I'm Oliver from France,I allow myself to write you because I have a GAZ GOLD KIT with top mount oem, I'm not too happy for the moment, I asked a track session and a lot of trouble to adjust a real kangaroo ... today I'm the only french guy to have this kit and so I'm in shit lol, I had this kit built for the road and the track from time to time. I read very carefully the many posts on the subject on the forum but I am lost, my springs have these characteristics: front 500lb back 250/550lbs on this last point I do not understand why there are two values?
moreover the car at the lowest is much lower than the original I would have wished to have slightly lower frown
Can you help me please ? to understand what does not work (springs too hard? settings knobs?)
best regards coupé's fans
Signature picture too large: 300 x 100 maximum size allowed.
I followed few basic rules from a guy named Ron Sutton, who gives very nice advices for trackdays, however for RWD cars mostly, but here is few....... -A production based car, can go no faster through a corner than the front tires can grip. Balancing the rear tire grip to the front … for balanced neutral handling … is relatively easy … compared to the complexities of optimizing front tire grip. -The front tires need force, from weight transfer on corner entry, to provide front tire GRIP. Too little & the car pushes … too much & the car is loose on entry. -Tuning to allow a suspension corner … to compress quicker or farther … provides more force & therefore more grip to that tire … up to the limits of the tire. Tuning to allow a suspension corner … to extend/rebound quicker or farther … provides more force & therefore more grip to the opposite corner’s tire … up to the limits of the tire -Softer springs allow more compression travel & therefore more force onto the tire … for MORE GRIP. Stiffer springs reduce compression travel & therefore lessen force onto the tire … for LESS GRIP. -Springs primarily control how far a suspension corner travels under force, and only secondarily influences the rate of travel. Shocks primarily control the rate of suspension corner travel under force, and only secondarily have influence on how far. -Anti-Roll Bars primarily control how far the front or rear suspension (and therefore chassis) “rolls” under force, and only secondarily influences the rate of roll. Stiffer bars reduce roll angle, keeping the car flatter, working the inside tires better. -
All handling cars need to travel the suspension to work.
The car can’t run flat … it needs to travel … so it’s either got to Roll or Pitch … that’s the primary difference in the two tuning concepts I’ll outline. There are two common strategies that work. One relies more on the roll angle & the other on pitch angle.
Roll Angle vs Pitch Angle • A competition car should not pitch AND roll a LOT … it would be dangerous & undrivable • A competition car should not pitch AND roll a LITTLE … running too flat would make it just skate on the road surface. • A competition car can pitch a lot & roll a little … OR … pitch a little & roll a lot
You need to pick a path … so here is what they look like.
Conventional: • Stiff front springs & soft rear springs • Small, soft rate sway bars front & rear (if any in rear) • Higher Roll Angle when cornering • Less Pitch Angle Change in dive under braking
Old School – Let it Roll • High Roll Angle (3° +/-) • Front suspension doesn’t compress much on corner entry. (1” +/-) • Work the outside tires for grip & work the inside tires less so it will turn.
Drawbacks: • Too much roll angle overworks the outside tires in corners & underworks the inside tires. • The tires heat up quicker & go away quicker, providing a better short run set-up. • After tires “come in” the car is “knife edgy” to drive. • Very line sensitive … drivers say, “can’t drive it just anywhere” … meaning it handles poorly out of its optimum groove. • As the track grip increases & the car rolls more … these problems magnify. • When it rolls a lot & you brake hard, the inside rear tire has no grip. So to prevent from being loose on entry you must run stiffer front springs. • The stiffer front springs make the car tight/pushy in the middle … requiring the driver to brake more and run slower corner speeds.
Modern: • Soft front springs & stiff rear springs • Big, stiff sway bar in front & small sway bar in rear • Known as SS/BB … soft spring/big bar … if no bump stop or coil bind is utilized • Same concept used in conjunction with travel stops: Bump Stops or Coil Bind • Lower Roll Angle when cornering • More Pitch Angle Change in dive under braking
New School – Get the nose on the ground & run the car flatter • Roll angle is minimal, controlled primarily by the sway bar in front & stiffer rear suspension. (1° +/-) • Front suspension travels a LOT in dive (compress) to put maximum load & grip on front tires. (3” +) • Load the outside tires only slightly more than inside corners for optimum 4 tire corner grip.
Disadvantages: • Even when optimized … it still can not be driven as deep on corner entry as a conventional set up. • When racing door-to-door in a field of race cars running a mixture of set-ups, the SS/BB set-up is susceptible to dive bomb passes.
Advantages: • Flatter Roll Angle works the tires more evenly. • The tires heat up slower & last longer … making a better long run set-up as the tires are “good” way longer. • Less line sensitive … drivers say, “I can drive it just anywhere” … meaning any line on the track. • As the track grip increases … the advantages show more. • The soft spring/high travel front end puts creates maximum grip on front tires for highest cornering speeds. • Will produce faster cornering speeds & quicker lap times over conventional set-up, all other things being optimum.