Subframe Engineering - Y'all know more than I do. (Page 1 of 2)

I don't already have them, but I do have an Austin 1300 subframe which has potential. I know a place that would sell me front and rear Mini subframes for $400 though. So... just figure out a way to mount the spindle onto the Mini/Austin control arms? Seems doable depending on 107836 factors. Any advice on shortening half-shafts? And what should I know about mounting the steering rack? Just keep it as square as possible to the splindles when zero degrees of steering?

Shorter axles for a metro engine?  I'd chop the axle in half, cut it down, sleeve it back together with some thick pipe and weld it back together.  If you want to get fancy, a decently equipped machine shop can cut it down and weld it together with full penetration or re-spline it at a shorter length.

For setting the rack location-
Assemble the suspension fully but without springs, (car on jack stands, obviously)
Get the rack where you think you want it and clamp/weld/affix it into place temporarily
use a jack to move the hub/control arm through it's normal operation travel and measure your toe at different heights  (tape measure is plenty accurate)
ideally, you want as little toe-induced as possible.  Adjust the rack as necessary to improve.

Would it be easy to remove the upper control arm and just convert the suspension to McPherson?

The drawing would work if you had an upper ball joint, not a bushing.  I'm guessing you want to be able to steer the car.

With that drawing, you also stand to easily introduce some wonky caster if the top 'adapter' isn't well planned.

Potentially, although height is a potential concern. The fenders on Berkeleys are very low, and Macpherson designs are inherently tall.

At this point, straight-only might be a safer option. Haha. I feel dumb for making that mistake, though. I forgot how the top pivot on Macphersons work.

I was actually thinking of something similar to that. Height is a problem, though. The Austin subframe only gives about 8 inches between the upper and lower control arms.

Is there such a thing as a directory of splines? I wonder if some other car out there uses the same spline as a Metro. The hub spacing is just 4x4.5 on 59.6 which is pretty common.

I did a little mocking up last night, and it's going to be tight, if it's even possible. The Suzuki engine is very narrow, but the transmission isn't. Luckily, the outputs for the transmission are fairly close to the center, so I can cut some width out without making the half-shaft angle too extreme. I'm not really sure how much of an angle is too much, really.

I was hoping that I would only have to remove 6" from that subframe. It's looking like closer to 8" or 10". That's... a lot. The transmission will definitely be over the driver side frame rail. I'm going to take some more definitive measurements tonight and start sketching widths. Uggh. This is a lot of variables.

My current thought it to make an adapter like the_shaolin posted, but in reverse. Make an adapter than uses a bolt-on ball joint, then use the stock Austin control arms. So both castle nuts will be on the bottom.

See that green car next to the Berkeley?

Yeah... I know Minitec's work. Haha

As Leno would say, "This is the Japanese power British front-wheel-drive section of the garage."

I mean, in truth Spank, I am kind of putting the components I want where I want if I can get that adapter to work. I want the Metro hubs, but I'd prefer the Mini wishbones for height. So if I can make that work, and somehow be narrow enough, that'd be perfect.

The angle between the upper and lower ball joint was exaggerated a lot in my drawing. It would actually be very close to straight. I would just take an Austin hub, figure out the dimensions of that, and replicate the geometry using the adapter for the upper ball joint. The hub itself it a static entity of course, so if I can make the relative angle of the hub and the mounting points the same as on the Austin hub, it should matter that the adapter if there, or that the ball joint is upside down, right?

Here's closer to what I meant:

So it will just drop a balljoint below the upper mount on the Geo hub, lined up with the lower ball joint.

To replicate the spacing of this:

What would that really achieve, though? For one thing, FWD's with double wishbones are rare. And I'd still have to narrow it. And then the axles would have to be custom made because they'd be splined differently...

Probably nothing, but you're already looking at narrowing a subframe and somewhat custom axles anyway.  If a few minutes of browsing gets you at a better starting point, or even just confirms that you're current plan is the best starting point, than it's time well spent.

They do indeed, but the top of the spindle is extremely long, so it won't work.

My current thought is to use Mini hubs but on a custom subframe and with custom wishbones. This would, theoretically, allow me to make the frame wider for the engine by shortening the wishbones. Does anyone know the dynamics of wishbones, and why it might be a bad idea to have very short (6" or so) ones?

This appears to have good travel, the camber is agreeable, and the role center is in a good spot. Thoughts?

http://tinyurl.com/ku2zxog