[needless rules]

Hello,
Has anyone seen proof that the stock toe links really bend as Carbahn claims? Has anyone seen proof theirs do not bend?
I have talked to Carbahn twice and they said they have no proof but their product is better??
I will appreciate any opinions or proof one way or the other. Thanks

[pbonsalb]

Have not read of them bending in the 3-4 years I have been here. I installed the Dinan rear kit on my car. It includes 4 arms, not just 2. The 2 that Carbahn includes are the ones that are flimsier sheet metal. It might not be that they are permanently bending, but rather deflecting a little and that changes the rear suspension geometry under load. Maybe you could just weld them up to be stiffer, but Carbahn and Dinan also stiffen the bushings at the one end (by using a heim joint instead of a bushing) compared to stock whether non-Comp or Comp. Comp is stiffer than non-Comp. The smaller forward arms that Dinan may not need additional stiffness but the bushings are stiffer.

Do you need these parts? Will they make a dramatic difference? Probably no to both for most people. Track guys could probably notice, or canyon carvers. I am neither. The best I can do is on/off ramps with an S turn. I feel like the rear end is a little more planted, with less wiggle in the transition.

[needless rules]

Originally Posted by pbonsalb

Have not read of them bending in the 3-4 years I have been here. I installed the Dinan rear kit on my car. It includes 4 arms, not just 2. The 2 that Carbahn includes are the ones that are flimsier sheet metal. It might not be that they are permanently bending, but rather deflecting a little and that changes the rear suspension geometry under load. Maybe you could just weld them up to be stiffer, but Carbahn and Dinan also stiffen the bushings at the one end (by using a heim joint instead of a bushing) compared to stock whether non-Comp or Comp. Comp is stiffer than non-Comp. The smaller forward arms that Dinan may not need additional stiffness but the bushings are stiffer.

Do you need these parts? Will they make a dramatic difference? Probably no to both for most people. Track guys could probably notice, or canyon carvers. I am neither. The best I can do is on/off ramps with an S turn. I feel like the rear end is a little more planted, with less wiggle in the transition.

Thanks for the reply, pbonsalb,
True, the heim joint will be much stronger, I just have a problem with sellers that expect me to believe them without proof.
Especially when they tell me there has been no testing of their product whatsoever.
Thanks

[pbonsalb]

The rear trailing arm is a part that has been upgraded on other BMW over the years. They are 3 sided sheet metal. Some say that allows them to bend if you hit a curb, possibly reducing other damage. Some say they flex and don’t maintain toe under severe use.

I don’t really know how you would test them. Have a consistent track driver run some laps? Do a bend test? My guess is that most of the benefit comes from the stiffer bushings. Comps already have stiffer ones so any improvement would be less for them. If BMW thought stiffening the bushings was good for Comp models, probably a little stiffer is even better since BMW is still compromising for the average Comp driver who really is not a competition driver but rather a regular guy who wants to be one.

[PDOT]

The rear-toe link was the best mod for me at the track. It calmed the rear end down.

[RobRed]

i did the carbahn mono balls and rear links. Quality products. Surprisingly this mod actually improved the steering feedback and feel - more hydraulic feeling than stock. Cheap mod. I'd give it a thumbs up.

[martinm0]

Originally Posted by RobRed

i did the carbahn mono balls and rear links. Quality products. Surprisingly this mod actually improved the steering feedback and feel - more hydraulic feeling than stock. Cheap mod. I'd give it a thumbs up.

I'd love to hear more about the change in steering feel. Might not be the right thread to get into this, but could you elaborate more on how things improved in your experience? Does the steering pick up any more consistency with small turns at lower speeds?

What bugs me the most about the F90 M5 steering is that it doesn't hold steering weight consistently through a turn or corner. I can turn in and hold it, but the weight doesn't build with g forces and grip, and I then I often make micro corrections that are either too much or too little since there is nothing pushing back through the steering. Additionally, the steering feels like it's on a winding spring that wants to spin back to center on its own.

If any of these issues are resolved with the monoballs I think this will have to be a first mod for me and the car.