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  View original topic: Front Beam - Removing center torsion bar holder thingy?
bungi Tue Jul 23, 2013 1:32 pm

Guys -

Setting up the front beam for my street buggy finally, going the formula V route for softening the front springs, removing top torsion bars, installing sway bar & installing an adjuster in the bottom tube. How do you remove the center bulkhead to make room for the sway bar?

I don't want to cut the top tube if I don't have to...

Thanks
Rick

BL3Manx Tue Jul 23, 2013 2:42 pm

The square sections of the end of the sway bar should be the same dimensions as the torsion leaf stack, so one end of the sway bar should fit right through the center anchor and the smaller diameter of the center of the sway bar won't even contact the center anchor.

Just pull out the set screw and slide the sway bar through.

slalombuggy Tue Jul 23, 2013 4:50 pm

You'd have to remove the bushings/bearings from one end and pound it out that side.

I did the same thing on my buggy using 3/4" square stock. It's just a hair bigger than the torsion bar holder and had to be filed down to fit in the upper arms.

Your best bet is to just cut the center 2" out of the tube, press the holder out and weld back together. It's be quicker than fighting it all the way through the tube and R/Ring the bushings.

I also rounded the edges of the square stock except for the very ends and welded up the set screw hole in the beam when I did mine.

brad

BL3Manx Tue Jul 23, 2013 6:31 pm

This is what the Formula Vee anti-sway bar I bought from Campbell Motorsports looked like. I simply removed the stack of torsion leaves and slipped it in place, no cutting or mods required.





http://www.campbellmotorsport.com/Pages/fv26fstswaybarsandspacers.aspx

The rigidity varies with the diameter of the bar which comes in four different diameters.

An alternative is to use a threaded rod with greased washers at both ends. It will accomplish the same as removing one stack of leaves, but will have zero anti-sway (roll) resistance.

EVfun Tue Jul 23, 2013 6:40 pm

One of the old buggy build manuals mentioned drilling out the center anchor with a 1 inch drill bit on a 3 foot extension. I bet trying to drill out a square at the end of a drill extension would be fun. You would certainly need a powerful drill 2 good handles. The drill is smaller than the bushings so they don't need to be removed.

I've thought about just cutting out the top tube and welding in a section of 2 inch tube. Then I'd build up a lower bar with 6 wide bars (instead of the stock 4 wide and 4 narrow that is stock for most K&L beams.)

I'm a little concerned about how a buggy would handle with that much front sway bar. I've seen pictures of Rabbits (and other FWD cars) with the inside rear wheel off the ground in turns. I could see that happening to the inside front tire on a buggy with a stiff front sway bar and most of the weight at the back. This could also effect braking.

slalombuggy Tue Jul 23, 2013 6:52 pm

Mine handles like a slot car. I run 6 big springs in the bottom with light gas shocks.

brad

manxdavid Wed Jul 24, 2013 12:49 am

When you fit either a thru bolt or a FVee type sway bar do you need to replace the stock roller bearings with urethane bushes? I'm just wondering how the stock grease seals/bearings would cope with sideways/thrust forces.

BL3Manx Wed Jul 24, 2013 6:48 am

The trailing arms are retained in their normal lateral positions by washers or set screws. They move freely vertically (in a pair with an anti-sway bar), but the range of their lateral movement is unchanged.

Mike_CNYBuggy Wed Jul 24, 2013 12:20 pm

I wish I understood more about the suspensions. Anyone know of any Websites or videos where I can learn more?

My old rail had the stock swaybar on the front and the inside wheel would leave the ground as mentioned but it handled great. My buggy has no sway bar and when I hit a bump or pothole the car likes to float around.

I don't know if it's the missing sway bar or some other issue within the front suspension, heck, could even be the 60 series tires on the swing axle I don't know for sure but I would like to have a better understanding of it all.

slalombuggy Wed Jul 24, 2013 2:50 pm

MY buggy would pull the inside front wheel 6-8" on big sweepers and you could feel the rear suspension bouncing on the outside rear wheel. I put stiffer torsion bars and a rear sway bar in the car and that went away. It also made the turn in better in the front as I would have both wheels on the ground all the time.

There's an entire section on the shoptalks forum reguarding racing and suspension set ups. You probably won't go that far with your car but it will give you a good understanding of how things work and how different parts affect handling.

brad

EVfun Wed Jul 24, 2013 3:13 pm

Hey Brad,

Was that with a swingaxle rear, or IRS? The idea that the limit is reached by virtue of the rear end bouncing is rather scary with a swingaxle set up with slight positive camber (about stock ride height.) Direct experience with these altered frames is most helpful.

I haven't found the "loose it" point yet in the mini-t. The K&L front beam is cut and turned 1/4 inch (for a stock bug that would be about a 1.5 inch drop.) I have removed the 4 small bars from the upper tube and replace with spacers. The front sway bar fell into the trash 20 years ago. I don't currently have shocks up front and stock single acting type oil shocks rear. The front would bounce horribly, except that it tops out on rebound easy enough to kill that (that is unnerving and will be fixed.)

I've tried reading some of the traditional suspension set up web sites and found the information not quite relevant to the antiquated suspension on the Beetle, and usually quite incomplete in tail-heavy details too. If anyone has something Bug(gy) specific, perhaps even on the Samba, that they find accurate I'd love to read that thread (lots of completely armchair quarterback threads on handling around the web.)

slalombuggy Wed Jul 24, 2013 4:46 pm

MY car is pretty well balanced as far as handling. The center of balance is still under my butt, but I have got it turning better than ever before. It's king and link in the front and IRS in the rear, although I did race for years with a swing back end. The things I did to the front were. Beam narrowed 3".Offset linkpin bushings like the FV guys use, the internal sway bar and replacing the rubber bushings on the trailing arms with aluminum pieces from FV, I still use factory micarta bushings in the beam. I run only big springs in the bottom tube with a Puma style adjuster. All controlled by cheap Empi gas shocks. For pylon racing I ballast up the front end with 85lbs of lead on the front bumper. In back I have 27mm torsion bars (not for a streetcar) adjustable spring plates, urethane bushings in everything, 3/4" swaybar and run SoCal Speedshop Shorty shocks as I relocated the shock mounts on the trailing arms.

brad



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