Originally Posted by Pete_vB
Not sure if you've missed the point. Stiffening the back springs as you've done as well as presumably stiffening the shocks has been the cause of the increased twitchiness you've experienced. Going stiffer with the mains is unlikely to help.
Find a good setup guy to test the car, not just a good driver.
I get what you're saying, but I also know that general guidelines are just general guidelines. There are many exceptions to those rules. I chose to avoid directly answering some of your questions because of the possible of ensuing internet argument; I despise internet arguments. The truth is, I know which direction the setup is going to go. And yes, I do have professionals working on it.
The 1M forum seems to be all about HP figures, selling crap, stupid ass "exclusive" polo shirts. So, I made this post just to stir up some actual suspension talk. The transition to oversteer in my car is actually better than it was stock, but not as progressive as an m3. So it's not bad, it's just not where I want it.
Originally Posted by robertm
One thing you might consider doing now is switching to r-comps. Lots of little adjustments needed when you switch and if you are at the level of playing with valving and spring rates then it seems a wasted effort to do so on street tires only to redo everything again once on a proper track tire.
Removing the rear sway seems a blunt way to fix a problem that's likely not solely related. When are you getting the sudden loss of grip? Spring rates and high or low speed valve adj are usually the best avenue of adjustment. Possibly initial static alignment could be an issue too? Changing out factory bushings may help as well. Another source of information would be the M3 track guys; dynamically a bit different but still very similar geometry and hardware. I'm just spit balling here but let us know what you end up with!
Because it's a street car that will mainly be used with street tires. I'm not racing, nor do I care about lap times, so ultimate speed on R-comps isn't something I plan on chasing. They'll just be applied whenever I feel the itch and put back on the shelf once the rash is gone.