swing axle tricks

I am about to pick up a new car,, and this one is equipped with a swing axle. I am used to the handling of my current irs setup,, and a bit concerned about the charactoristics of the older swing axles. I read about all the various tricks used to make it behave as well as it can. Here is my list:
ride height set just above neutral camber,, ie: slightly positive.
A shimmed Z-bar
small sway bar
camber compensator
camber shims

Anyone been down this road before ?? Did you use all of the above,, or a combination of some of them ?? How did it work out ?? What were the pro's and con's ??
thanks,
Alan

A camber compensator would seem a definite requirement and the first thing to install. (IRS speedy owner, but looong time Corvair owner.)

Yes, David,,
Camber control is certainly a recurring theme. I forgot to add coil over shocks and travel limiting straps to my earlier list. Anything to hold the swing axles as level as possible, would be the intent. I did read, in an excellent article on Aircooled.net, that the swing axles also tended to squat on hard acceleration. The drop induces large negative camber,, and can thus reduce tire traction. But then I have also heard that drag race swing axles can do very well, with proper setup.
Alan

I'm making a rear sway bar for mine. The camber comp was worthless, and I do not think the body will take the stress of the "Z" bar.

you dont set up a swing axle with positive camber, you can go as high as 1 and 1/2 degree neg, and still get good tire wear. it is a natural carastic of a swing axle set at straight up to want to go into a positive camber sitication.and that causes the toe to go to toe out. not what you want. set it up with about one and one half degree neg, with the camber comp. bill

My 2 cents.

You do defiantly need a chamber compensator! Take this positively from an ole North Carolina mountain Speedster owner and blockader! I drive roads that are worse than the Tail of the Dragon. My Beck's rear assembly would literally jump up and down when decelerating from speeds of 100 M.P.H. + on mountain interstates . Doesn't do that any more and stays "flat" in the curves while traversing the every day roads.

Go to aircooled.net and find type 1 suspension tuning tips...... There is an outstanding article on both swing axle and cv joint setups.... Article is by Greg Ward, of the Austrailian hill climbing crowd..... He has reccomendations for track, road, and all out hill climbing....on both systems.... Good read.

Alan - I'm no racer by any means, but FWIW the cornering characteristics of my VS swing-axle improved tremendously with front sway-bar, rear sway bar, 185x15 radials...

Front sway bar installation (with slight mod to bumper bracket)



Rear sway bar (attached to trans/horn)...



Hard cornering on decreasing radius curves...

Kevin,, why did you find the CC worthless ?? Did it not fit,, or was it ineffective ?? Also, why make your own sway bar,,, as they are resonably priced c/w hardware,, ie: http://www.cip1.ca/ProductDetails.asp?ProductCode=ACC-C10-4035

Bill,, I think the idea behind setting up a slight positive camber when the car is at rest, is that cornering or acceleration is going to induce negative camber. This would be due to rolling and/or squatting. This of course is before any bad stuff starts to happen.

Aaron,, Sounds like a wild ride in your neck of the woods,, so you want to have confidence in how your car will respond. From what I have read, the CC and a mild roll bar are pretty commonly used. I think that leveling out the axles is smart too. Limiting straps might resist any tendency for the rear end to "jack up" on engine braking decelerations.

Leon,, right on,, great article. I followed Greg's recommendations when setting up the IRS on my first Speedster. Thanks all,, Alan

Can I just ask; What size is your engine and the expected horsepower?

Hi Gord,,
The car is coming with a 1600sp,, but that will have to go. My latest favorite engine size is 2275. You would be better to attach hp values to them, than I. But I don't want to put more into the stock gearbox than it can handle. Cheers, Alan

THe camber compensator is basicaly a week leaf spring and is easy to over come. It's function is the opposite of what a sway bar does in a corner. As the outside wheels gets pushed up it inturn pushes the inside wheel down, making the spring rate greater thus causing more body roll. I did install limiting straps on the back of mine to keep from ever having my rear suspension going into possitive camber. The only draw back is at high speed when you go over a rise the rear end can come off the ground.....
As for making my own sway bar. I wanted a very high quality part and wanted to tune it a certain way. The off the shelf parts are fine for most everyone out there, I'm just a little more crazy when it comes to handling, and normaly push the limmits of this short wheel base.

Allen,
Carey set-up Merlot as I requested...Porsche old school handling. My 356 B Super was imported via a military owner. It was complete with a special camber compensator installed by the Porsche people. What a handling machine...very flat cornering machine

The roads here,can be a pain because of elevation changes, reverse slopes and 180 degree hairpins plus horse shoes.

Kevin.

I cant see how the camber compensator could "push the inside wheel down" as the leaf ends do not strap to the axle tube. It simply rests on the bottom of said tube with a nylon pad and therefore only responds with upward thrust, not being capable of a downward pull or push.

AFWIW I did this install, and it was the best $60 (the CC) I ever spent (coming from a Pro Licensed Racer) on this speedy. Miraculous difference & quite literally made the car fun. I'm just say'n.

I have a swing axle sway bar like Jim's that I might be persuaded to part with.

Seems to me that the Z-bar and the camber compensator esentially try to perform the same function,, so you would choose one or the other, but not likely use both. CB claims that their compensator is %50 stronger than the "original" empi unit. I am inclined to first of all,, level out the car to what ever height gives zero rear camber, with a camber compensator in place. Then go find a parking lot,, and start testing to find the limitations and characteristics !!
Alan

Just installed my camber compensator last week....and WOW! What a difference. Will I notice even BETTER handling after installing the 3/4 front sway bar?

Mike

No what I w=meant to say is that when the outside wheel is getting pushed up by body roll, the strap that goes around the axle tube actuly pulls up on the camber compensator. This does help the outside wheels spring rate making it harder to compress the suspension, however like a teater taughter the other wheel is being pulled up lifting the inside of the car and creating more body roll.

Cool Kev.

Yeah Mike, you will notice a lot with the front 3/4 bar. Enjoy.

So Gord,, what do you think,, given the engine size that I described ?? I anticipate mounting the fattest tires that I can fit. But I am lot likely to spend a great deal of time power sliding or doing hill climbs. Just don't want to wind up flipping or spinning off a sweeping curve somewhere. Alan

Hey all,, still searching for enlightenment on this topic,, and found a good thread and photo's on this site. Has anyone seen a z-bar for sale ?? Can't say as I have seen them carried by the usual parts outlets. Alan

http://www.shoptalkforums.com/viewtopic.php?t=122567

Alan, Unless you trip over one in a junk yard, you will probably have to fabricate one.....

Someone made, or offered, a 5/8 dia. rear sway bar, that was a great compromise on ride and comfort....

I'm looking for one of these for a cv joint rear end.... No luck yet...

Alan:

Sorry.....been a bit busy lately and not checking in as much.

I have never run either a "Z" bar or a camber compensator. Well, OK, I ran a camber compensator on my '57 oval sedan for about two days, hated it and gave it away. The next guy loved it. Whaddo I know...

What I've run in the past on a swing arm car (I've never run a swing arm rear on a Speedster, just on Dune Buggies and my '57 sedan) is a similar anti-sway bar as the one MUSBJIM is running. I got them from Fiat 124's way back when, then moved on to anything that had the same width but was, maybe, thicker. We tried bars from a number of different cars, as long as they had the right dimensions. Mounted the bar mounts to the torsion bar tubes for a while (I think that's similar to what Jim has), but didn't like that so we moved to the rear of the pan with some stock welded in to take the stress. We were also running pretty beefy bars by then, sometimes 1-1/4" dia.

On Pearl (which has an IRS rear) I'm running 3/4" (19mm) bars front and rear. Started with just the front and that made a big improvement. Added the rear (it mounts to the torsion tubes, too) and saw a little improvement and a LOT more road vibration. I am not preloading either one. It's very flat and tends toward understeer and I have never got it to oversteer (yet), but then I have been running 225-55-R16's on the rear - that's a lot of rubber to try to break loose. I've just changed to 205-55's all around so expect it to be less aggressive but I'm getting older, too.

Hope this helps. OBTW: For that bigger engine and the expected 150-ish ft. lbs. of torque and a stock body dictating tires no larger than 195's (if you can stuff them in there), 3/4" bars front and rear should be sufficient. Sorry I can't speak to camber compensators or "Z" bars.

gn