How to make your own Variable Ackerman Steering (VAS), Variable Toe Steering(VTS) or DAS, tight corners and understeer.

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yamahasho
yamahasho
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How to make your own Variable Ackerman Steering (VAS), Variable Toe Steering(VTS) or DAS, tight corners and understeer.

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Many cars have been using variable ratio steering racks for a long time, take your pick, Honda (Civic or RS, HRV), Toyota, Mercedes, Audi etc. But take it a step further can combining all of them. Use two racks with one common steering axis input.

standard VGS steering box:
Image

Lets start with toe adjustment, my rough sketch:

Just toe adjustment:
Image

Take it further with using 2 rack and pinions with a non-ratio gear box:

Image

Now combine them:
Image

Instead of ball screws or using two steering racks. You can use a half moon shaped gears since that would have a larger pitch than a ball screw, this before or at the inner toe link connection:

Image

And you can achieve crazy ackerman angles (from an old post):
Image

Will also help understeer because inside wheel is usually too far turned, with this system, you can put less lock (anti ackerman effect) but better because anti-ackerman is set and cannot be adjusted, with this you can vary the steering angle of the inside wheel for each turn. The driver now has good geometry for the low and high speed turns and can vary as needed.

Kind of like using a 2nd brake pedal on the inside wheel to reduce understeer. Old Mclaren days.

The toe system can also do that but it's faster with the variable ratio steering and without all the bump steer issues you would get with that.

It’s the same as the Honda half gear VGS system but no longer before the main pinion, it sits at the steering rack gear toe links. So the motion is still in y-axis since the FIA has banned dual axis. And resolves the bump steer issue.

For a four wheel drive car, or 4 wheel steering car, it also works as traction control.

It does add weight but figuring a mass damper was like 10kg and so was the interlinked suspension. It's not that much.

I call it Variable Ackerman Steering (VAS) or DAS on steriods (banned). But this system should fit the FIA requirements since the steering is still on the same axis but they'll probably consider it under some catch all rule.
Supercharged Ford Taurus SHO 5spd. Sold.

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coaster
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Joined: Sat Jun 30, 2012 4:10 am

Re: How to make your own Variable Ackerman Steering (VAS), Variable Toe Steering(VTS) or DAS, tight corners and underste

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I take it the i.p is protected?
I think your idea is fantastic.

yamahasho
yamahasho
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Joined: Sat Jul 23, 2022 5:04 am
Location: USA

Re: How to make your own Variable Ackerman Steering (VAS), Variable Toe Steering(VTS) or DAS, tight corners and underste

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coaster wrote:
Wed Nov 09, 2022 3:41 am
I take it the i.p is protected?
I think your idea is fantastic.
Thank you. Not sure what you mean by i.p but I’m sure the idea needs tweaks.

I’ve been trying to figure out a driver adjustable caster angle system but haven’t gotten too far into it since it’s a difficult thing to change on the fly, along with my frictionless magnetic sealed combustion chamber engine but not much info out there.
Supercharged Ford Taurus SHO 5spd. Sold.

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chrisc90
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Joined: Wed Feb 23, 2022 8:22 pm

Re: How to make your own Variable Ackerman Steering (VAS), Variable Toe Steering(VTS) or DAS, tight corners and underste

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Intellectual property. Protected by patent
No Mikey Noo! No! Nooo Mikey! That was sooo not riiight!!

yamahasho
yamahasho
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Joined: Sat Jul 23, 2022 5:04 am
Location: USA

Re: How to make your own Variable Ackerman Steering (VAS), Variable Toe Steering(VTS) or DAS, tight corners and underste

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chrisc90 wrote:
Fri Nov 11, 2022 1:15 pm
Intellectual property. Protected by patent
Thank you, I don’t see any intellectual property here l, these are just someone putting together parts that are readily available. Now if I was to market and sell this, that might be a different story.
Supercharged Ford Taurus SHO 5spd. Sold.

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coaster
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Joined: Sat Jun 30, 2012 4:10 am

Re: How to make your own Variable Ackerman Steering (VAS), Variable Toe Steering(VTS) or DAS, tight corners and underste

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Moving a normal rack fore or aft of the ideal ackerman position could have similar effect, also tie rod length, if you only want one prescribed set of outcomes then i would just have the rack move fore or aft maybe 12mm or so, could save alot of headaches with the dual rack system.
The problem with race cars now is energy recovery systems make cars too heavy, just because all that space exists it doesnt mean we can fill it up with stuff, dual racks is another layer of complexity filling the voids.
Race cars should be light.

yamahasho
yamahasho
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Joined: Sat Jul 23, 2022 5:04 am
Location: USA

Re: How to make your own Variable Ackerman Steering (VAS), Variable Toe Steering(VTS) or DAS, tight corners and underste

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coaster wrote:
Fri Nov 11, 2022 8:44 pm
Moving a normal rack fore or aft of the ideal ackerman position could have similar effect, also tie rod length, if you only want one prescribed set of outcomes then i would just have the rack move fore or aft maybe 12mm or so, could save alot of headaches with the dual rack system.
The problem with race cars now is energy recovery systems make cars too heavy, just because all that space exists it doesnt mean we can fill it up with stuff, dual racks is another layer of complexity filling the voids.
Race cars should be light.
Agreed, I had a sketch with the rack moving forward and back but decided I wanted more adjustment for each wheel to achieve the different Ackerman angles.

An all in one rack would be great.
Supercharged Ford Taurus SHO 5spd. Sold.

Greg Locock
Greg Locock
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Joined: Fri Jun 29, 2012 11:48 pm

Re: How to make your own Variable Ackerman Steering (VAS), Variable Toe Steering(VTS) or DAS, tight corners and underste

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Please can you post a plot of what you are trying to achieve? left steer angle and right steer angle vs Steering Wheel Angle is probably the easiest?