TheSamba.com :: View topic - Dune buggy torsion bar conversion to coilovers

Sat Apr 20, 2013 8:34 pm

Ok so my dune buggy has balljoint front suspension and the shock towers are done for. Every time I hit a bump, they move back and forth like crazy and they are really starting to make me nervous. They are rusted out on either side and cracked towards the top and there is no possible way of fixing them. I already have new off road shock towers for a kingpin suspension and coilover shocks. I know they won't fit the balljoint suspension but I'm going to fabricate them. Next weekend I'm probably going to cut the stock shock towers off, take the trailing arms off, take the torsion bars out, put through rods in and put the coilovers shocks on. Right now, in the center of the beams there is one nut on each beam. Once I undo these nuts, will the torsion bars just slide out? There is one bolt on each of the trailing arms. Once I undo these, will the trailing arms just slide out? What parts should I replace once it's apart? Does anyone have any tips for me? Is there anything that I should know? I'm open for suggestions. Thanks.

Sun Apr 21, 2013 9:52 am

I would be concerned about the reliability of the lower ball joint. You do realize that by running a true coil over ALL of the supporting force will be on that lower ball joint, right? With the torsions, half the force is on the lower ball joint, and the other half is on the upper. Also, there isn't really anything to gain by using a coil over on stock length arms.

I strongly sugest keeping the torsions in place, re-fabricating the shock towers, and using regular shocks.

Not to blast a hole in your plans or anything...I just think it's taking a step backwards to pull the torsion's and run coil overs on a ball joint beam.

Sun Apr 21, 2013 6:43 pm

I didn't think of that. I know that people replace the torsion with coilovers all the time. They even sell a kit for it. There's no way of fabricating the shock towers that are on it now. They are done for. I also already dropped more than 200 dollars for the shocks and the towers so I am convinced that I am going to put the new shocks on. I'm not going to be jumping it or anything so the ball joints shouldn't be under too much stress. Right now I took one of the shocks off because the shock tower is literally just about to snap off. So there is only 1 shock on the front. It seems to handle exactly the same as before. I took both of the shocks off and drove it for about 5 minutes and the suspension was 10 times better than before but it was traveling pretty far, so I put the 1f shock back on. Is it fine to run it like this? I'm not going to keep it like this. Is it fine to run it with no shocks at all? Does anybody else have anymore suggestions on the conversion from torsion to coilovers? Thanks

Mon Apr 22, 2013 6:54 am

Quote: I know that people replace the torsion with coilovers all the time.

The true coil-over shocks (not the dumb shocks with stiffening springs) and through rods that you are seeing are on link pin front suspensions. These do not have the quirky ball joint on the bottom that is constantly in tension. To much tension can rip the ball out of the socket. By using coil-overs, you are doubling the stress, and thus the changes of ripping that ball out of it's socket...not cool dude. With link pin beams, you have a solid 22mm in diameter hardened steel "link pin" in shear. This is much stronger than the lower ball joint on your beam and can take true coil-overs with no trouble.

Quote: There's no way of fabricating the shock towers that are on it now.

Cut them off and fabricate new ones. 1/4 inch steel flat stock is cheap.

Quote: I also already dropped more than 200 dollars for the shocks and the towers so I am convinced that I am going to put the new shocks on.

Maybe you could convince yourself to use the shocks on the rear of your ride, then just buy some el cheapo oil shocks for the front. Or, you could sell them and put the money towards things that will improve your ride. Ball joint beams are very durable in stock form. Why undo that by spending 200 bucks on a pair of coil-overs? If you already have shock towers, just cut off the lower part with the two holes spaced for the link pin beam, cut off the existing shock towers, and weld the upper part of the new towers to the top of the beam. What travel shock towers did you get, 8 or 10 inch? If you got shock towers made for 8" travel shocks you can use 69 and later rear VW Bus shocks. They are about 22 inches extended, and about 14 inches fully collapsed.

Quote: I'm not going to be jumping it or anything so the ball joints shouldn't be under too much stress.

Off roading of any sort puts A LOT of stress on that lower ball joint. You don't need to be jumping it to put too much stress on it. Shock loading them is what hurts them the most. I suppose coil-overs could be ok on your ball joint beam if you are only street driving....but I am guessing that won't be the case since you posted in the off road forum...

Quote: Is it fine to run it with no shocks at all?

It is doable. You won't notice much of a difference on the street other than increased wheel movement. Off road you will probably notice that you will bottom out the suspension more, and that your front end will start to bounce around easy.

Again, I am not trying to poop on your plans. I am just trying to get you to see that spending lots of money on fancy parts does not always improve the overall assembly.

I hope this helps

Mon Apr 22, 2013 7:10 am

Here are a couple quotes that I love from Jeff Hibbards' Baja Bugs and Buggies.

Quote: I don't know how many times I have seen an off-road car with some of the best equipment here and little or nothing there. I'm always curious whether this is the result of an over-fix or the work of some hotshot salesman.

Quote: Avoid building a "cosmetic" off-road car. Don't start with the highly visible components such as trick wheels and tires, and forget the suspension. Many people like visible, easy, bolt-on fixes. This approach is fine as long as you keep in mind that super heavy-duty trick parts won't make an assembly any stronger than the weakest part in that system. Understand that some expensive parts are never worth the money unless used along with a full complement of heavy-duty or modified parts.

Mon Apr 22, 2013 1:57 pm

If you are going to build something with coilovers, you have to build it right, and a balljoint isnt the way. If you keep a balljiont front end, build it correctly, with clearanced balljoints, good shocks (like bilsteins) and do the hook & pin suspension travel stops. you will be surprised at the results. You will have to run balljoint modified travel shocks to do it correctly.

Mon Apr 22, 2013 2:50 pm

Md perf speaks words of wisdom. Good shocks with the hook and rod stops is hard to beat. This combination will give you a very durable ball joint suspension.

Me personally, I would save the clearanced ball joints for lowered road cars. Talk to the class 9 guys, they swear by the stock ones.

Mon Apr 22, 2013 3:36 pm

Ok I just thought of an idea. Could I take just the bottom torsion bar out then put the coilovers on? And does anyone have any ideas that doesn't involve me getting rid of the new shocks besides putting them on the back because I already have the same shocks on the back. Thanks

Mon Apr 22, 2013 6:14 pm

Anything is posible to do...your outcomes may vary...

Your suspension will be outlandishly stiff if you run coil-over + upper torsion...and your lower ball joint will still be under tremendous stress unless you go find softer springs for your coil-overs...which will just cost you even more money.

Remember, your torsions are not nearly as stiff as that coil over. Adding torsions to the upper arm does not change how stiff the coil spring is, and thus, the stress on the lower ball joint for a given amount of cycle. All that combination will do is make your front suspension so stiff, you may as well not even have one.

As I said earlier, you can remove the rear torsion bars and run your coil-over shocks back there. That would be much better than using them on the front ball joint beam.

-

Here is the bottom line with using the coil-overs you have in the front. You will have a suspension that is VERY stiff, and your durability of the lower ball joint will suffer greatly. No ifs, ands, or buts.

Mon Apr 22, 2013 7:01 pm

So if I did put the coilovers on, about how long would I have before a balljoint broke, or would they break at all? And I guess it wouldn't damage the suspension to run just torsion? About how much does a new balljoint cost and do they make heavy duty ones that won't break as easy? Also, how hard is it to put a new balljoint on?

Mon Apr 22, 2013 7:54 pm

It all depends on how you drive. If you keep it to nice flat paved roads you will probably never have a problem with your ball joints. If you take it off road you could potentially pop that ball joint the first big bump you hit. Washboard will also bone them up when under so much tension.

As far as what ball joints are the strongest, this might be more of a question to ask the class 9 guys. I know there are a couple floating around the off road forums. Hopefully they will pipe up. If i had to guess I would say original German stuff...pretty safe guess.

As far as replacing them, you have to pull the arms and put them on a hydraulic press and push them out, and reverse the process for replacing them. Be careful when you replace them. They have to be aligned properly.

I am a bit confused by your question about using torsions...do you mean to run the torsions and no coil-overs(aka, using regular shocks)? If so, it is how the germans designed it. They knew what they were doing. The torsion bar suspensions work amazingly well in stock form.

Hope this helps!

Mon Apr 22, 2013 8:03 pm

I meant just running torsion with no shocks which I will most likely not do I was just wondering. Hmmmmm... what could be done to make ball joints stronger or to make the coil overs work?

Tue Apr 23, 2013 12:23 am

The only potentially damaging stuff due to lack of proper shocks would be bottoming out the suspension quickly (resulting in damaged ball joints), or losing control in rough terrain off road due to the front end bouncing around. If your tires are not on the ground your front brakes will be worthless and it will be difficult to steer the car in the direction of your choice. Shocks are the key to keeping your tires on the ground because they damp the tendency for suspension to oscillate.

Suspensions are nothing more than a spring (torsion bars, coil-overs, leaf springs, etc...), a mass (suspension components, brakes, wheels, tires, etc...), and a damper (shock absorber and other frictional losses). You can also think of it from an electrical standpoint. The spring is potential energy, the mass is kinetic energy, and the damper is resistance. If you send alternating current through an circuit with a capacitor (potential energy) and inductor (kinetic energy) in series, you can get some crazy oscillations.
I have personally done a lot of electrical engineering stuff. With only a 5 volt input at the right frequency and the right inductance and capacitance values, you can measure over 1000 volts across the components due to oscillations. If the oscillations are not controlled, high voltages can seriously damage components. Add a resistor in there and you can damp some of that out by turning electrical energy into heat. Your shock absorbers do the same thing, they dampen your suspensions oscillations (due to the interaction of springs and masses) by turing mechanical energy into heat. This keeps your car from becoming a pogo stick on wheels. :lol:

Sadly, nothing can really be done to make the ball joints themselves any stronger. Truth be told, the ball joints are actually very strong...its just the mechanics of the suspension that expose their weaknesses. The best thing you can do is use the german ball joints (which are the strongest ones available) and use travel limiters so that you don't over extend the ball joints. Over-articulation is the biggest downfall of the ball joints. Limit articulation and a stock ball joint beam is super tough. Avoid the clearanced ball joints as these are inherently weaker.

Why do you want your coil overs on the front so bad? Your coil overs will work fine on the rear suspension if you just remove the torsion bars and add some nice solid shock mounts to the trailing arms and frame. Regular shocks are cheap. Get a pair at any auto parts store for the front and be done with it...

If you are absolutely dead set on using coil-overs on the front...for whatever reason...Here is another option, but just adds more money into the equation...Get some Thing spindles and swap your lower trailing arms side to side. Thing spindles are getting harder to find...and more expensive. The up side to thing stuff is that both the ball joints are pressed in from the bottom so that the ball is always being driven up into the socket. You also get a couple inches of lift and a tiny bit extra track width due to the spindle design. With the lower ball joint facing down, it will be able to better support the wight of the vehicle, and you can do your crazy through rod and coil-over suspension...for what it's worth. When this conversion is done, you will have successfully sunk $400 into making your suspension look cool...whoopty-do... :?

I hope it makes you happy...

Tue Apr 23, 2013 7:31 am

IF you want coil overs on front go to "A" arm front clip AKA Mendeola... other wise just repair and reinforce you torsion front end... What you have is already better then any coil over conversion you can scab together is home garage...

http://www.mendeolasuspension.com/t-1-front-suspension.html

Dale

Tue Apr 23, 2013 9:45 am

Bingo :wink:

Tue Apr 23, 2013 1:47 pm

yup. If class 11 guys can jump the crap out of a balljoint front with no coilovers, so can you. Do the proper work, or go with the option B or C of Link pin conversion or A arm conversion....

Tue Apr 23, 2013 1:58 pm

The link pin conversion is an excellent choice for coil-overs if you or someone you know has good fabrication skills. 2.5x1 inch arms will have good performance.

Tue Apr 23, 2013 3:44 pm

I can't put the coilovers on the back because I already have the exact same pair on the back and they are fairly new. If I did use gas shocks on the front what ones should I buy? I need some that are 22 inches when fully extended. I would also really like to get some that are not stiff at all because the ones that were on there before were STIFF the suspension hardly traveled at all. Where could I sell the new coilovers that I have now? I cant return them because i have had them for about 6 months now. If I bought gas shocks, I wouldn't want to spend over 120 dollars and I would like to stay below 100.

Wed Apr 24, 2013 3:42 am

You can sell your coil-overs in like new condition in the classifieds.

Go to an auto parts store for your regular shocks for the front. I wen't to autozone and got a pair of gabriel shocks for the rear of a 68 and later vw transporter (type 2). They are just short of 23 inches fully extended and have about 9 inches of travel...perfect for the front end. They have a light gas charge to keep cavitation effects down under rough driving. They also have a lifetime warranty, so when they go bad you can bring them back and get new ones. They are 20 bucks each. Cheap. Napa sells a similar shock made by Monroe that is also about 20 bucks a pop with a good warranty.

If you want a step up you can get KYB gas-a-just shocks. I think napa sells them. They are a bit more expensive. Maybe 50 bucks each??? A lot of performance VW places sell them too, like Appletree Automotive. They are a little more durable than the gabriel or monroe shocks, but they lack the lifetime warranty...so if you break them, you will likely have to buy a new set.

Keep in mind that most gas shocks will be on the stiff side...but for off roading that is ok.

If those are still to hard for you, you can try and find some simple oil shocks with no gas charge. They are getting hard to find though. I think CoFap still makes one for the back of those late busses. They are on the expensive side though. Someone quoted me 70 bucks for one...so I went back to autozone and picked up a pair of the gabriel shocks for just under 40 bucks with a lifetime warranty :wink:

Wed Apr 24, 2013 11:40 am

Don’t read too much into the ball joint itself. Configured correctly the ball joints can take a lot of abuse and can support coilovers. The trick as outlined above has to do with the position of the ball joint.

Below is a stock ball joint location, look at the lower compared to the upper ball joint. The upper arm is resting on the ball over the spindle; the lower is below the ball under the spindle. With torsion rods, this is ok as the sprung load is mainly on the upper, over the spindle. Coilovers usually attach at the wheel to the lower arm, using the shock mount will do this. That will effectively force the ball out of the socket from under the spindle. If you could attach the bottom of the coil over to the upper arm, you'd be set to go, but that’s not practical.

As highlighted above, using a thing spindle allows you to rotate the lower ball joint over the spindle so the weight rests above the mounting point. A hard impact now will force the spindle into the suspension, not away from it.

Or, if you have fabrication capabilities and a lot of time to calculate geometry... you can do as I have and go the a-arm route using type 3 spindles/ball joints (which mount much like the thing spindles) and achieve the same results. Bonus of the type 3 ball joints is they easily unbolt rather than press/weld in so they can be changed in the field.

…and before you ask, no you cannot use type 3 arms on a type 1... The length of the arms and geometry is all different. You can cut the front horn off and use a complete type 3 front end for longer travel and softer ride since the torsion rods are twice as long as stock vw and net around 11" of travel. Below is a stock type 3 front end: