I’ve been having this issue since the Alfa 33 but with more cars and I’m wondering how to minimize or stop the 3 wheeled madness, the cars I own that do are: 67 Stingray, 66 Nova, 63 Beetle, Alfa 33,
Renault 5, Datsun/Nissan 510 and others I can’t remember; But how should I try to fix this?
(I’ll be checking this later)
In a word, its too much anti roll bars. ARBs limit the amount of travel opposite of the compressed side meaning the opposite corner cant extend as far.
Edit: I should probably add more to this because there’s quite a bit to it. The balance between the front and rear also matters because having one set high and one set low can create a twisting effect.
Example: Setting a rear ARB very high and a front ARB very low will make the inside rear tire lift… desirable on some FWD cars for oversteer, but not on RWD cars. Flip the two values around and the front inside tire will lift.
Best method of fixing would be to choose which is the correct one first. If the front feels good in corners, keep that one. If the rear feels better, keep that one.
Then do the following calculation
Notes :weight balance = % of the BAD end of the car as decimal. (ex: if weight balance is 52% but you need to fix the rear ARB it is 48%)
weight balance * 2 = X
GoodARB * X = New Bad ARB value.
Hopefully that’s not too confusing, but it will definitely fix the three wheels issue.
All in the tuning man. Also some cars are more prone to it than others.
Stiffen suspension and stiffen the ARBs pretty much, had same issue as u before.
Post 2 and 4 are saying opposite things. I wonder which is correct. I will see if I can find a car that misbehaves and test it.
Basically, to simplify what post 2 said (if I understand him correctly), look at the weight distribution of the car. He’s given a fairly common one for front-engined cars: 52% front.
The heavier end requires more ARB stiffness, in this case about 2%. Makes sense to me?
What about their opening line - too much anti roll bars suggesting reducing ARBs is the answer (obviously at one end). Post 4 says stiffen everything.
True, but post 2 sounds more knowlegable. His processs also makes more sense to me- to simply stiffen everything ignores the car’s initial balance, no?
Every tuning setting of the car is related to every other setting in one way or another because they ultimately control the same thing, the mass of the car. If one wheel is lifting then you have too much weight being transferred to the diagonal wheel. If your left rear lifts then you have too much weight being transferred to the right front. In this situation, you can stiffen the front sway or soften the rear or a combination of the two but this is not the only solution by any means.
Different settings control the mass of the veichle in different situations or stages of acceleration. Shock compression comes into play during braking, turning in and acceleration. When you brake you are transferring weight to the front and compressing the shock. When you turn into a corner you are transferring weight to the outside of the car and compressing the outside shocks, front and rear. When you are accelerating, you are transferring weight to the rear and compressing those shocks.
The stiffer the compression setting, the lower amount of weight will be transferred to that side I.e. the force will travel the path of least resistance and “fall” onto the softer shock. If your car is under steering going into a corner, one thing you can do is soften the front compression to transfer more weight to the front, providing more grip in the front of the car.
If you are having trouble with the rear end not getting traction under acceleration you can soften the rear compression setting to allow more weight to transfer to the rear.
Keep in mind that these settings will affect how the car reacts under all circumstances and may have unintended consequences. Lets say you soften up the rear to get better drive off the corner, you could find yourself sideways at 150mph heading towards the outside wall because that bump in the middle of the corner that you didn’t pay much attention to earlier has now bottomed out your suspension travel essentially providing no compliance in the suspension, overloading the tires and causing loss of traction.
This is just one example of the dynamic art of tuning trying to give a glimpse of how every setting affects everything else. There are multiple remedies for that situation and it depends on how the car is behaving, not just in that corner but in all corners around the track and your driving style.
Keeping it simple:
Your rear stiffness is too high relative to your front stiffness.
How to fix:
Set suspension stiffness relative to the cars weight distribution. Example: 55% front mass distribution means the front wheels are carrying 55% of the cars weight at rest. Converted to ratio terms it is 55:45 which is equal to 1.22:1. This means that your front suspension stiffness should be about 1.22 times higher than your rear stiffness.
Anti roll bar settings are usually adjusted to set up the balance of the car for cornering. As others have already said, having a very stiff roll bar at one and and a very soft roll bar at the other can cause a twisting effect, which may cause the inside tyre at the stiff end to lift off the ground when cornering. To stop this from happening simply adjust the ratio of the roll bars front:rear closer to 1:1 until the wheel no longer lifts off the ground. The best way to go about this is to decide which end of the car you are happy with and adjust the other end, then when you find a nice balance you can keep the ratio the same but make the ARB system as a whole stiffer/softer.