I would recommend the Hahn stage 4 or Werks stage 2. I like the DDM stage 2 supercharger, but I understand it is 240hp. Both turbo kits are 60+hp on the DDM. The downside is the money. You want the insurance that any car that pulls next to you and revs up is going to be left with their jaws dropping.
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2007 gxp solstice loaded + smokers package
2006 cobalt
2007 Corvette
2006 lotus exige
2005 hayabusa
Red Bull Drift team 2008
Team Yankee!