Suspension rebuild help

I just picked up a speedster kit from a guy in TX that didn't finish the job. It was all put together without wiring. So, I wired it up and it has been running for a year. Well, I am ready to take the engine out and rebuild and I'd like to do the suspension at the same time. I would like to eventually autocross it or maybe some local road racing. Is there some where I can get some good guidelines on how to do the suspension? I am currently sporting a swing axle. I have heard there are alot of flaws with that design. Is there an aftermarket designer that has a drop in without too much work? Is there something I can fabricate myself? Is it possible to add a newer 911 suspension? What are your ideas? I would like it to be some what competetive. Think outside the box. I am not just talking about changing springs and torsion bars. Thanks for you help.

Start here:

http://www.aircooled.net/gnrlsite/resource/articles/handling.htm

First read through Gordon's link, carefully. You just may decide to keep the swing axle set-up with a handful of upgrades.

I looked into an irs swap for the 356 when I was converting it from Porsche to VW. The work is easy, but the parts list is extensive, an without a donor car, expensive.

For a swing axle to irs conversion you'll need:

-Two weld on brackets to accept the new arms.
-A bolt on template/jig to position the brackets.
-A MIG or TIG to weld on the brackets.
-New bushings, boots and bolts all around.
-A complete rear suspension, rebuilt, from the axle bolts in, including a good irs transaxle . . . or the parts/internals, tools and skill for the conversion. Probably a complete brake job as well.
-A template to re-drill the torsion plates, or a pair of irs torsion plates. Might as well add new adjustable ones at this point.
-New rear transaxle mounts and cross bar.
-New/irs length bolts for frame horns.
-Early style front transaxle housing, mount, gasket, seal, and hockey stick.
-New irs length bowden tube.
-New clutch cable, good time to replace with the correct irs length/year.
-New rear hard and soft irs brake lines and fittings/clamps.

At some point you'll need to deal with the five lug/four lug change over.

You may need a few more little things. Some new but most can come off of the donor car so don't worry about them.

I had the stuff, and the energy, but no time to complete the conversion to irs, so I just swapped the old Porsche swing axle components for VW swing axle and STILL managed to assured myself a place in HELL for my efforts.

Well...Gordons post was definatly helpful. Sounds like the swing axle can work good for straight line accel or cournering, but not both to a certain extent. I have been planning a 200+ hp engine, so I would like to get both or at least a reasonable balance between the two. So, I guess if the swing axle will not suffice I will have to look into the IRS or something seperate all together. What did the early 911/912s use? Is there an aftermarket company that has a kit?

If you can weld there is away to change a swing into a IRS. Once you have a IRS you can easily change it to coil-overs or air and lose the torsion bars.

look at www.airkweld.com they have info posted on how to install their air kits. Take a look at that for ideas. You can make something similar without spending $1500.

Go to www.shoptalkforums.com and look at the offroad or suspension sections, you might get some ideas.

bryan

Peter, I'd consider staying with the swing setup.
My car started as IRS, and we hacked the suspension components completely away in favor of stub axles. They're shorter, so there's a lot of cutting to do, but the ride is MORE than worth the effort.
Shorter axles = wider tires on a straight-bodied car.
If that's a flared body, you've got more options.
(Thinking outside the box? I don't even know where the box IS anymore.)

I was browsing through some speedster sits and picked up on this kit by JMS Performance. Does anyone have experience with it? Is it worth while?

http://www.jps-motorsports.com/suspension.html

Pete

Cory -

You are sooo far out - you'd need to catch a bus BACK to the box!

I had read article awhile back on using Porsche 944 rear suspension components (trailing arms, brakes) for the rear on an IRS bug. Gives you strong parts, disc brakes with parking brakes, and Porsche wheel lug pattern. (This might be the article http://www.cbperformance.com/Jan2007b.asp). Suspect 944 parts could be found reasonably at a "junk" yard. I'll try to find link to article.
From another article: "The rear suspension uses front linkpin shocks and Porsche 944 cast-aluminum hubcarriers, which bolt up to the VW IRS pickup points, and allow us to use 944 rear disc brakes"

Another article talked about using Chrysler Horizon front brake components (should be able to do search as I wrote up something from that article and poster here).

Anyone have this book on VW Suspension Tuning?
http://www.ecampus.com/book/190129580X

Wolfgang
The link for the 944 rear suspension does not work. 944...Hmmm... Boy does that give me an idea... Wicked, wicked wonderful idea. (I'm actually Cory's think-outside-the-box spyder-sister).

angela

try ---

http://www.cbperformance.com/Jan2007b.asp

Peter; that kit certainly looks interesting; that front sway bar looks like it clears the front bumper brackets so that you don't need to modify the brackets like we did.

I changed mine to 944. There are 2 sizes. The aluminum are appox 2" wider that stock on each side.