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Anyone tried this front lower control arm brace?
- Thread starter jackmott
- Start date
Looks very interesting. I like how it ties the rear lower control arm mounting points together. Not sure how effective it would be given that there is still a large section of the front subframe that is open and not tied together. I have seen other ones from Ultra Racing for the front subframe as well,
Tesla Model 3 Chassis Bracing.
The difference here is that the Hardrace one seems to still provide room for the front subframe to collapse and fold back upon itself and for the front motor to drop or rise in case of a serious head-on crash - like the subframe is designed to do. I remember seeing a frontend crash video showing the underside of the M3 and how the whole front subframe folded basically downward in half and the front motor pivoting on the front mounting point either going up or down (I can't remember), upon impact. Pretty cool to watch but I can't seem to find it now online. The Ultra Racing front subframe bar seems like it would interfere with how the subframe and motor a designed to collapse.
Threre is probably obvious flex in the front subframe under extreme cornering on track. I think MPP has mentioned that as well. Unfortunately given how the subframe is designed to collapse, I am no expert, but I would think it is probably not a good idea to try to brace it (X Brace or box brace) to help eliminate this flex. As we all know, ICE sports sedans and sports cars don't seem to have this crash design issue and often have an X-brace design tying the front subframe together for greater rigidity. I have used aftermarket braces like this in the past with great results, and often thought about this for the M3 as well, but I would be worried about changing its crash safety performance and dynamics.
One thing that would be great to add to the Hardrace design would be to add some sort of additional front battery and front battery hose protection. Telsa really missed the ball on providing some type of real protection for that area on the M3 (too cheap???). The Model S plaid has a shield surrounding that area - you can watch Monroe's video on it. The Hardrace bar seems to have two unused holes on the bar, perhaps they are someone could come up with a protection shield to mount and attach to the bar to help protect this vulnerable section of the battery and cooling infrastructure.
Just my thoughts... I would love to hear Sasha's (MPP) thoughts on all of this....
Tesla Model 3 Chassis Bracing.
The difference here is that the Hardrace one seems to still provide room for the front subframe to collapse and fold back upon itself and for the front motor to drop or rise in case of a serious head-on crash - like the subframe is designed to do. I remember seeing a frontend crash video showing the underside of the M3 and how the whole front subframe folded basically downward in half and the front motor pivoting on the front mounting point either going up or down (I can't remember), upon impact. Pretty cool to watch but I can't seem to find it now online. The Ultra Racing front subframe bar seems like it would interfere with how the subframe and motor a designed to collapse.
Threre is probably obvious flex in the front subframe under extreme cornering on track. I think MPP has mentioned that as well. Unfortunately given how the subframe is designed to collapse, I am no expert, but I would think it is probably not a good idea to try to brace it (X Brace or box brace) to help eliminate this flex. As we all know, ICE sports sedans and sports cars don't seem to have this crash design issue and often have an X-brace design tying the front subframe together for greater rigidity. I have used aftermarket braces like this in the past with great results, and often thought about this for the M3 as well, but I would be worried about changing its crash safety performance and dynamics.
One thing that would be great to add to the Hardrace design would be to add some sort of additional front battery and front battery hose protection. Telsa really missed the ball on providing some type of real protection for that area on the M3 (too cheap???). The Model S plaid has a shield surrounding that area - you can watch Monroe's video on it. The Hardrace bar seems to have two unused holes on the bar, perhaps they are someone could come up with a protection shield to mount and attach to the bar to help protect this vulnerable section of the battery and cooling infrastructure.
Just my thoughts... I would love to hear Sasha's (MPP) thoughts on all of this....
drpheta
Member
I wonder how much rigidity increases with the alu skid plate itself.
More to my point about crash testing you can check out this crash test video.
Go to 40 sec. mark to see how the front subframe compresses and folds over in front crash. I would think additional braces like the Ultra Racing braces would hinder the way the subframe is supposed to collapse. This is not on a dual motor, but you can probably guess that the motor moves up or down on the front mount attachment point where the motor attaches to the subframe. It is attached on the middle of the front subframe with a type of swing arm pivot bushing so it can move up or down.
I don't think the aluminum front skid plate that you can install would provide much bending resistance in a crash - it does not seem all that stiff and would probably fold over easily.
Go to 40 sec. mark to see how the front subframe compresses and folds over in front crash. I would think additional braces like the Ultra Racing braces would hinder the way the subframe is supposed to collapse. This is not on a dual motor, but you can probably guess that the motor moves up or down on the front mount attachment point where the motor attaches to the subframe. It is attached on the middle of the front subframe with a type of swing arm pivot bushing so it can move up or down.
I don't think the aluminum front skid plate that you can install would provide much bending resistance in a crash - it does not seem all that stiff and would probably fold over easily.
The aluminum skid plates are bendable by hand if you try hard enough. One may reasonably assume that 3mm of aluminum held in place by 10mm hex heads isn’t going to interfere much with the forces seen in a head-on collision.
I will be interested to see whether the Hardrace brace has any perceptible effect on stiffness. A 20mm sway bar from Whiteline did (I’m putting it back on because it made the car feel much “flatter” in turns). If not, at least it didn’t cost too much.
regarding the hose guards, they are available aftermarket, but this is a great point and I will see whether a simpler and more silent solution exists now that you have pointed it out. That would be dandy; when fiddling with the compression arms it becomes quite obvious that an errant hit down there could be disastrous.
Even wrenching the compression arms to specified torque is a little scary given how close that assembly is to coolant hoses. I have no idea if this has been addressed in the Highland updates, but I do have a couple of the cheap aluminum hose guards in place, and the hardrace assembly appears a lot more confidence inspiring than 3mm of Al alloy.
Will update when I have more data.
One last note: along with all the other somewhat concerning issues for the Ultra Racing product, it is explicitly noted that the brace won’t work with Mountain Pass Performance’s FLCA bearing.
I suspect a great many people who might be in the market to stiffen up the front have already installed the MPP FLCA bearing, so that’s another potential gotcha with this approach.
I suspect a great many people who might be in the market to stiffen up the front have already installed the MPP FLCA bearing, so that’s another potential gotcha with this approach.
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