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I definitely appreciate it's a fairly mammoth undertaking alright and I'm conscious of not making it unpleasantly difficult so I think it may definitely be a better idea to try and utilise some existing suspension from a donor car and working from that but it would be nice to read up on it all first to have an idea of why I'm choosing a particular donor car and why it works well!
I feel like removing the actual suspension geometry from the equation makes it a lot more manageable possibly? I don't doubt the bodywork will be a big ask too, I was loosely thinking kevlar would be a good way to go but again I'm only beginning to think about this whole idea for a project so I'm not in a rush to get started until I've done the homework and come up with a good plan that should be achievable rather than diving head first into something I'll never finish!
Nahguavkire-
I feel like removing the actual suspension geometry from the equation makes it a lot more manageable possibly?
It does, as long as you keep the overall weight of the car and the weight distribution the same. If you don't, then you'll end up with the wrong suspension geometry for your car. You can't use the same suspension geometry from a front-engined car on a mid-engined car as the weight distribution is going to be totally different, so the roll centres, anti-dive and anti-squat are going to need to be different too. You could use it, but it's likely it'd handle like a total dog and at worst leave you in terminal oversteer situations.
You're also likely to have the issue that most production cars use McPherson struts up front, and they won't work with a low-level spaceframe chassis - the tops of the tower struts would be at eye height. On the Sylva range of cars they got round this by chopping the McPherson struts down and welding in a top-eye with a taper to turn the strut into an upright which could be used with a double wishbone suspension system. However, once you start doing that, you're moving so far away from the original suspension system that you're basically working from scratch albeit with some fixed geometry limitations.
I don't doubt the bodywork will be a big ask too, I was loosely thinking kevlar would be a good way to go
Super bold. I've done quite a bit of work with carbon (wet lay-up and pre-preg), kevlar and GRP. Kevlar is a total and utter swine to work with. I do use it, but only very sparingly and only for reinforcing carbon honeycomb panels to prevent intrusion into the passenger cell. It is a total unmitigated bitch of a material to work with.
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Good youtube rabbit hole here - https://youtu.be/Jdj-kGo4j3U
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bodywork
No idea if it is feasible on something the size of a car, but a motorcycle YT I watch made bits of bodywork using SS wire welded to make a frame, then super glued cut up t-shirts to make the rough shape. Once that "soft" frame was made they painted resin on the fabric and then fibre glassed and filled properly over it all.
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I used to work for a really small kit car firm in Kent, we did a car from scratch while I was there.
I designed a chassis for them made from 25x25 ERW box with tubular double wishbones - the chassis was a bit of a mash up of pre-existing ideas from their other car they made and some stuff transferred from the caterham +4 chassis.
It took us ~9months to do the first chassis, we had designed the bodywork and had various scale models / renderings of it but they refused to tool for any of it until they had 10 orders for cars
Brommers
nauls
hugo7
mcmyk
I don't have a 'busa powered kit car. I do have one with a ZX9R engine, one with an R1 engine, and one incomplete car with a Blackbird engine though.
Designing a car from scratch would be a bold move unless you've had a lot of experience in building cars before. Working out roll centres, spring rates and damping ratios from scratch is hard, and while there are rules of thumb you can work around, it's far from simple. If you're determined to give it a go, then a reasonable starting point would be the Ron Champion book on how to build your own sportscar, which gave rise to the Locost craze. The car in the book is front-engined, but it would be a good starting point to learn what's involved in the process.
P.S. The other issue would be bodywork. If you're building a one-off with a custom chassis then presumably you'd need custom bodywork. And that's a big, big job. It can be done - a friend of mine made a custom bodyshell for his race car from carbon fibre using resin infusion technology. However, it took him the best part of 9 months solid work (he's retired) to make the buck, the moulds, and the bodywork and he swears he's never doing it again.