After all these upgrades, some testing had to be done to validate the improvements. But before testing, I contacted Brad Schaffner at George's Imports once again and ordered the Aquamist DDS2 display unit. This unit is spliced into the hose before the water injection jets to read pressure and the presence of water. The signal is then transferred to an LED readout in the cockpit so you can rest assured the water injection is properly working.
After tuning the water injection to the M3, I have become quite reliant on it to lower intake and combustion temperatures, especially for the road course.
This month testing only happened at the dragstrip or, in this case, the airstrip. Just for safe measures, Sunoco 112 Octane fuel from Downs Commercial Fueling was used. Race fuel, especially with a motor octane this high, brings real peace of mind. I've tested various fuels from Sunoco, and they all work extremely well. I wouldn't be caught dead with a full tank of 91-octane pump in this tank unless I was running less than 9 psi on the street--forget the race track.
No burnouts were used to preheat tires, and launches were done without dumping the clutch. Even with these easy launches the car had some serious traction problems at the 15 psi boost setting until I shifted to third gear. This was expected with the stock 3.15:1 gearing, because I was more concerned with the 50-mph and beyond acceleration times.
To get more traction, however, I clicked the Greddy boost toggle switch on the steering wheel to low boost for the first two gears and made a couple more passes, clicking to high boost for third and fourth. In drag racing the speed at the last 60 ft before the trap is averaged, and my goal was to achieve 120, but we saw just over 118. I'm sure this had something to do with the very fuel-rich chip, which has been dumping fuel at a 10.9:1 to 11.1:1 air/fuel ratio--I'll have AA lean it out to mid-upper 11s soon.
Even in low boost launches (at 8 to 9 psi) the traction was so bad I couldn't better the 0-to-30-mph times I had with the car's stock 213 whp and 235/40-17 Pirelli P7000 Supersport tires at the same airstrip. However, grip was achieved in second gear at low boost, resulting in a much quicker 5-sec. blast to 60 (30 to 60 mph improved from 3.5 to 2.7 sec. at low boost). If I could only match, let alone improve on, the stock 0-to-30-mph times, I'd be seeing mid 4-sec. blasts to 60 mph. On slicks this car should be able to do it in four seconds flat in the high-boost setting, easily.
High boost launches were even worse that day because the loss of traction, now in second gear, resulted in not much of an improvement in 0 to 60 mph from stock. Let's just say it's good for show boating, and the car definitely needs bigger rubber--or drag radials--to make use of that kind of power in second gear.
The real gains came from third gear on: Nearly half the time was shaved to go from 70 to 100, and it reached a speed of over 120 mph in the same time it took the stock car to hit 95 mph from a standstill. And the last eighth mile only takes 4.3 sec. in this car versus a stock M3 averaging 5 sec. That's a 100-ft advantage from the last half of the dragstrip alone. From third gear on, an AA Turbo M3 doesn't walk but runs away from a stock E36 M3. However, those of you into drag racing may want to get some drag slicks to put the power down. I hear turbo M3s have seen upper 11s this way.
One very impressive aspect of this project is the water injection. It virtually eliminated heat soak. On the dyno, three back-to-back runs yielded practically no loss in horsepower at 14 psi. On the dragstrip, a heavily loaded fourth gear produced 100-to-120-mph times that ranged from 3.13 to 3.15--only a 0.02-sec. variation from four back-to-back quarter-mile runs with no cool down in between. Stay tuned; Project M3 will return to the road course next.
Special thanks to Stoptech for its assistance with the quarter-mile testing.
Downs Commercial Fueling Inc.
George's Imports Ltd. (Aquamist system)
Sunoco Performance Products
(800) RACE GAS (722-3427)