bought the car about 2 & 1/2 years ago, relatively stock 3.0l with a few aesthetic accessories, like Hamann blacked out grill surounds, pedals, rear spoiler and aviation style (functional) fuel filler (since removed as it looked like a stick on one) also A.C. Schnitzer short shift kit, and BMW motorsport front coilovers and full set of King Springs, later found out coilovers and springs were from an original M3R.
drove it around quite happily for a few months, then saw a BMW club motorkhana was coming up in december 04, so decided to enter, had a ball and did most events looking out side window, not fast, but fun, then started going to some circuits for some more fun, then found some deficiencies in the handling, it had far too much understeer for my liking, so new rear bisteins were fitted, front billsteins were sent away and rebuilt and revalved to suit intended track use, I also fitted noltec adjustable solid camber/caster plates at same time, next was motorsport chassis brace and ebay front strut brace, this improved handling a great deal. then I saw a cutaway of the inside of a muffler, they are very restrictive and heavy, so decided comercial ones were a ripoff, so set about making a muffler, I aquired some 304 polished stainless, and perforated 2.5" stainless tube, made what is basically 2 muffler internals, each with 2 X 2.5" straight through perforated tubes, sat them about 50mm apart, end to end on stainless sheet, and wrapped it around and welded, then took it to exhaust place and they bent up cat back pipes and fitted, next was replacing 27Lb duel mass flywheel with 8.5Lb alloy flywheel and M5 clutch. the muffler and flywheel lifted power from 170.1rwkw to 191.1rwkw, so it was quite an improvement, during this time, I also bought second set of wheels for R compound tyres, they are single bigggest improvement in lap times you can get in my opinion (and still be road legal) next on list was enclosed pod style filter, and different E Prom chip that raised rev limiter from 7600rpm, to 8000rpm, this further lifted power output to 199.6rwkw
in amongst all that was several track days, skidpan days, hillclimbs and drags, the net result was a lot of worn out tyres, and stripped splines on LSD plates, so a replacement open 3.64 diff was purchased to replace the 3.15 with non functional LSD, a couple of steel plates and an hour later, I had CIG locker 3.64 diff. then after being happy with the way it was going, had almost dialled the understeer out, I spotted a group buy on suspension components, so I purchased some powerflex rear trailing arm bushes, and an H&R adjustable rear sway bar, these have done the trick nicely, and car is very nearly totally neutral now. then by sheer chance, I spotted an ad for a carbon fiber plenum for about 1/4 the price they usually go for, so I snapped it up, and went searching for Alpha N (maffless) chips to match, ended up finding some copies of now defunct, but highly respected H&H racing chips in Holland, a few emails later, they were on their way. I had a few fitment issues with plenum, and gained over 2 mph at drags (best of 106.48mph), so is definately making more power, but haven't been back to dyno with it as yet, heavy front seats were replaced with some lighter ones, and with only 1 seat in car, and all door trims, boot lining etc removed for a trip to drags, still weighs 1440kg, so circuit race weight is around 1550kg