What is your interest in having a bolt-on A-Arm front suspension???
 

Guys,

I have been talking with Jason (Volksdent) and also with John Busceme of XV Motorsports about the possibility of designing and marketing an a-arm bolt on system for the aircooled VW community.

My question and also John's is do you think it is a viable marketing venture. I realize that there are a lot of possibilities. Jason and Eyeball Engineering both have I believe the right idea of being able to use as many VW/Porsche parts as possible to minimize the costs to the car owner. Also, having a bolt on system that can be converted back to torsion bar is the way to go.

A little background on John Busceme of XV Motorsports. I first saw his 'business' on "Dream Car Garage" of the Speed Channel. His approach to changing a Challengers front torsion suspension to unequal lenght a-arm set up was done extremely well. I was so impressed that I purchased his DVD on the whole series of his build and testing. Please go to http://www.xvmotorsports.com/ and check out his company. I talked with John a little the other day and we would have to do a lot more discussion on the particulars, but rest assured, if he were to get involved, it would be done 110% correct.

I guess the main concern would be for everyone involved is costs as always ;) . I can see the base system eventually being the cradle/a-arms/steering rack. Having different options or combinations of springs/shocks available being the main cost variable. Possibly having different steering box/rack options is another thought.

This is just a thought and I am in the infancy stages of seeing what can be done; if anything.

Your thoughts and constructive input is greatly appreciated. Also, how much in very rough costs would you be willing to spend?

Thanks,

Kelly (Cohibra)

Kelly,

Sounds like a great project! Thanks for taking the initiative with Jason on this project.

I am definately curious to see what comes of the project. If it makes the car handle better I am game!

The price point would be flexible. If the kit came with a custom brake set (like Wilwood calipers and rotors) it could definately be a higher $ sale due to the added value... It is always a hard sell when you get 2 control arms for $1000! :(

I think design wise it has to be bolt on w/o cutting up the car. Reversible is always a bonus as well.

Thanks!

I also get questions about my wishbone design fitting earlier cars but the torsion bars are closer together, so maybe keep in mind the option to adjust the jig to cater for early/late chassis?
Rich

Take a look at the current offerings for the street rod market. If you haven't planned on spending $1500-$2500, you are kidding yourself. Obviously, those guys have their kits down to a generic, mass produced package and they still ain't cheap.
How would this package compare in price and complete-ness? How many parts will the end user have to source? Will the spindles accept diff brake setups?
I think offering a stripped down kit and a full tilt kit would be good if possible but not sure how feasible? too many options might make it harder to keep your costs down.

Whatever the outcome, count me in!

Jeff-

Anything that uses off the shelf stock parts will be the way to go. I am trying to develope something similar for supers. The only non stock part will be the actual A arm and the mounts for it, the rest will be off the shelf bushings, ball joints and break parts. The one I am building will allow an owner to conver back if they wish.

That will be good. I am looking forward to get one.

I would have no problem with $2500 for a bolt on A-arm conversion.
I just wish it were already available. I've followed several threads that sounded like they were going somewhere and then petered out after a couple of years. Patience, patience...

Well the problem is not so much putting one together. Just about any one with a little math and access to welding equipment can put together a modified suspension member for a VW. Getting a quality mass produced version of it on the market that is in the price range of the consumer is another matter entirely. Most find the start up costs to prohibitve or cannot find a company to produce them at a fair price.

For me it is more a matter of liability that may stop me selling my design...

I was at Laguna Seca last Mon and Tues. 034 Motorsports was there. They make HiPo aftermarket older Audi stuff. They have a 90 coupe with 450hp and all the LSD Quattro stuff done. Christian Miller(Speed Touring Car Championship Jetta driver) was slamming that thing around the track at insane speeds. They had installed a new lower control arm that they fabbed up to increase castor. Worked great for 6 sessions. Coming in to turn 2 under braking one of them let go. Tire squashed into the fender and locked up, but he was able to take it straight off the end of the track and the only damage done was related to the broken control arm.

Moral of the story, aftermarket stuff that is under load needs to be tested. Christian is a professional race car driver testing under controlled conditions. Had this occured on a freeway offramp, someone could have been killed. I'm not going to be selling my design till it has been vigorously tested by me and people like Christian. He would love to thrash my bug around the track. If something breaks there, it's within possibility. The product that I will hopefully end up selling HAS to be safe, well constructed, efficiently built, and function properly under a lot of different conditions.

I know everyone interested is chomping at the bit to get their hands on this thing, but it's not really worth it unless its done properly. Eyeball engineering has about 3 of their design on the road, but most are trailer queens. Nobody else has a design that is close to the strength built into mine, but that doesn't mean it's infallible. If anyone else cares to start this project they are free to do so, but it is a long, long road if done properly, and I think, in regards to my design, patience will be rewarded by a carefully thought out, safe, and relatively inexpensive product that can be used for many years without the fear of failure.

Jason

Sorry Guys,

I was out of business for the last few days. My computer took a major, well, you know what I mean. :evil: I am just now getting it back together. I lost almost everything on my hard drive. Very frustrating.

I had been meaning to compile the questions from all the sites/forums that I originally posted to and make one cohesive thread/post.

One thing for thought...My original intent, and I believe James and Bill (EyeBall Engineering) was to use as many VW parts as possible to keep the options open for everyone. I was hoping to keep the ball joints out VW. I also wanted to use a VW rack and pinion steering from the Rabbit/Jetta/Golf/Fox if at all possible. I guess what I am saying, I was hoping for a completely engineered bolt on cradle and a-arms using VW parts. I am sure that all the lowering/track width/adjustability concerns will be addressed later. This just started out to ask the feasibility and interest of having one available. The costs will be discussed later. As with any product, the more people signing up to buy one, the lower the cost :D !!!

Take care,

Kelly (Cohibra)

Agreed. At first I thought I could just put something together rather quick and safe but due to posts and interactions here on the board ( thanks Volkdent) I came to realize it is going to be a rather long hard road. I plan the stress test the heck out of my designs both on and off the car to ensure reliabilty. I would rather over build a little safety into the control arms than save a littel weight and have a disaster. As for race safe control arm members I leave it up to the racers to decide if an item can be used safley on their cars. ( insert race disclamer here)

I plan to use the prototypes I build as a base design to have a more refined version derived from. I am looking into companies that take items and redesign them for optimum preformance and ease of creation. That way the control arms are safe and well designed for safety.

PS. Volkdent I would like to kick a few ideas around with you later.

bolt on A-arms $2500...... for that money your well on your way to full costom tube chassis with front and rear fully independent adjustable suspension. just a thought

Whose got those? How much? Not a drag chassis right?

Jason

I forgot where I found this

http://www.rorty-design.com/content/beetle.htm

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

I do most of my modeling in Autocad, then fine tuning using the performance trends software.

http://www.dsswebservices.com/scage/locost/rear01sm.jpghttp://www.dsswebservices.com/scage/locost/rear02sm.jpg
based on Thundrbird components
designed around 5" ride height, RC 2" off the ground, less than 1/8" movement of rc in 3 degree roll or 3" bump.
I used all-thread rod in a couple place to bolt it together temporarily to check articulation. Built this for My lotus 7 replica

excuse the messy shop

I'll be doing something similar on my Bus once the lotus is on the road.
I'll build my own spindles to use VW or porsche components/brakes

front will use Beetle spindles with porsche components(on the bus that is)

Super nice work there!

Got my rear suspension completed (sans shocks and antiroll bar) and am pleased with the results. everything will be dissasembled and painted/powdercoated before its finished. But the design is plenty strong and will do well.

http://www.dsswebservices.com/scage/locost/rear03sm.jpghttp://www.dsswebservices.com/scage/locost/rear04sm.jpghttp://www.dsswebservices.com/scage/locost/rear05sm.jpg

Next go around will see a 914 transaxle in the center with its diff flipped, this will be in the rear of my bus.

http://forums.rennlist.com/rennforum...d=185811&stc=1

-ok then what about the 928 - use the gts disc -or the 964 turbo
-use the spindles
-and the upper a - arm
-

better strenght and lower weight with a tubular A-Arm, plus its easier to set geometry if you are designing both A-arms rather than working around one with a predetermined length
but ya, the 928 spindle would be a good choice

Don't know if you guys are talking front or rear, but just be prepared to hack off the frame horn up front if you use 928, the tie rods mount low, as well it is way overbuilt for bug applications, it was designed for a car with a V8 sitting up front, and, you'll have to cut quite abit out of the bulkhead to get the angles you'll need to get to the rack. If you are doing a tube chassis, go for it, it should work out well. The brake rotors for it are insanely heavy and large, ask ME how I know...

http://www.freewebs.com/dobergoose/page3.html

http://www.freewebs.com/dobergoose/page4.html

Jason

a bolt on front suspension would be a great product idea, but from the perspective of ideals, the frame horn has to go, a completely new chassis would be even better.

Keeping the frame horn limits the length iof your A arms, which is not terrible, just limiting.

the ability to use Longer bottom a-arms make dialing in your suspension geomery/design much better, you have less compromise, you can have reduced bumpsteer, ideal camber gain, and a well located and stable roll center, you don't have to choose one.

if you were doing a 1 off custom chassis the 928 spindle would be a nice piece of kit. But for a bolt on front suspension, stick with the beetle spindle
it worked well with the paralell trailing arm suspension, so it will translate well to a paralell eqyual lenght A-arm setup, or even an paralell non-equal length suspension.