Making upright actually work

[ERT]

Hi all
Iv been working on the suspension and my upright design as a kpi of 3 deg and a scrub of around 2mm. Aiming as little as possible to lightn the steering. My problem is i cant fit the caliper and rotor and everything in. Iv seen in other post that teams have 1 kpi and 8mm scrub so i take it it is in someway possible

Thanks everyone

[ERT]

Hi all
Iv been working on the suspension and my upright design as a kpi of 3 deg and a scrub of around 2mm. Aiming as little as possible to lightn the steering. My problem is i cant fit the caliper and rotor and everything in. Iv seen in other post that teams have 1 kpi and 8mm scrub so i take it it is in someway possible

Thanks everyone

[RacingManiac]

did you try adjusting your wheel parameter? changing your offset will help somewhat to get your scrub back....

[Dave K]

You may want to increase your scrub. I know you want to lighten your steering, but that is only static scrub... it will change dynamically as your steer angle changes, as well as while your tire deforms from cornering.

A couple other things you could do is go with a larger wheel offset and a wider wheel, and play with your upright and hub geometry that allows you to use a brake hat design to offset your rotor farther away from the wheel.

Keep playing with everything though, you will get it eventually http://fsae.com/groupee_common/emoticons/icon_wink.gif

[ERT]

Thanks for the ideas
I think i will just have to have more scrub is the only solution. if i offset the wheel another 15mm im think i can get about 15m of scrub or slightly less.

[exFSAE]

Why are you tuning scrub radius for steering feel, rather than mechanical trail?

[ed_pratt]

Hi ERT,

exFSAE beat me to it, but I'll second what he said.
Also, don't forget that some amount of scrub radius will contribute to steering stability at speed and under braking.

- there are more conventional ways of tuning your steering feel than altering the scrub radius, try to get a look at a copy of the Dixon suspension book, I found it easier to understand (wrt steering) than milliken.

thats my tuppence anyway,

Ed

[ERT]

Alright il try and find that book and have a look. I wanted to reduce scrub to make the steering lighter as our car is very heavy. I figured the trail from caster and the kpi would play enough of effect on stability of the car at speed.
thanks for your help