Semi-trailing arm rear suspension - roll center change

[sierra4000]

How can I change the roll center semi-trailing rear axle?
for stiffness rear end car (for understeer limitations )

Thanks for ideas!

 

[sierra4000]

If racing car is neutral corner balanced -although static car weight balance is the 60/40 percent
temperature and pressure of tires will identical?
there is a rule?

tomorrow I'm going to the race track I have a small change rollcenter
I'm curious

 

[dynatune]

In an ideal world your tires should - if tire size is adapted to weight distribution and power distribution - be more or less equal in temperature. Tire pressure should increase proportionally front and rear starting from eventually different static pressures that are related to wheight etc ...

I am curious too. Go kick some ass ...

 

[sierra4000]

Hi,

after about 15mm pivot up change and rear bar a little less stiff
car is closer to neutral but are still slightly understeer (I will smaller front bar use next time )

after 20 min run - on the half inner side of the front tires can see graining texture
what is cause?

rear tires OK

 

[dynatune]

Too much static negative camber ?

 

[sierra4000]

Probably yes,
is about 0.7 - 0.8 degree-rear is about 0 - 0.2 degree

 

[Tmoose]

"after 20 min run - on the half inner side of the front tires can see graining texture
what is cause?"

I'm not sure static camber settings with different suspension types (as are your front and rear) are very comparable. The "best" static camber setting might be quite different to achieve "best" camber when cornering hard.

Have you measured temperature across the tread when cornering on a skid pad?
Do you have copies of books by (Carrol) Smith, Van Valkenburgh, and probably others? They talk about suspension tuning.

 

[sierra4000]

I know that I can not compare the front vs rear static camber because dynamic camber curve is different.

I didn't make it measure temperature tire for the time being.I will make great skidpad test at springtime.