Double A-arm suspension
 

Recently completed "bolt-on" double A-arm front suspension built for type 1 pan. This was discussed in the past on another thread. Comments?

I like it. All Bugs should have struts :silly:
What spindles did you use?

Great to meet you at the show last weekend.

The photo doesn't do the design justice. I just wish i had my digital camera last week.

Keep us informed the tested you're doing.

pure55vw,

please email me pictures of you super sweet suspension for the suspension gallery.

Thanks,

Alex

looks real good.

congrats :D

Thanks all for comments! Next up is installing on a car for steering column fab, static load testing (brake windup, frame twist, etc..), turn circle measurement, ride height and clearance checks, overall ride evaluation, etc., etc., I'll keep posted how it goes. VW Type III spindles were used. Alex, I'll get that E-mail out to you. Thanks for posting pics on the gallery.

Hi,

Do you have any closer pics of that front end, it looks awesome!!

Cheers
D

Congrats! I'm heading in the same direction eventually, it's awesome to see something I've been thinking about for months in the flesh. Good luck on the testing.

Jason

The "Double Wishbone" thread referred to progress made on A-arm front suspension project. How's it going on some of the other A-arm conversion projects mentioned before?? Mine, which is shown on a pan in the suspension pix gallery, is now on a car. Steering shaft connection, static load tests, etc.. are finished.
Some things I have to fix, and there's a "million" little details to be done before it's drivable, but suspension compliance, camber gain, Ackerman, track, fender clearance and all that stuff looks good. I'll post some pix of the "test vehicle" installation soon.

Jay

Can't wait to hear how your front end turned out. I'll post some pics of my progress on my website when I get chance. It's very slow but steady.

Jason

pure55vw, do you have any advice for somebody thats lookin to do something similar to what you have done? What books have you read to decide on a design and did you use any suspension design programs?

For books, there was a previous thread on here ("Chassis Engineering", I think) with some suggestions. There are design programs that work well, although I worked all the geometry out graphically. That's the easy part. The hard part is deciding to make it "bolt-on" and working around the existing VW pan and body layout, using commonly available parts without modifying them, while not compromising your "optimum" geometry too much. Start with your 'givens' like wheel size, track width, required steering angle, ride height, type of steerin gear you want to use, etc., etc.. and work backward from there. Go to a wrecking yard and look at how all the different OEM's build suspensions, and also look for any parts you might be able to use. Study some of the A-arm IFS kits made for street rodders to see how they worked it out (I'd like to someday see VW customizers have the same type of kits available to them). This is just a start, but it gives you an idea. I guess the EASIEST way is to just copy someone else ;-) Good luck and pls keep posted on your progress.

Jay

Ive spent alot of time lookin at this guys site and I like how he went about designing his supension. http://www.beardmorebros.co.uk/index.html . Right now im looking for a good front spindle that I can use out of another car. Basically I want one with good brake options, plenty of rim options and can adapt to a double a arm setup. I like his idea of using a ford sierra (merkur xr4ti) steering knuckle and I might just try that too if another better option dosent come up. Right now I want to get rim size figured out and find out what steering rack to use. I heard the 914 rack was a good rack to use so I might just look into that. Im runnin a ford 2.3 engine so I could add power steering quite easily if I really wanted to but Id have to look into that aswell. Right now im collecting the caroll "To Win" series of books that basically goes over on how to build a racecar suspension among other things. I have an extra pan for my ghia so it wont be too big of a hassle to take measurements and whatnot. Do you have some closer spics of your setup? It looks awesome by the way. Oh and hey do you think I could get some measurements like camber change, roll center and caster toe in all that just for refrence? Thanks

What steering are you using? Can't really see any in the pic.

I used a Nissan rack on mine because it had the wide tie rod pivot centers I figured I needed. Had to adapt the tie rod ends and steering U-joint to VW, but could probably just as well have used a Golf rack to avoid that.

Pure55, what's the latest?

Jason

Progress has been disappointingly slow due to other commitments, but so far: The suspension has been on the car about 3 months (car is an otherwise bone-stock '74 beetle). Subjectively, the ride is better, but needs some tuning with the adjustable front and rear shocks it has. Steering is very light (almost too light), which causes it to "dart" slightly with any bit of steering input. May need more caster (has 3 degrees now). Still looking at roll angles and intial turn-in feel of the steering, and I'm considering a stiffer anti-roll bar although I can't do too much with the skinny stock tires. Nothing seems to be wearing out too fast, but I'm still planning to replace the urethane a-arm pivots with OEM-style rubber bushes. I promise to post later with more info as it comes in and those always-popular pictures!

Jay

I'm glad to hear its still on the go. How come stock rubber bushings vs PU? I made some serious progress tonight. I bolted on the complete suspension chassis mockup(wood) and it fit like a charm. One snafu though, it looks like I may have to raise my ride height a bit so the input shaft for the steering rack will be able to make a decent angle with the stock steering shaft. We'll see.

Jason

you could always use a steering knuckel like in some modern cars to fit the angle. I rember when we put a new front end in my grandfathers 1959 International truck we had the same problem and just put in one of the universial joints to make the angle worked pretty slick. :cool:

Universal joints don't work at severe angles, which is the situation I'm in now. I'm planning on using 2 high angle joints, but at this point I think the angle may be too much. The input shaft is inboard quite a bit, as well as being very high, almost the same level as the stock steering shaft. So, we're talking about an abrupt 90 degree turn, no universal joints can handle that!!

Jason

I recieved a MkII non-powered rack universal joint today, so I can hack off one end and see what its max limit for angulation are. I did some more brainstorming, and I figure that if I put the second UV joint up inside the tube the steering shaft is in, it will give me some more room to work with and shouldn't effect much of anything.

Jason

Jason, going to try rubber bushings for the same reasons the OEM's do: less maintenance, less suspension friction (good in a light weight car like this), and less cost! Since my lower A-arm pivot doesn't have to "twist", I can use a stiffer bushing to keep the radial stiffness high (though not as much as PU). I've done the "wooden mockup" thing too, so I know what that's like! I solved the steering U-joint problem with wide spaced A-arms allowing the rack to sit closer and further forward on the pan. The tie rods are at a slight angle in the top view, but not bad. Since T-III knuckle steering arms are bolt-on, they're easily changed or shifted to adjust the Ackerman. With the second ujoint inside the steering tube, you'll need to put another through hole in the firewall, something I also considered

Actually, it looks as though I'll be OK with the steering tube just trimmed down till it is just meets the rubber grommet in the bulkhead. I've had a Teflon bushing made to reside inside the steering tube, and I've ordered a Flaming River 5/8" - 5/8" U joint. Here's a peak at what I've come up with thus far. This was designed by Bob Frost-Stevenson at Rorty Design in Melbourne AU.

Suspension View

Its not all in yet, but I found that with a 20deg. roll of the rack, I could get a decent angle to the output shaft. I've cut down the stock steering shaft now, and pressed in the Teflon bushing and all is good. STILL waiting for the Flaming River U joint, they must be slow on the draw right now. Bob wanted to machine down the rack to allow it to be rotated at any angle, but then I'd have to have a clamp machined and then it would also be a solid mount, more noise. I have PU bushings for the rack now, and I may switch to rubber in the future if the road feel is too much.

The design is finished, so just waiting on parts before fabrication begins!

Jason

Just a consideration: are you hard-mounting the bottom end of the steering tube to the body? As you know, stock form uses just the rubber grommet isolator between the tube and firewall. I originally tried a metallic bushing in the steering tube to support the bottom of the shaft, but found that steering reaction forces working against the grommet kept causing it to back out of the firewall hole, in turn causing the shaft to become loose. I built a seperate lower bearing support that attaches to the suspension subframe, so the bottom half of the tube no longer has to support the shaft (like stock).

Apparently you just saved me a lot of time. I was planning on using the stock grommet, but as of today, I've realized I have issues with the U-joint that will push it through the firewall anyway. So, I'll be making a bracket too, but on the inside of the firewall. Do you have any pics of your steering setup?

Jason

Well, it turns out that the whole upper U joint is going to have to reside on the INSIDE of the bulkhead. I'll have to shorten the steering column some more, then have a clamping bracket made that holds the lower end of the steering column. The Teflon bushing will sit inside that, then the upper U joint, then the intermediate shaft through the bulkhead, then the stock U joint attached to the input shaft of the rack. The angles are tight, but it looks like its going to work, so I have one less thing on my todo list.

Jason

The shafts and U joints are at the gear cutter as we speak to be splined. I have a pair of QA1 Proma Star 11 1/4" shocks sitting here, and I have someone working on another balljoint option. So, nothing too concrete, but getting warmer!

Jason

Pure55, can you take some pics of your steering linkage as it attaches to the steering shaft? Thanks,

Jason

Plans?
 

WOW, I got to this a little late, but this setup is incredible Pure55! As is yours Volkdent.

I have access to a cnc plasma cutter and a few other play toys, Would it be possible for a set of plans to go up for sale? I'm interested in the setups, but it'll be a little harder to get all the money at once. This'll make things a little easier on the checkbook. This would also be easier to ship to my address (email). You name the price.

I love your ideas guys! I like the idea that i can upgrade to a higher end shock because it is a more common performance application. If only Ohlins shocks weren't $3010 each.

Let me know the price.

Thanks a lot,
Russ

I would rather use your guys ideas and pay you, but I'm pondering the idea of a 996 macphereson strut front setup. I'm sold on the Multi-link 993 rear setup. All one clip, just have to worry about the angles of the strut towers.

Plans for mine won't be available till it's been road tested as a minimum, which probably won't be till next summer. You'll have to ask Pure55vw about what he can offer.

Jason

a-arm stuff
 

I've been looking at all your stuff and it looks pretty cool. I'm designing my own a-arm setup for my kit car but I'll be putting the inner arm pivots closer together and running longer arms. I'll probably lob off the frame head early on. I'll be running VW ball joint spindles with disk brakes with a Chevy bolt pattern. The biggest difference is that I'll be hooking up a torsion bar setup with non-coilover shocks. It's going to be a little radical but the height will be fully adjustable. It may be a little stiff but sporty. Very low center of gravity as well. Once I get to the building point, I'll post pictures.
JiI

Keep us posted, sounds interesting!

Jason

Any progress here?

Jason

hey jason and pure55 how's it coming? any pics and what's going on with test drives? I'm looking to do this to my 69 but it comes down to the $$$ for it now but love what you guys have done keep us updated.


___________

69 Becoming a GL on the slow road
72 std run about
93 nissan u/p

Life is happening to me right now. I have a house that I'm selling, one that I'm getting ready to rent, and another that is getting renovated and an addition, so I've not even touch the bug in a long time. I have not been idle though, Lanner at V-Dub Customs is still finishing off my front brakes. I imagine about 2 months and I'll be back to working on it again.

Jason

Haven't been on here in quite a while but here's the latest on the double A-arm suspension project: Recently completed a 4000 mi. test of the suspension over all kinds of roads (and weather conditions). No "high-speed racing" unfortunately, since the car is just an otherwise stock '74, but it would be interesting to see how it performs under those conditions. The suspension structure held up generally very well. No chronically loose bolts or unusually worn parts. It's now coming off the test car and going on my '55, which was it's ultimate destination. There's a bit of work to do before that, though. I'll be busy a while cleaning and re-painting a few rusty parts, replacing a torn ball joint boot, etc. I increased the caster to about 5 degrees to help straight line tracking, but seems like it could stand more. So part of the work the next few months will be adjusting steering and suspension geometry to get it, plus a few other improvements that seem worthy. Jason, I see you asked for a pix of the steering connection. Since it's already off, I'll mock it up and post it. Sorry for taking so long..

Not a problem! Glad to hear your making progress. I hope to be doing trials on the suspension this winter, but at the rate I've been going that looks to be aways off. I'm really looking forward to the process though. I'll look forward to the pics.

Jason

hey Pure hows it going?? so any good new on the front end??
I"m really wanting to get my hands on one :D

thanks
Chris.

My single A arm project for supers was put on hold for the recent ice storm. However I should have the tubular Test Jig I am building to hold all the parts in place as If they were on a frame and chassis and not just a frame, done soon. This option allows me great access to all the parts and areas I will be working on as well as mocking up their position. As for the mounting points for the arms, they will be able to either be bolted on or welded in depending on the end users wishes. The down side to this project is that the A arms will be a total custom affair. However all the supporting parts will be off the shelf. Parts such as the A arm bushings, ball joints and sway bar busings, allowing for rebuilds if needed. I plan on offering 2 versions one that will use a bolt on Porsche ball joint and one that will use a bolt on ball joint that will fit beetle spindels. This will offer easy options to the two main schools of break modification. I may in the future also offer I arms with these options as well for people that wish to keep a more stock suspension. Expect some detailed updates in the main thread for this in the next week or so.