While there are plenty of cars that come from the factory fitted with engines that are plenty powerful; however, there is no doubt that for some gearheads a stock engine is never enough. For these people, a stock engine is just the beginning, a stock engine is an engine that must be tuned in order to flex every single bit of horsepower out it. Click play to see the nine nastiest custom tuned engines you will ever witness starting with the Subaru EJ25 and EJ20. You will have to watch the tuned car video to learn what the other insanely tuned car engines are.
Wait. What!? Check out the below video for more crazyness!