If I sounded too critical, I didn't mean to be. I was assessing the design, more than the paper.
Well, outboard coil over shock is easier to engineer, and package, has half the number of hardpoints, half the force at the fulcrum (roughly) and is therefore lighter and cheaper. Spend a bit of the costsave on anodising and/or painting the shock. The judges must be bored witless by seeing so many inboard suspensions (I'll admit to only having seen 3 FSAE cars, this may be an exaggeration). Another option that would be harder to engineer is torsion springs, they are sexy and work well with SLAs, and spaceframes.
I reckon by eyeball 20 kg would be a more reasonable target for the spaceframe mass, I'm really not convinced that materials or analysis techniques for spaceframes have changed much since 1955, never mind 1995. Frankly the whole spaceframe just looks too complex. A genetic search for an optimum structure would be an interesting project that could be done now, but not then, I suppose. I'd certainly expect to see other design criteria than just torsional rigidity, and would be interested to see a justification for the figure chosen. (I think I can guess, and disagree with the choice).
My comment on the RCH was a bit harsh. By doing what they did they will have slowed the weight transfer side to side on initial turn in. This means they can tune it with shock valving, which is easy. Also the car will be less jittery. This could be very important for a car driven by students.
On the other hand the scrub radius seems needlessly high, which is bad for bump steer. They'd be better off using more trail and less scrub to get their steering feel, if the tyres are at all like a road car's tyres. I doubt the test speeds are high enough for the pneumatic trail effect to be important.
OK, I'll stop poking holes, after all there aren't many student projects that even raise interesting questions like this. I wish we'd had FSAE at uni, but then we'd have had to get our hands dirty, oh the horror!
Cheers
Greg Locock
