Sorry the original post was short - I haven't had a chance to read all the reply's yet but thought some might want to know what the results were on the 3.8 after a Supercharger. It is a RIPP system. The install was fairly simple. The boost is fantastic and comes on great throughout the RPM's. It is a lot of money - about $6,800 including long tub headers, hushpower and MBRP SS exhaust. I have a 4 1/2 inch lift (radius long arm), 37" tires, 5:13 Yukon gears, Rubicrawler gear reduction, and a bunch of Smittybilt parts on the jeep etc about 30K in total extras. It's a 4 door 2010. I will post pictures soon. Ripp did a great job tuning this S.C. for a jeep - no doubt it was worth the money for me personally - it's a chunk of change I agree. My jeep weighs 5,900 LBS and was a slug and now it just drives a lot easier and I'm not always mashing the gas to get the jeep up to speed. It's great 4x4ing as well - getting the Blow-Off (by-pass) valve set right is really key - Love the JK - as I have 2 other jeeps 75 CJ and a 79 CJ.