Basically if you increase the boost, you take your chances. I would not go to 10 psi without EMS. Some have blown at stock boost. Of course, alot depends on driving habits, etc. I has been shown that these cars are not very consistent in regards to what the engine, LSD, etc. can handle. If $ is the issue, then check out DSM's AFC. It is priced pretty cheap and will help you run 10 psi much safer, not to mention the gains you will get from the AFC alone. However, regardless of EMS, you have to keep in mind that the rods in this car a pretty weak. From what I've heard and experienced 250 hp is pretty much the max and that is like walking a tight rope. If you really want to build on this car, get EMS and forged internals. Otherwise, its all a gamble.