Tweet
Pick up a copy of Caroll Smith's "Engineer in Your Pocket" (And really the whole "... To Win" series would be a good idea too)
It is a little flip book and if you read it one way it tells you PROBLEMS and what the CAUSE is.
If you read it the other way it tells you the CAUSE and what the PROBLEMS are.
Has sections for chassis setup/alignment/shocks/springs/ARBs
Here's some info from it:
Then there's some stuff on bump steer, bla bla bla. Most of this stuff is generic, some may be different with a 4WD vehicle (parts about reduced accel... in our case it would be excessive front wheel engagement).
Make sure you invest in a good contact type pyrometer and a good tire pressure gauge.
It is a little flip book and if you read it one way it tells you PROBLEMS and what the CAUSE is.
If you read it the other way it tells you the CAUSE and what the PROBLEMS are.
Has sections for chassis setup/alignment/shocks/springs/ARBs
Here's some info from it:
Front toe-in: too much
- car darts over bumps, under heavy braking and during corner entry/is generally unstable
- car won't point into corneres, or, if extreme, may point in very quickly and then dart and wash out
Front toe-out: too much
- car wanders under heavy braking and may be somewhat unstable in a straight line, especially in response to single wheel or diagonal bumps and/or wind gusts
- car may point into corners and then refuse to take a set
- if extreme will cause understeer tire drag in long corners
Rear toe-in: too little
- power on oversteer during corner exit
Rear toe-in: too much
- rear feels light and unstable during corner entry. car slides through corners rather than rolling freely
Rear toe-out: any
- power oversteer during corner exit and (maybe) in a straight line
- straight line instability
Front wheel castor or trail: too little
- car too sensitive to steering (twitchy)
- too little steering feel and feedback
Front wheel castor or trail: too much
- excessive physical steering effort accompanied by too much self return action and transmittal of road shocks to driver's hands
- general lack of sensitivity to steering input due to excessive force required
Front wheel castor or trail: uneven
- steering effort harder in one direction than in the other
- car will "pull" towards the side with the less castor - good on ovals, bad on road courses
Camber: too much negative
- inside of tire excessively hot and/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 track and characteristics of the tire, inside tire temperature should usually be 10-25*f hotter than the outside.
Camber: not enough negative
- outside of tire will be hot and waering. this should never be and is almost always caused by running static positive camber at the rear in an effort to prevent the generation of excessive negative camber under the influence of download at high speed.
- a better solution is improved geometry and increased spring rate. dynamic positive camber will always degrade rear tire performance and if extreme, can cause braking instability and/or corner exit oversteer
- car darts over bumps, under heavy braking and during corner entry/is generally unstable
- car won't point into corneres, or, if extreme, may point in very quickly and then dart and wash out
Front toe-out: too much
- car wanders under heavy braking and may be somewhat unstable in a straight line, especially in response to single wheel or diagonal bumps and/or wind gusts
- car may point into corners and then refuse to take a set
- if extreme will cause understeer tire drag in long corners
Rear toe-in: too little
- power on oversteer during corner exit
Rear toe-in: too much
- rear feels light and unstable during corner entry. car slides through corners rather than rolling freely
Rear toe-out: any
- power oversteer during corner exit and (maybe) in a straight line
- straight line instability
Front wheel castor or trail: too little
- car too sensitive to steering (twitchy)
- too little steering feel and feedback
Front wheel castor or trail: too much
- excessive physical steering effort accompanied by too much self return action and transmittal of road shocks to driver's hands
- general lack of sensitivity to steering input due to excessive force required
Front wheel castor or trail: uneven
- steering effort harder in one direction than in the other
- car will "pull" towards the side with the less castor - good on ovals, bad on road courses
Camber: too much negative
- inside of tire excessively hot and/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 track and characteristics of the tire, inside tire temperature should usually be 10-25*f hotter than the outside.
Camber: not enough negative
- outside of tire will be hot and waering. this should never be and is almost always caused by running static positive camber at the rear in an effort to prevent the generation of excessive negative camber under the influence of download at high speed.
- a better solution is improved geometry and increased spring rate. dynamic positive camber will always degrade rear tire performance and if extreme, can cause braking instability and/or corner exit oversteer
Make sure you invest in a good contact type pyrometer and a good tire pressure gauge.
Comment