This Velocity Stack Kit has been tested extensively on our demo BMW E46 M3 which is driven daily we have covered approximately 20,000 miles over a 2 year testing period and we have found no substantial impacts on drivability, and it responds well to all types of driving environments and weather conditions.
The conversion responds very similarly to OEM at low rpm (sub 3.5k rpm) and then comes into its true power at mid to high range power.