The VetteMOD project

[mrvette]

The twisting force on the frame is quite a bit less on a manual steering gear vs. a servo assisted gear (Jeep).



.

Why is that?? the lateral motion of the knuckles still takes X force to turn the wheels applied at the end of the pittman, why should the actuation force at the steering wheel make any difference to the twist on the rail???

isn't 99% of it from the lateral 'stiffness/drag' on the link???:huh2:

 

[Yellow73SB]

Damn, it's been more than a month since I promised to do this. I have finally mocked up my Jeep steering gear. I hit kind of a snag with the 73-up A-body pitman arm. It seems that no one is really restoring these later Chevelles and so there is really no call for the pitman arms (making them very difficult to find).

I have changed my design to use the 68-72 PS A-body arm which is available and actually being reproduced.

For more information on this project, go to:

http://www.vettemod.com/forum/showthread.php?t=1098

What did you change in the design from the 68-72 and the 73 and up

 

[BBShark]

Damn, it's been more than a month since I promised to do this. I have finally mocked up my Jeep steering gear. I hit kind of a snag with the 73-up A-body pitman arm. It seems that no one is really restoring these later Chevelles and so there is really no call for the pitman arms (making them very difficult to find).

I have changed my design to use the 68-72 PS A-body arm which is available and actually being reproduced.

For more information on this project, go to:

http://www.vettemod.com/forum/showthread.php?t=1098

What did you change in the design from the 68-72 and the 73 and up

I went back to the 73 pitman when I found a source for them. Also the 68-72 needs to be machined for the ball stud and the 73 is a bolt-on.

 

[BBShark]

The twisting force on the frame is quite a bit less on a manual steering gear vs. a servo assisted gear (Jeep).



.

Why is that?? the lateral motion of the knuckles still takes X force to turn the wheels applied at the end of the pittman, why should the actuation force at the steering wheel make any difference to the twist on the rail???

isn't 99% of it from the lateral 'stiffness/drag' on the link???:huh2:

The highest twisting force is when you are trying to turn the wheel while stationary or very slow speeds. The force is dependant on how fast you try to turn the steering wheel. Manually you are limited by your own strength through a 16:1 ratio. With a servo assist on the gear, there really is no limit.

 

[mrvette]

The twisting force on the frame is quite a bit less on a manual steering gear vs. a servo assisted gear (Jeep).



.

Why is that?? the lateral motion of the knuckles still takes X force to turn the wheels applied at the end of the pittman, why should the actuation force at the steering wheel make any difference to the twist on the rail???

isn't 99% of it from the lateral 'stiffness/drag' on the link???:huh2:

The highest twisting force is when you are trying to turn the wheel while stationary or very slow speeds. The force is dependant on how fast you try to turn the steering wheel. Manually you are limited by your own strength through a 16:1 ratio. With a servo assist on the gear, there really is no limit.

Could say the same thing for a rack then also...same force, essentially coming from same spots, and it's a 12-1 ratio...so quicker even under assist, the frame takes even a further twist...for any given steering input....

been so long since I have looked at that, I wonder what releasing the cross support on the A arms would do for that flex issue???

:clobbered: