Conference oass::racers

    
    Who told you to put in 1/4" of toe-in?  A competitor??  ;*)
    
    SUGGESTION:  Before you start making numerous changes, measure
    		EVERYTHING, so you can get back to those settings.
    
    	Make changes ONE AT A TIME!
    
    Things to check:  Caster angles at the rears identical?  Caster angles
    at the fronts identical?  Typically zero (0) in the rear, and as much
    as you can get in the fronts, typically 6-8 degrees.  A large
    difference in caster angle between the two rears may be causing a
    "torque steer" turn-in.  The same is true at the front.  How does the
    car behave during heavy STRAIGHTLINE braking?  Straight as an arrow, or
    do you feel you are fighting the wheel?  Camber angles are track-speed
    dependent; but for this discussion, the fronts should be identical, and
    the rears should be identical.  If you have verified that the car is
    "SQUARED" without needing adjustments, measure everything all over
    again, twice, from two different points of reference, and KEEP A
    LOGBOOK of these measurements.  Draw diagrams for yourself to follow
    the next time you check these measurements.  Read that: NEXT WEEK!!!
    
    OK let's assume no changes were necessary.  Before you put that 1/4" of
    toe-in into the car, put the STICKY tires (tyres) back on the rear,
    BUT, LEAVE the brake bias alone.  If you go out and the car
    "misbehaves," NOW adjust the brake bias.  ONE CHANGE AT A TIME!!!!!!
    And you KNOW the car is "square," so you are not fighting a suspension
    geometry-induced problem.  So, how much time before the next race??!!?!
    
    In the meantime, check and/or replace the brake pads, inspect the
    caliper seals for heat cracking, replace if needed, replace brake hoses
    if any "sweating" is observed, etc. etc. etc.
    
    And finally, about that 1/4" of toe-in.  Is the person who told you
    that tidbit of info the current National Champion, and willing to prove
    to you that HIS CAR has 1/4" of toe-in??   Even if the answer is YES to
    both, 1/4" is a LARGE change.  Does this guy have a tyre dealership as
    a sponsor??  My hope is that you cure this "spinning" problem before
    you get to this 1/4" of toe-in idea.  It sounds like an awful lot.  If
    you need to correct some of the suspension angles, stay with zero (0)
    toe-in initially, and in the meantime, try to confirm through other
    sources that EVERYBODY runs 1/4" of toe-in.  That just sounds like TOO
    much, especially at the REARS.
    
    
    Hope all this helps,
    
    Bob R. 
    who_has_done_his_fair_share_of_spinning_off_this_year_also !!!
    

    one thought, how experienced a driver are you?  (I didn't find any
    introductory posting, not sure if one was never posted or if it got
    pruned in the "clean-up" of the conference.)  Also, what history does
    the car have?
    
    Reason for asking is, if you are inexperienced and the car has a
    reasonably good history, the odds might favor the existing setup being
    correct.  On the other hand, if you have considerable experience and
    the car is known to have an untrustworthy setup, the odds shift.
    
    My thinking is that you should worry about driving the thing first, and
    think about changing it only after you know you can drive it well
    enough that the existing setup is the limiting factor.  Yeah, it's
    easier to drive if the setup is right - but if your driving skills are
    not adequate to detect and analyze the handling characteristics, your
    chances of improving things by changing them at random are nil.  If you
    truly believe the setup is so buggered that the car is undrivable,
    invest in professional expertise to get the settings in the ballpark. 
    It'll be money well-spent.
    
    Incidentally, I can attest from first-hand experience that it is
    possible to drive a car with evil handling characteristics, without
    having problems.  I've also demonstrated (many times) that a
    good-handling car can be made to spin by a ham-handed driver.  The
    trick is knowing which of those situations you're in...

	The Guy happens to run in a different class but has many years
in FF2000 FF1600 and has observed this type of car from close behind on
the track. Another person who is building his own chassis from scratch has
said the same.
	I'm keeping a record of the set up. In fact I'm going back to the
original setup that put in good times and didnt spin.
	On reviewing the record I made the mistakes of

1) Thinking a previous brake balance measurement was wrong ( The brake
balance bar had shifted rearwards which probably caused the spin at 
Mallory after it going so well)
2)Then moving the tyres around to increase grip at the front.
(Which made it worse)
3)Moving the brake balance even further back.

The next trial will be as before (Without the mistakes, i.e. when it was 
handling well and I was putting in good times)
 with JUST the Rear toe in
BTW the 1/4" is across both wheels so the the track difference is between
the wheel centres and the between wheel rims on this measurement the front
toe in just 1/16th (Heck I'm going quote all im metric instead of converting)
The front toe in helped steady the straights)

I agree with the previous comments. I was wondering if the people you were
talking to were thinking 1/4 degree toe in? That seems much more reasonable.

If my math was right (not overly likely) 1/4 degree on a 13 inch wheel
is about 1/32 inch.

I run about 1/16 inch total toe in in rear (~1/32 per wheel) and
the same amount as toe out in the front to help turn in.

    
    Copied w/o permission (so what else is new!!) from PREPARE TO WIN by
    Carroll Smith
    
    	TOE-IN
    
    	The classic reason for toe-in at the front is to ensure that the
    wheels cannot toe out under braking loads.  This reason went away with
    rubber suspension bushings and narrow based wishbones.
    	Front toe-in (or toe-out) is now provided to promote straight line
    stability and/or to influence corner entry characteristics during the
    transition period when weight is being transferred.  In order to
    minimize scrub and rolling resistance it should be very close to zero
    on present generation racing cars (1/32" one way or the other covers
    the range).
    	Rear toe-in (never toe-out) is used to promote stability under
    acceleration loads and is basically a function of available torque.  It
    can be as little as 1/32" per wheel on a Formula Ford and as much as
    1/8" per wheel on a Can-Am car.
    
    
    	Note:  All measurements are in inches, which is where an apparent
    disconnect is occurring.  Your spelling of "TYRES" vs. "TIRES" should
    have tipped me off.  I think we are both trying to say the same thing,
    but stubbing our toes (haha) during a conversion process.
    
    	Good luck with your next track session, and remember;
    
    			NEVER LIFT
    
    	Bob R.

 I've got rubber bushes ( Very Very Stiff ones ) not rose joints

	So i've got a 1/16 or so fine!

Toe in at the rear  Yep them rubber bushes are there
and the car has a much wider track than a FF and has more torque + power
(165 Bhp machine)

So I 'll keep the front as it is and maybe have not quite so much on the 
rear!

	
		Derek

    Set up for Brands is
    
    1mm toe in Front ( Combined )
    4mm toe in rear  ( Combined )
    
    

    
    
    
    
    Carroll Smith's books, Prepare To Win, Tune To Win, Engineer To Win,
    and a new fourth book,  (?????? To Win) are an invaluable source of
    information.  I highly recommend them to anyone with a desire to anyone
    wishing to further your understanding of "the racing vehicle."
    
    The following is offered as Carroll Smith's discussion of suspension
    setups, and what the telltale signs are for a misaligned setup.  
    
    Reprinted without permission from TUNE TO WIN by CARROLL SMITH
    	pp. 135-139
    
    	Table of Handling Characteristics
    		Causes and Effects
    
    	Section Two - Cause Listed First
    
    			C - WHEEL ALIGNMENT
    
    	FRONT TOE-IN -- TOO MUCH
    
    	  Car darts over bumps, under the brakes and during corner entry
    
    	  Car won't point into corners, or, if extreme, may point in very
    	  quickly and then wash out
    
    	FRONT TOE-OUT -- TOO MUCH
    
    	  Car wanders under the brakes and may be somewhat unstable in a 
    	  straight line, especially in response to one wheel or diagonal 
    	  bumps and wind gusts
    
    	  May point into corners and then refuse to take a set
    
    	REAR TOE-IN -- TOO MUCH
    
    	  Rear feels light and unstable on corner entry
    
    	REAR TOE-IN -- TOO LITTLE
    
       	  Power on oversteer -- during corner exit
    
    	REAR TOE-OUT -- ANY
    
    	  Power oversteer during corner exit or in a straight line
    
    	  Straight line instability
    
    	FRONT WHEEL CASTOR -- TOO MUCH
    
    	  Excessive physical steering effort accompanied by too much self
    	  return action and transmittal of road shocks to driver's hand
    
    	FRONT WHEEL CASTOR -- TOO LITTLE
    
    	  Car too sensitive to steering
    
    	  Too little steering feel, self return and feedback
    
    	FRONT WHEEL CASTOR -- UNEVEN
    
    	  Steering effort harder in one direction than the other
    
    	  Car swerves in one direction (toward the side with the high
    	  castor setting) in a straight line
    
    	CAMBER -- TOO MUCH NEGATIVE
    
    	  Inside of tire excessively hot or wearing too rapidly.
    
    	  At the front this will show up as reduced braking capability and
    	  at the rear as reduced acceleration capability.  Depending on the
    	  race track and the geographic location of the tire measuring
    	  point inside tire temperature should be 10 degrees F to 25
    	  degrees F hotter than outside
    
    	CAMBER  -- TOO MUCH POSITIVE
    
    	  Outside of tire will be hot and wearing.  This should never be
    	  and is almost always caused at the rear by running too much
    	  static positive camber in an effort to prevent excessive negative
    	  under the influence of wing at high speed.  Will cause corner
    	  exit oversteer and reduced tractive capacity.  If extreme, may
    	  cause corner entrance instability.
    
    	  At the front it is usually caused by excessive chassis roll or by
    	  insufficient roll camber compensation in the suspension linkage
    	  and will cause understeer after the car has pointed into the
    	  corner
    
    	BUMP STEER, FRONT -- TOO MUCH TOE-IN IN BUMP
    
    	  Car darts over bumps and understeers on corner entry
    
    	BUMP STEER, FRONT -- TOO MUCH TOE-OUT IN BUMP
    
    	  Wanders under the brakes and may dart over one wheel bumps or in
    	  response to wind gusts.  Understeer after initial point in on
    	  corner entry 
    
	BUMP STEER, REAR -- TOO MUCH TOE-IN IN BUMP
    
    	  Roll understeer on corner entry
    
    	  Tippy-toe rear wheel instability on corner entry
    
    	  Darting on application of power on corner exit
    
    	BUMP STEER, REAR -- TOE-OUT IN BUMP -- ANY
    
    	  Same as static toe-out but lesser effect -- oversteer on power
    	  application
    
    
    
    I keep a copy of the ENTIRE Table in my logbooks and notes, so when I
    am testing different chassis setups, I can pick and choose the ones 
    that seem appropriate to whatever change I am testing, and point me in
    the right "corrective action" decision. 
    

    
    re.-1
    
    Something 'bout the name CARROLL must have sent me into a typing
    frenzy, with references to reply #.8, first paragraph.
    
    Bob who_can't_type_worth_a_damn_to_begin_with!  60 wph (words per HOUR)