Greg is correct. If you look at these as if they were a truss, and, understand the loads placed on them, the greatest potential for deflection is in the middle. Trusses are thin at the ends and thicker in the middle for this reason. These are more than simple locating links.

 

so long as we are on the topic, what do you guys think of solid rod arms? I figure they would flex much easier, and therefor not as good, or does 1 inch thick 6061-t6 not flex over a 17.5 inch length, especially with primarily linear loads on them (i think). Onasled, how much did those sexy control arms run you? (pm if you would rather), and where did you get them? Thanks alot

Beecher

 

I understand the concept you explained, however I would have to disagree with your scenario. In the case of the MINI, these links are not experiencing a force at the center.

With that said, I agree that you wouldn't want your weak point at the very center of the link due to buckling. Certain links such as Hotchkis and SPC use a deflecting bushing rather than a spherical bearing. This will create a bending situation during suspension articulation. Think of your same scenario and instead of fixing both ends fix only one end and apply a force at the other end. Your results will be the opposite. The link would break easily with the slots at the ends compared to the slot in the middle. You will notice on the Hotchkis and SPC links that the threads (weak points) are not situated near the ends or the center, but somewhere in between. This was my point I was trying to make. When using spherical bearings, you wouldn't have any bending moments since all of the force is transmitted axially. I guess I should have been more specific.

Cheers

 

Just a speculation; if the Helix's are the lightweight of the lot, does that mean the other (heavier) ones hold up better under more extreme conditions?

 

So, I think this was asked but I didn't see any answer as yet:
Are most of you purchasing two sets for the rear or just one set?

In other words: 4 control arms or ust two to get the right alignment you need when you add lowering springs or coilovers.

Thanks,
Paul

 

From my recent reading, it seems that you do just the lowers (requiring 2 arms) or both uppers and lowers (4 arms). The lower arms control camber. The upper arms control toe.

For a 'sport street' configuration (whatever that might mean... lets say something better than stock but not ready for full competition track use), the lower-only setup is sufficient if you have lowered the car a bit with springs... it is used to dial back the negative camber that you added when you lowered the rear of the car. I'm looking at this right now because I'm running -2.7 degrees of camber in the back from my heavy car and lowering springs.

For a full 'track' setup, you replace both sets so you can control camber and also toe... giving you even more control over your alignment settings.

It also appears that adjustable control arms for MINIs will fit in either the upper or lower position, so you can buy 2 pair of the same part if you want to do all of the rear control arms.

I'm fairly new to all of this... so I'd appreciate any corrections/additions you might have!

 

Toe is actually adjustable in all MINIs by loosening the three bolts at the trailing arm attachment bracket and moving the bracket from side to side. Only one set (one arm per side) is needed on pre-04 MINIs to allow camber adjustability (later models have a limited amount of adjustability built into the trailing arm-end mounting point).

Installing a full set of four adjustable arms gives a wider range of camber adjustment, and can actually be used to fine-tune away slight rubbing by narrowing or widening the track slightly and readjusting toe at the trailing arm mount. Most people replace all the arms for lighter weight and/or increased strength as well. The lower set takes the most abuse in lateral maneuvers though, and works best for camber adjustments compared to replacing the uppers only.

 

This is a great thread. And I have searched many others for answers/opinions to my questions.

I need rear control arms since I lowered my car with M7 springs. My main goal is to maintain the same level of comfort and quietness as I have with the stock units and keep the street tire from wearing out. I only track the car 5-6 times a year. It's my wifes daily driver otherwise...that should sum things up! LOL!

1. Are any of the adjustable rear control arms quieter than others? (I have seen questions concerning this but no answers)

2. Is it really an issue at all?

3. Any bad experiences?

4. I am leaning towards Helix or Alta (price is a reason, but I like the look.) but am open to any thoughts.

I would appreciate any help as I just really don't understand the differences betwen the joints.

Thank You in advance!

 

The Alta and Helix arms use heim joints which will give a harsher ride than stock and are usually recommended for track use. Personally I like the IE units. They use urethane bushings and should be a nice compromise between OEM and race setups. It's also recommended to keep the bushing material the same for all four arms, so if your choice has a different bushing material than stock, I'd change them all. Look for a good alignment shop also because this amount of adjustment tends to be more than the economy shops are used to coping with.

 

OK, your wife drives this car and you are looking for comfort. Then stay away from heim joints and do an alignment with more comfort in mind. One extreme is to adjust the alignment to stock settings- this offers very good tire wear and comfort and less performance. Or you can set the rear to more negative camber like -2 degrees and get a little rougher ride- depends on your roads and toe settings. I'd suggest stock settings for alignment with rear camber -1.2 to -1.5 degrees.

For comfort your tires make a big difference. What do you have now and what are you planning for the future?

1. Are any of the adjustable rear control arms quieter than others? Yes.
Polyurethane bushings are not as noisy but only by a little bit.

2. Noise is not something most owners notice under normal use. There are other sources of noise so I think we look elsewhere most of the time. I don't think it is much of an issue.

3. I have H-sport lower rear control arms that have done well. No complaints after 3 years. Used for track, driving school, autocross and street.

4. Control arm decisions-
Usually just get the rear lower pair not all four. You have a range of prices, colors, different weights, designs with some that are easier to adjust than others-for the benefit of who is doing the alignment, but functionally they are similar.

Which year is your MINI? If you have a late year model you have some rear camber adjustment built in. Can you use that alone to even out camber on right vs left sides. Even if it is more negative like -2 degrees as long as toe is set to stock settings your ride quality should be OK, along with some decent tires.

 

Thanks for the response, guys.

Mine is an '04.

I am seeing now that the poly bushings are the way to go for me.

I go through lots of tires and have used Yoko's, BF Goodrich KDW's and others...all chosen with the track in mind.

I am taking a different tack now and am getting Toyo Proxes 4's for the everyday tire on my Flik 17" wheels.

I plan to get some 16" wheels and tires and go to R-compounds for track use only.

Thanks!

 

Can the my 05 oem adjustable lower control arms be retro fitted to
my 02-03 ? or are they a different size ?

cool thred by the way

 

The stock lower control arm part is the same for each year.

It is the attachment of the control arm to the lower subframe of the rear of the later model years that has a small adjustable feature- you change the position of the stock arm. It isn't much but it does help. It cannot be transferred easily.

Adjustable lower control arms will work for any year MINI because you can adjust the length of the control arm to adjust rear negative camber.