After doing a lot of searching and reading everything i could find on the 2.4L world engine (3rd gen optima engine) i have found out nothing but great news. Everything i have read over the past month says that the aluminum block and internals are engineered to handle heavy engine loads. This means it can handle extreme temperatures thus resulting in an engine that can take alot of horsepower very easily. Some sources say 300 horsepower is safe. Here is one source, it is from the SRT-4 Caliber (same engine, but with TD04 mitzu turbo).
2008-2009 Dodge Caliber SRT-4 / SRT4 Review - Modern Racer - Auto Archive
So, sometime in the near future the options are going to be endless. And, hopefully, this could turn out to be one of the best street racing motors to date. Maybe it'll finally put KIA into some serious performance. Keeping my fingers crossed!