Am I correct that the "passanger side" is based not only on the direction of the rotation of the engine but also on whether the car is LHD or RHD. If so what happens with the "mono posto" chassis? Which is the preferred short side at Indy [all left turns] or the typical road course with more right hand turns?. Finally how then did they set up for 14.7 miles of the Ring or 45 + or - miles of the Targa Florio?. Finally do we know who came up with this theory? There must have been a real effort to keep it secret. just one man's opinion tongascrew
The WW2 German Tiger Tank had one more link on the right track than the left. My thought is that it made sense on that because of the torsion bar suspension, but not on a vintage Ferrari.
We have 5 Prototypes from the 60ies all assembled by different people before we bought them including one that came directly from the factory (Dino Competizione) and before we worked on them we carefull measured them and their suspention settings. All were and continue to be set up with wheel base stagger. It makes sense on any car with torque steer especially vintage prototypes with flexable chassis.
OK. I believe you, but - It just seems somehow so mechanically wrong to me --- I am assuming that you mean it was done by offsetting the rear axle lineup and thus building in a slight steer effect? That is, not just making the wheelbase a little different, but putting in a static steer component? BTW, did you ever find any documentation on this other than discovering it yourself?
Think of a high power race boat like my 1983 38 Cigarette, no suspension but subject to torque steer. To counteract it you increase opposite side water line (similar to wheelbase) by adding trim tab to one side slightly more than to other. Same as your tank with extra link making a longer one side "wheelbase" that counters torque steer enabling you to drive straight easier.
There was a Renault model where one side's wheelbase was significantly longer....maybe a couple inches, IIRC. I attributed it to the quirky French; was there some valid engineering reason, I wonder now?
Going to try to explain it as easy as I can. A lot depends on weight distribution (what side the drivers on, front/front mid/rear mid/rear engine) ect, which direction the engine turns and weather it's longitudinally or horizontally mounted and which way the final drive turns. Best example is a Chevy (Vette Camaro all the same), front mounted left hand drive (US) engine turns clockwise from the drivers perspective, as does the final drive. Inherently the right rear wheel will get more torque than the left rear because the engine is mounted to the chassis and you have torque feedback from both the engine and rear suspension. So in this case you shorten the wheel base on the passengers side slightly so the car tracks straighter upon acceleration. Take a shoe box push one side slightly harder with your right hand than your left hand, it doesn't track straight, now add length which increases resistance on the right side and it tracks straighter when you push it. Sorry that's the best I can explain it, not a physicist so it's hard to explain. And yes it depends on chassis flex ect... Full frame vehicle especially a ladder frame car will have more flex than a unibody.
makes sense, i've always heard either they were strong frames, or weak chassis.....but if chassis flex is significant, then makes sense to counter it interesting that all you vintage cars have exhibited this WB stagger in design probably the lecar you're thinking of....it did, but wasn't handling, it was cheap and easy solution to house the suspension, using the same set-up on each side.....there wasn't anything 'performance' about that particular car LOL (my ex had one)
I see how this would work on a boat - (waterline asymmetry) because of the great amount of water drag. What I don't see is how just a half an inch of wheelbase could make any difference UNLESS IT AFFECTED THE LONGITUDINAL PATH ALIGNMENT OF THE WHEELS. Instinct would tell me that a car would not be "steered" to any significant amount by just a half inch more wheelbase on one side - IF all four wheels were still pointed directly in alignment with the direction of travel. Somebody straighten me out if I am totally off base here... Incidentally, what I read about the Tiger Tank was that it had big torsion bars that ran all the way across the belly of the tank. Because of the way they were laid down, the road wheels on one side had a longer wheelbase, so they made up for it by putting in the extra link. That thing was way too heavy to have any carlike torque steer - even with 12.5 litres. But it did have a distributed torque steering mechanism, so something like what Napolis says may have been necessary for that. Fascinating topic, Napolis.
Shorter rt side wheel base would definetely make rt turn in easier and as race courses have more rt turns than Lt turns that may be part of the reason. Our drag racing friend, the MB tech, the Tauris example all show that others have used different side to side WB to counter torque steer.
Yes, I had overlooked that factor. This does make sense in that context. (I was thinking in terms of going in a straight line) Still thinking about this - it may be a subject for some weekend research.
Having spent sevetral decades with boats both power and sail, with boats it is the rotation of the prop in the water that really effects the steering. The easy way to show this is to put the right turning prop engine in reverse. With the driver facing aft the boat with automaticly turn left and it is almost imposible to make it turn right. Another example is the always prefered bow in portside docking.When the bow is drifting close to the correct position the driver puts the engine in reverse and reves it up which pushes the aft end in towards the dock and stops the boat parallel to the dock. This has nothing to do with the torque but completely with the direction and power put to the prop. Comparing boats to cars really is not a good one.Off subject I know. Sorry just one man's opinion tongascrew
I have never heard of the "stagger" when dealing w/ 1950s cars; but could that be because the small tire patch size and poor adhesion characteristics of 1950s tires would have made no difference in overcoming the physics of torque-steer, even if one did set up the suspension w/ stagger?
The same reason as the Tiger tank that James mentioned, transverse torsion bar suspension in the back, the bars ran the full width of the car, so one side had to be in front of the other side.
How does the tendency of the LF wheel wanting to lift on acceleration figure into this? Is this the torque steer referred to here? I still do not understand why a shorter WB on one side would effect straight line driving if both wheels are pointed straight.
If a rear wheel wants to move to off of the centerline due to torque steer it puts a rotating force through the length of the chassis onto the front wheel in the opposite direction. The longer the wheelbase the longer the lever of the chassis the shorter the shorter the lever. Staggering the wheelbase balances torque steer.
Now I get it. Thanks I love this section of the forum, there is hardly a day I view it that I don't learn something.
Unlike a car which sends its power to wheels which are in contact with pavement [ low resistance], the prop on a boat is surrounded by water which has considerable resistance. It is the force [torque if you will] of the prop to overcome the resistance of the water that effects how the boat handles not the torque thru the drivetrain from the engine that appears to effect how a car's chassis reacts.If I am correct twin engine race boats are set up with the two props, not engines, turning in opposite directions. Another way to explain the difference is that with a boat the effect of the prop rotation starts to take effect from the time it is engaged regardles of the power or RPMs employed. It appears the car chassis issues, so well explined here, don't take effect until high power and speed is employed. It would be interesting to get the opinions of the top fuel dragster people partiularly the "funnycar" builders to see how they handle the problem. The torque forces there on a chassis with a wide track has got to be the ultimate challange. At least these cars don't have to change direction. Hope this has been helpful tongascrew
Nope. My high powered Cigarette race boat engines aren't counter rotating and require asymmetric trim to keep straight due to torque steer. We've already heard from a drag racer who confirms wheelbase stagger.
Torque steer is the tendency for the vehicle to turn in one direction or the other when power is applied. Both boats and most common drag cars aren't relevant to the conversation and here's why. In drag cars torque steer is associated with live axles and limited slip or locking differentials. The difference in rear wheel forces in these cars comes from the driveshaft torque that is applied to the axle. This torque is reacted across the rear track width and results in one rear tire having much vertical force than the other. With a locked or limited slip differential the wheel with more vertical force will put down more tractive force and the car will steer away from that wheel. Torque steer is common in cars like this, but the cars we are talking about here dont have an open driveshaft, so any discussion of drag cars, unless they have torque tubes or the engine is bolted directly to the rear axle arent relevant. Similarly boats arent relevant since propellers act on the water to roll the hull to one side, which causes the boat to steer to one side due to hull drag. Again, thats not relevant because it is in no way related to the torque steer in a car. Both of these vehicles have torque steer, but that isn't related to the torque steer that occurs in cars that have a transaxle that is bolted to the frame and an engine bolted to the transaxle.
