MII Directional Stability

[rockable]

El, how much is 1/8" toe in in degrees? We put .2 degrees per side and that was a little less than I calculated as being 1/16". I thin.25 was right at 1/8" total. Did I goof? I watched the tech align it and I know what the end result was. This was an experienced tech, too.

[gimpyshotrods]

Originally Posted by rockable

El, how much is 1/8" toe in in degrees? We put .2 degrees per side and that was a little less than I calculated as being 1/16". I thin.25 was right at 1/8" total. Did I goof? I watched the tech align it and I know what the end result was. This was an experienced tech, too.

This would depend on your tire diameter. What do you have?

[ELpolacko]

If you have a 26" tire, .2 degrees should be .045" and I am going to assume this is per side. So both sides would be .090" and that is close to 3/32" toe.

At this stage of the game ask your guy to set it at 0 degrees of toe and see if that makes a difference.

I referenced in my first response that there is some creative "you can get away with that" engineering (ahem) in your IFS kit. So stock alignment settings are out the window.

[rockable]

Originally Posted by gimpyshotrods

This would depend on your tire diameter. What do you have?

Approx 27". Sorry. I forgot to post that.

[rockable]

Originally Posted by ELpolacko

If you have a 26" tire, .2 degrees should be .045" and I am going to assume this is per side. So both sides would be .090" and that is close to 3/32" toe.

At this stage of the game ask your guy to set it at 0 degrees of toe and see if that makes a difference.

I referenced in my first response that there is some creative "you can get away with that" engineering (ahem) in your IFS kit. So stock alignment settings are out the window.

Your math is very close to what I calculate, too. I always thought toe in added additional stability. I wasn't aware that toe in could make the car very sensitive and darty. I knew from my racing days that toe out would.

I'm going to check the pump before I go back to the alignment shop. It's 30 minutes away. I had a helluva time finding someone who could do it. My car wasn't "in their database" at the tire store. Jesus.

[George/Maine]

The crossmember to me doesn,t look like made by Fatman.
The a arm hole is to high.
Your steering is off bacause the tie rod is not parrell with a arm.
Your wheels are going in and out as the car goes up and down.
You say its good on level.
When the front end is aliglined they don,t check up and down on a arm.
If you draw it out on paper you will see whats happing.

[rockable]

My God, nothing is easy. Today, I went back to the alignment shop. Once there, we discovered that I had a leaking rack. So, I pulled the plug on the alignment and went on a wild goose chase until I got the right one from NAPA. While installing it, I checked the pump relief valve and discovered that it already had 4 shims installed. So much for that theory.

My alignment guy set the toe with less toe in for my ride home and it felt better. I'm taking it back Friday and following El Polackos advice. It will have 4 degrees caster, 1/4 degree pos. camber and virtually no toe in. I think it will drive a lot better.

[johnod]

Let us know how that works out please.

[Rattle Trap]

I think you are on the right track. My alignment guy recommends zero toe in and lots of caster and a degree of camber. Works well for me. And this is on my Mustang DD.

[rockable]

We were only able to get 3 degrees caster in it while maintaining .2 degree negative camber. We set the toe at zero and it track and drive much better. The steering is still quick but not unmanageable. I'm convinced we've got it as good as we are going to get it without changing to a manual rack. Thanks for the help!

[BrerHair]

Great thread Rock, very informative (once again, thank you ElPolako!)

Am I correct in saying that one of the take-home messages is use a manual rack on an MII conversion?

At first, I was upset with the CE guys who told me that I cannot use a power rack in my '51 chevy MII when I found out from others later "Oh, a power rack will fit!"

Now I'm feeling pretty good about their advice.

[rockable]

Jimmy, I would go with the manual rack as NeedLouvers said. Heck, I wish I had converted this week when I had to replace the rack. It would have been easy to do.

ElPolacko, you are the man! Thanks!

[need louvers ?]

It was the perfect time! Oh well, I understand that you had it plumbed and set up and all, why undo. Just remember the manual rack and stock wheel deal for the future. if I had not seen that tiny, adorable, psychotic female driving my car as much as she did, I would have thought I had to have power too. I do have to admit that I am not a huge fan of power steering in any thing though...

[rockable]

Originally Posted by hotroddon

I got one of the Borgeson Pressure reducer kits - It not only uses shims, but also a little piece of tubing to restrict the flow. BIG difference compared to just shimming.
$16.97 at Summit http://www.summitracing.com/parts/BRG-899001

I have one of those kits. I'm not overboosted, the ratio is jus really quick for this car.

[rockable]

Originally Posted by need louvers ?

It was the perfect time! Oh well, I understand that you had it plumbed and set up and all, why undo. Just remember the manual rack and stock wheel deal for the future. if I had not seen that tiny, adorable, psychotic female driving my car as much as she did, I would have thought I had to have power too. I do have to admit that I am not a huge fan of power steering in any thing though...

I agree. My 41 is gonna have manual steering!

[gimpyshotrods]

Come to think of it, how many turns is your rack, lock-to-lock?

[rockable]

Originally Posted by gimpyshotrods

Come to think of it, how many turns is your rack, lock-to-lock?

3. I got a replacement rack a NAPA that was 2.5 and I took it back!

[gimpyshotrods]

Yeah, I wanted to make sure that you did not have the 2-1/2 turn one.

[neverdun]

We set my truck up with the specs from a mustang. Thats what it was designed for. Never had a problem. It did do some wandering on high speed turns so we put a sway bar on it and it never felt better.
Good luck.

[rockable]

From this point, a sway bar would likely improve it a little. It's a big car and it bounce a bit. An improved rear suspension would help a lot but I'm not putting that kind of time and effort in.

When you turn a car with leaf springs in the rear, as the car rolls it steers the rear due to one spring lengthening and one shortening. That's why 4 bar setups are better. They keep the rear pointed straight ahead.