[M1500Z]

Originally Posted by medphysdave

Thanks for sharing. I like this well sorted approach to your goals. In the coding you have Euro MDM. Did you notice a difference when going from stock to Euro? I run MDM at the track in the CS and rarely do I get interference. I've contemplated turning everything off, but a Performance Center instructor suggested there is no point if I'm doing my part to drive the right line. I'm curious if you keep it in MDM, switch it off? If you switched it off what was your tipping point, or where did you notice MDM holding you back?

I never took the car to the track prior to coding Euro MDM so can't comment on the differences. There have been times where I'd rather have been able to stay in the throttle and ride the slide rather than being interrupted by MDM. Being more intrusive (US MDM) would certainly be a detriment. I've turned it off at small club tracks and not really noticed a difference.

I don't fully disagree with your instructor, but to my experience above, there are times where you may exceed MDM's threshold for slip and have it intervene when in reality you'd only have had a little slide or understeer and gone quicker. I've also had it potentially save my ass before.

Originally Posted by ThreeStripes

Thanks for the additional thoughts. This piece in particular is something that has me curious.

I’m interested as I’m currently on TCK doubles in the rear and singles up front. Having experienced top shelf damping via Nitron and MCS, I have a growing appreciation for what they deliver over more middle of the road options like a TCK or Ohlins R&T but wonder if I hold off upgrading in favor of CSR sways.

Dropping the rear sub-frame sounds like it may be worth it. I don’t think they’ll impact ride comfort much. TC Kline said they would when I asked his thoughts, but I’m not convinced.

You don't have to drop the subframe—it can be lowered enough on the studs to wriggle the old one out and new one in and it's helpful if you have an aftermarket exhaust that doesn't have to be supported. It could be possible with quickjacks and a transmission jack to lower/raise the subframe. I believe the subframe is "keyed" so it goes right back where it was.

Sways are part of the equation for roll-stiffness (they also affect pitch). I was effectively using my dampers to try and keep the car flat by excessively slowing the valving, e.g. not their intended usage. Part of me wonders if I'd tried them in the stiff setting, I may have had a little more roll stiffness and backed the dampers off, but in reality I doubt it because it's a pretty marginal increase. Personally, I would never do just a front bar—just seems like you're asking for push.

Originally Posted by medphysdave

I think it was FaRKle! that may have put out a YouTube video with Shaike that showed how little the rear bar is doing on the M2. Unsure how much this changes with the rear CSR bar. My thought is that the rear bar isn't worth the hassle. Seems the rear toe arms provide a lot of bang for the buck by getting rid of the rear end squirm. I have a CSR front bar going in shortly, but leaving the rear alone.

I'm not a suspension engineer so take this with a grain of salt. If you're taking a car that has understeer engineered into it and increasing front-roll stiffness without increasing the rear, then it seems like you'll end up with even more understeer. I know it's a strut front and you want to keep the camber from going negative, but I still think the rear should be increased in kind. I'm simplifying it, but that's my general opinion.