More on why I went with these in another post. In short, I was hoping I could add some negative camber without dialing it in at the camber plates, keeping SAI and thus overall suspension geometry (especially roll center height) as close to stock as possible.
I had read that F8x spindles add a touch of negative camber on their own. On top of that, there are “camber correction” variants with either +0.5º or -0.5º vs. the standard ones. I went with the -0.5º variants – BMW PNs 31217853639 (left) and 31217853640 (right).
Results are a bit beyond what I was expecting. I was able to get -2.5º camber with ~14.75º SAI.
Factory spec per original training docs is apparently -1º camber with 15º SAI (source – thanks karter16). The "targets" on my alignment sheet say -1.25º camber, though. Maybe that's because I'm lowered 10mm (stock ZCP ride height) – but that'd also mean the SAI target would have to be over 15º. Either way, it looks to me like I got over 1º more negative camber at the same or less strut angle. If you see something I'm misinterpreting/misunderstanding, please let me know.
I'm running Öhlins R&T coilovers and TMS Hybrid camber plates, so I can't say for sure whether others would get the same results with these spindles on a stock suspension or any other setup. Either way, pretty eye-opening.
There should be plenty of room to dial in more camber – possibly beyond -5º, depending on setup. I’ll probably never get to that point, but it might be useful for someone else.
More relevant to me, roll center height should be basically unchanged from stock.
I can’t say for sure how other aspects of the suspension geometry are affected, if at all. The only attempt I've seen to address that is this post on M3Post, which suggests the pickup point locations are close or identical between F8x and E9x M, at least for the standard F8x spindles. That's not authoritative enough for me to feel comfortable repeating it as truth, and it doesn't say anything about the camber correction F8x spindles. However, it's good enough for my purposes; I expect that overall suspension geometry is very close to stock, barring the additional static camber.
At my first track event with this setup, I ran Yokohama ADVAN Neova AD09s in the stock sizes (245f/265r). Wear and temps seemed to be nice and even across the face of the tire once I had the pressures dialed in. I didn’t see any evidence of sidewall rollover.
For whatever my subjective opinion is worth, the car seems to handle quite nicely. It drives like stock, but with a bit more tramlining and much more front end authority.
Initially, I had hoped that this mod would allow me to dial out a little bit of negative camber at the plates. Looks like I can't do that without bringing SAI well below factory spec, venturing deeper into uncharted territory. But this setup seems to work brilliantly (for me) on track and fine on the street, so I'm not complaining.
Hope this is useful to someone.
I had read that F8x spindles add a touch of negative camber on their own. On top of that, there are “camber correction” variants with either +0.5º or -0.5º vs. the standard ones. I went with the -0.5º variants – BMW PNs 31217853639 (left) and 31217853640 (right).
Results are a bit beyond what I was expecting. I was able to get -2.5º camber with ~14.75º SAI.
Factory spec per original training docs is apparently -1º camber with 15º SAI (source – thanks karter16). The "targets" on my alignment sheet say -1.25º camber, though. Maybe that's because I'm lowered 10mm (stock ZCP ride height) – but that'd also mean the SAI target would have to be over 15º. Either way, it looks to me like I got over 1º more negative camber at the same or less strut angle. If you see something I'm misinterpreting/misunderstanding, please let me know.
I'm running Öhlins R&T coilovers and TMS Hybrid camber plates, so I can't say for sure whether others would get the same results with these spindles on a stock suspension or any other setup. Either way, pretty eye-opening.
There should be plenty of room to dial in more camber – possibly beyond -5º, depending on setup. I’ll probably never get to that point, but it might be useful for someone else.
More relevant to me, roll center height should be basically unchanged from stock.
I can’t say for sure how other aspects of the suspension geometry are affected, if at all. The only attempt I've seen to address that is this post on M3Post, which suggests the pickup point locations are close or identical between F8x and E9x M, at least for the standard F8x spindles. That's not authoritative enough for me to feel comfortable repeating it as truth, and it doesn't say anything about the camber correction F8x spindles. However, it's good enough for my purposes; I expect that overall suspension geometry is very close to stock, barring the additional static camber.
At my first track event with this setup, I ran Yokohama ADVAN Neova AD09s in the stock sizes (245f/265r). Wear and temps seemed to be nice and even across the face of the tire once I had the pressures dialed in. I didn’t see any evidence of sidewall rollover.
For whatever my subjective opinion is worth, the car seems to handle quite nicely. It drives like stock, but with a bit more tramlining and much more front end authority.
Initially, I had hoped that this mod would allow me to dial out a little bit of negative camber at the plates. Looks like I can't do that without bringing SAI well below factory spec, venturing deeper into uncharted territory. But this setup seems to work brilliantly (for me) on track and fine on the street, so I'm not complaining.
Hope this is useful to someone.
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