Damper Movement on single seater race cars

[FrazM]

If you are designing a single seater race car from scratch what sort of suspension travel are you ideally looking to achieve in terms of wheel movement and damper piston travel?

I am talking in terms of a small light weight hillclimb/sprint type of car not big F1 or high downforce type of car.

I initially thought you would want to maximise the damper travel and use as much of it's stroke as possible. Does this generate too much heat though? I have come to the conclusion that I really don't have much of a clue so I have come to the experts!!!

In terms of bump travel I guess you never want the tub to hit the ground so if you are running say 40mm above the ground you don't really want anymore than 40mm of wheel travel in bump???

What about droop? What is a realistic droop figure to work to at the wheel such that you can be confident you won't be lifting wheels? Is 10mm too little? Any wisdom out there on zero droop suspension and lifitng of wheels???

Anyone any experience, wisdom or random thinking they can offer me?

[FrazM]

Thanks for the quick response. More than can be said for mine!

All good stuff. So I'm not barking up the wrong tree with the amplified damper movement versus wheel travel to overcome the stiction problems in the damper? However this does pose heat build up issues on longer runs.

So if my installation doesn't easily allow for an amplified motion ratio that isn't necessarrily the end of the world is it? Just means my car would benefit from those tasty penske shocks more than yours?

Droop or no droop is then down to the tyre charecteristics and the duration of running? You are saying the zero droop setup in hillclimbing allows the outer tyre to heat up from cold faster giving a net increase in grip than an evenly loaded pair of colder tyres? For a balanced circuit car however droop is good to more evenly use the warm tyres?

You couldn't point me towards that other forum you discussed all this on to save me wrecking your head going over old ground?

The dampers I have allow for 1" of travel plus bump stop compression. Therefore I have 1" to design in droop and bump before bump stop. I am designing a front pull rod system and at the moment my design will hit the bump stop with 30mm of wheel bump (0.7" damper travel)and allows for 10mm of wheel droop (0.3" damper travel). In your experience does this sound feasible? Should I sacrafice some droop travel to allow the 30mm wheel bump to be used over more of the damper stroke? Should I get longer dampers? As I said before the nature of the installation doesn't allow for much amplification of the wheel travel even though it has been designed to try and maximise this through the leverages.

Thanks for your help!