935 style heim joint front control arms

[doozer]

How about this??

[randywebb]

Thx Jeff - maybe you can post your entire setup, roads driven and ride impressions.

[Chuck Moreland]

Doozer, that design is not safe. The only thing killed will be your car and perhaps you! It will snap off at the base of ball joint-attached double adjuster in short order.

I'm not being a smart ass here, but cautioning for your own safety. You are into a catagory of suspension component that, if it fails, will result in serious property damage, physical injury, or even loss of life.

These components need to be engineered, not just "designed". There is a big difference and it involves understanding and calculating the forces involved, strength of materials, structures, assigning proper safety factors, and more. Key word being "calculate". An engineered "design" is backed up with equations.

If you don't have the background to engineer a proper solution, I would highly advise you to buy one of products currently on the market. There are at least three manufacturers of 935 front suspensions already.

Again, not being a smart ass. But be safe!

[Jeff Alton]

Randy, will do. Car will also see some track time in the spring again. It is my daily driver as well, but, I am nuts!! I'll start a new thread with pics and all when I get going on it. Do you need the weight of anything? I can weigh hollw 21 mm torsion bars, solid 27mm torion bars., stock a-arms, spring plates, stuts etc........

Let me know, I can weigh them on a postal scale this time so it will be fairly accurate.

Jeff

[Quicksilver]

Like Chuck said the design is ready to fail. Specifically the double adjuster isn't overkill; it is more of just plain kill. It is in a bending load and weakens the design significantly.

Using a heim joint for the outer ball joint isn't a very good idea on a street car. Rod-end bearings are designed to be installed in tension and compression. They can be used like the outer ball joint in racecars but it is really a bad engineering practice but falls in the catagory of "you can get away with it" On the street, unless you keep track of the hours on the joint and regularly inspect it for cracks, I would expect it to fail.

On the flip side most recommendations will say that you can't use rod-ends for long life street suspensions. I have found that the teflon lined rod-ends have a remarkable life even when used without shields and under harsh conditions. I have a set of rear control linkages that came out of a very high horsepower street car that have no measureable slop even after 30,000 miles (which includes Alaskan winters with salted roads and a trip down the Alaska hiway).

If you attach a normal balljoint to the end of it it should be undestructable.

Wayne

[randywebb]

Thx Jeff - Sure weights would be great!

[doozer]

Wow - Tough crowd!

Thanks for the reality check Chuck and Wayne!

I was not planning on running off and ordering the parts just yet, but I can see your concern!

I actually own a ASME/PVHO Pressure Vessel Shop and a Medical Device Prototyping / Mfg. company ( http://hypertec.ws ) and I am really lucky to have direct access to a number of really good PE's to laugh at the things I dream up and then tell me what to change to make them work ( this is probably why I am still alive ).

Like Wayne says " On the flip side " - I owned a tube frame, off road vehicle that had heim joints and double adjusters used in the exact same application with no problems, and we beat that thing to hell.

Thanks everyone for their input and keeping me in the safe zone!

Thanks
Todd

[doozer]

Wayne - Thanks for the info on the outer ball joint! I was trying to find out if using the heim in place of the outer ball joint was a bad idea for the street and I think you just answered my question.. I have a new pair of ball joints on the shelf anyway - hay I have inventory! You know you are an addict when you have inventory!

Thanks Wayne!
Todd

[project935]

The double adjusters aren't needed - that's what LH/RH threaded tube (easily purchased) and heims are for in this instance. The main link is a set-it-and-forget-it kind of think once you have the track width dialed in that you want. The strut link is important to be double-adjustable, but like I said that's what LH/RH threaded tube/heims are for.

Here's the main link design ...


And here's the strut link ...

[doozer]

Hi project935 - ya, I was being a smart ass and got put in my place

I have used threaded tube L/R on a lot of stuff and I know that the double adjusters are not really needed but it is kind of cool to be able to tweak everything without breaking the link ( removing a bolt ).

The strut link does not matter either way because it can rotate free, but the main link can not because of the clevis and ball joint.

I had an off road monster and everything was QA1 with 3/4-16 double Adjusters and it was great to back off a jam nut and make a change with a wrench without jacking and pulling bolts.

I got your email and I am waiting to see what kind of liability I would incur by doing it here.

Thanks
Todd

PS: Current off road / p-car hauler

[doozer]

Project935 - What about using these as the inside pivot of the main link in place of a rod end? It would still be much stiffer than OEM but suck up the vibration.

[doozer]

The $35 price seems kind of cheap seeing that the NHBB brand rod end (ARHT12ECR) I was going to use was $120

[project935]

I thought about offering the urethane end for a street application - no reason why it wouldn't work.

What's the ultimate radial static load rating? I didn't seen any info in a quick glance thru my QA1 catalogs.

The QA1 XM series is the strongest - probably the most expensive. I wouldn't shy away from using these other QA1 series if there is a cost savings;
* HM
* HM-T
* HM-CP or HM-TCP

The PCM and PCM-T series are about half the strength of the ones listed above, but still have a relatively high load capacity.

[KobaltBlau]

Originally posted by randywebb
Oh yeh - this is related...

Bose is working on an active suspension setup that is supposed to kill all conventional suspensions. Info is posted online - maybe at the Automobile magazine site. It bears watching.

odd that the bose page shows a fairly old LS400 for testing. Might be a coincidence, but maybe they haven't gotten this off the ground in some years. I haven't read the automobile article, so I could be just plain wrong.

edit: sorry, I like the way this thread is going, don't want to derail.

[doozer]

I ordered some QA1 rod ends and they were stamped made in China..

Also they looked like crap so I sent them back and reordered the NHBB and I will let you know what they look like soon..

project935 look at this page:

http://www.bakerprecision.com/rodpick.htm

[doozer]

project935- These look good!

STRUT ROD TUBES
UB'S FAMOUS LIGHTWEIGHT SWEDGE TUBES
3/4" THREADS RIGHT & LEFT HAND

http://www.ubmachine.com/page17.html

[doozer]

Project935 - How long is the aluminum threaded strut link tube??

[project935]

15"

[doozer]

Groovy!

[doozer]

Would you go with Aluminum or Swedge Steel??