steering effort

[MSA]

I want to calculate the torques and forces applied to steering system from wheels to find out how much torques our drivers should apply to steering wheel to turn it(steering effort).And I want it to design shafts and tie rods and etc.but I havent found any equations about it.can anybody tell me some information about it .where I can find these equations?
And I want to know what is the range of steering effort in your cars?

[MSA]

I want to calculate the torques and forces applied to steering system from wheels to find out how much torques our drivers should apply to steering wheel to turn it(steering effort).And I want it to design shafts and tie rods and etc.but I havent found any equations about it.can anybody tell me some information about it .where I can find these equations?
And I want to know what is the range of steering effort in your cars?

[kwancho]

Look at aligning moments in your tire data, and then back calculate through your steering ratio.

[markocosic]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I want to calculate the torques and forces applied to steering system from wheels to find out how much torques our drivers should apply to steering wheel to turn it(steering effort).And I want it to design shafts and tie rods and etc.but I havent found any equations about it.can anybody tell me some information about it .where I can find these equations? </div></BLOCKQUOTE>

Numerically it's all classical physics/mechanics 101:

http://www.vectorsite.net/tpecp.html

The best text ever written on the subject:

http://en.wikipedia.org/wiki/The_Fey...res_on_Physics

Fill gaps with assumptions in the abscence of data, but keep track of which ones you make/why and try to tally wiht existing data as you are doing:

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">And I want to know what is the range of steering effort in your cars? </div></BLOCKQUOTE>

[Jersey Tom]

You want the suspension/tires to give enough force feedback to the driver that he can feel out the car's grip, but not so high that its a full body workout every lap.

You tell me. Figure out roughly how many footpounds of torque you want the driver to be resisting mid-corner.. take a look at self-aligning torque from the tires and how much additional resistance you need from mechanical trail.

Of course you'll have to kind of guess how much the footprint moves around from lateral and longitudinal tire stiffness.. and good luck with that.. but it'll get you in the ballpark.

[MSA]

hi tom .The problem is that I dont have any tire data and also I dont know how much torques is reasonable!It is our first car and I have recently started studing about steering.can you help me what I should do ?can you tell me some useful web sources?I dont know what is the procedure of steering design!

[ad]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by MSA:
hi tom .The problem is that I dont have any tire data and also I dont know how much torques is reasonable!It is our first car and I have recently started studing about steering.can you help me what I should do ?can you tell me some useful web sources?I dont know what is the procedure of steering design! </div></BLOCKQUOTE>

I'd be guessing RESEARCH, im entering this field myself (i.e. steering design) and im going to start by reading books, searching web, critique other designs, and physical testing

sorry thats all i got...

[JHarshbarger]

You can get tire data by donating to the Tire Testing Consortium (TTC). Search for it on here and you find the links to it.

If you want to find out what forces are reasonable, create a testing rig, do some calculations, and VIOLA, your very own personalized steering force preferences.

[Jersey Tom]

Whether you buy it or not is up to you and your financial situation, but buying into the $500 tire test data is one of the best and most educational investments you could make.

[Marshall Grice]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Of course you'll have to kind of guess how much the footprint moves around from lateral and longitudinal tire stiffness.. and good luck with that.. but it'll get you in the ballpark. </div></BLOCKQUOTE>

now correct me if i'm wrong, but doesn't the moment data for the tire tell you exactly where the contact patch has moved too?