TheSamba.com :: View topic

Tue Dec 24, 2013 10:59 am

I have a few questions for you guys:
Are stock training arms with gussets stronger than aftermarket boxed arms?
If i decide to go with aftermarket arms, how wide/long can I go until i can no longer use my torsion bars and have to go to coilovers?
Thanks guys!
Colton

Thu Dec 26, 2013 9:50 am

The strength issue I think GOOD aftermarket arms are stronger, but strength comes from the internal structure and the size and type of materials being used. The biggest I would go and still run the torsion bars would be 3x3.

Thu Dec 26, 2013 9:59 am

If you run stock torsions with longer arms, prepare to bottom out a lot.

What length torsions? for anything with any travel to it, you need to run long torsion bars (26") with the correct accompanying hardware. If you try to run short bars, the first good jump or bump you hit will snap it.

you need to run about 28mm-ish diameter if they are for that bug.

Make it worth your time to go the extra mile to get the long travel end plates, 930 cv's. get the most for your money if you go down that road.

maybe this will help http://www.swayaway.com/techroom_vwguides.php

Thu Dec 26, 2013 10:49 am

cmiller95 wrote: I have a few questions for you guys:
Are stock training arms with gussets stronger than aftermarket boxed arms?
If i decide to go with aftermarket arms, how wide/long can I go until i can no longer use my torsion bars and have to go to coilovers?
Thanks guys!
Colton

This is my opinion, not experience. If I was staying stock with my arms I would just box them. I've seen plenty of these look like they take a pounding.
JFYI, you don't have to go coil overs - you can always use airbags and lose the torsions all together. You just have to have some fabricating skill. They might even be cheaper in the long run...

Thu Dec 26, 2013 10:54 am

yeah, Airbags would be a cool way to go too!

I run 2x3 arms on my buggy, you can go 3x3, you don't need to run coilovers; you can do regular shocks with torsion bars, or now the mention of airbags with regular shocks..... I like that airbag idea; I see it, like it, then forget about it myself. Hmm.... Maybe I should do that on my Baja, since I haven't done anything with the suspension yet.....

How much travel can you get out of airbag though? I am completely ignorant about them, other than what I have on the rear of my truck

Thu Dec 26, 2013 12:43 pm

If I remember right my bags go from a couple inches to almost 13 inches. There is a single airbag that seems to do the job the best. I tried to fight that when I was being advised and I made a big ass out of myself in the process and now I have the right ones. I actually bought 4 and was planning on selling the two extra but I haven't made up my mind yet.
The idea is you have a bag with a very high working pressure/volume but run it at a fraction of that. This avoids the bounciness that can occur in a stiff bag. You then run a normal shock to control the rebound from the bag - exactly what shocks are meant to do. Air bags are technically a spring so the torsion bar is no longer needed and you can run hiem jointed eliminators which open up the door to long travel limited only by your wallet. I plan to run around 3-4" sag with 6"-7" under that. Should be like riding a cloud and great for whoops. I will have an air tank, compressor, and solenoid switches so I can adjust ride height with the air pressure on-the-fly.
It's not for everyone. The only difficulty comes in deciding where to mount the bag and optimizing it's effect which can mean sleepless nights for over-thinkers like myself. ;) I love it!

Thu Dec 26, 2013 12:50 pm

What brand, part number & where to buy?

Thu Dec 26, 2013 12:59 pm

If you are looking for ideas for where to mount the air bags, Funco has been using air bags setups on there buggies for many years now.

www.funcomotorsports.com

Thu Dec 26, 2013 1:19 pm

md perf wrote: What brand, part number & where to buy?

http://www.airbagit.com/v/vspfiles/pages/AirBags_PAGE.htm
Air lift

#3800
Double Convolute
Air Spring
Diameter 8.50"
Closed 2.8"
Extended 12.50"
5,000lbs per bag
400psi rated

Thu Dec 26, 2013 1:37 pm

Ill be running it in a sand rail, i have torsion bars and spring plates off a swing axle and a irs car so i've got the long and short. Im perfectly fine running stock arms as my front end isnt widened. I was curious as to how much stronger aftermarket arms are. And for the cost, are 3x3's worth the extra but if I it would be best to run coils with them ill stick with my stockers.

Fri Dec 27, 2013 8:41 pm

If you're not going to modify the front much, then going wild in the rear will be almost a waste of money. I would just box the stock arms and go. I would also recommend that if your tire will clear, run the longer torsion bars. They don't wind up as fast as the short ones and will give you a better ride. Also, if you find that the stock long torsion bars are a little weak, see if you can scrounge up some from a square or fast back. They are a little stiffer and you can usually find them pretty cheap.

Sat Dec 28, 2013 11:50 am

I found that the short 28mm torsions quickly fatigued and twisted on my Baja Bug with 3x3 arms. The new 28mm long ones seem to hold up fine and the tires clear easily with the 3x3 arms.
On my other Baja with reinforced stock arms and long torsions there is only about 1/2" clearance with 31" tires. The plate type reinforced stock arms are heavy but seem to hold up. I have never run the tube style, they seem too light for a torsion sprung Baja Bug and my old vintage Wampusskitty buggy will remain a swing axle even though the swing arm front is now a beam axle.
My Buggy at about 800# and swing axles easily maxed out the stock torsions with paddles on 12" wide wheels. The 8" wide desert tires and wheels did not do this much. Maybe I'll try to reuse the short 28s there, but they are likely too stiff.
HotVWs gave a chart for stiffness vs diameter recently. As I recall, 28s were about 3x stiffer than 23s and the others fell in between. Theory says that the stiffness increases at the 4th power of diameter and decreases linearly with length. The wheel offset [linearly?] and increased arm lengths [squared?] also decrease effective stiffness.
Dennis

Sat Dec 28, 2013 5:12 pm

Dhale,

You are right when it comes to torsion bar thickness. The increase is exponential and not linear. A lot of people go too stiff by making big jumps in the torsion bar size, and then they get beat to death. That is why I recommend the squareback bars. They are 23.5 mm compared to the T1 that is 22mm. They are stiffer yet more compliant. They work really well for a street / off road Baja, or for a rail that is ran fairly hard. This is with stock length arms though

Mon Dec 30, 2013 2:17 pm

I went back to the swayaway website for the numbers:
Stock short [21.75"] bars are rated at 122#/".
Stock long [26.56"] bars are rated at 98#/".
28mm long bars are rated at 257#/". More like two and a half times rather than three times as I had recalled.

If you have about 10" of travel and 1000# of car [including passengers], you need about 100#/" offroading. Less travel, more spring rate. More weight, more spring rate. Running out of spring will break something that's not supposed to flex.

SwayAway recommends 25 or 26mm in buggies and 26 or 28mm in Baja Bugs.

Dennis

[img][/img]

Mon Dec 30, 2013 3:29 pm

I run 26mm 300m bars with about 60% weigh in the back, 22gal.fuel cell, spare tire, jack, battery, air filter, fuel pumps.need weigh in back for better traction if I could lower first gear more it would climb like a mountain goat still does pretty good.

Mon Dec 30, 2013 5:14 pm

Good info from Dennis and Multi69s.

As to the original question posed in this thread, whether boxed stock or fabricated from plate rear arms are stronger...
It depends on a lot of factors such as how well they were welded and how well the fabricated arms were designed. Stock with box-in or tubular reinforcing kit, fabricated box arms, or fabricated tubular arms are all pretty equivalent strength and the choice is down to personal preference.

If their comparative strength is an issue, the intended length must be stock. As such, I see no sense in spending the extra cash for fully fabricated arms. The off-the-shelf box-in kits will produce an arm plenty strong enough for off road racing in 1600 buggy or 5-1600 class, unless you want to keep the stock shock mount location. The notch for shock clearance in the box-in kit makes the arm extremely weak at the notch. For that situation, a tubular beef up kit for stock shock mount is needed. Check with the Kaddie Shack for those. I have never yet seen any fully fabricated stock length arms built to accept shocks that will use the stock upper mounts. Not that it cannot be done, just that I haven't seen them available off the shelf.

But since you ask “If I decide to go with aftermarket arms, how wide/long can I go until I can no longer use my torsion bars and have to go to coilovers?”, consider this:
A friend of mine has a 4-seat buggy with 5x6 rear arms on 30mm torsions. With 20" of travel and an Acura NSX V6 of about 400hp, and in spite of generally carrying 4 adults, and in a great many miles of very hard offroad use, I have only once or twice felt the rear suspension bottom. The original center adjusters needed to be upgraded to the "King Kong" adjusters, but the torsion bars have never failed. That car is fine with torsions where many say coilovers are the ONLY way. And I see the airbags suggested by ORANGECRUSHer to be fine too.