Project BMW M3 Part 6: Acceleration Testing

Due to the unavailability of the coastal test site we used for baseline tests, Project M3 was instead taken to California Speedway for acceleration tests. The same Pirelli P7000 Supersports used in my baseline tests were used this time. I took the average of the two fastest times for each category.

The car was tested with the Schrick cam and Supersprint exhaust setup--no pulleys had been installed yet. If you recall in my baseline testing, my launch rpm was 3600. Now, because of the AA clutch and flywheel and the torque improvements, I had to drop the launch rpm to 2600 rpm. What was worse, if I accidentally went up to 2700 rpm, I'd end up peeling out in place, whereas a 2500-rpm launch bogged the car down too much. Nevertheless, wheelspin all the way through redline in first gear was inevitable--the hard-compound P7000 tires wouldn't grip. I really tried to break that 100-mph barrier in these conditions but was stuck at 99 mph in every one of the seven runs recorded! I bested a 13.93-sec. quarter-mile run in these conditions, with three other runs at exactly 14.02 sec. Because of the lack of grip, notable improvements didn't happen until after first gear (notice the improvements in the 30-to-70-, 50-to-70- and 0-to-70-mph comparisons).

The other factors that played an important role were the altitude and temperature. In Fontana we were at 1,200 ft, versus our 100-ft baseline testing on the coast. The temperature this time, in the middle of summer, was 90* F. By contrast, our baseline testing was done in mid-60*F weather. To give a better idea of the new upgrades' performance, I also included corrected acceleration times using NHRA correction factors for altitude, temperature and barometric pressure differences. Fortunately, the baseline tests were right-on.

Given the conditions, Project M3 performed very well. In the end, I compared trap speeds (a good indicator of lb/hp) with another car we had testing out there, which happened to be none other than a 280-bhp Japanese-spec 2002 Mitsubishi Lancer Evo VII. Even though the Lancer, with its all-wheel-drive advantage, had the Project M3 beat by over 3/4 sec. to 30 mph, the trap speeds were almost identical. That was good enough for me. I firmly believe that given a good set of sticky, summer tires and good testing conditions, this car would have been capable of a 13.6-sec. blast at over 102 mph.

Author's note: With the clutch/flywheel upgrades and previous 229 rear-wheel hp setup, as seen in Parts II and III, the M3 posted a 0-to-60-mph run in 5.46 sec. and 1/4-mile time of 14.11 at 100.0 mph on my first and only run, before the radar gun went out of whack. This was done at the same location as our baseline tests but on a 12*F warmer day (77*F). The baseline 235/40-17 Pirelli P7000 all-season Supersports were used as well.