I have a 2008 scion xd with a stock engine and i would like to know if i should do a full engine swap or just soup up my current engine. Which will be faster? Better price? Any help is much appreciated.

 

it would be more wise to work on the engine already in the car.

 

Why? Any specific reasons?

 

Because swapping in an engine, seriously, any engine other than the one designed for that car will be a major PITA. Because of the wonderfully complicated computers, sensors and electronics involved and the harnesses, just being able to shoehorn in a different engine doesn't mean that once hooked up, you can just turn the key and off you go.

To get an idea, read this and think about it for a bit. http://www.caranddriver.com/features...n-mazdaspeed-5

the most cost effective way to add power to a car is a good turbo kit. Swapping engines in modern cars not quick, easy, fun or particularly fruitful.