I went with millway polyurethane front LCA monoball replacement and they have been fabulous. Very impressed with stiffer feel under braking and turning but not metal so I can still drive to and from track with no noticeable harshness or noise
Thanks for this video! Front thrust arm monoball upgrade is my next DIY project on my F80. I’m leaning towards the Turner solution because it is sealed and sold pre-pressed in new OEM thrust arms with new ball joints. Any advice on this approach?
It's certainly A LOT easier to just install a complete arm/monoball assembly. This is what I would recommend for most people unless you're handy and have access to a press (and the appropriate pressing cups). Turner is a good unit and it's nice that it's sealed.
It's disconcerting that one of the bars failed. That should not happen, unless the car was involved in a collision. I think that while the strut arm locking clamps have benefits over a locknut, they look susceptible to corrosion. I think they should have rubber boots to protect them from the elements. The claim that the monoball has tight tolerances, so it doesn't need to be sealed also seems to be asking for trouble over the long term, especially for cars that are driven in wet or winter conditions.
Agreed. I really don't like exposed ball joints for vehicles seeing significant mileage driven in the elements. SPL's recent TSB for the bolts that connect the arms to the knuckle shearing is concerning too...
@@FaRKle0079 If I were you, I would remove this junk from my car. Failures of suspension components can cause loss of life and/or property. This is inexcusable.
I was at that day with the apex e92 m3. Quite an impact at t1 and definitely a nerve racking experience. Was the failure caused by this SPL part specifically?
Yeah the incident was caused by the SPL arm snapping. Even the corner worker heard it *pop*. Here's what one of the drivers had to say: "Just after turn 1, before braking, an SPL control arm fractured and pulled his steering to the left, into the pit-out lane ,and then into the wall. The corner worker heard a pop before impact... Annoyed as it was a stupid failure of a fresh part intended for this type of use, and the car was clean, well sorted, and modded. TCD half cage, painted interior, special stitching on racetechs, AIM MXG, fire system, JRZ motorsport series dampers, ap brakes... The control arm fractured right at the last internal thread where it was thinnest. Some of the other arms are much beefier, but many on the car are this thin aluminum tube design. This front arm was the longest of this style. All the other damaged front arms have clear signs of bending or shearing off from an impact. This part definitely could have been designed better. Car was well serviced, arms put on only a few events ago and joints always inspected. We weren't expecting the arm body itself to be the failure... My recommendation is to avoid this type of thin walled, heim jointed arm from anyone. I added it for caster, but I wish I could have done that with something more robust..."
Has this added much nhv? I think I’d get the bushing and run the stock arm for strength, but if there is significant nhv increase, I think I may consider the Turner bushing/arm combo, or the millway street bushing.
I haven't noticed any noise increase, There is some vibration and harshness through the steering wheel, but that's the tradeoff you get with feeling, and it's not excessive at all.
Maybe theoretically, but I think you might run into other limitations/clearance issues before getting there (like pulling the wheel into the wheel well liner).
@@FaRKle0079 agreed! But I run M2 front fenders and arch liners. The wheel sits too far back so I want to move it forward a few cm. I did some calculations and seems like shortening the caster arm by 1cm could move the wheel forward by over 2cm, which would make the 3+° of caster range plausible. I plan to install an xdrive caster arm, which is about 9mm shorter than the rwd one, and see where that gets me. If this works, much cheaper than either of the spl parts. 😎
On an M-car I don't think the PU bushings have much to offer. The thrust arm M-bushing is solid rubber and decently rigid. Where a PU bushing would be a slight upgrade is that it doesn't have a "normal" position since the center metal cylinder rotates within the PU. They can develop a squeak however once the grease dries. A PU bushing where the LCA is would be a downgrade on an M-car since that's a monoball from the factory.
I don't know if it's hosted online. I met a guy at a local car meet and discussed the Laguna Seca failure, and he showed me the in car camera footage from his friend's E92 M3 at ACS going around T2 and near the exit having the arm snap sending the car into the straight part of the wall before T3. The video was saved in local storage on his phone (not streamed online).
oh man - I was talking with Tony @ Edge and he told me about the snapped arm.... But I'd never guessed it was a SPL arm..
I went with millway polyurethane front LCA monoball replacement and they have been fabulous. Very impressed with stiffer feel under braking and turning but not metal so I can still drive to and from track with no noticeable harshness or noise
Very informative, good job and thank you
I agree with sticking to stock m solid control arm and replace bushing than a hollow tube...
Thanks for this video! Front thrust arm monoball upgrade is my next DIY project on my F80. I’m leaning towards the Turner solution because it is sealed and sold pre-pressed in new OEM thrust arms with new ball joints. Any advice on this approach?
It's certainly A LOT easier to just install a complete arm/monoball assembly. This is what I would recommend for most people unless you're handy and have access to a press (and the appropriate pressing cups). Turner is a good unit and it's nice that it's sealed.
It's disconcerting that one of the bars failed. That should not happen, unless the car was involved in a collision. I think that while the strut arm locking clamps have benefits over a locknut, they look susceptible to corrosion. I think they should have rubber boots to protect them from the elements. The claim that the monoball has tight tolerances, so it doesn't need to be sealed also seems to be asking for trouble over the long term, especially for cars that are driven in wet or winter conditions.
Agreed. I really don't like exposed ball joints for vehicles seeing significant mileage driven in the elements.
SPL's recent TSB for the bolts that connect the arms to the knuckle shearing is concerning too...
@@FaRKle0079 If I were you, I would remove this junk from my car. Failures of suspension components can cause loss of life and/or property. This is inexcusable.
I was at that day with the apex e92 m3. Quite an impact at t1 and definitely a nerve racking experience. Was the failure caused by this SPL part specifically?
Yeah the incident was caused by the SPL arm snapping. Even the corner worker heard it *pop*.
Here's what one of the drivers had to say:
"Just after turn 1, before braking, an SPL control arm fractured and pulled his steering to the left, into the pit-out lane ,and then into the wall. The corner worker heard a pop before impact...
Annoyed as it was a stupid failure of a fresh part intended for this type of use, and the car was clean, well sorted, and modded. TCD half cage, painted interior, special stitching on racetechs, AIM MXG, fire system, JRZ motorsport series dampers, ap brakes...
The control arm fractured right at the last internal thread where it was thinnest. Some of the other arms are much beefier, but many on the car are this thin aluminum tube design. This front arm was the longest of this style. All the other damaged front arms have clear signs of bending or shearing off from an impact. This part definitely could have been designed better. Car was well serviced, arms put on only a few events ago and joints always inspected. We weren't expecting the arm body itself to be the failure...
My recommendation is to avoid this type of thin walled, heim jointed arm from anyone. I added it for caster, but I wish I could have done that with something more robust..."
Has this added much nhv? I think I’d get the bushing and run the stock arm for strength, but if there is significant nhv increase, I think I may consider the Turner bushing/arm combo, or the millway street bushing.
I haven't noticed any noise increase, There is some vibration and harshness through the steering wheel, but that's the tradeoff you get with feeling, and it's not excessive at all.
The spl website states +- 4 degrees of caster adjustment for the bushings, is it really that much from that small offset?
Maybe theoretically, but I think you might run into other limitations/clearance issues before getting there (like pulling the wheel into the wheel well liner).
@@FaRKle0079 agreed! But I run M2 front fenders and arch liners. The wheel sits too far back so I want to move it forward a few cm. I did some calculations and seems like shortening the caster arm by 1cm could move the wheel forward by over 2cm, which would make the 3+° of caster range plausible.
I plan to install an xdrive caster arm, which is about 9mm shorter than the rwd one, and see where that gets me. If this works, much cheaper than either of the spl parts. 😎
How do you feel about powerflex polyurethane bushings ?
On an M-car I don't think the PU bushings have much to offer. The thrust arm M-bushing is solid rubber and decently rigid. Where a PU bushing would be a slight upgrade is that it doesn't have a "normal" position since the center metal cylinder rotates within the PU. They can develop a squeak however once the grease dries.
A PU bushing where the LCA is would be a downgrade on an M-car since that's a monoball from the factory.
Can you share some info or a link to the ACS failure?
I don't know if it's hosted online. I met a guy at a local car meet and discussed the Laguna Seca failure, and he showed me the in car camera footage from his friend's E92 M3 at ACS going around T2 and near the exit having the arm snap sending the car into the straight part of the wall before T3. The video was saved in local storage on his phone (not streamed online).
@@FaRKle0079 I believe I have seen that video and it was a tire failure.