I own my cooper S for over two years now and I am ready for more power. My goal is to get as close to 300hp without touching the bottom end. Any advise on how best to proceed? What are the weak links in this car? Can the tranny handle that much power? What upgrades are needed to do achieve this much power? Any and all suggestions are welcome. Thank you.

 

300 hp is going to be almost impossible to reach without bottom end being built ... All the 300+ mini's have had extensive bottom end work to handle the power ...You don't state what tranny you have auto or manual , so can't comment on the tranny ....
Another question is how many miles on the motor ?? Higher mileage the motor might not take the extra stress on the motor...
Good starter work is the largest underdrive pulley for the S/C , crank pulley , headers, exhaust and intake, JCW injectors with a proper tune can get you around 240hp or so

 

You won't get near 240hp without head work and almost no one has any bottom end work done... the R53 engine is bullet proof. There's plenty of guys between 300 and 500 hp on the stock bottom end.

To get 300whp you're looking at twin-charge or turbo only. It's not going to be cheap or easy. If you do head, cam, injectors, intake and exhaust and tuned by RMW you should be in the 240-250whp range.

 

I have a manual transmission and the car has 37K Miles.

Adam,you are the second person to tell me the bottom end is strong. What do you know about the tranny? How much power can it handle?

What brand would you both recommend using? I notice a few manufacturers offer a19% S/C pulley, but I heard detonation is possible at high RPM. What brand and size pulley would you recommend? Which camshaft would you recommend? What computer? Piggy-back or re-map? Who does good head work on Minis?

I am not going to go turbo. Too expensive. I definitely plan to do the head work, the usual bolt on partsand throw a cam in it. I am considering Nitrous. Maybe a 60 shot. Single fogger Wet kit.

 

The transmission can take as much HP as the bottom end. A good clutch is a decent idea though.

Pulley, stick with 15-17%. Head, cam, injectors and tune should all come from Revolution MINI Works if you're looking for big power. Trust me, once you get all that on and tuned up you should be in the 240-250 WHP range and you won't need any more.