i don't believe the hp numbers are that high. i think 450 is more usefull and believable in a course w/alot of turns rather than long straights.

 

those car actually make more torque than HP, i think i saw one that made 300hp and 480tq. 1000hp would be kinda hard to control on the dirt AWD or not

 

It's true.
I''ll see if I can find some old movies of them. They were much faster than F1 cars are now...
For instance there was a Metro(model car), they put in engines toping over 1000 hp...If you'd ever seen the Metro... You wouldn't believe your eyes. Its a very small car.
Lancia had an 1600cc engine with about 650 hp!! Ford did also, with their FORD S200 or something.And that in the eighties.
This class was introduced with no limitations. You could do what ever you wanted(more or less), I believe only rule was that the car or bodyshell was in production.
But ther were way too many people killed so they banned the group B.