I am considering getting a Downing/Atlanta supercharger for my 1997 1.9L Z3 that is just about to go off warrenty (49K miles & 48 months). I'm not interested in racing, but hope to make my Z3 drive as well as it looks. I hope to hear pros and cons from people who have actually made, seen, driven, or done this modification. Specifically, I hope to learn:
1. How is the performance, fuel economy, noise, requirement for 92+ octane fuel, reliability, etc.
2. Are there any BMW clubs or other groups that receive a discount from D/A for the Z3 supercharger (D/A quoted $3,395 for the complete kit + $55 shipping).
3. Does the modification affect the reported MPG, etc reported by the onboard computer?
4. Did you find that you needed other modifications to realize the benefits of the modification (exhaust, snorkle intake, etc). D/A recommends that they be performed after the mod, if at all.
5. Did you do the modification yourself - if so, would you recommend self-installation? How were the instructions supplied by D/A and did you encounter any other expenses or require supplies that weren't included in the kit?