Suspension changes and what they do

[ConeDodger]

Spring Rate Changes
Modification-----------------------------------Effect on Suspension

<Increase front and rear rate>>> Ride harshness increases; tires may not follow bumps causing reduced traction. Roll resistance increases.

<Increase front rate only>>> Front ride rate increases. Front roll resistance increases, increasing understeer or reducing oversteer.

<Increase rear rate only>>> Rear ride rate increases. Rear roll resistance increases, increasing oversteer or reducing understeer.

<Decrease front and rear rate>>> Ride harshness decreases; tires follow bumps more effectively, possibly improving traction. Roll resistance decreases.

<Decrease front rate only>>> Front ride rate decreases. Front roll resistance decreases, decreasing understeer or increasing oversteer.

<Decrease rear rate only>>> Rear ride rate decreases. Rear roll resistance decreases, decreasing oversteer or increasing understeer.

Antiroll Bar Changes
Modification-----------------------------------------Effect on Suspension
<Increase front rate>>> Front roll resistance increases, increasing understeer or decreasing oversteer. May also reduce camber change, allowing better tire contact patch compliance with the road surface, reducing understeer.

<Increase rear rate>>> Rear roll resistance increases, increasing oversteer or decreasing understeer. On independent rear suspensions, may also reduce camber change, allowing better contact patch compliance with road surface, reducing oversteer.

<Decrease front rate>>> Front roll resistance decreases, decreasing understeer or increasing oversteer. More body roll could reduce tire contact patch area, causing understeer.

<Decrease rear rate>>> Rear roll resistance decreases, decreasing oversteer or increasing understeer. On independent rear suspensions, more body roll could reduce tire contact patch area, causing oversteer.

Shock Absorber Changes
Modification------------------------------------------Effect on Suspension

<Increase rebound and bump rates>>> Ride harshness increases.

<Increase rebound rates only>>> On bumps, tires may leave track surface.

<Increase bump rates only>>> Body roll resisted; outside tire loaded too quickly; car won't stabilize into a turn.

<Decrease rebound and bump rates>>> Ride harshness decreases; car may float over bumps.

<Decrease rebound rates only>>> On bumps, tires follow track surface more effectively; car may continue to oscillate after bumps.

Decrease bump rates only Body rolls quickly; car is slower to respond to turn-in.

[Nylander]

I take is slight changes of one of these will effect an other? is this a matter of finding the perfect balance of all these settings to properly set up the car?

[rick2]

Originally Posted by Nylander

I take is slight changes of one of these will effect an other? is this a matter of finding the perfect balance of all these settings to properly set up the car?

Yes... Sort of. If you improve front grip, you may do so by decreasing the grip your rear tires have... or you may just increase front grip to the point where you're able to push the car harder, and the rear grip isn't up to par...

So, while it is a balance... sometimes you can modify one setting and gain a lot... sometimes you will modify the same setting, and gain what you were trying to gain, but lose the handling elsewhere...

Also, track conditions make a big part of it... a hot asphalt track will be wildly different than a cool concrete track... and weather conditions play a big part... so you may find the perfect setup for a particular track on a particular day, and a month later the setup may not even apply...

usually for any given car, you can find a nice middle of the road starting point, tho, after running a few events at different places under different conditions and learning the car (each car has its base tendencies you can learn if you make minor changes one by one), and then at the track use these guidelines to further dial in your car for that specific event.

[ConeDodger]

Great points Rick.