Why always softer springs on rear?

[ben_shoe]

Just a general question. Why does everyone seem to run softer springs on the rear? eg 8k on the front and 6k at the rear? From all my experience with cars they seem to oversteer more with a stiffer rear end! Is the stiffer springs at the front just to compensate for the weight of the engine and if so what would the cars handling be like with equal rate springs front and rear?

[rthy]

they would oversteer everywhere and be very hard to use for anything outside a farm

[aaaaah]

More weight up front dut to engine etc means that in order to have a balanced setup the spring rates at the front have to be higher.

[Billzilla]

More weight up front dut to engine etc means that in order to have a balanced setup the spring rates at the front have to be higher.[/b]


On a stock-ish AE-86 there's only about 3% more weight on the front so it's not that. It's to do with the live-axle rear end, as to work tehy need fiarly soft spring rate, to stop the inside wheel from picking up and spinning, and/or creating oversteer.
Look at the well setup old Escorts and so on, they often have the inside front wheel cocked up in the air when cornering hard. That's because the rear springs are so soft the car rolls enough to lift that wheel.

[Cerby]

So what causes axle tramp? Cos i get that a bit in my car and i would have thought that my springs are too stiff. Tho the setup is a little dodgy and i could be completly backwards and the springs are to soft just really short.
Cheers
Cerby

[Billzilla]

So what causes axle tramp? Cos i get that a bit in my car and i would have thought that my springs are too stiff. Tho the setup is a little dodgy and i could be completly backwards and the springs are to soft just really short.
Cheers
Cerby[/b]


Very little to do with the springs, though stiffer ones would reduce the effect a little.
It's simply the soft factory rubber bushes flexing around, then unloading. Worn dampers also aren't a direct cause but will help make the propblem worse.

[Cerby]

Cool thanks! Well i've got new dampers coming and a rebush is on the cards when i upgrade the swaybar and panhard rods after exams so hopefully that will fix it!
Cheers
Cerby

Very little to do with the springs, though stiffer ones would reduce the effect a little.
It's simply the soft factory rubber bushes flexing around, then unloading. Worn dampers also aren't a direct cause but will help make the propblem worse.
[/quote]

[Stomp86]

i have short shoks and springs and trd 2 way in the rear of my car...i find that it seems to "hop" around corners at slow speeds ...ie street driving through a roundabout turning right....so going 3/4 way around it...has anyone experienced something like this....

its fine if u give it some stick so the lsd chirps but at nanna pace its all wierd...

any ideas?

Adam