question about steering system

[MSA]

hi.I and my friends are designing our first car.I am working on steering system.I have studied some books obout steering systems and state of vehicles in turning.For example I studied "fundamentals of vehicle dynamics" by gillespie.in chpater 6 it has discussed about steady state cornering and ackermann geometry and understeer gradient and ... but I think we dont have many of these parameters to calculate understeer gradient and steering angle .for example we dont have lateral stiffness of tyres.so I want you to guide me what should I do.What do you calculate for designing the steering system.Are these equations are useful for us?And what is the procedure of designing the steering system?
thanks!!

[MSA]

hi.I and my friends are designing our first car.I am working on steering system.I have studied some books obout steering systems and state of vehicles in turning.For example I studied "fundamentals of vehicle dynamics" by gillespie.in chpater 6 it has discussed about steady state cornering and ackermann geometry and understeer gradient and ... but I think we dont have many of these parameters to calculate understeer gradient and steering angle .for example we dont have lateral stiffness of tyres.so I want you to guide me what should I do.What do you calculate for designing the steering system.Are these equations are useful for us?And what is the procedure of designing the steering system?
thanks!!

[benjo]

Perhaps you should have the data for your tyres? Have a look around on the net theres lots of papers about teams starting out and lots of people recommend making a tyre choice first. After all, tyres are the only thing keeping you in contact with road. Surely they must be an important design choice.

[Jersey Tom]

Be sure to understand both static Ackermann and Ackermann progressio through steering, and what influences both, before you design anything.

[kbuckert]

make sure that you consider bump steer! I designed the steering on our 2007 car, and found that the tie-rods need to run through the instant center of the suspension (so that all suspension components travel about the same point). you can adjust this by changing the mounting height of the rack or location on the upright.

[flavorPacket]

if it's your first car, I'd recommend getting tire data asap, and then being conservative, meaning:

-avoid bumpsteer
-make a choice for ackermann and move on. Don't obsess about it, just have good reasoning on why you made the choice you did. And personally I wouldn't make it adjustable on a first year car. It's just another thing to worry about.
-make sure you can steer enough (sounds dumb, i know)