3.5" air intake [Archive] - Bimmerfest - BMW Forums

: 3.5" air intake

05-26-2008, 08:17 PM
I've heard an easy HP upgrade is changing from the stock 3" intake & filter to the european 3.5" airflow MAF and aftermarket cold air intake. can anyone validate that w/ experience or facts? can i keep the stock air filter and just change the airflow MAF and get the same results? are there any risks to making these changes?

05-27-2008, 06:04 AM
To get the most power, you also need to change the software.

The OBD II cars (96 and later) do not respond as well to bolt on mods as the OBD I cars do. With OBD II you need to replace the cams to get most of the possible HP gain. With the OBD I cars, the cams add like 20% of the max gain. On OBD II it is more like 20% form bolt ones and 80% of max for the cams.