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Toe out in turns exploration


Tony
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Toe out, at the front at least, should be in the forum swear filter.

No mate Toe-out-on-Turns.... this

 

post-2-1158606482_thumb.jpg

 

Not Toe out.

 

I want to develop a method to increase the inner lock by another 2 or 3 degrees, this evolution is for the Drift racers.

 

Most cars nowadays use the tie/track rod end as the expedient

post-2-1158607021_thumb.jpg

 

I have two main options

1:Increase the bend in the tie rod

2:Move the steering rack location

 

Number 2 involves much more work since the column will also need to be moved.

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Obviously my blind hatrid of toe out overtook :D

 

Moving the steering rack would be a tough job, i know in my mr2 and civic there's not that much room for new mounting points.

I agree... So logic points toward the initial design, the track rod curvature... In the old days with the hot rod and oval regime i simply bent the steering arm :D with good results i might add :D but obviously i need a more professional method..... To add insult in my wannabe design i want the curvature to be adjustable :D :D

 

I know that some major players in Drift have accelerated TOOT, but this involves much modification... my approach is as rewarding but much cheaper so would envelope a wider audience, especially if the curvature is adjustable (A first to my knowledge)

 

My head is in angry mode... i know what i want, i know how this would help the sport, but i am dammed if i know how to construct such a beast?

 

Oh well another paper in the wim 'to do' pile :unsure:

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not sure of its exact name but the part of the hub where the track rod end goes into, what if you were to change the angle of this part, would tht change anything?

 

26016324872.jpg

 

 

this bit

Yes it would but the adjustment would be permanent, i want this development to be adjustable for a few reasons. One reason is for testing so extended exploration, another reason is so the TOOT can be adjusted according to the Drift track/driver requirements.

 

Compounded in this development are other concerns that need to be addressed. As we know the steering arm and wishbone need to follow the same radii during suspension compression and release, this radii also needs to me maintained on a lock, i am not entirely sure i can test or manufacture this with my current equipment, nevertheless i will pursue the possibility.

Have a look at this example of the radii

 

post-2-1158741832_thumb.jpg

 

We can can see the two pivotal points, in straight line travel the compression/release is easy to image, once the TOOT is activated then i need to measure the Delta-curve probably with a pull down and to be absolute with corner weighting... This type of equipment would be available in future wim but i need to act on this now

to encompass next years season.

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Correct me if i'm wrong, but if you could move the outer end of the steering arm up or down then this would achive the objective, albeit the radii may not be perfect?

 

Steeda in America do a device, the details of which escape me at the moment, that effectively allows this to be done. Its prime purpose as sold is to reduce the effects of bumpsteer on very low cars, but may be able to achieve your objective?

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Correct me if i'm wrong, but if you could move the outer end of the steering arm up or down then this would achive the objective, albeit the radii may not be perfect?

 

Steeda in America do a device, the details of which escape me at the moment, that effectively allows this to be done. Its prime purpose as sold is to reduce the effects of bumpsteer on very low cars, but may be able to achieve your objective?

Moving the end would only involve bump-steer. Although i need to encompass this into the development, my main concern is the evolution of the TOOT.... So Roger you are not wrong... stop doubting your abilities :rolleyes:

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Just so i can get this clear in my mind, if you were to take the move the rack route, in which plane would you move it? Fore/aft?

 

Im struggling to see how bending the arm (track rod?) changes anything. If the pivot points are still in the same place, surely the geo stays the same?

The route depends on the initial position.. in front or behind the wheel centre.

The bent steering arm is difficult to image since it's so foreign to our daily examples... If the arm is bent and the toe recovered then no noticeable difference. If the bend in the arm supports the curvature of the track rod end then as the arm is reduced (turn in, inner wheel) then this will excellerate the TOOT since the pivotal points are drastically displaced..... a simple case of moving knuckles.

 

My example is an extension of the manufactured method albeit they confine the reaction to the TRE or hub. Look again

post-2-1158782430_thumb.jpg

That bend suggests a progressive delta-curve. I want to expand that curve and the magic for modification is on that bend!

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I think im with you.

 

2 questions that would clarify it for me.

 

My orginal question, moving the rack fore / aft would achive the objective?

 

If you could move the ball joint on the track rod fore and aft on the steering arm this too would work, ie adjustable? (leaving the practicalities aside)

 

Put another way, its the relationship between the pivot point at the rack and the ball joint at the steering arm in a fore/aft plane . the further "out of line" these 2 piints are the greater the TOOT. (if done in the right direction of course) I could do a sketch on paper, but we can't do that here

 

The bend itself is merely a means of achieving the objective of altering the relationship?

 

 

 

One more!

 

Is this going to work on a conventional set up? Ie not the one you have shown with the double ball joint arrangement at the bottom of the strut.

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I think im with you.

 

2 questions that would clarify it for me.

 

My orginal question, moving the rack fore / aft would achive the objective?

 

If you could move the ball joint on the track rod fore and aft on the steering arm this too would work, ie adjustable? (leaving the practicalities aside)

 

Put another way, its the relationship between the pivot point at the rack and the ball joint at the steering arm in a fore/aft plane . the further "out of line" these 2 piints are the greater the TOOT. (if done in the right direction of course) I could do a sketch on paper, but we can't do that here

 

The bend itself is merely a means of achieving the objective of altering the relationship?

 

 

 

One more!

 

Is this going to work on a conventional set up? Ie not the one you have shown with the double ball joint arrangement at the bottom of the strut.

 

Moving the rack would change the TOOT but the column is an issue. Moving the track rod fore/aft?... I'm not sure.... possibly i will need to think on that idea.

 

The method is dependant on design... most cars nowadays use the TRE for TOOT activation... cars that use the hub with an off-set catchment for the TRE could not play a part in this evolution.

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If moving the rack, practical difficulties aside, achieves the aim, then my idea of moving the track rod must surely work? I feel a design forming!

 

"cars that use the hub with an off-set catchment for the TRE could not play a part in this evolution "

 

Not sure i understand that. Would the idea work on a conventional McPherson strut set up with single lower ball joint?

 

Having thought about it further, i still don't see how altering the bend in the example you posted changes the TOOT. One end or the other of the track rod has to have its position altered. Shame, because i feel that making such a device could be achieved.

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If moving the rack, practical difficulties aside, achieves the aim, then my idea of moving the track rod must surely work? I feel a design forming!

 

"cars that use the hub with an off-set catchment for the TRE could not play a part in this evolution "

 

Not sure i understand that. Would the idea work on a conventional McPherson strut set up with single lower ball joint?

 

Having thought about it further, i still don't see how altering the bend in the example you posted changes the TOOT. One end or the other of the track rod has to have its position altered. Shame, because i feel that making such a device could be achieved.

The steering rack position and the direction of the TRE curvature determines the TOOT, as the steering arm is retracted on the inner wheel then the curvature generates a disparity in the pivotal point, whereas the extension outer wheel is belayed most of the disparity.

I am disinterested on the suspension construction only the steering construction, if the steering configuration supports the design suggested then i feel manipulation of the curvature welcomes some consideration.

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a replacment hub with the bit i pointed out before not there but a socket instead to take 'arms' with different angles , expensive but not permanant you would be restricted to maybe 4 or 5 different angles but once he hub is fitted it can stay there and then you just change the part between the hub and t/r/e depending on needs.

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a replacment hub with the bit i pointed out before not there but a socket instead to take 'arms' with different angles , expensive but not permanant you would be restricted to maybe 4 or 5 different angles but once he hub is fitted it can stay there and then you just change the part between the hub and t/r/e depending on needs.

 

Interesting, maybe i have not explained my market to you correctly.... FWD tends to use a hub castings arm to accelerate the TOOT. RWD uses the TRE, my intended market is Drifting so prodominatly RWD.

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The steering rack position and the direction of the TRE curvature determines the TOOT, as the steering arm is retracted on the inner wheel then the curvature generates a disparity in the pivotal point, whereas the extension outer wheel is belayed most of the disparity.

I am disinterested on the suspension construction only the steering construction, if the steering configuration supports the design suggested then i feel manipulation of the curvature welcomes some consideration.

 

STOP! What do we mean by TRE curvature? Are we talking its physical shape, or its travel (arc?)?

 

A curve in the arm will make no difference. You can put as many curves as you like in a bar between 2 points, but the arc that it strikes will be the same, dictated by the pivot point at each end.

 

Are we talking cross purposes?

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The steering rack position and the direction of the TRE curvature determines the TOOT, as the steering arm is retracted on the inner wheel then the curvature generates a disparity in the pivotal point, whereas the extension outer wheel is belayed most of the disparity.

I am disinterested on the suspension construction only the steering construction, if the steering configuration supports the design suggested then i feel manipulation of the curvature welcomes some consideration.

 

STOP! What do we mean by TRE curvature? Are we talking its physical shape, or its travel (arc?)?

 

A curve in the arm will make no difference. You can put as many curves as you like in a bar between 2 points, but the arc that it strikes will be the same, dictated by the pivot point at each end.

 

Are we talking cross purposes?

The steering track rods are parallel to the longitudinal axis of the vehicle, and that they remain parallel during a turn, the same thing happens to the wheels, which are unable to take on the necessary toe-out position,

 

The toe-out on the turn can only be achieved if the two steering track rods form an asymmetrical parallelogram with the other track rods, which means that the steering track rods converge towards the rear part of the vehicle,

 

In the asymmetric steering parallelogram, when a turn is made, the steering rods follow two arcs of different circumferences, this condition that links the steering geometry of the front wheels (directional) to the position of the rear wheels (non directional), in order to avoid sideways drag occurring on the rear wheels, it that extension of the axis passing through the steering track rods meet at the exact centre of the rear axis,

 

The angle taken by the steering track rods thus becomes a function of the track and wheel base of the vehicle and consequently the ratio of the track rods must be equal to their length.

I am talking about accelerating the circumference of the arc.... Your idea for moving the TRE, any thoughts on how this could be achieved?

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