Um, yeah, Bob (Rorty Design) is the guy who designed my suspension, one similar to we are talking about selling here. The prototype fabrication bill alone was $1600, not including machining, laser cutting, or steel. I think Bob's design bill was more than half that, but it's been awhile, it might have been more, as I'm not great at tracking costs...

Take a look at what Panelfantastic has said, and those suspensions are used for everything, not just a specific car.

Jason

I'm interested. Any plan on doing something similar for the rear? I don't mind sinking 5k on both front and rear.

I'll be getting there eventually, but don't hold your breath..... Hope to have a bolt on rear suspension that you can use with stock configuration AND any sort of mid-engine transformation like I've done. Not sure that the rear will be double wishbone though, more likely strut.

Jason

why not then

-utilise a 944 turbo cast alloy lower wishbone
-short adjustable coilover
-fill the rest in
-is frame head , 2 tubes like a stock beam, -strut top mount, fully adjustable
-then just pick up onto the 944 like its stock mounts

-then at least, you have the turbo spindle and hub, so any aftermarket bell bolts on, plus if you use a 968 -mo30 spindle, you get radial mount bosses

-plus the roll bar would be real fat

-plus the whole lot would be light

And you think using P-car parts will make it CHEAPER:laugh:

The "fill the rest in" part is the funny part though. Suspension design is one of the the most complicated aspects of a car next to the engine IMO. Why is it that Domestic vehicles don't handle like European cars for the most part? Why wouldn't they just take a late 90's BMW and copy the suspension so they could compete with BMWs? It's not cut and paste, suspensions are built for the car they reside under typically.

Back to the suggestion, I have many of the 944 Turbo front suspension parts collecting dust in my garage. 944 Turbo parts are SO overbuilt for a bug application, it's ridiculous. The spindle is also a low-mount steering setup, so unless you are interested in cutting off the front end of the pan, this is not an option that will work. And it was designed for a large front-engined V8 grand tourer, not a small, light, rear engined econo-car.

I'm all for imagination, that's how I got myself into this project. I think it's really great to think outside the box. But please don't ask questions that make it look like it's easy to design a custom double-a arm suspension, especially utilizing off the shelf parts. As far as I know, I own the most comprehensively designed suspension built for this application to date. If there is one better out there, I would LOVE to compare notes, I always strive for better and if there is better, I want to know about it.

If anyone want's to got through the struggles I have to design one, go for it. To do it right involves hours and hours of research, a lot of knowledge, and probably a lot of $, at least that is what I ended up going through.

I guess that's why I get a little frustrated when someone suggest " just do this", armchair suspension fabrication won't yield much in the way of results.:D

Jason

Agreed. It seemed like it may be easy but to creat a "quickie" suspension fix for my project. Alas time, observation and the gentle tutelage of volkdent showed me that I needed to slow dow take my time. From volkdent and others here as well as a fair amount of resarch I Realized there was alot more to it that just sticking on some chunk of metal and making it work.

Ricola just sent me these taken at the VolksWorld show. Looks like a one-off setup, you will notice they extend the wheelbase by quite a bit though. Cool concept!

http://images.thesamba.com/vw/gallery/pix/340006.jpg

http://images.thesamba.com/vw/gallery/pix/340007.jpg

http://images.thesamba.com/vw/gallery/pix/340008.jpg

Jason

you'll need to use the mk2 gof rack,not the mk1, mk1 doesnt have enough movement to use the beetle spindles (unless you were going to use something else)

ask me how I know.

a cast alloy wishbone will by design be much heavier than a welded tubular steel of equivalent strength.
no real benifit other than being able to claim you're using factory parts.

That Volksworld suspension looks interesting Jason - but would appear to have very poor (short!) virtual swingarm lengths and excessive RC movement? I wonder how much additional bump movement those ball joints have left!
Definitely looks like a "hot rod" & cruiser set-up, not really for any kind of performance application. It's purdy though! :laugh:

I'm finally getting the design finalized for my fiberglass buggy A-arm front suspension - using MII spindles and Chassisworks A-arms. I did spend hours and hours on the computer re-working the inner pick-up points to optimize the geometry, the "design" aspect definitely something one shouldn't take lightly! Talk about variations on variations!
I'm winding up with a RC about 2" or so above ground, with minimal RC movement in roll, and not too bad in bump and roll. I'm making my upper pick-up points fairly adjustable for camber, caster and RC changes - if necessary.

When I finally get something in real hardware I'll put up a few pics. Not really applicable to a VW front end though - but maybe food for though if you want to go fully custom forward of the firewall?
Jeff

thats the devil in the details, a nonequal nonparalell a-arm suspension by design is a racecar suspension, performs well in bump, and also in roll, but in a bump/roll (both at the same time) not so well. so you can compromise and have a roll center that moves more thanit should in bump or roll, but moves less in a combined bump/roll

in a dune buggy, if its an offroad machine, this shouldn't be too bad since suspension movement is for the sake of articulation, not handling. but street machine, you can offset this with a big antiroll bar (what I will be doing on my lotus) front and rear.

perhaps its possible to build a perfect suspension, but we don't have the budget. so even F1 suspensions are all about compromise.

OH ya one more thing. If you want to bag your ride for adjusting your ride height, go with a equal length paralel A-arm setup, otherwise you'll have horrible handling at any height.

Mine's definitely a street (and maybe sometimes track) "buggy" Shadow. It'll look more like a Can-Am race car under the skin - tube chassis and mid-engine. Anti-roll bars and wide low-profile tires are definitely part of the equation.

One interesting thing I discovered while going through the multitudes of geometry variations, as the (static) RC was moved up the bump+roll dynamic RC movement became less and less - to the point of essentially no RC movement at all - but with a RC height at 6-7" or higher! Everything I've read suggests keeping the RC closer to ground, generally 1-3" high or so, so that's where I put it. But watching the dynamics of RC movement in all the different variations sure was interesting - and informative. One thing I definitely learned - if you're going to design your own layout having a computer program to model it on is pretty much a must-have tool.

Jeff

I ususlly rough model mine in autocad, then refine with an suspension program. and abolutly you need a suspension program, you can do in 5 minutes what would take 3 hours to do in autocad, and do it more accuratly

considering it all comes down to 1/8" to get optimal geometry

Which suspension programs are you 2 using? I have modeled my single A arm against the stock I arm and they seem to preform the same in Front Suspension Geometry Pro. This is due to the fact that the A arm is the exact same length as the I arm. However I would like to double check against another program.

Thanks.

I use Performance Trends - Roll Center Calculator. It's not their full blown Suspension analyzer software, but a lot less expensive and does 95% of what I need it to do.
http://www.performancetrends.com/

I sarted modeling mine on paper - scale drawings. That was an interesting exercise for a "first cut", but quickly became apparent that method was going to be too time consuming and tedious to give me the information I needed. The PT software really opened my eyes in seeing how small changes affect the geometry. You quickly realize that trying to "wing it" when laying out a suspension design could yield less than desirable results!

Jeff