It has been a while so time for little update as we get ready for the 2019 season.
Right now the car is at Turner Motorsports for the rear diff.... FINALLY I pulled the trigger. I went with diffsonline 3 clutch with 35/60 ramps as recommended by Dan from diffsonline and Brew at Turner for our platform and my application. I also upgraded the diff bushings with the Powerflex 95A track/race.
I removed my JB4 and had Turner do a dyno Cobb Pro-Tune. These are my crank numbers with stock turbos, pump gas and mid-cats still on the car. The 3 runs are separate maps: base setup, wet map and full power. You can see the limitation of the stock turbos in the plot.
I have proactively replaced the rear link hardware with ARP bolts given the single shear design of our links. At the end of last season I also proactively replaced the rear lower arm camber bolts since after my local BMW tech shared horror stories of damaged subframes from these bolts seizing or shearing on removal.
I also added the Hard Motorsports rear upright kit (e90 fitment) with the 67" APR wing. Good news, there were enough threads on bumper studs that I am still able to run my trailer hitch.
To balance that rear aero I also picked up an e90 M3 front splitter from Hard Motorsport. I needed the added width to match the Evolution Racewerks wide body. I will install this after I get it trimmed up.
I have stripped out the headliner from the half cage forward in preparation for the carbon fiber moonroof panel install. I will report back exact weight savings once I complete. Note: the moonroof control panel throws an SRS code if unplugged due to the passenger airbag light. Since I am still road legal I temporarily moved that panel into the glove compartment.
The e90 Hard Motorsport radio delete panel also fits e82 without modification.
Yesterday I ordered some Federal FZ-201(Soft) in 265/35-18. I am curious to see how they hold up and plan to try the Medium compound later this season as ambient temps rise.
I post some more updates and thoughts on the aero once I get out on track later this month.