpressure, fuel) and note how the car isfeeling.

That is one lap of Buttonwillow done clockwise, a marvelously flexible and entertaining track.

Credits: The GGR track driving documents were prepared primarily by Hank Watts (GGRChief Instructor) and Brad Maker. Hank did the photography and the text first draft; hehad the final say about the text and is therefore responsible for it. Brad did the largeramount of work, putting the text, photos and graphics together, graphics parsing andediting, the entire layout and provided input to the text as well. Others contributed to thephotography process (Neil Yonk, Fred Nelson, Warren Walker, Evan Williams) and insuggesting modifications and additions to the text (especially John Tavernetti). Sourcetrackmaps were by Trevor Swallow..

Buttonwillow Raceway Park - Clockwise · PDF fileTIME TRIAL DRIVER HANDBOOK BUTTONWILLOW...

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