[Larry B]

I would like to know what the spacers ( three sizes 10,20,30 ths ) used to space out the lower a-arm do, and how this helps in tunning the chassis?

 

[tw78911sc]

Lengthens A arm/axle length making spring rate softer the bigger spacer you use.

I would like to know what the spacers ( three sizes 10,20,30 ths ) used to space out the lower a-arm do, and how this helps in tunning the chassis?

 

[LARCGuy]

By spacing out the arm itself, the front track width changes, but the spring rate remains the same. Adjusting the front track width changes how the car turns in and off.
RF Out - Less weight transfer/Less Steering ("tire bite") going in.
RF In - More weight transfer/More Steering

Opposite on LF.
LF out - more overall corner steering/particularly center off and vice versa.

 

[davepull]

By spacing out the arm itself, the front track width changes, but the spring rate remains the same. Adjusting the front track width changes how the car turns in and off.
RF Out - Less weight transfer/Less Steering ("tire bite") going in.
RF In - More weight transfer/More Steering

Opposite on LF.
LF out - more overall corner steering/particularly center off and vice versa.

spot on

 

[Roman Pemberton]

Lengthens A arm/axle length making spring rate softer the bigger spacer you use.

if you run a longer axle and change your tread width that way it will have more leverage over the spring and will react as if it is softer and there are times when i will run it that way just for that reason.