[Ant]

Not being an expert, but having driven a variety of fast cars on circuits here in NZ, I remember going out in my first race with about 100bhp in a Ford Anglia on slicks, in those days 1970's we had cars like the PDL Mustang (banned in Aussie, and not allowed to race in the US) , this car was ahead of its time cleaned up, when you get this yellow streak and about 20 fast V8 sports sedans going past at the end of the straight and your little Anglia physically gets pushed off the track, with the wind pressure and me hitting the edge of track, as I was on pole, being slowest, one learns about horsepower and racing quickly.

Most of the people in CC who say that 300 and whatever horsepower is enough, they are right for a lot of people who have just got interested in these cars, a lot of guys haven't done any driving on the track in competitions, driving 600hp on slicks took me some time to get the momentum up and start to produce some good lap times, having said that now I am a bit to agressive in my old age and make every lap count.

I would think if your car has a good chassis, tires and is setup properly somewhere between 400 - 500bhp is fine in a lightweight car, and then that depends on what size engine, a smallblock is more driveable, and if you have a BB then you get that sheer grunt, these cars can be driven with the tail out if they are setup, but I found with BB 600+hp I would bascially show off and give it the gas a bit early and start going from one side of the track to the other, and my heart would beat a bit faster. Tires are a big issue, get good tires and they will transform your car, most street or performance radials are wanting!
A lot of exotic road cars with 550+hp etc are either 4WD or rear engined and do put the power down extremely well! In a 2wd Cobra this task is a lot more difficult.
Thats my $10 worth and I still get a big buzz out of these machines, when I get this one going I will probably make a Joe hunt of myself!!