Wishbone suspension bolt on kit

[GS guy]

Sure looks purdy Jason. I see accommodations for camber adjustment, what about caster? Shims at the inboard upper control arm mount (front to back)?

The angled shock placement - though looking good and in all aspects "classic", results in falling rate on the spring rate, pretty much opposite of what you want. Unfortunately, there's not a whole lot of ways around it unless you go with a push/pull rod system and rockers like a modern formula car set-up. Just something to be aware of (if you weren't already).
I'm guessing you've worked out the camber curves, what kind of ride height is it optimized for? Any anti-dive incorporated?

Any of the parts off the shelf except for the spindles and ball joints, like the a-arms? How much do you figure it'll cost you to build it, roughly? When I was briefly looking into this for my car I was thinking around $2.5K.
(Sorry for the 20 questions!)
Jeff

[Ephry73]

All of the designs look grea. I like the fact that it may also add some weight to the fron of the car as well as more controlled handling. Price, what price? lol



Ephry

[volkdent]

I've asked the designer about the anti-dive and more castor adjustment, but he says that for the travel we are working at, that it really won't be a factor. Apparently anti-dive is for cars that dive, which this one won't. Hot rods with big V8s over the front end and traditional big NA cars may need this, according to him, but this little bug with controlled limited travel won't need it.

I personally would like more castor adjustment built in, as the only castor adjustment now will be by the stock eccentric bushing, but this suspension is designed specifically for my car, so the castor is already dialed into the design. I have a small rake on my car though, so I do wonder if I'll need any more. This is prototype 1.0, so there will be some kinks to work out when it gets on the road I'm sure.

Everything is custom, except for the rack, tie rods and ends, spindles, and balljoints. Once all the kinks are out, I'll be looking into finding parts that might work that are off the shelf, perhaps at a slightly wider track etc.

Jason

[volkdent]

Ooops, oh yah, Cost? what ephry said. I've so far spent about $1100 just designing this thing, so I'm really not counting pennies. I have a pile of spindles, brakes, balljoints, bushings, and a few other things that I've purchased but where discarded as plans changed. I really haven't been keeping score, as it really doesn't matter, the end result is the end result, whatever the cost. I will have the best double wishbone suspension I've ever seen on a AC VW, and it will bolt on, so that says something when there have been a few million of these little bugs running all over the world with people as crazy as me thinking about this possibility.

Jason

[GS guy]

The Mustang II hardware might be of some interest. All the stuff is readily available, nice (Wilwood) brake set-ups, all off the shelf. Some of the parts are a little expensive, depending on who makes and sells, one of the more interesting sites I've come across (from a cost perspective) for this hardware is Speedway Motors:
http://www.speedwaymotors.com/default.asp
Click on theit Street Rod products, then down to Chassis and Mustang II suspension and (tubular) controll arms. I know using 'merican products on the old Bug might rub some folks the wrong way - but you can't beat the availability of mass produced parts. This suspension design (and supporting parts) doesn't appear to be going away anytime soon. All you'd need is a custom subframe (like the one you're developing) that accepts the bolt-on tubular MII arms, spindles, brakes, R&P, etc. Having the subframe available allows the user to pick and choose from various manufacturers for the other items. Their complete tubular kit, including rack and (vented) brakes is $1400. Just need the appropriate subframe to attach it to! You have to admit, that would make a nice tidy package. Only drawback I can see is the available bolt patterns - but lots of alternate (non German) rims available. Wilwood might even have a blank hub and rotor combo that could be set up for 5 x 130mm. Might have to call it "German Resto-Mod Look".

Don't get me wrong, one-off is cool and can be beautifully done, but unless you go into production for all the custom items, if one ever needs to replace anything they'd have to start from scratch. I'm doing the same on a rear suspension, all mostly custom. I wish there were off the shelf parts I could use, but the stuff isn't out there. Just thinking out loud - you're custom suspension looks great Jason, definitely looking forward to hearing how it works on the road!
Jeff

[Ephry73]

That sounds very good. I wonder how one can build it at home with just the parts that work(hint) I like the fact that one can turn a standard VW and turn it into something worthy of the German Look name. Plus, being able to add just a little more weight to the front of the car is always a good thing to balance things out.



Ephry

[GS guy]

It sure does sound good Ephry. In fact, it sounds so good I think I've talked myself into doing just that! My car is a tube frame buggy anyway - what's a few more tubes to mount those A-arms! This is a big decision - I'm already heavily invested in an all new Balljoint suspension with all the tricks, custom Wilwood brakes, plated custom drilled & studded rotors, dropped CB spindles, Bilsteins, etc. etc. etc. It's a tough call, I'm going to have to give this some serious thought........ :idea:
Jeff

[Ephry73]

You can always keep the brake setup and such. are the spindles for disc brakes? if so, you may have found a buyer for them already



E

[volkdent]

Not to throw a big monkey wrench into this whole thing, but this was discussed before. The problem is getting the roll centers correct and then matching up a rack. If you can work out the correct geometry with those, please let me know, as just getting some hubs redrilled for some metric pattern would be a snap. I still don't like the idea of adding Standard parts to a Metric car, but for the cost savings you probably couldn't argue. Just order them up already!

Pure55 made up his own for very little I'm sure, but if you'll read the "Double Wishbone Suspension" post, you'll read that currently the ride is twitchy at speed. I really admire the work he's put into the whole setup, but unfortunately I think he's going to find that the geometry of the whole setup is what is causing the problem.

Off the shelf works for the products they were built for, not for others usually. I may work backwards once I've got everything lined up, but to work forwards for a pile of parts isn't the way to build a correctly functioning suspension system as far as I can tell.

I'm hoping that in the end this system will be available for sale. Not cheap, but available. Once all the tweaks are done I can make a jig and then reproduce them relatively easily. I'm also aware of someone else who's building a doulbe wishbone setup. Currently he's built a rod style one. It is of tubular construction and should be good.

The reason I'm going with the laser cut plates is space. I'm planning on running a radiator in front of the beam area, but behind the body, with ducting to draw the air through. I need the space under there that a tube style one would take up.

Jason

Jason

[Vincent]

Drawing looks good the only thing i find that may end up being a problem is the lower shock mount. It apears to be welded under the bottom A arm.


It seams that this could be a potential weak point would it be better to weld that mount on top of the a arm that weld could break over time when hitting a lot of bumps or pot holes or apex curbs racing.

Just my 2 cent worth might be something to look into.

[volkdent]

The strength is the same whether its on top or on the bottom, so that's really not an issue. As far as hitting curbs there, if that happens to hit a curb, there are many other issue more important than that, for example it will be ripping off the whole bottom of the car. From the ground to that point is at least 6 inches I think, so the suspension would have to be in compression and going over something very bad to be able to hit that. This won't be a rally car, or a hardcore track car for that matter. It's supposed to be a daily driver with autocross or track day potential.

Jason

[GS guy]

Agree on your points Jason - Ideally you start from scratch and work it from the ground up - optimizing roll centers, camber gain, all the important pick-up points and details. Sometimes you can reverse engineer a bit, using off the shelf parts as much as possible - similar to what you're doing with the spindles, etc. Sometimes this works out OK, sometimes it ends up being a hack job just to make parts work together that were never intended to. IMO, it takes a real artist to do this (not that I'm even close!), make it work well and look like it was designed that way - as I'm sure you've found out! What the hey though - I wrote Speedway to see if they'll divulge the A-arm C-C lengths and overall front to back widths, in addition to the OEM track width of the M-II. At least get some idea if it's at all feasible. Model it a little and see if it'll even fit, what the compromises are. At a minimum you'll be converting the car to front steer, which is a pretty significant change in iteslf! That might ease up on those steering shaft u-joint angles though.
Jeff

[volkdent]

Bob, (the designer) has been under the weather lately, and although we are apparently very close to the design being completely finished, the last details are not yet finished so I have to wait till Bob's back on his feet again.

The custom struts for the rear turned into going with the KW Variant III coilovers that fit a MKII body. I wasn't going to have the travel I needed with the modified strut, thus the stock fitment size, so I'm going to have to cut a hole in the top part of the wheel well for the strut to go through to the inner superstructure. Anyway, they showed up and their gorgeous, I can't wait to get this thing on the road!

Jason

[volkdent]

Design is complete now. Next up fabrication.

Front End

[miller]

Looks great. What shock/coil combinations are you looking at?