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I am allowed one more modification to my NB8A to run in clubman class as I already have a Torsen.

I want to go suspension, so am allowed good shocks or springs or swaybars, but only one. I also want to maintain a good road touring car, so low and stiff isn't the go for me.

I have 0.9 -ve camber front (maximum available) and 1.5 -ve rear. The car turns in ok, but pushes into understeer mid-corner, losing corner speed and cannot be balanced on the throttle.

Gus runs springs with considerable success, but it is fairly low and may compromise ride ?

Bryan has the Bilstein set-up which also is quick. If I go shocks I was thinking along the lines of Koni yellow adjustables with stock springs to maintain a good ride compromise.

Swaybars seem like they will control weight transfer, and may maintain the best road set-up, so this seemed another way to try.

Any-one with a quick Clubman class have a good reason to support either option, with the limitation of maintaining an acceptable ride height/ride for a daily user?

Sways control weight transfer but don't really improve grip or laptimes although the car feels better.

Springs increase bounce frequency and do improve grip, braking dive and general control.

Shocks improve comfort, damping and provide fine adjustment of front/rear balance.

I'd go springs first in a combination that keeps the natural understeer/oversteer balance correct with the OEM sway bars.
7F/5R Kg/mm, 6/4 or 5/3 would work well. Obviously 7/5 is more track oriented whie 5/3 is more DD. I run 10/7 on Tein shocks with OEM sways on a daily driver but it's all on country roads with 100kmh limits. The harshness is not too obvious under those conditions. That setup is good enough for 1:12.1 at Wakie with a motor that only just keeps me up with standard NBs down the main straight.

Not an expert, nor particularly on topic but could reducing the rear camber slightly help with your mid-corner understeer issues?

----------------------------Stiffer-----------------------------------Softer
Front Sway Bar---------More Understeer--------------------- Less Understeer
Rear Sway Bar----------More Oversteer-----------------------Less Oversteer
Front Spring------------More Understeer---------------------Less Understeer
Rear Spring------------More Oversteer-----------------------Less Oversteer
Front Tire Pressure----Less Understeer----------------------More Understeer
Rear Tire Pressure----Less Oversteer------------------------More Oversteer
Front Shock------------More Understeer, later in turn-------Less Understeer, later in turn
Rear Shock------------More Oversteer, later in turn--------Less Oversteer, later in turn

Understeer corrections
Increase positive caster
More front toe out
Reduce rear toe in slightly
Increase front negative camber

Oversteer Corrections
More front toe in
Increase rear toe in
Reduce front negative camber
Reduce positive caster