When the BMW E46 3 Series was released, the entire BMW aftermarket went into a frenzy trying to be the first to offer performance enhancements. In order to see the potential of some of today's upgrades for the E46 BMW, we got our hands on a 2000 BMW 328i. For the tuning toys, we contacted Active Autowerke to test its chip, intake and exhaust upgrades for this model.
Probably best known for its turbo applications (as used on Project M3), Active Autowerke has been in business for more than 20 years and is an authorized Bosch service center. The company specializes in making some of the fastest BMWs this world has seen, but it also supplies many entry-level upgrades.
Active's exhaust features 100% polished stainless steel, a large 70mm mandrel-bent inlet pipe and dual 76mm tips. Active reports the exhaust flows up to 40% more than the stock unit. To test the exhaust, we strapped the car to our Dynojet 248 at the Primedia Tech Center. The car registered peaks of 175.4 hp and 182.4 lb-ft of torque at the wheels. Technician Dominic Conti then put the BMW on the lift and went to work on the exhaust installation.
To replace the rear exhaust, the pipe leading to the center muffler had to be cut. Dominic measured precisely how far down the pipe to cut so as to create a perfect fit of the AA exhaust. Before the installation, I weighed both the AA exhaust and the stock unit. The AA exhaust was only 1 lb lighter, but we saw its real advantages on the dyno, where the car made power down low and in the midrange-increases of 6.1 hp at 4240 rpm and 9.1 lb-ft of torque at 3350 rpm, to be exact. Above 5000 rpm, the increases were minimal. Nevertheless, driveability around town was improved. The system can't be considered loud, but it does emanate a nice, solid rumble.
Desiring more power, the car's owner sent off his ECU to AA. This was required because, for non OBD-I cars, the chips have to be soldered on to the ECU circuit board. AA's turnaround is three business days. We also received an East Coast Induction Systems intake. The system includes a K&N conical air filter, an adapter and a double-insulated heat shield and was designed to replace the factory air box. The ECU maps are changed, the rev limiter is increased to 7200 rpm, and the speed governor is removed. Both units were easy to install, the job taking just over half an hour.
Back at the Primedia Tech Center, Dominic placed the car once again on the dyno, and this time we saw even bigger gains. Not surprisingly, since the exhaust only helped out at engine speeds up to 5000 rpm, our biggest gains with the ECU, intake and exhaust over the AA exhaust alone happened at higher engine speeds, with 13.3-hp and 10.8-lb-ft gains at 6500 rpm. The car was considerably improved throughout the rev range. Compared to the baseline runs, the final configuration made power everywhere. Peak power increases revealed 13.1 hp at 6480 rpm and 14.0 lb-ft of torque at 3570 rpm over stock. Testing was done using 91-octane fuel, and no smoothing features were incorporated into the graphs.
So, what do all of these numbers mean in real-world driving? During a test drive, I discovered that the car had a little more grunt to it and a nice, roaring intake sound at higher rpm. With the new rev limit set to 7200 rpm, the car pulled all the way to 107 mph in third gear! But, as you can see in the dyno charts, the power begins to drop off after 6500 rpm.