CP sway bars question

[TomM6]

Does anybody know what the stiffness difference is between the standard and CP sway bars for the M6? Any cross section dimensions for both are appreciated. Has anyone swapped sways on his M6? Does it reduce body roll noticeably?
Thanks

[Flying Ace]

According to this presentation from BMW, the sway bars are 15% stiffer. I'm not sure what this figure even means. Is it a measure of the thickness of the bar or torsional strength? Also, it doesn't describe whether this is the net increase on both bars. There's ways to dial in "more neutral" steering by increasing one bar's stiffness more than the other bar's. None of it is detailed.



https://f10.m5post.com/forums/showthread.php?t=873975


My view on changing any suspension pieces on the car is this: Generally, you'll notice the difference on the margins. So if you're really driving the car at 9/10ths then you'll probably notice the difference. Further, most upgraded suspension pieces are tuned with other upgraded pieces. IMO, if you're going to buy the rear swaybar, you should buy the complete set (front and rear) with the ZCP springs shocks as they were designed and tuned together.

[Flying Ace]

Also I will add, the comments from people who have driven ZCP and non-ZCP cars generally is about the added steering feel. I suspect that's primarily from the revised steering ratio on the ZCP cars.

You'll probably get a bigger bang for the buck getting the steering tuned to the ZCP specs. It's actually possible I believe. The hydraulic M Servotronics actually have an electronic tune that adjusts the boost levels. They were able to retrofit it in E9X M3s.

Talk to Mike Benvo at BPM BPMSport to see if he can find a M6 ZCP tune. This will be your best bang for the buck.

[BMWDriverX]

When Mission Performance set up the tune on my car it included the comp pack steering adjustments, made it feel significantly more stiff.

[TomM6]

Great feedback, thank you. I will look into custom tuning

[Flying Ace]

Yep, good luck. Let us know how it turns out

[SE7EN335]

wait what you can get zcp tune on a non-zcp m6?!?! how?!?!?!

[BMWDriverX]

Originally Posted by SE7EN335

wait what you can get zcp tune on a non-zcp m6?!?! how?!?!?!

Flash Tuning.

[Flying Ace]

Originally Posted by SE7EN335

wait what you can get zcp tune on a non-zcp m6?!?! how?!?!?!

For the steering boost, yes

[SE7EN335]

Originally Posted by Flying Ace

For the steering boost, yes

ah right what would the zcp tune do for the steering in a non-zcp m6? more direct steering ratio and faster steering?

[Flying Ace]

Originally Posted by SE7EN335

ah right what would the zcp tune do for the steering in a non-zcp m6? more direct steering ratio and faster steering?

Read the link

[BMWDriverX]

Originally Posted by SE7EN335

ah right what would the zcp tune do for the steering in a non-zcp m6? more direct steering ratio and faster steering?

What a tuner can do is start out with a Comp pack based factory flash so you get extra fueling, the steering becomes more stiff, probably some suspension mode changes, and then they build on that for a stage 1 tune or stage 2 for more power depending on your supporting mods.

[SE7EN335]

Originally Posted by SoCalM6GC

What a tuner can do is start out with a Comp pack based factory flash so you get extra fueling, the steering becomes more stiff, probably some suspension mode changes, and then they build on that for a stage 1 tune or stage 2 for more power depending on your supporting mods.

awesome thanks. how can you change suspension mode changes through tuning? wouldn't you need to change hardware as well like with different dampeners at least?

[BMWDriverX]

Originally Posted by SE7EN335

awesome thanks. how can you change suspension mode changes through tuning? wouldn't you need to change hardware as well like with different dampeners at least?

No, Dinan does it with the shockware software. Just like you have different modes to choose from they just make it more stiff as your suspension is already adjustable.