I've wondered about how the in-wheel design affected loading, but really never gave it too much thought. I do wish the S2000 wheels showed a little more lip.

At the opposite extreme from F1 cars we have the old Jag's with inboard brakes. The lower unspring weight wasn't worth all the problems the setup brought to the table. I think the brakes on F1 cars are inside the wheels primarily (or at least partly) for aerodynamic reasons. They need air flow to cool, but if they were out in the raw airstream they'd be pretty nasty.

 

I never even took a class on it, and I had a job doing it for 13 years. Funny how these things work out. Every one of the latest generation 737s flying around the world has parts on it that I did the functional design for. That's the really cool part about being an engineer.

What makes something a black art is not that people don't understand the fundamentals of it. It's that it is so sensitive to uncontrolled/unknown factors that predicting the final results analytically is hard to do.

That's why racing car setup does kind of fall into the "black art" catagory. Ever watch NASCAR, where they spend the whole race "chasing the track" and trying to fiddle with the suspension enough to gain an advantage? The basic mechanical design is just regular old engineering. But tuning it just right for that exact moment in time -- that's more of a black art.

 

Maybe the in wheel consept was a carry over design element from the NSX?

 

The chassis is super stiff due to the Xbone

 

Only other nicety that comes to mind apart from what's been mentioned here are the remote reservoirs on the rear shocks.

The stiff chassis is really the key to everything, in my opinion, at least with this vehicle.

Does the compactness of the inwheel suspension lead to less unsprung weight - i know Honda is big is unsprung mass and thus are usually conservative with their wheel sizes.

 

That is far and away the best definition of "black art" I've ever heard. All my life I've had people talk about some of the things I do as a black art, but this is the first time I have ever had ANY insight into what they were talking about. I always just thought of it as tweaking or tuning, and associated the idea of a black art as something that involved some kind of special insight (or magic) that mere mortals lacked. I'm still not sure that most people who use the term don't mean exactly that.

Given my new understanding I have to agree that acoustics is a black art. I guess I have been drawn to black arts my entire life without even realizing it.
LOL, the things I learn here on S2kI never cease to amaze me.

It is cool seeing your own work on CNN, but I think the coolest thing about designing new stuff is that there is so much variety. By the time you fully understand a task the job is done and you get to move on to something else you've never done before. I just think it's really cool not to have to do the same job over and over, day after day, year after year. If variety is the spice of life then R&D has to be one of the best jobs possible.

Every time I hear the term "black art" I think about passive crossover design. For my own use I've always employed active crossovers, because they are so much easier to work with, and the first time I was tasked to re-design a passive crossover I tried to beg off, because it is "common knowledge" that passive crossover design is a "black art." The idea of trying to build filters that would work properly when the impedence was all over the place looked like an unmanagable can of worms. The big surprise came when the first attempt at a textbook design, worked better than the crossover that had been previously used in the system. After a little tweaking (LOL, a little black art) the darn crossover worked as well as any of my active crossovers. It's funny, beause as simple as crossovers are, having successfully designed a passive crossover was as satisfying and personally rewarding as anything else I've ever done.

Don't you just love working in a field that you start out knowing little or nothing about?

 

Keeps life interesting.

 

My only issue here is the word conventional. To me conventional means dodge or GM. There are a few things about the S2000 that sets it apart from a K-car. Though compared to other roadsters, I personally don't see anything unconventional.

Passive crossovers? Are we talking about?
http://tangentsoft.net/audio/mlxfeed.html
Sometimes I confuse crossfeed and crossover...

 

RED MX5, I'm not exactly sure what you wanted to learn, and how are you now satisfied? With MikeGarrison's first post?

I have some suspension design background and the double a-arm suspension is the most common type found on racecars. It is a good compromise between roll center migration, camber gain, stiffness and packaging. It is simple, fairly easy to analyze and pretty straightforward. Not many road cars nowadays use double a-arm. Honda swore by them for years but have recently started moving towards MacPherson struts and doesn't the new Euro Civic have a semi-independent torsion beam rear suspension?

What's this other thread you bumped? And what's up with the half shaft diameter?

I am interested in learning more about the suspension, I'd like to get hardpoint locations and control arm dimensions for some 2D and 3D analysis. I was thinking of starting from scratch, analyzing the suspension, mass properties, etc. and developing a custom spring and damper (custom valved) setup for autocrossing and roadracing. I think the stock suspension is amazing, and really doesn't need to be changed when using street tires. But perhaps it needs something more if I were to move to race tires and try to improve transient response further.

 

[QUOTE=Suspension,May 10 2007, 07:12 PM]RED MX5, I'm not exactly sure what you wanted to learn, and how are you now satisfied?