Purple Tag Steering Rack
For some reason BMW specified a quicker steering rack for the e46 compact. Instead of being 3.5 turns lock to lock, the ‘purple tag’ racks are only 3 making it an inexpensive upgrade to the steering system. All for the princely sum of £75. (Planned May 2021)
Change the final drive ratio:
Standard final drive on a 330Ci Manual is 2.93 which is WAY to tall. Future upgrade to a 3.43 or 3.73 would be more competitive giving better acceleration at the expense of top speed. Bokchoys.com have a fantastic calculator for the e46.
With the standard final drive and a the limiter set to 7000rpm gives a geared top speed of 177mph! (2.93WET225:45R17) a 3.73 final drive would reduce this to 139mph which is much more realistic.
However the Quaife differential already installed (14F) has a different offset than any differential designed to carry a final drive of 3.15 or greater. Essentially I’m stuck with the 2.96 final if I want to keep this differential. The only way on a 188K differential is to purchase a new 13F Quaife ATB at £920 +vat and replace the existing one. There is a possibility that I could buy a good used differential out of a 330i Auto with the 3.46 final drive and then buy a 13F diff from Quaife, selling off the complete 2.96/Quaife ATB to someone who wants it for road use. It would be ideally suited. At this stage it’s just prohibitively expensive. But will add it to the wish list.
(Update March 2021: I’ve found the ‘unicorn’ component that enables the existing Quaife 14F ATB to mate with a 3.15+ final drive. It effectively offsets the crown gear by 10mm to the correct offset for the 188K casing and comes with 10 longer bolts. It’s a cost effective way to get that 3.73 final drive that I’ve been looking for into the car. Made by racingdiffs.com )
Update the fire extinguisher
The rules will change in 2022 so that the extinguisher must be a minimum of 4 litres capacity, have 8mm piping and have 6 nozzles.
(Update March 2021: This new extinguisher has been installed with 8mm piping and 8 discharge nozzles.)
Data logger and race software
Aim do the Solo 2 DL which integrates canbus info from the ecu with gps from the unit to data log. You can also combine this with their very expensive camera to see where incremental gains can be had. Race logic also do a similar system. Both are expensive and probably overkill at this stage (Dec 2020)
(Update March 2021: I went for an Aim Solo 2 in the end. It’s the entry level model and doesn’t have the interface into the CANBUS. However that frees up the mounting position options and I’ve gone for a steering wheel mount which is perfectly in line of sight. Video is taken care of using a used GoPro Hero4 and a new GoPro Max 360. These can both be controlled simultaneously by a GoPro remote on the key ring. A perfect compromise and massively cheaper than a dedicated system. All I’ll have to do is match the data from the Solo 2 to the video timeline in the software.)