Standard stuff is fine as long as you don't go mad - on a well specced/built/designed engine (such as for example Rod Tarrys) he can run 150bhp, possibly more with no issues.

On a car with tired old parts, or with an already iffy head gasket 50 bhp might be 'the straw that broke the camel's back'

Basically a healthy Cossie engine should happily run 50bhp, and more with a controller and sensible basic uprating of parts - you'll find most likely that your ignition system will be one of the weak links - you need a good strong spark for Nitrous - something a lot of Cossies lack, hence the popularity of Stu's Coil pack coversions!

My advice: Get your engine checked over by someone who knows about healthy Cossie engines! Only fit nitrous if you're confident everything else is up to it - good tyres/brakes, healthy clutch etc.

Take it in steps = start at 25 bhp and only go for more power if you're sure it needs it and it can take it!

If you can afford it - do it... I'm going to!

Simon