How to tune handling?
05-25-2003, 07:44 PM
#1
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How to tune handling? Ok, lets get a big long thread going about how one would adjust thier handling.
What are the pros and cons of running a bigger swaybar instead of stiffer springs? What effect would more or less rebound and compression have? If you have coil overs, how would adjusting the ride height effect things? With double adjustable Koni shocks and different spring and sway bar combinations, how do you tune a car's handling correct? Pick springs who's rate works well with what you need, then the sway bar, then the shock valving, and then down to tire pressure?
J.
What are the pros and cons of running a bigger swaybar instead of stiffer springs? What effect would more or less rebound and compression have? If you have coil overs, how would adjusting the ride height effect things? With double adjustable Koni shocks and different spring and sway bar combinations, how do you tune a car's handling correct? Pick springs who's rate works well with what you need, then the sway bar, then the shock valving, and then down to tire pressure?
J.
05-25-2003, 08:52 PM
#2
Re: How to tune handling? Read this. It helps a ton.
http://members.aol.com/sccacuda/cars/1SmthTa.html
Also, : http://www.ls1.com/forums/showthread...eferrerid=1904
After all that, I run a 35mm S/T bar with Eibach pros and revalved Sam Strano Bilsteins.
2 points:
1. The spring, shock, tire and swaybar all work in concert. Change one, and you've affected the rest.
2. Suspension setup for autox will be different than road race. You can't use a single solution. Well you can, but one will suffer.
To your questions.
1. "The very first consideration in discussing the anti-roll bar is the fact that its only job is to handle roll resistance. It has nothing to do with spring rate. Changing bars can only make the front end stiffer or softer in terms of roll rate and not spring rate."
2. "Shock absorbers work hand-in-hand with springs. Think of it: a shock is useless without a spring to control, and a spring is useless without a shock to control it. They have to work together as a team. A shock, with its varying rate of action (varying from a 60/40 to a 70/30, for example) can tailor the action of a spring and create several different personalities in one spring. It does this by varying the resistance the spring uses to bounce or rebound."
"Shock absorber rates are measured in percentages of rebound to compression. Compression, which is also referred to as bounce, jounce, or bump, is the motion that pushes the s hock stem down into the shock body. Rebound, then, is the opposite stroke, or the pulling out motion of the shock stem."
"The Koni shocks are externally adjustable in both bump and rebound in varying amounts up to 300% of firmness from initial lowest setting.
In adjusting the settings of the shocks, remember that the minimum amount of damping control required to keep the wheel firmly on the ground at all times is most desirable. To start out with, set the rebound control one third of the distance towards heavy (that would be four clicks counter-clockwise from the minimum stop). Rebound is controlled by the adjuster on top of the shock absorber (see photo). There are 12 positions which "sweep" or click from minimum to maximum. Moving the adjuster counter-clockwise increases rebound damping control. When adjusting each shock be sure to record the number of clicks from minimum it is set at.
Bump adjustment is made by the **** on the side of the shock. The minimum position is found by turning the **** counter-clockwise to the stop point. Then damping can be stiffened by turning the **** clockwise. There are twelve click positions along the bump control ****. As with rebound, start the shock out adjusted four clicks toward heavy. Additional setting changes are made after testing."
3. Not sure
4. "The basic reason behind doing anything in chassis building is to make chassis movement predictable. Lateral acceleration, braking , acceleration and centrifugal forces all put a tremendous strain on the car. Frames, bodies and other seemingly indestructible parts twist and bend.
Proper chassis building , then , is a logical step by step improvement of the chassis, making rigid what flexes, insuring normal and non-interfering movement for all suspension components and redesigning geometry so it conforms to all theories and principals"
There's more to 4 than that. All of the above I've quoted from the source above.
Good start?
http://members.aol.com/sccacuda/cars/1SmthTa.html
Also, : http://www.ls1.com/forums/showthread...eferrerid=1904
After all that, I run a 35mm S/T bar with Eibach pros and revalved Sam Strano Bilsteins.
2 points:
1. The spring, shock, tire and swaybar all work in concert. Change one, and you've affected the rest.
2. Suspension setup for autox will be different than road race. You can't use a single solution. Well you can, but one will suffer.
To your questions.
1. "The very first consideration in discussing the anti-roll bar is the fact that its only job is to handle roll resistance. It has nothing to do with spring rate. Changing bars can only make the front end stiffer or softer in terms of roll rate and not spring rate."
2. "Shock absorbers work hand-in-hand with springs. Think of it: a shock is useless without a spring to control, and a spring is useless without a shock to control it. They have to work together as a team. A shock, with its varying rate of action (varying from a 60/40 to a 70/30, for example) can tailor the action of a spring and create several different personalities in one spring. It does this by varying the resistance the spring uses to bounce or rebound."
"Shock absorber rates are measured in percentages of rebound to compression. Compression, which is also referred to as bounce, jounce, or bump, is the motion that pushes the s hock stem down into the shock body. Rebound, then, is the opposite stroke, or the pulling out motion of the shock stem."
"The Koni shocks are externally adjustable in both bump and rebound in varying amounts up to 300% of firmness from initial lowest setting.
In adjusting the settings of the shocks, remember that the minimum amount of damping control required to keep the wheel firmly on the ground at all times is most desirable. To start out with, set the rebound control one third of the distance towards heavy (that would be four clicks counter-clockwise from the minimum stop). Rebound is controlled by the adjuster on top of the shock absorber (see photo). There are 12 positions which "sweep" or click from minimum to maximum. Moving the adjuster counter-clockwise increases rebound damping control. When adjusting each shock be sure to record the number of clicks from minimum it is set at.
Bump adjustment is made by the **** on the side of the shock. The minimum position is found by turning the **** counter-clockwise to the stop point. Then damping can be stiffened by turning the **** clockwise. There are twelve click positions along the bump control ****. As with rebound, start the shock out adjusted four clicks toward heavy. Additional setting changes are made after testing."
3. Not sure
4. "The basic reason behind doing anything in chassis building is to make chassis movement predictable. Lateral acceleration, braking , acceleration and centrifugal forces all put a tremendous strain on the car. Frames, bodies and other seemingly indestructible parts twist and bend.
Proper chassis building , then , is a logical step by step improvement of the chassis, making rigid what flexes, insuring normal and non-interfering movement for all suspension components and redesigning geometry so it conforms to all theories and principals"
There's more to 4 than that. All of the above I've quoted from the source above.
Good start?
05-26-2003, 05:24 AM
#4
Re: How to tune handling? Springs support the car's weight ...
Sways control the weight distribution ...
Shocks minimize the abrupt changes ...
Some folks like a soft spring and heavy bar while others like stiffer springs and a lighter bar. It's driver preference.
Keeping the chassis "free" is probably the single most important thing in a "handling" mod. If the suspension binds as it attempts to go through it's range of motion, this is additional spring rate and constantly changing.
Handling is all about reducing or eliminating variables. Consistency is key.
Sways control the weight distribution ...
Shocks minimize the abrupt changes ...
Some folks like a soft spring and heavy bar while others like stiffer springs and a lighter bar. It's driver preference.
Keeping the chassis "free" is probably the single most important thing in a "handling" mod. If the suspension binds as it attempts to go through it's range of motion, this is additional spring rate and constantly changing.
Handling is all about reducing or eliminating variables. Consistency is key.
