Caster adjustment

[Unique 289_FIA]

Is the caster adjustable on the MGB front suspension? While we're at it, what about camber and toe?

Unique Motorcars 289 F.I.A. # 9142
Southern Automotive 354 stroker

[eliminator]

Absolutely on all questions:)
The absolutely just refers to toe in.
Rick
#4279405

[nolastyankee]

Rick,
Are you sure about that? If we are talking the stock MGB front suspension I really don't think the caster nor the camber are designed to be adjustable. The kingpin on a stock MGB can be shimmed slightly for a minimal caster change, and there is no easy camber adjustment other than playing with ride height, which obviously has other implications. On a '91 vintage car like 289FIA has, unless the front end is upgraded to Unique's current version, it is stock MGB with gas shocks added on in place of the integrated upper control arm shock.

On our car we upgraded to Hawk front suspension which retains most of MGB components and uses the same rack while providing adjustability, improved geometry, and a lower cost than swapping the whole front end and brakes.

Unique 9122 - 289 FIA Cobra - The Legendary "Spence" Car

[Poorboy]

No, the only way to adjust the caster or camber on the MGB is to mill or shim the bottom of the lever shock. Toe is adjusted as in most front ends.

Poorboy

[eliminator]

Sorry Guy's, you are correct.
I stand corrected.
I was thinking about the current front end under my car which is modified and not the stock MG front suspension.

Rick
#4279405

[nolastyankee]

289FIA,
Send me an e-mail if you want to discuss the Hawk front end upgrade that we did. It's a really nice unit.

Unique 9122 - 289 FIA Cobra - The Legendary "Spence" Car

[K.Wilson]

Poorboy is correct. However, I have read about some of the MG guys slotting the holes where the lower control arm bolts to the crossmember. This would give some caster and camber adjustment although it may not give much.
I have always been hesitant to do it as this connection may be the weakest part of the whole suspension as all the shear load passes through 4 - 3/8 inch bolts. By slotting the holes it would only make this condition worse.
Have you put the alignment gauge on it yet to see where it is?
Keith

[clayfoushee]

Gasman,

You gonna weigh in here?

Rick, What mods did you do?

This whole front end discussion has me very confused, considering what my brother is going through.

Clay

'98 Unique #9299, 427FE side oiler (452.1-stroker), top-loader (close), 3.31 rear

Annapolis, MD

[nolastyankee]

Clay,
Your brother has the new suspension and not the older MGB style. I am not sure on this, but I think the new suspension is all Mustang II based. Thoughts from the crowd?

Unique 9122 - 289 FIA Cobra - The Legendary "Spence" Car

[Unique 289_FIA]

Thanks for the replies, guys. That's what I was afraid of. I entered an autocross event this weekend after a 2 year hiatus and was somewhat disappointed with the Cobra. Most of my frustration stemmed from the fact that the steering will not "self-center" after a turn (meaning if I make a turn and let go of the steering wheel, the car will continue in a circle instead of straightening out). Seeing how the course was set up by a Miata guy and it was nothing but a series of decreasing radius turns punctuated with a few slaloms, I had quite a difficult time keeping the car in line. For example, I came out of one turn, gassed it for the very short strait and when I hit the brakes, the car dove left because the steering wheel had never straightened out. The course was nigh impossible to run trying to manually center the wheel after every turn. Usually this is the result of not enough caster. Could there be another cause I'm not aware of?

Nolastyankee,
I've been eyeing that setup. I would definitely like to discuss it with you. I'm sending an email.

Unique Motorcars 289 F.I.A. # 9142
Southern Automotive 354 stroker

[gasman]

Most of you know that my motor had to be completely overhauled recently. After we put the motor back in the car, I asked the mechanic to look at the suspension setup and make recommendations on ways to improve the handling.
He put the car on a two post lift and lowered the car on to scales he had positioned under the front wheels. As the suspension settled onto the scales it literally moved the scales across the floor. The scales had four feet each. The only foot that didn’t move was the right rear on the left front wheel and the left rear on the right front wheel. In other words, as the suspension settled the wheels would toe out on each side, not just a little bit. He took measurements and determined that the MG steering rack was 5 5/8” too long for the wheel base and the positioning of the upper and lower control arms. In his opinion the steering rack created a bump steer issue. To make a long story short, he convinced me to allow him to make modifications to the front end. Flaming Rivers confirmed our measurements and fabricated a new steering rack based on the Mustang II. We dropped the sub-frame and discovered the four mounting holes were wallowed out as someone else has described earlier in this or another thread. It appears this design is intentional to allow for lateral alignment adjustments as needed. This left us wondering how you would ever know if the sub-frame slipped under hard driving conditions without pinning. We also discovered the left front spring was overly compressed and almost a full inch shorter than the right front.
The work is progressing nicely. The MG steering rack mounts were ground off the sub-frame and new mounting pins were made on a lathe. The photo attached shows the new steering rack in place before the mounting pins were welded on to the frame.
The alignment of the lower control arm with the shortened steering rack is now completely vertical to the pivot point for the tie rods. In short, it should be much easier to align and I suspect much easier to steer. Robert (Unique 289 FIA) talked about how the steering wheel would not true itself, this should correct that problem. At the same time, Bilstein is making the same shock and spring package for my car that he made for Rick Bagley. Rick has been very pleased with this setup and the Bilstein sales rep swears the car will be a joy to drive with the changes we are making. I’m looking forward to finding out.
http://www.uniquecobra.com/uploaded/gasman/IMG_0293.JPG
http://www.uniquecobra.com/uploaded/gasman/IMG_0292.JPG
http://www.uniquecobra.com/uploaded/gasman/IMG_0291.JPG

Steve Foushee
Unique #4279389

[Unique 289_FIA]

Very interesting, Steve! Please keep us updated on how it turns out! I'd also be interested in the cost of your modifications, you can email me if you would rather not publicize it.

Robert


Unique Motorcars 289 F.I.A. # 9142
Southern Automotive 354 stroker

[clayfoushee]

I'm glad you posted this Steve. You and I have been talking about it for a long time now, and I thought it was time to get it out for others to think about.

I've never autocrossed my car, and use it just for cruising, and I've never experienced the same odd handling characteristics you've described, and my car doesn't "hunt" or "dart," as you have experienced. Yet, I've been confused by what you found on your car, and would love to hear a reasonable explanation.

Clay

'98 Unique #9299, 427FE side oiler (452.1-stroker), top-loader (close), 3.31 rear

Annapolis, MD

[eliminator]

Steve,

The Flaming River Rack and Pinion appears to have a very short steering shaft. Looks like that will create another u-joint and the addition of another shaft in the steering set up. Is this correct?
Very intresting, I know what you mean about the 4 holes and ability of the front end to move. These bolts should be torqued about 150 ft. lbs. but even at that it is possible under certain conditions to shift. Intresting front end work, keep us posted. You wont regret the change to Billstein Shocks and new Hypercoil springs[^].

Rick
#4279405

[gasman]

Rick, The steering shaft will be a little shorter but we don't anticipate needing more than one U-joint and are planning to modify the one I have. To eliminate the possibility of cross member movement, we are going to dowel pin the front end to the frame after we get the cross member back in the car and are sure it is square. After doing all this, we are going to take it apart and have it powder coated. (not taking any more of your abuse at homecoming) I spoke to Jim Hiland yesterday about the proper spring. He wanted to order 8" 450 lb for the front and seemed to be under the impression this is what you used. I pulled the old thread and saw you had 350 lb springs but were not sure about the length. He was going to pull your order but I'd rather hear it from you, could you please clarify?

Steve Foushee
Unique #4279389

[eliminator]

Steve,

Also a picture of you old rack and pinion and the new one in the same picture would be good. This will let us see the difference you are talking about.

Rick
#4279405

[gasman]

I'll try to do that when I get home tonight Rick. The big difference is the pivot point for the tie rod ends. With the old rack they are approximately 2 1/2 inches outside vertical for the control arms on each side. Using the shorter rack keeps everything vertical which eliminates toe out with suspension travel.

Steve Foushee
Unique #4279389

[Poorboy]

Steve,
I think if your tie rods & lower arms were vertical your car would be on it's side.

Poorboy

[gasman]

Pivot points are lined up vertically.

Steve Foushee
Unique #4279389

[eliminator]

F-15's are Vertical[8D], Cobra's are Horizontal:D

Rick
#4279405

[gasman]

Rick, I do not have a picture of the old rack in place. Here is a recent picture of the cross member modified for the new rack before we sent it out for powder coating. We also made a pass through for the radiator hose which will be hot jet coated. Still debating on black or chrome finish, what do you think?

http://www.uniquecobra.com/uploaded/gasman/IMG_0295.jpg

[gasman]

fixed

[GeorgiaSnake]

:D Looks fine from where I'm sitting.[:o)]

Randy

Unique 289 FIA #2899420
Southern Automotive 396
Team III 16's
Brilliant Silver

[eliminator]

My suggestion would be black.

Rick
#4279405

[clayfoushee]

Please.........not chrome, unless you're trying to get it on "Pimp My Ride."

Clay

'98 Unique #9299, 427FE side oiler (452.1-stroker), top-loader (close), 3.31 rear

Annapolis, MD

[Brent]

Clay is your car back from Lee's yet?

Ready to go?



Brent
427 SC Chassis #4279401
Candy Apple Red/White
402 FE/Toploader/3.54

[clayfoushee]

Brent, I haven't had my car at Lee's since the gas tank was replaced before Spring Fling last year. All the last stuff I did, I did myself, believe it or not:D.

Yes, it runs great.

Clay

'98 Unique #9299, 427FE side oiler (452.1-stroker), top-loader (close), 3.31 rear

Annapolis, MD

[nolastyankee]

Steve,
I am making you an honorary member of the "Rescue Cobra" club...Your membership card and window sticker will be in the mail soon. You have almost done as much renovation to your car as we have to ours!


Unique 9122 - 289 FIA Cobra - The Legendary "Spence" Car

[gasman]

Brian, Can't wait to get it back together and actually enjoy the car. I've owned this car exactly a year and driven it less than 200 miles. [B)]

Steve Foushee
Unique #4279389

[gasman]

Got the powder coated cross member back today too!

http://www.uniquecobra.com/uploaded/gasman/powder coated cross member.jpg

Steve Foushee
Unique #4279389

[Brent]

Steve what type of automotive specialty shop is performing the surgury on your car? Do they specialize in a certain type of motorsport?

Looks good.



Brent
427 SC Chassis #4279401
Candy Apple Red/White
402 FE/Toploader/3.54

[gasman]

Brent, They are primarily a transmission shop but they do a lot of SCCA racing. They race Mustangs at several different tracks and work on a lot of spec racers.

Steve Foushee
Unique #4279389

[gasman]

Here are the latest pictures of the conversion to the Flaming Rivers steering rack. Easy to see the difference in tie rod angle with the radiator out. Bump steer has gone from over an inch to less than .0002. Ordered heim joints today to take it to .0000.
http://www.uniquecobra.com/uploaded/gasman/bump steer.jpg

http://www.uniquecobra.com/uploaded/gasman/new steering rack in place.jpg

Steve Foushee
Unique #4279389

[clayfoushee]

Looks good. What are you doing about the rear end? That's equally important if not more according to the experts I've spoken with.

Clay

'98 Unique #9299, 427FE side oiler (452.1-stroker), top-loader (close), 3.31 rear

Annapolis, MD

[eliminator]

The car will seek its own static height depending on shocks, front springs and coil over adjustment. The height you have set it to may or may not be the actual height. So that will change the bump steer measurement as well as the car with a driver and passenger and a load of fuel. How did you determine the height where the measurement was made?
Bump steer. This is what happens when the wheels alter their steering angle as the suspension moves.

Rick
#4279405

[gasman]

Rick, the measurement we used is the length of the shock and spring without passenger load.

Steve Foushee
Unique #4279389

[bstandley1]

Steve,

I've been following your front suspension mods with great interest. I'm really curious if the changes to the geometry of your front suspension significantly changes the handling characteristics of your car. Looking forward to your next installment.

Bob

[gasman]

Thanks Bob, The car is almost ready to road test. With a little luck, I think we will see what impact our changes have made early next week. Today, we are changing the tie rod ends to a type that has verital adjustment possibilities using different thicknesses of nylon shims. Everything is coming together very nicely.

Steve Foushee
Unique #4279389

[gasman]

The adjustable tie rod ends have been installed. We should be able to test it early next week as anticipated.
http://www.uniquecobra.com/uploaded/gasman/FR rack with adj tie rods.jpg

http://www.uniquecobra.com/uploaded/gasman/adjustable tie rod ball joints.jpg

Steve Foushee
Unique #4279389

[eliminator]

Steve,

Christmas is coming, are you going to get that car of yours on the road this year??? Last update was over a mont ago[:O].
We havn't had a update in a long time[?][?]
I am curious how all the upgrades to your front end are working out.


Rick
#4279405

[nolastyankee]

I'm beginning to think that we may get our car on the road before Steve does!

Brian Carlson

Unique 9122 - 289 FIA Cobra - The Legendary "Spence" Car

[clayfoushee]

I'll let him give you the details, but he's back on the road and very happy.

Clay

'98 Unique #9299, 427FE side oiler (452.1-stroker), top-loader (close), 3.31 rear

Annapolis, MD

[gasman]

Spence, think again.

Steve Foushee
Unique #4279389

[nolastyankee]

Just kidding guys...If we're rolling this calendar year I'll be a happy man. The aggressive stretch goal in Pigeon Forge.

Brian Carlson

Unique 9122 - 289 FIA Cobra - The Legendary "Spence" Car