it would cost big money for a twin turbo set up and to strengthen the internals just for a mid 13 sec car...
* you would probably need to upgrade the injectors, im not sure what the standard injectors are rated at but im pretty sure they wouldnt be sufficent enough for a turbo charged set up.
* you would definately need to copgy back the stock ecu, if that is possible. i dunno if re-mapping is an option but if none of those options are available you would definately need to change the ecu.
* you wouldnt need to change the internals, but it would be good idea...
and a 2nd hand garrett turbo is always going to better than any kkr turbo. the cheaper you keep the set up costs, the more problems your bound to have with the set up. your better off getting quality parts from the start if you want to turbocharge your non turbo engine...
i would choose to supercharge my car if were looking at boosting my engine. less hassles and by the looks of things alot cheaper...