The car in the second video uses a 4 cylinder Volvo motor. I think that it is a B23FT with a B234 16V head. The B23FT was the strongest motor Volvo ever made, but they have become hard to find. The most that I have ever seen this engine make is around 750HP. This one makes more though.
http://www.volvoforums.org.uk/showthread.php?t=115858
The B230FT is about the same as the B23FT, but not as strong.
Here are some videos:
http://www.youtube.com/watch?v=Lf1_dDU19P8
http://www.youtube.com/watch?v=ks9o7nYhX00
http://www.facebook.com/video/video....50174239271749