MKC technician, Nelson, quickly got to work on our pulley installation. You’ll want to allow a few hours for this. Notice the intake system is gone, and now he’s getting to work on removing the fan shroud and fan.
Removing the shroud is a more complicated procedure on an E46 than it is on an E36 M3. We won’t bore you with the details but, as a previous E36 M3 guy myself, I’d much rather have to work on an E36 M3 than E46 M3.
A view of the VAC water pump pulley going on. It’s possible to do this job without removing the radiator or alternator, but it is a tight fit.
With the pulleys installed we felt a noticeable difference. And, while our peak horsepower numbers only went up by a handful, there were several areas between 7000-8200rpm where the gains surpassed 8whp. Not a bad, uncompromised bang for your 250 bucks in the M3 world!
All told, we gained 12 horsepower at 7000rpm and 5 lb-ft of torque at 4300 rpm with our new Corsa cat-back and VAC pulleys installment. The car feels stronger—like on a colder day—with a 4whp gain throughout the midrange and an average 7-8whp gain in the upper revs.
While we couldn’t get good torque readings, we had to plot against vehicle speed. However, looking back at the broken-up graphs we could see peak torque figures rising from 248 lb-ft (from our baseline) to over 252 lb-ft, with the largest gain being 8.2 lb-ft at around 3200 rpm (54mph) with our exhaust and pulleys combo.