Fred wrote:I saw a few people knocking the MacPherson strut setup because they make the camber value change , to me this is a good thing .
During cornering the strut compresses and due to the lower suspension link moving in an arc , the camber value is increased .
This is a good thing , because if it didn't , the contact patch of the tyre would be more on the outside edge of the tyre , due to tyre deformation . The increased camber value , allows the tyre to have a fuller width foot print .
With most double wish-bone suspension setups , the wish-bones are unequal in length , this has the effect of increasing the camber value , under compression , just like the MacPherson setup .
When I first got my MR2 it needed new tyres , so I went to the tyre shop . When I got there I had the correct size tyres fitted to the rear , instead of fitting the correct sized tyres to the front , I fitted ones with a lower aspect ratio (195x50x15 instead of the correct size 195x55x15) , because they were cheaper .
The result was the car tried to throw me off backwards at every bend , this introduction to oversteer was a real eye opener to me and taught me to respect this car like no other before .
Luckily I recognised my mistake and the next set of tyres were of the correct size , and to say the car was transformed is an understatement .
I was amazed that such a small change could upset the car in such a way , I wouldn't have believed it if someone had told me . With the right sized tyres the car has become very predictable and an absolute joy to drive on the ragged edge , it doesn't scare me any more and is easily balanced on the throttle now .
Rev2 MR2-turbo (LSD) , bog standard + K&N panel .
Actually Fred, under compression the wheel goes toward positive camber, exactly the effect you do not want and thus this is why the outside shoulder of the tyre wears quickly on trackdays.
A double wishbone setup means that under compression and throughout the arc of the suspension travel, camber can be a known quantity and engineered to either increase the neg camber or keep it constant etc.