1. Nullzwei

    Nullzwei Newbie

    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.
  2. 'bant

    'bant Loyal Comrade

    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.
    Last edited: Sep 7, 2015
  3. Nullzwei

    Nullzwei Newbie

    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/volkswa..._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 .

    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.
  4. 'bant

    'bant Loyal Comrade

    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


    Oh and make sure you check the lap times at the end of the video :)
  5. Nullzwei

    Nullzwei Newbie

    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/n...els-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).

  6. mati0921

    mati0921 Loyal Comrade

    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. :)
  7. RHFabrications

    RHFabrications Loyal Comrade

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

    Nullzwei Newbie

    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-...1::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.
  9. Austinpowers

    Austinpowers Loyal Comrade

    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.
  10. Nullzwei

    Nullzwei Newbie

    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.
  11. Nullzwei

    Nullzwei Newbie

    Austin,

    Front sway bar - scroll down to the bottom of the second post by "fierosound" to see how this guy fitted a bar to the bottom of the front subframe of a Pontiac Fiero (also FWD) http://www.fiero.nl/forum/Forum3/HTML/000077.html, the same thing would work on a Trabant, the trick is finding a bar that would fit, but the Addco guys (http://www.addco.net/aftermarket/catalog/) have such a range there must be something that could be adapted, just would have to get dimensions from them.
  12. Austinpowers

    Austinpowers Loyal Comrade

    Thanks for the info Nullzwei, I will have a look at what's available here in the UK that I can adapt.
  13. Nullzwei

    Nullzwei Newbie

    Austin,

    You might want to consider Summit Racing over on this side of the ocean, as you can see they have literally thousands of sway bar mounting bits so finding what you need to mount the things would be a snap. They also sell the Addco line (I don't have stock in the company, but I do have their bars in a street car) and have generic coil-overs (though I haven't run the dollars to Euros to Pounds conversion to see if they would be any cheaper). http://www.summitracing.com/search/...g-bushings?SortBy=Default&SortOrder=Ascending

    Anyway, they are totally reputable, and everything is right there, SAE & Metric (no Whitworth). I have been dealing with them for years, I doubt the shipping would be that horrible on the small hardware if you could source the bar(s) over there.
  14. Austinpowers

    Austinpowers Loyal Comrade

    Thanks once again for that. I have heard of summit racing before, probably from watching episodes of road kill on YouTube.
  15. Nullzwei

    Nullzwei Newbie

    No worries, it is an interesting topic to research, but it looks size wise like the best fit would be something off an original Mini.

    Over here there are a few tuner stores (e.g., minimania.com) who are selling everything you could want including complete sway bar and coil over sets (not exactly easy on the wallet, though). I would be amazed if there aren't similar stores over in your neck of the woods seeing as how sparse original Minis are over here.
  16. 'bant

    'bant Loyal Comrade

    I remembered recently he old Minis came out of the factory with positive camber on the rear swing arms. The Trabant and Mini share the basic same suspension layout, albeit implemented in very different ways. I never had any problems with the way that my Mini handled. It was by far and away the most predictable and at the same time responsive car I have owned. Now I am running (winter) radials on my Trabant (instead of original crossply tyres) it handles at least as well as my old Mini did.
  17. Wartburg353W

    Wartburg353W Loyal Comrade

    The rear wheel isn't lifting off the ground because of the camber. And I don't see how changing the camber would make it not lift off the ground. I'm not sure a sway bar would make much difference either.
  18. Guys !!!!!
    What's with you all ? Take it from me, a fully qualified Vehicle Technician who's been in Vehicle Development for blooming years.... the condition you are discussing is NEGATIVE CAMBER . It is NOT positive camber !
    When the wheels are turning inwards at the bottom, that is NEGATIVE. When they are wider at the bottom, that is POSITIVE. Simples !
  19. You are quite correct. The inside rear wheel leaving the ground is due to the outside front wheel suspension compressing. It also makes the front wheel's suspension alter it's angle of attack too. If you want more grip, you got a long thorny road to travel. 'Sway bars' or the British equivalent, 'anti-roll bars', only cause less lean angle, not more grip (unless the tyre is no longer spreading it's tread on the road fully). They make both wheels thus connected affect each other, not always to the benefit of roadability, often just to sate the uninitiated dumb motorist's belief that firm suspension is somehow 'better', which is utter b*ll*cks. You only need look at properly designed road cars, which never ever fit them. Most Lotus' have none for example. The list isn't very long as most cars on the road are plain bl**dy awful when you look into their design. Few of us ever push a car anywhere near it's actual limits, only to our own limits, thus we tend to believe the sales hype heaped upon our hapless heads. The Trabbie was extensively developed and for what it is, for what it was designed to do and for the environment within which it was going to operate in, it is pretty nearly perfect. It is not the same environment it occupies now though. The best thing one can do for a Trabbie is to use fully synthetic two-stroke oil and simply enjoy it for what it is. I only ever do one mod to mine, which is to fit an ignition-switched current via a relay to a solenoid fuel tap. It stops the need to turn taps on and off whenever you go anywhere and prevents the inevitable leaking tap letting fuel fill the bottom of the engine when left, causing the seals to blow out and result in a rebuild. Even the old 'points' ignition is OK if kept an eye on, plus it's more interesting and original if it was built with it.
  20. RHFabrications

    RHFabrications Loyal Comrade


    That's not how I understand it.

    https://www.google.co.uk/#q=negative camber

    https://www.google.co.uk/#q=positive camber

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