Rear suspension set up ??

Post a photo of the rear wheel well area, the lip should be about 1/2" above the steel wheel.

Yeah, front toe-out is not good (rather hard on tire wear and makes the front end a little squirrelly), so it's good you got that corrected. Beetles came with about 3 degrees caster from the factory, which is barely enough for lower freeway speeds. Does your car have offset spindles or have the beams been turned? With the speeds your car is capable of, you definitely need more!  If he's measured right, 1.3' is not enough; somewhere in the 4-6' range will make it much more predictable at higher speeds, so you need at least another caster shim on each side.

With the assumption you like the rear ride height at present, I think you need to limit suspension travel. If the car is swing axle, a camber compensator will go a long way to getting things under control, while with irs an anti-sway bar is the right move. What shock absorbers are on the car? While most of us tend to like shocks for the front that are fairly light, for the back something a little firmer may help. And how new are the spring plate/torsion bar grommets? Handling (and predictability/safety) go out the window when they get worn or soft as well.

A further word about front caster- guys, don't assume that because you don't normally push the car past it's limits that the stock setting (a little over 3' I think) is fine. THE STOCK CASTER SETTING IS BARELY (AND I DO MEAN BARELY) ADEQUATE FOR TODAY'S HIGHWAY SPEEDS! All it takes is a few seconds of blasting down the highway at higher than the posted speed to get in trouble (now who would ever do that?); you're playing around doing 85 or 90 mph just for a moment (as Uncle Stan says, the dang thing does say Speedster on it, you know!), a crosswind hits you and before you know it the car is half way into the next lane. If you're lucky and haven't been flattened by a semi, it'll just scare the begeezuz and (hopefully) there will be a lesson learned. It shouldn't take much imagination to come up with how I was imparted with this knowledge... Al

Thank you Al.

I have a swing arm car. JPS

Stock spindles.

Shocks are new KBY gas.

Spring plate grommets are in good shape. Car only has 13,700 miles on it.

Alan, I measured the top of the wheel arch to the ground, 20", before putting it up on jack stands.

Also came across a suspension article on aircooled.net where the guy had sorted out his car and provided specs on what he did. He indicated that the front of the car needed to be 1" higher than the rear. I have torsion bar adjusters. Is that something I need to do?

Car is running radial tires with 2,000 miles on them.

Caster Shims

-  Because the car has been lowered almost 4” from the stock running height, the caster on the front wheels has been altered.  Caster is adjusted on these cars by adding curved metal shims between the lower torsion tube and the beam mount on the frame.  The shims are longitudinal sections of metal tube and may be found as a kit at CIP1, Bug City, CB Performance and others.  They may offer different thicknesses.  Where you take your car for a 4-wheel alignment WILL NOT HAVE THESE SHIMS IN STOCK.  Buy a couple of sets and bring them with you for the alignment.

-  Tell the technician to get it to 5-7 degrees caster by inserting the proper number of shims behind the lower torsion tube and the mount.  Your axle beam MAY need longer, lower mounting bolts after the shims are inserted – Those same supply houses have longer bolts, too.

I've never heard anything about the front end being 1" higher than the rear.  I have, at worst, had the rear an inch or so higher than the front but didn't like the look so have set it dead level at the the bottom sides of the car and that looks right. 

If your rear ride height is suitable (meaning that you like the look of the height and nothing is rubbing on corners) but the rear squats a lot on take off,  then be assured - ALL of these cars squat on take off - It's just physics.  If you're bottoming out or something, that's different, and you may need stiffer rear torsion bars or coil-over helper springs.  It might even be that the torsion bars in there are old and tired, but it is impossible to remove/replace them without either lifting the body off or creating holes in the side of the body to allow the torsion bar end caps to move out far enough to remove them and then run the torsion bar out through the newly created holes.  All this makes coil-over springs look better and better, right?  We'll need more info for a better response.  If you have rear spring plate adjusters you can certainly adjust rear ride height with those, and much easier, too.

- 17º on the spring plate is a nice figure, but it really doesn't apply to our cars, mostly because we're somewhat lighter in the rear than the VW Beetle to which that 17º figure applies.  So, here you go:

Adjusting rear ride height on a Speedster Replica

 This article should give you enough information for you to re-set the rear ride height on a VW pan-based Speedster, regardless of whether it starts out high or low and regardless whether it is an IRS or swing-arm suspension (although we’ll be showing IRS suspension in this article).  The job is relatively simple (and what isn’t simple on a pan-based car?) and should take about two to three hours to re-set BOTH sides.

Make sure that your car has settled the suspension by either driving it around or rolling it back and forth across a 20 foot distance a couple of times.  Start out by measuring the distance from the ground to the top of the wheel well arch on both sides and write them both down. When I started on mine, the passenger side was sitting at 23-7/8”, while the driver side was a mere 23-1/4”  A difference of about 1/2”!

 Once you have the starting heights, you’ll need to decide how you’ll adjust it.  In my case, the passenger side will be left alone and I’ll raise the driver side the needed 1/2”

 We’ll start by getting the car up on Jack Stands such that it is comfortable to work on and securely stable.  Once that is done, remove the wheel on the side(s) you’ll be working on for access to the suspension, and then remove the shock absorber and put it aside. 

 The rear hub is attached to the spring plate by four bolts.  Before you touch any of them, use a metal scribe to outline the hub casting where it attaches to the spring plate, and make a line mark on both the hub casting and the spring plate to reference later on for alignment.  I used a cold chisel a while back and marked both permanently (look close to see the mark).  On my car I have a rear sway bar attached, so the hub mount for that must be removed along with the spring plate bolts, as shown (just swing the bar down out of the way once it’s been let go on both ends).

 Once the alignment mark is made, go ahead and remove all four bolts.  Be careful in case your hub is loose between the spring plates, but it usually stays put.  Now loosen the four bolts holding the torsion bar end cover in place - back them out 1/2” or so to allow the cover to move out.   Place a floor jack under the bottom end of the spring plate(s) (use a wooden block between jack and plates) and slowly jack it up until the inside plate just clears the stop on the torsion bar mount, then use a small pry bar to gently coax it outward and then slowly lower the jack to allow the spring plate to swing down beyond the plate stop.  Remove the torsion bar cover.

 Find a socket that will just fit through the big hole in the torsion bar mount so that it’ll prevent the spring plate from moving up in the next step.  Use a socket extension as a handle and hold it in place while you do the next step:

 Put a floor jack under the brake drum (use a wooden block between jack and drum) and jack it up until it  clears the spring plate - it should be free of the plates.

 Scribe a line along the top edge of the spring plate onto the torsion bar mount as a reference of your start point.

 Now for a little info on how the rear suspension is adjusted:  Rear torsion bar inner and outer splines are different. Inner splines move 9 degrees per spline, while outer splines move 8 degrees, 10 minutes per spline.   Measuring my car (a 1969 Beetle pan with IRS) gives 17 inches between the centerlines of the torsion bar and the axle, so using C = pi(D) you get a circumference circle of 106.814 inches (imagine drawing a big circle with the torsion bar center at the middle and the axle centerline at the circumference). Break that up into degrees and its .297 inch per degree and .005 inch per minute.

 Applying the math gives one inner spline (9 degrees) for 2.673 inches of axle travel (either up or down), and for one OUTER spline (8 degrees, 10 minutes) you get 2.426 inches of travel (either up or down).   Using combinations of inner and outer splines allows a little less than 1/4" travel at a time by going one way with an inner, and the other way with an outer.

 Here’s a table I did to save you all that math:

 Table 1:

U = UP

D = Down

Inner  -  - -  -  -  -  -  -   Outer -  -  - -  -  -Result (inches)

1D .  2.673 .  . .  .  .   1U 2.426 .  .  . .  .  .  D  .244

2D  .  5.346 .  .  .  .  . 2U 4.852 .  .  . .  .  .  D  .488

3D  .  8.019 .  .  . .  . 3U  7.278 . .  .  . .  . D  .741

4D  .  10.692 .  .  .  .  4U  9,704  .  .  . .  . .D  .976

5D  .  13.365 .  .  . .  5U  12.130 .  .  . .  . .D  1.235

6D  .  16.038 .  .  . .  6U  14.556 .  .  . .  . .D  1.482

7D  .  18.711 .  .  .  . 7U  16.982  . .  .  .  . .D  1.729

8D  .  21.384 .  .  . .  8U  19.408 .  .  . .  . .D  1.981

9D  .  24.057 .  .  . .  9U  21.834 .  .  . .  . .D  2.223

10D  . 26.730  . .  .  . 10U 24.260  .  . .  .  .D 2.470

11D  . 29.403  . .  .  . 11U 26.686  .  . .  .  .D 2.717 

12D  . 32.076  . .  .  . 12U 29.112  .  . .  .  .D 2.964

13D  . 34.749  . .  .  . 13U 31.538  .  . .  .  .D 3.211

14D  . 37.422  . .  .  .  14U 33.964  . .  .  .  .D  3.458

 Ok, so in my case I have to move the car UP 1/2”, so the spring plates must move DOWN 1/2” at the rear axle.  Pretty simple, but I will also be sitting on the driver’s side, so I’m going to increase ride height a little more than that for my weight - say, 3/4” or so.  Looking at the table, I need to go three splines DOWN on the Inner end, and three splines UP on the Outer end.

 Now for the trickiest part of the job, because you want to do each end of the torsion bar separately, but not screw up one end while adjusting the other.  Let’s start on the inner splines first:  Grasp the spring plates and the torsion bar end cap and apply a sideways pressure to them by using the spring plate as a lever so as to keep the outer end from coming loose on the torsion bar.  Now rock/jiggle the torsion bar out of the inner splines but do it gently so you can feel when it just lets go.  Now gently press it back in to feel the splines and move it in the desired direction - in my case I have to move the inner splines 3 up, so I gently start to move the spring plates up, feeling each spline until I get to three, then I push the torsion bar back in as far as it will go.

 Now for the outer splines:  Again, grasp the spring plates and bar end cap and gently wriggle it around to work the end cap off of the end of the torsion bar.  When you feel it let go, gently hold it in place and rotate it in the desired direction - in my case, I now need to go three splines down so I rotate while gently pressing on the cap and spring plates to feel one, two, three splines down and then push the end cap onto the splines, but not yet all the way on.

 For the next step, you’ll need a small container of Baby powder with which to “lubricate” the torsion bar bushings.  The inner bushing is held captive by detents in the housing, so all you’ll need to dust is the inside of the bushing and/or the outside of the end cap where it inserts into the torsion bar tube bushing.  Be liberal - dust it up nicely white, then push the end cap all the way on/in. For the outer bushing, grasp it and slide it outward on the end cap tube, then liberally dust the tube and slide it back into place, then dust the outside of the outer bushing as well as the inside of the end plate.  You can then slide the end plate onto the end cap.

 If you’re not using new spring plate bushings at this time, then the end plate should slide on far enough that it’s bolts will thread into the torsion bar end mount.  If they do not reach, you may need to go get four new bolts the same size and thread pitch and about 3/4”-1” longer to get everything started.  Simply thread the new bolts through the end cover and into the casting and tighten them so that the cover goes on far enough to, one by one, replace the longer bolts with the proper ones.  Get them threaded in, but do not yet tighten them down.

 Re-position the wheel hub flange between the spring plates and gently slide it down more-or-less into place.  You may need to use a small pry bar to get it in between the spring plates again, but it should fall right in.

 We have to get the spring plates back up onto the bottom stop of the torsion bar mount.  To do that, place a wooden block onto your floor jack and position under the rear end of the spring plate and jack it up until the bottom of the plate just clears the stop on the mount.  Now, tighten the four bolts of the end cap cover a little at a time in a cross pattern to keep it even until all four are tight.  Torque them to 30-35 ft. lbs.  Remove the jack.

 Line up the wheel hub holes with the slots in the spring plates, insert the four bolts but do not yet tighten them.  Line up the scribe marks you made earlier and tighten the single bolt at ten o’clock, then tighten the other three bolts (unless you have a sway bar mount - for that you’ll need to assemble the mount and THEN tighten the bolts.)

Yeah, if you're after the absolute best handling then I guess the front should be higher than the rear, but most people don't like the look when the front is noticeably higher and it can still perform well with the car being level (or the front ever so slightly dropped). Part of what we love about these cars is the look (the lower all around the better!), so you'll have to decide where the ride height is right for you.

With stock spindles, the front ride height is set by the beam, but lowering this way takes away caster. Lower the front far enough and you can even end up with negative caster; this probably explains why even with shims under the bottom tube you only have just over 1' caster. This is the big plus of lowered spindles- the first 2 1/2" of drop doesn't affect caster. Get the caster back up to even 3-4' and you'll notice a difference. Does your beam have adjusters? Most people find that gas shocks on the front are just too stiff for a street car and go for a stock replacement oil shock.

Does your car have a camber compensator in the rear?

"dropped front spindles" also gives you a 2 times 1/2" wider front stance -- Pontiac wide track for better cornering.

Thanks to all.

Gordon, I hope that was cut and paste...lots of information.

I don't have drop axles. They're stock.

In order to get 5 degrees of caster shims on the front I need to add .390" to the lower truss bar on top of the one shim that is in place. Does that sound reasonable?

ALB,

It's been my understanding racing karts that caster is caster. Doesn't matter if I raise or lower the chassis. On these cars I would think you would get the ride height where you want it then dial in your caster, camber and toe. Trying to figure out track width for optimal handling on these cars...? Unless you are racing it don't waste your time! If you are looking for stick around a corner then get the softest tire you can find and put a little weight in the front end. 

Jim:  It's not unusual to have multiple caster shims on the lower torsion tube, nor is it unusual to have more on one side than the other.  These pans are gettin' kinda old and sometimes have been bent outa shape a bit and need some TLC to get them back.

The kid who did my last alignment used one of my thicker shims on the Driver's side, then went out and made another, even thicker shim out of a piece of chainlink fence pipe to add to the first shim to get the caster where he wanted.  The other (passenger) side has a single, thinner shim from CB.  

I've never heard of anyone adding length to the truss bars - we can usually dial it in with just the Caster shims.

And I tend to agree with Rusty - I've got Pearl nicely dialed in and she handles like a banshee, BUT you only get to appreciate what she can do on a track when you can really push it.  Out on the street you can't usually find the road or lack of traffic/dog walkers you need to appreciate what the suspension can do.   Softer compound road tires can give you a lot of that same feel.

Yes, it was a cut-N-paste from Pearl's service manual.

Lots of great info here, Jim! Yeah, you might have to add that much under the bottom tube to get an acceptable amount of caster. And as Gordon said, your pan may not be the same side to side- a front end collision on the donor car will do that and how close it is will depend on how much attention the guy who pulled the frame head back into shape gave it. What do you mean by "truss bars"?

And Rusty makes a couple of great points as well- a good summer high performance tire (if you can find it in your size) will help, as will adding 30 or 40 lbs. of weight up front.

Another thing you can do to improve handling- change the front camber from 1/2 degree positive to 1/2-1 degree negative. This is accomplished by bending the top trailing arms in a press (the old school way) or using "extra adjustment camber adjusters" (the new, easier way)-

http://vwparts.aircooled.net/E...ber-adjers-extra.htm

Does your car have a camber compensator?-

http://vwparts.aircooled.net/C...mber-compensator.htm

It looks like this installed-

The pic is an Empi unit; the CB Perf. one is better quality (meaning it doesn't fall apart like the Empi p.o.s.).

Hope this helps. Al

ALB & Gordon,

It looks like I didn't finish my last post.

I do not have a compensator installed yet. I intended to do that over the winter. The bottom studs on my transmission are too short and will have to be replaced in order to mount the compensator. I hope the existing ones are not put in with Locktite.

The CB Performance compensator is what I'll use.

Ordered The Gene Berg caster shims. He was the only one I could find that knew how much angle they add. I measured the angle from level of the beam and it indicated 1.3 degrees which is what the front end machine indicated for both sides. I laid out the beam in Autocad to see how much I needed to add to get 5 degrees. The shim in place is half the thickness of the Berg shims which add 2.36 degrees each. I'll end up with 6 degrees of caster.

Mississippi only has 3 million folks; about the Size of Atlanta. I live on the Natchez Trace Parkway. 50mph except October when the guvment runs out of money. Then it's a little faster. We have nice country roads with little traffic. I'll find some place to run it out.

Thanks for all your help. I really appreciate it.

If the bottom side plate studs are original (which they should be, as there's not reason to take them out or replace them normally, even during a trans rebuild) they should wind out after being double nutted. You'd think that the camber compensator kit would come with the longer studs, but check. Get the camber adjusters as well when you order the camber compensator; I've never run a car with negative front camber, but I know people who have and they all say it's worth doing. Again, if you're serious about the car handling it's best, adding weight to the front end is also worth doing. 40 pounds changes the front-rear weight bias by over 2%. Remember to add the weight before setting ride height and alignment.

PS- I'm not surprised that the crew over at GBE know exactly how much the caster changes when using their shims. Now if some of the other parts houses put that much effort into it... 

Jim Gilbert - Madison, Mississippi posted:

ALB & Gordon,

It looks like I didn't finish my last post.

I do not have a compensator installed yet. I intended to do that over the winter. The bottom studs on my transmission are too short and will have to be replaced in order to mount the compensator. I hope the existing ones are not put in with Locktite.

The CB Performance compensator is what I'll use.

Ordered The Gene Berg caster shims. He was the only one I could find that knew how much angle they add. I measured the angle from level of the beam and it indicated 1.3 degrees which is what the front end machine indicated for both sides. I laid out the beam in Autocad to see how much I needed to add to get 5 degrees. The shim in place is half the thickness of the Berg shims which add 2.36 degrees each. I'll end up with 6 degrees of caster.

Mississippi only has 3 million folks; about the Size of Atlanta. I live on the Natchez Trace Parkway. 50mph except October when the guvment runs out of money. Then it's a little faster. We have nice country roads with little traffic. I'll find some place to run it out.

Thanks for all your help. I really appreciate it.

@Jim Gilbert - Madison, Mississippi

When I added my CB Perf camber compensator the installation was very easy. Remove one of the nuts on the transmission stud and add that to one of the other studs and use your open end wrench to put torque on the bolt closest to the transmission. The studs come out very easy. If you haven't done that before here's a video of the process. The technique in the video is a little different in the sense you won't need that much leverage but you just add a second nut to the stud and remove the nut closest to the transmission and the stud should come out easily.

https://youtu.be/OwtKVq355ns

The new longer studs I used had a torx head on them and I installed them with a torx head socket and some Loctite. Very easy.

@Robert M said- "...The new longer studs I used had a torx head on them and I installed them with a torx head socket and some Loctite..."

Did the longer studs come with the camber compensator or did you have to source them yourself?

PS- if you do get around to adding front end weight, it would be interesting to note how much the addition affects the ride height.

ALB posted:

@Robert M said- "...The new longer studs I used had a torx head on them and I installed them with a torx head socket and some Loctite..."

Did the longer studs come with the camber compensator or did you have to source them yourself?

PS- if you do get around to adding front end weight, it would be interesting to note how much the addition affects the ride height.

I asked about them and the guy at the counter gave them to me at no charge. If I didn't ask I don't think they would have been included which is a shame because you need them.

PS - When I had my new transmission put in it had the heavy duty side plate and the cc had to be modified to fit.

PPS - And they may have been an allen head on the stud or a torx. I don't recall anymore. But it was still easy. LOL

Thanks for the heads up, Robert. My car has irs, but the info is valuable to other people.

UPDATE!

The shims arrived afternoon, yesterday. I installed then in about 10 minutes (the car was already on jacks).

HUGH improvement!

Why would any manufacturer send out one of these cars without being properly shimmed? The cars are DANGEROUS without this simple modification. My car had 11,400 miles when I took delivery. The owner must have been brave.

Caster measured 1.3 degrees before installing the shims. Specifications for the VW in 1964 was 2 degrees +- 30minutes. Porsche spec for the Speedster is 5 degrees. After installing the shims I'm at 6 degrees.

Now to install the camber compensator on the rear and I should be set.

As for adding weight; I'd guess that would be the missing spare tire. The CMC Speedster I built back in the 80's had room for the spare and the battery up front. The JPS does not seem to have as much room as I remember.

Thanks to all for your help.

Jim,

I got a 3" spun aluminum (front) drag racing rim, and put a space-saver spare on it. That'll fit up there (and leave some room for luggage), no matter what you've got. 

Glad to hear the rest of it worked out.