Could anyone have any idea what bolt ons would have the most impact on my 08 Elantra. And if I can turbo or not.??
Elantra performance parts are probably pretty scarce. Do some Googleing for Elantra performance parts or post on an Elantra forum. Turbo is possible, but unless there is a kit made for your car it would be very expensive to build a kit from scratch, install it and then tune it. Perhaps if you want performance choose a different vehicle.
The best add-on for hp besides a turbo is a custom exhaust system. Buy one off the shelf or have one made at a muffler shop with a tube bender. Note: A single 3" pipe will flow more than duel pipes. And use 3" inlet & outlet cat convertor & muffler too. If availible install tube headers.