Mustagn II alignment

[Learpilot]

My 36 Dodge is set at 4 degrees positive caster.  I have a '88 Mustang power rack. I also have the Heidts  adjustable  pressure regulator. Everything is fine until I get above 65 MPH and the steering feels too sensitive. I have adjusted the pressure up and down. I have it now where it is hard to turn while going slow.  Do I need more caster or a new rack from a T-Bird. What is the performance rack that the Auto Parts Co list ? It has about a 1/2 a turn less or quicker ratio. Would that be better or worse for high speed stability ?

THANKS for Your input !!!

[Leon]

I've got a power rack on my 54 and almost wish I had gone manual.  I'm running about the same caster, and have the valve set so it is a little stiff at parking lot speeds, but the power rack is a little quicker than a manual.  When (if) I get to the 53 delivery, I'm going manual with it, partially because of the blower drive - less room for a PS pump belt anyway.  I'll probably be happier with a manual rack.

[Learpilot]

I've got a power rack on my 54 and almost wish I had gone manual.  I'm running about the same caster, and have the valve set so it is a little stiff at parking lot speeds, but the power rack is a little quicker than a manual.  When (if) I get to the 53 delivery, I'm going manual with it, partially because of the blower drive - less room for a PS pump belt anyway.  I'll probably be happier with a manual rack.

I don't know what your front axle weight is but mine is 1600 # and a manual rack was too hard to turn at low speed. I even went to a 17" steering wheel. It was also about the same at highway speeds as the power rack.

[enjenjo]

You can try more caster, 6 degrees is not too much.

[Learpilot]

You can try more caster, 6 degrees is not too much.

That will make it more stable at highway speeds ?
Can I get that much caster with stock upper a-frames ?
I have a FATMAN crossmember.
THANKS

[enjenjo]

You can try more caster, 6 degrees is not too much.

That will make it more stable at highway speeds ?
Can I get that much caster with stock upper a-frames ?
I have a FATMAN crossmember.
THANKS

Yes it will make it more stable. you have to remember that Mustang II were designed in the era of bias tires, which are less sensitive than radials. In general, radials need less toe in, and more caster to steer good.

You can get 6 degrees with stock arms, no problem. Depending on how the hats were installed, you may have to elongate the adjustment slots, the front one out, the back one in, to get that far

[Learpilot]

You can try more caster, 6 degrees is not too much.

That will make it more stable at highway speeds ?
Can I get that much caster with stock upper a-frames ?
I have a FATMAN crossmember.
THANKS

Yes it will make it more stable. you have to remember that Mustang II were designed in the era of bias tires, which are less sensitive than radials. In general, radials need less toe in, and more caster to steer good.

You can get 6 degrees with stock arms, no problem. Depending on how the hats were installed, you may have to elongate the adjustment slots, the front one out, the back one in, to get that far

THANKS for the INFO !!!!

[papastoyss]

My 36 Dodge is set at 4 degrees positive caster.  I have a '88 Mustang power rack. I also have the Heidts  adjustable  pressure regulator. Everything is fine until I get above 65 MPH and the steering feels too sensitive. I have adjusted the pressure up and down. I have it now where it is hard to turn while going slow.  Do I need more caster or a new rack from a T-Bird. What is the performance rack that the Auto Parts Co list ? It has about a 1/2 a turn less or quicker ratio. Would that be better or worse for high speed stability ?

THANKS for Your input !!!

I don't know about your 88 Mustang rack but the 85 up T Bird rack is 3 turns lock to lock & is much less sensitive than the Mustang 2 which is 2 &1/4 turns . I've used the T Bird rack w/good results.

[Learpilot]

My 36 Dodge is set at 4 degrees positive caster.  I have a '88 Mustang power rack. I also have the Heidts  adjustable  pressure regulator. Everything is fine until I get above 65 MPH and the steering feels too sensitive. I have adjusted the pressure up and down. I have it now where it is hard to turn while going slow.  Do I need more caster or a new rack from a TA-Bird. What is the performance rack that the Auto Parts Co list ? It has about a 1/2 a turn less or quicker ratio. Would that be better or worse for high speed stability ?

I haved checked with the auto parts stores and they list a 88 T-bird and a Mustang as having the same rack.
Friday I was in Phenix AZ and went to Arizona Street Rods and asked them if they had run into this problem. They had and they said that the Heidts pressure regulator is not the way to go. They said to use a set of shims in the flow valve. I got a Mullins 899001 power steering flow valve kit for $18.00. They said that 4 degrees positive caster is what they use in there  M II front ends. They said that the heidts regulator will starve the pump and rack when turned to lower pressure because it dumps fluid back to the reservor causing too much heat.
The Mullins will just lower pressure.
When I get back home I am going to put the Mullins shims in and see if my steering is better

[Leon]

The shims cause the excess pressure to dump the fluid back into the reservoir also, it just does it closer to the pump.

[enjenjo]

I haved checked with the auto parts stores and they list a 88 T-bird and a Mustang as having the same rack.

You are correct. The standard rack for a Mustang, is the "sport" rack for a Tbird. The standard rack for a Tbird is slower.

[Learpilot]

I haved checked with the auto parts stores and they list a 88 T-bird and a Mustang as having the same rack.

You are correct. The standard rack for a Mustang, is the "sport" rack for a Tbird. The standard rack for a Tbird is slower.

How can I tell if I have a "sport" rack ? It came off a 88 V-6 Mustang.
The shims on the valve did nothing. I am now trying an orfice in the pressure hose. I made one from of some 3/8" aluminum bar stock. I turned it down on my mini lathe. I put a small ridge in it where the #6 hose is screwed to the pump to keep it in place but not affect the seal. The first hole size is 1/8",  some better but not right.
I am going to make some more orfices going 1/64" smaller at a time until I get it like I want it.