Trabant Tech Forum

I have not laid a level against the tire to see how far it's off but to me, the camber looks just like any other car.

Rather than use a level, if you don't have access to a camber gauge, a better tool is a carpenter's square, assuming your garage floor is level.

The rear suspension appears as though it sits a bit lower in the rear than the front. Unless it's an optical illusion due to the quaterpanel arches.

Measure from the garage floor to the bottom of the side frame in front of the rear wheel, and behind the front. The should be about equal with the front a little lower (not surprising reflecting the 59:41 weight distribution) . The repair manual states that the distance is 155mm (6.1 inches), YMMV depending on age, whether the tires are the stock size, etc.

I know that leaf springs are bad about sagging.

With the exception of the fact that there are no half shafts, the single transverse leaf spring of the non-coil spring Trabants are very much like that of early Corvettes. Regardless, if the leaf spring is sagging, that will lower the rear end, and reduce the factory built in and totally useless positive camber.

how do the camber correction cups work/fit. Seen the rear units for sale at trabantwelt but cannot figure where and how they would fit.

They fit between the floorpan and rubber bushing on the upperside of the transverse arm of the trailing/transverse arm (this is the mounting point closest to the centerline). Because the trailing/transverse arm is a fixed unit along with the brake backing plate through which the stub axle runs, lowering the transverse arm will cause the unit to rotate around the rubber bushings at the front end of the trailing arm (the outboard bushings) which rotates the brake backing plate & stub axle along with it which decreases the positive camber.

If you look at page 87 in the Parts catalogue from the tech forum there is a good picture of the trailing/transverse arm, the camber corrections fit between bushing 5 at the right side of the picture and the floorpan, the bolt that comes with the kit replaces bolt 7. The kits fit over Part 6 shown on page 137 of the Parts catalogue which are the trailing/transverse arm mounting points.

The pictures here should give you a good idea how they fit. http://www.reich-tuning.de/en/tuning/ifa/trabant/axle-parts/camber-correction-rear-for-coil-spring-for-trabant.html The leaf spring version work the same way.

Your a legend, thanks

Thanks, Razibilla, but I'm not sure about the legend part, more of an inveterate tinkerer - my Trabant is a recent acquisition and one of the first things (after moving the driver seat rails back 5 inches) I did was start poking around on how to get rid of the positive camber which, unless you are the left front wheel on a NASCAR car, is one of the most vile handling suspensions you can have.

Driving around town or in a straight line it is no big deal, but the reality is that you are really driving around with the weight mainly on the outside half of the tire tread. If you have to make an emergency move or just get sporty you load up the wheels on the outside of the turn (e.g., the right side in a left turn), and in particular the rear wheels as the positive camber will get more positive. Of course, this is the wheel you want to have the most grip in this sort of maneuver.

With all the positive camber in a (for example) sporty left turn, what happens to the right rear is that it will actually tend to tuck under which will put you way out on the edge of the tire (which is skinny enough to start with) and overload the sidewall which, as you can imagine, might make the sporty turn more sporty than intended.

Getting the camber to neutral will tend to eliminate this problem, but a couple of degrees of negative camber is preferable. In the case we have the opposite of the above, driving in a straight line or around town you are on the inside part of the tread, but in our sporty left turn as the right rear is loaded, the negative camber becomes less negative as the wheel becomes more perpendicular to the pavement which means you actually have more tread in contact, more grip, and less chance the back of the car is going to swap ends with the front.

Not sure about this. A Trabant, like many other small FWD cars with stiff suspension (VW Golf is one) will lift the inner wheel when cornering hard. Before the inner wheel lifts most of the grip will be on the outer wheel anyway. Is a difference in camber at rest going to make that much difference the amount of grip the inner wheel contributes?

I am assuming that if you have neutral camber/slight negative camber at rest at the rear then you will remove the transition from positive to negative camber on the outside wheel as you start to turn. I think that that is what would make cornering more predictable.

The important thing is to differentiate between suspension types first. I am not familiar with all VW models and variants but Golfs and Polos have beam rear axles as do many FWD cars (I know there is a Polo GTI with an independent rear set up). With a beam rear axle,( http://workshop-manuals.com/volkswagen/golf-mk3/running_gear/rear_suspension_drive_shaft/servicing_rear_axle_(vehicles_with_front_wheel_drive)/ ) there will always be a tendency to lift the inner wheel under hard cornering because the wheels cannot move independently of one another. The Trabants, of course, have the trailing arm independent set up, so in theory, under hard cornering the unloaded inner wheel should be free to move downward to maintain contact.

With the Trabant, or any car with an independent rear suspension for that matter, the limiting factor for wheel lift is the spring rate and sway bar stiffness (if you have them). The springs on the Trabant are pretty mushy so they allow a lot of body roll that eventually exceeds the amount of downward movement of the trailing arm, and the inside wheel will lift. The fix is stiffer springs (and/or a sway bar), the trade off is a harsher ride.

This gets us back to camber - if you look at this picture http://cohoauto.com/wp-content/uploads/2015/03/wheel-alignment-camber.jpg , the picture on the left is the Trabant from the factory. In a hard left turn, the camber on the right tire will become more positive, reducing the contact patch on the loaded wheel, while the camber on the left wheel will decrease, increasing its contact patch, but its contribution to lateral grip is significantly less than the loaded wheel.

The picture on the right is how most road racing and F1 cars are set up front and rear http://cdn.bmwblog.com/wp-content/uploads/bmw_sauber_f107_1.jpg. In a hard left turn the camber on the right tire becomes more positive increasing the contact patch on the loaded wheel and so on.

A NASCAR car has a mix of all this. They have solid rear axles which function like beam axles on FWD cars, but the right front wheel will have negative camber, and the left front positive camber because as they are only turning left that increases the contact patch on both whenever the thing is turning.

Here is a great video of an 80 HP Trabant at Hockenheim that corners flat as a pancake eventually repeatedly passing an E30 BMW M3 (I am embarrassed to say), so these things can be made to handle [MEDIA=youtube]lCDJngP9Sdc[/MEDIA] .

So, bottom line, lower it a bit, stiffer springs, get the camber at least to neutral on all four corners and 50kg over the rear axle and it should handle like a go-kart - a good thing. If you have to pick an order in which to do them, camber first, then springs.

A standard Trabant will lift its inside rear wheel like other small FWD cars. It is not just a feature of cars with rear beam axles. See here
[MEDIA=youtube]lDRTjIETPww[/MEDIA]

Oh and make sure you check the lap times at the end of the video

Yes, I know they can lift the inside wheel, the point is that they don't have to, and one can either accept the quirky handling, or tweak them a bit and make them more fun (and safer) to toss about.

It is not a feature of being a small FWD car, any car will do the same thing if it is cornered hard enough. Here is a BMW 3.0 CSL, one of the most successful race cars in history, lifting a wheel: http://www.gettyimages.com/detail/news-photo/sam-posey-gets-the-inside-wheels-off-the-ground-while-news-photo/151381371. The big difference is that it is nowhere near out of control.

What causes the Trabant to lift with little provocation it is the combination of positive camber, weak springs, no sway bar, and skinny tires. If you notice in your video every time the inside wheel gets off the ground the loaded wheel is running almost on the rims because of these factors, chief of which is the absurd amount of positive camber absent the four hulking STASI aboard to make the camber go negative as the shop manual describes. By contrast, if you look at all the Trabants in the following video, not one lifts a wheel and the common theme among them is that all of them have had the camber corrected (along with other modifications).

[MEDIA=youtube]lf77O3Wm-gY[/MEDIA]

Mine is lowered 100mm on the fron and have adjustable rear coilsprings. i dont fell a significant change in handling, but i have never dared pushing it to where it lifts a wheel.
I have only tested it to the limits in the rain because i know it will slide instead of rolling over.

How does one go about adjusting the camber on the front? Is there a generally accepted 'right way' of doing it?

Adjusting the camber in the front is a little more complicated than in the rear. Trabantwelt and other people sell these parts https://www.trabantwelt.de/Trabant-Tuning/Tuning-Fahrwerk-Bremse/Sturzkorrektur-Vorderachse-Paar-12mm-Trabant-601::854.html?MODsid=3i1tng6nm0utmdfd2u63f0t6g4 which come in varying sizes.

They replace Part 15 on Page 76 in the Parts Catalogue, the outer wishbone bearing, that connects the wishbone with the bottom of the steering knuckle. A stock outer wishbone bearing looks like this: http://www.danzer-autoteile.de/Trabant-601/Vorderachse/Aeusseres-Lenkerlager::265.html and you can see it also on Page 53 of the Repair Manual.

By increasing the wishbone to the steering knuckle distance with the adjusting parts, the camber is decreased, and the track slightly increased as well.

I often amuse my work colleagues in the morning by doing a u turn in to a parking space. Apparently the back wheel lifts off the floor a good 12 inches when I do this. Mini roundabouts have similar results. I would like to fit some adjustable rear coils, but I think the ones that the trabant specialist sell are a bit pricey. So I was thinking that maybe some from a VW polo might fit? If they could be made to fit then I could pick some up quite cheap. As for the front I was toying with the idea of making up a lowering block to fit between the spring and the subframe.
I have a spare subframe to help me get the shape right for the block. Then I have to find some bolts that are long enough and strong enough to hold it together. I wonder if it would be possible to fit an anti roll bar to a trabi. It would make a big difference to how it handles.

A sway bar would be fairly straightforward in the rear, you would need to make two reinforced attachment points to the floor pan, a broad U shaped bar - the trick is guessing the thickness (I am thinking about 17 mm) - and links to connect the bar to the transverse parts of the trailing/transverse arms. This one for a BMW 2002 is probably too wide and thick, but it gives you the idea of the sort of thing you would need - the two red urethane bushings on the right are what the center of the bar passes through and which would attach to the floor pan, the limbs of the bar go through the upper part of the other links and then the botom would attach to the transverse arm. https://www.iemotorsport.com/bmw/2002-suspension-steering/02rearbar.html .

There may be something for a VW more suitable, but would likely work much the same way, regardless, you could buy the individual linkage bits and have the bar itself fabricated.

The front would be more of a challenge because everything is so compressed - maybe something like these Mini Cooper sway bars http://new.minimania.com/part/G2NMS2130/Mini-Cooper-Sway-Bar-Hr-Front-27mm-R56-Cooper-Hardtop attached to the subframe and wishbones. Come to think of it, the rears might work too.