The range for the parallel setting should include anti-ackerman range, where the more you steer, the more toe-out you get. Here's a link to a web site with an explanation:

ackerman.html

As stated in the article you link to, and agreed with from many other sources, anti-ackerman hasn't been used in motorsport to any great effect for nigh on 50 years. It's just pointless, and you'll be much better of the a bit of static front toe-out and parallel steering.

Quote from JeffR :

The range for the parallel setting should include anti-ackerman range, where the more you steer, the more toe-out you get. Here's a link to a web site with an explanation:

ackerman.html

I guess you mean more toe-out on the outside tyre?

Sure, easy enough to implement I guess. Just allow setting parrallel steer above 100%. But I have to ask, in what situation do you need the inside wheel to cover a larger radius than the outside one?

Quote from JeffR :

The range for the parallel setting should include anti-ackerman range, where the more you steer, the more toe-out you get. Here's a link to a web site with an explanation:

ackerman.html

If as tristan said it has not been used in 50 years then why would someone put it into a game? Unless we get cars from the 1940's era.

Quote from Gentlefoot :

But I have to ask, in what situation do you need the inside wheel to cover a larger radius than the outside one?

doriftooo
i doubt anybody would use it as normal ackerman gives you more lock overall

Quote from Gentlefoot :

I guess you mean more toe-out on the outside tyre?

Isn't that still normal ackerman? Anti-ackerman would be adding toe-in, and thus making the car more stable, but slower on both the straights, and especially on the corners.

I guess the bump steer setting could also be used to accomplish the same thing. As the outside of the car lowers, and the inside of the car rises, the bump steer settings could adjust the toe factor as needed.

I had the impression from the article, that anti-ackerman might help with certain restricted classes of cars.

Ackerman is more toe-in on the outside wheel afaik. 0 ackerman is 100% parallel. Anti-ackerman, as I understand would be negative value.

That said, I believe ackerman is only used on road cars where it offers actual benefits at low speeds. At racing speeds it's not that useful and I read somewhere it is not used.

I've read they don't use it in most real racing due to extra complexity, weight, and possibly less strength. They make do with some static toe-out.

How for typically tighter courses, especially autocross, it becomes essential.

Here is another link to the Ackerman Principle: http://www.rctek.com/handling/ ... n_steering_principle.html

Essentially (IMO!), the Principle means that the more Ackerman angle you have, the more dynamic toe-out is created on the inside wheel only, hence having the effect of "pulling" the car towards the corner (just as static toe-out would affect the inside wheel). It doesn't affect the outer wheel, besides why would you want toe-out on the outer wheel :S Maybe toe-in, but that one can do by turning the steering wheel more

Yes - it's simply the fact that the track width of the car means that the outside wheel has to travel further than the inside one. Therefore you could think of the outside wheel as having toe out or the inside wheel as having toe-in.

So why, and I asked in my previous post, would you ever want the outside wheel to be set up for a smaller radius than the inside wheel? I'm assuming I understand you correctly with this term 'anti-ackerman'

Quote from Gentlefoot :

So why, and I asked in my previous post, would you ever want the outside wheel to be set up for a smaller radius than the inside wheel? I'm assuming I understand you correctly with this term 'anti-ackerman'

The outside wheel has more downforce on it than the inside wheel, and the theory goes that with some tires, the outside tire can handle more slip angle than the inside tire, so the inside tire would have less slip angle than the outside tire (toe in). I found a reference to why a car might be best setup with anti-ackerman, but you have to pay for a course to get this info.

http://www.motec.com.au/topics.htm

I've read a few forum posts that open wheel race cars use anti-ackerman steering (probably high downforce cars), so maybe the FO8 or the F1 could use it, but considering the source, I don't know if it's true.

However, the article I first linked to implies that with most tires and street type cars, the maximum force slip angle may increase when the downforce is decreased, and in this case parallel or pro-ackerman steering would make sense.

I wonder if radial and bias ply based racing slicks behave differently.

Just to translate from JeffR's language to normal language in reference to his last post for those that don't speak Jeff (no offence, but it took me a while to work out what you meant with downforce, so I thought I'd clarify it for others).

Downforce (in the context used above) = Vertical Load, not aero downforce as the word implies
Bias ply = crossply

And my point: is that you don't worry so much about the inside tyre. Not only is it lightly loaded, it's going to be at the 'wrong' camber, and quite possibly in the air. Whilst there will be a gain by making that tyre work optimally, it's a VERY small gain, and I think you'd find it brings more downsides that it fixes.

Quote from JeffR :

The outside wheel has more downforce on it than the inside wheel, and the theory goes that with some tires, the outside tire can handle more slip angle than the inside tire, so the inside tire would have less slip angle than the outside tire (toe in). I found a reference to why a car might be best setup with anti-ackerman, but you have to pay for a course to get this info.

.

Interesting, so really the benefit is to do with the amount of slip angle that is ideal dependant on the level of downforce. OK there is some sense there I suppose. Very interesting. Thanks for talking my language Jeff.

Quote :

Just to translate from JeffR's language to normal language in reference to his last post for those that don't speak Jeff

Sorry USA here.

Quote :

downforce

Downforce was a bad choice of words, vertical load is correct.

Quote :

Bias ply = crossply

USA folks / tire manufacturers call them bias ply.

Quote :

You don't worry so much about the inside tyre.

Except in a high (aerodynamic) downforce car, like the F1, or possibly the FO8 (less power, so less downforce). If there will be high downforce Lemans type cars in S3, then it would affect them as well.

I think F1 uses positive-ackermann, or maybe even parallel. I don't know 100%, but I am confident that I would be right.

Parallel, probably.