Coilover selection help needed/Anti-Roll Bar help

[LafayetteFSAE]

Hey guys,


As we are working on a Suspension design for next year, the next thing we need to start looking at is coilovers. Was looking into a mountain bike style setup. Just was wondering what brands you guys run/have success with for a formula car application.

Also another question in regards to Anti-Roll bars. What is the general consensus for a FSAE car needing front/rear anti roll bars?

Thanks in advance!

[LafayetteFSAE]

Hey guys,


As we are working on a Suspension design for next year, the next thing we need to start looking at is coilovers. Was looking into a mountain bike style setup. Just was wondering what brands you guys run/have success with for a formula car application.

Also another question in regards to Anti-Roll bars. What is the general consensus for a FSAE car needing front/rear anti roll bars?

Thanks in advance!

[exFSAE]

I believe this has been discussed a number of times, though the dampers available from MTB suppliers seems to change frequently.

My (slightly dated) experience:

Risse: Cheap. "Cost effective." Will also fall apart and leak as soon as they're installed (or before). Adjustment may or may not do anything.

Fox: Used to have a pretty good product in the Vanilla R/C (rebound/compression adjustable). Since then they've changed their product lineup around a bit. Some of the features on their current models I'm not sure you'd want. We looked into having the internals reworked by someone like Push, but it was expensive. And for the money..

Cane Creek DB: Expensive, but you get what you pay for. Very high build quality and wide range of adjustment. Damper curves available from the manufacturer. Couple clicks of adjustment and your driver WILL notice it. Springs are also pretty cheap. Just have to design your motion ratio accordingly.

Regarding roll bars... ideally you would have a front and rear so you can adjust roll stiffness distribution, and roll stiffness, independently. You can certainly get away with just one though. When it comes time to test and set the balance of the car you want something you can change quickly, which can be done with a good bar design.

If worse comes to worst though... 'perfect' is the enemy of 'good.' You can have a well-balanced car without any roll bars and just tuning springs and air pressure. You'll get knocked a bit in design unless you can explain yourself well (do-able), but you'll have a driveable car.

Thing to be aware of when designing bars is giving them enough stiffness range to actually make a difference. We had the problem one year we sized the bars around a real soft spring setup... and when we eventually went with a much stiffer setup (to prevent bottoming) the springs then dominated the handling and the roll bars didn't contribute enough to the balance to do anything.

[jrickert]

Risse == Not well built. We went through two of them before we even set our car on the ground. One didn't hold nose pressure and the compression knob broke off the other.