Suspension Tweak Table Also can be found in November 99 issue of Sport Compact Car   Suspension adjustment: Effect on vehicle balance: (Extreme useable adjustment limit) Range of adjustment: Symptom of too much adjustment: Front spring rate increase More understeer; increases proportional weight transfer to the front when rear wheel rate is not changed; reduces front traction when rear wheel rate is not changed. 150-600 lb/in Terminal understeer; front of car hops in corners; escess wheelspin of inside tire on FWD cars. Front spring rate decrease Less understeer; decreases proportional weight transfer to the front when rear wheel rate is not changed; increases front traction when rear wheel rate is not changed. 150-600 lb/in Too much oversteer; oversteer then understeer if spring rate is so soft that the car bottoms under lean.  Car bottoms excessively with a jolting ride. Rear spring rate increase More oversteer; increases proportional weight transfer to the rear when front wheel rate is not changed; reduces rear traction when front wheel rate is not changed. 100-600 lb/in Too much oversteer; sidestep hop in corners; twitchy, pretty scary. Rear spring rate decrease Less oversteer; decreases proportional weight transfer to the rear when front wheel rate is not changed; increases rear traction when front wheel rate is not changed. 100-600 lb/in Car understeers. If way too soft, car understeers then oversteers as car bottoms out under lean. Car bottoms out excessively with a jolting ride. Front anti-roll bar stiffer More understeer; increases proportional weight transfer to the front when rear bar rate is not changed; reduces front traction when rear bar rate is not changed. None to 1.25" dia Terminal understeer; lifts inside front tire off the ground which can cause massive wheelspin in FWD cars. Also not good for most effective tire usage as inside wheel is now doing nothing. Front anti-roll bar softer Less understeer; decreases proportional weight transfer to the rear when front bar rate is not changed; reduces rear traction when front bar rate is not changed. None to 1.25" dia Oversteer, scary! Rear anti-roll bar stiffer More oversteer; increases proportional weight transfer to the rear when front bar rate is not changed; reduces rear traction when front bar rate is not changed.  None to 1" dia Big-time oversteer. Can cause the inside rear tire to lift off the ground which is not too bad on a front-heavy, front wheel drive car. Rear anti-roll bar softer Less oversteer; decreases proportional weight transfer to the rear when front bar rate is not changed; increases rear traction when front bar rate is not changed. None to 1" dia Understeer; slow and boring Front tire pressure higher Less understeer by reducing slip angles on most tires. Up to 55psi hot No traction-- tire is crowned so more understeer. Adds wheel spin in FWD cars; jarring ride; center of tires wear out faster. Front tire pressure lower More understeer by increasing slip angles on most tires. Not less than 20psi Edges of tires wear quickly because tire is folding over; feels mushy; tires chunk because low pressure means more heat build up. Rear tire pressure higher Less oversteer by reducing slip angles on most tires. Up to 45psi hot No traction-- tire is crowned so more oversteer; bad wheelspin on RWD cars; jarring ride; center of tires wear out faster. Rear tire pressure lower More oversteer by increasing slip angles on most tires. Not less than 20psi Edges of tires wear quickly because of tire folding over and cupping upward feels loose in back; tires chunk becasue low pressure means heat build up. Negative camber on front Less understeer because of better lateral traction as the tread is flatter on the ground under side load. Up to 3.5° neg Poor braking; car is road crown sensitive; twitchy;  tires wear out faster on the inside edge. Posative camber on front More understeer due to less lateral traction as the inside of the tread lifts under side load. A little can make the tires last a little longer. Never used in performance apps Poor braking; car is road crown sensitive; twitchy; tires wear out faster on the outside edge. You almost never ant posative camber.  Negative camber on rear Less oversteer because of the better lateral traction as the tread is flatter on the ground under side load. More rear grip  (-3 degrees) Up to 2.5° neg More oversteer; car feels twitchy in back; tires wear out on the inside edge. Less breakaway warning when limit is exceeded. Posative camber on rear More oversteer due to less lateral traction as the inside of the tread lifts under side load. Never used in performance apps Car feels twitchy in the back; tires wear out on outside edge; more forgiving at limit. High-performance drivers do not want posative camber. Ride height too low Car twitchy with unpredictable dynamics. Bumpsteer makes you feel miserable. Usualy 1.5" lower than stock is max. Everything that could possible be wrong; Sudden over or understeer; twitchy due to bumpsteer; very harsh ride; premature tire wear. Toe-in front Car is stable while going straight. Turn in is average (1/8" total toe-in) 1/8" toe-in Car has slow twitchiness under braking; feels odd; kills the outside edge of tires. Toe-in rear Car is less likely to suddenly oversteer when throttle is lifted (1/8" total toe-in) 1/8" toe-in Weird, slow, rocking movement in back; feels slow but still unstable; wears the outside edge of tires. Toe-out front Car turns in well; works pretty well on FWD cars as they tend to toe-in under load (1/4" total toe-out) 1/4" toe-out Car is really twitchy under braking; car is very road crown sensitive; car wanters on straight road; kills inside edge of tires. Toe-out rear Helps the car rotate; useful on tight low speed courses and slalom events (1/8" total toe-out) This trick is useful only on FWD cars. Very common on FWD Pro-Rally and Autocross cars. 1/8" toe-out Not too good for street driving; causes lift throttle oversteer; car makes violent side-to-side rocking motions in rear; tires wear more on insides. Posative front caster Helps stability, steady state cornering and turn-in because the suspension will get more negative camber when the wheel is turned, reducing posative caster reduces steering effort (6 - 7° posative, negative is not useable.) 4° - 9° posative Can increase understeer expecilly in cars with wide, low-profile tires due to a non-linear increase in corner weight with its attendant increase in corner weight. Increases steering effort, Most FWD sport compacts are not easily adjusted. Shock stiffer Slower transient responce; quicker onset of over or understeer. Suspension becomes too unresponsive, ride gets harsh, car skips over bumps, thereby losing traction. Causes a big delay in weight transfer resulting in strange handling, lke understeer then late corner stage oversteer. Shock softer Car rides firmer; less likely to blow through travel on bumps on adjusted end of car. Car oscillates due to under-damped spring motion, like a boat, car gets twitchy in turns, feels unstable. Add strut tower braces The car is more responsive to suspension adjustment; car feels more solid, ride improves, suspension seems to work better; a stiffer suspension can be tolerated by driver. You can not make a chassis too stiff! Add poly bushings The car is more responsive to suspension adjustment. Feels more solid and responsive to steering input. More road noise and shock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .