Big discussion going on over this on a different Forum. Kenne Bell actually weighed in and said that it is a waste of money for 7 hp. Driveability problems as well as tuning. He said it lowers your boost about .5 psi. Another point he made is people put his kit on with headers,don't get the HP they expect and blame his unit for the problems. He asks that you put the headers on first,test it, then put his kit on so you don't blame him for performance issues.Someone replied another tuner other than Kenne Bell but that tuner weighed in and backed Kenne bell up. The whipple unit is also in the hunt. Interesting to see there numbers. I'm going to copy cgoeschel as he's definately done his home work. GGBIWcgoeschel, did KB indicate why they did not recommend headers with their supercharger?