I'm not talking about strut tower braces. I wanted to ask if subframe connectors are available for a 2011 MINI Cooper S. Would consider bolt in, but prefer welded in.

On a unibody car, I like to add subframe connectors to keep the car rattle free as the miles pile up.

Thanks for any info/guidance.

 

Are you talking about this?
http://gtspec.com/product/gtspec-min...t-ladder-brace

 

I think he's talking about connecting the front subframe to rear. At least that was what they were called 30 years ago. They were popular on high horsepower front engine rear drive cars back in the days when nobody knew how to build a car that wouldn't twist.

Totally unnecessary on a transverse engine front drive car. It would do nothing but add weight.

Then again, he may mean something totally different.

 

We have the X brace that you can actually feel the stiffness when you install it.

 

Yes, I am talking about connecting the front and rear subframes.

Subframe connectors are used for more than just drag cars. When you drive over a bad railroad track, your car flexes. The chasis twists. If you tie the front and rear subframes together, it is like when you tie the strut towers together with a strut tower brace. It prevents flex. On a track car, the roll cage does this for you. On my street cars, I look for something like the vendor above is offering. He has a X brace that ties the front and rear of the car together. I will look at all that is available out there, and if I don't find what I want, I'll fab it myself.

As you know, when they cut the roof off the MINI to make it a convertible, they add bracing from the factory under the car to try and gain back some of the rigidity that was lost with the roof. By adding that type of bracing to a hard top, you get rid of that final bit of twist/flex. When driving, it feels like the hinge in the middle of the car is gone. If you are used to it, you may not realise it is there. BUT, when you get rid of that flex, it is very obvious.

More info:
The X-style brace is designed to resist the twisting motion that goes along with the torsional loading of the chassis. In other words, the suspension will react more precisely to uneven surfaces, particularly in situations where one wheel experiences a bump or dip.

 

I absolutely agree with you that there is a need for it on a convertible. You've just taken away the largest contributor to torsional rigidity by removing the roof.

What Im saying is that if you look at it from a perspective of pure statics, you have a member that is pretty solid, which is your roof which is about 4-1/2 feet away from the frame rails. It uses that distance as leverage to increase torsional rigidity. Now take a member that you weld in which is in line with the frame rails. It has less leverage to prevent rigidity because it is twisting on the same plane. Not saying it makes no difference. Just saying you don't get the bang for the buck.

The X-Brace is something that is a good investment as it ties the lower suspension together. This counteracts the torsion some, but really where you are seeing the difference is the lateral loading of the suspension. It ties the lower points together and to the front frame rails to reduce inward flex on the outer (loaded) wheel. The same is true for a strut bar, it ties the tops of the strut towers together to counteract lateral loading.

I don't know how well it works on a MINI, but I do know an X-Brace improves turn-in significantly on an E36 BMW.

To each his own for sure, but the cost and effort vs result of welding in frame rails would be minimal (in my opinion ).