Shocks

[Oscar Gonzalez]

What are some of the advantages or disadvantages of using a bigge spring rate? Will it help increase the torsional rigidity of the car? Will it help in the handling of the car or will it make it worse? /infopop/emoticons/icon_confused.gif

[Oscar Gonzalez]

What are some of the advantages or disadvantages of using a bigge spring rate? Will it help increase the torsional rigidity of the car? Will it help in the handling of the car or will it make it worse? /infopop/emoticons/icon_confused.gif

[Sleeque]

Hi Oscar,
I think you have some reading to do. There are several available books that you should be reading before you get involved in design. By asking a question like that, you prove you have done no preparation and are just looking for a cheat or a shortcut.
The problem is that the design judges are more interested is 'why' you do something rather than 'what' you do. So unless you can answer 'why', then whether it goes better or not doesn't matter.:-(


Slan Leat
Sleeque

[Charlie]

Also, the internet is not the best place to ask questions you need to learn by /infopop/emoticons/icon_smile.gif He's right, it's best to learn on your own and them just compare what your thoughts are with others on a forum like this. Otherwise you are too easily misled.

-Charlie Ping
Auburn University FSAE 1999-present
http://www.auburn.edu/~pingiii/2002FSAE/carblank.jpg

[awhittle]

Generaly you want to follow a few guideline points

1) buy a shock that is designed to control the spring that is on it. If the shock you want use is disigned to control a 700 lb spring, keep that spring on it, at least for design purposes. Lated you can +/- say 600 - 800 for fine tuning.

2) do not run any spring preload (or slop) on the shock at full droop.

3) plan on using adout 1/3 of your available shock travel with the car sitting on the ground with average to large driver

4) design for about 3 - 4 " of total suspension (full droop to full compression). I relize many of you have less than this for ground clearance. At full cornering load and hitting bumps...you will use it. With a 2" shock travel and 4" wheel travle you get a motion ratio of right at .5 to start.

5) I would avoid rising rate suspension as life is too short to try to go thru that learning curve.

6) Plan on a natural frequency of about 2 - 3 cycles per sec.

7) get the book by Alan Staniforth read it and accept it as a great starting point. You have way too many other things to worry about Areo, packaging, drivetrain, Ackerman, fuel injection, roll center control, general reliability, the write up/presentation.... the list goes for ever.

Hope this helps

AW

PS my car has only one wire that is not stock snowmobile (kill switch) and its the only wire that has ever kept me from running. I have NO gauges as you have no time to look at then anyway.

see www.ncs-stl.com/racecar (http://www.ncs-stl.com/racecar)