Hi, I’m very new to this and have a 2005 mini cooper sport with 108k miles and 17in rims, I’ve seen a lot of conflicting data on engine mods and was wondering if I could get some feedback on a potential build. Car is bone stock right now and my goal was to try and make around 220hp, I’ve seen a lot of arguments on pulleys and intercoolers (aftermarket or stock) and lack of power from stock SC. Plan right now would be fuel injectors, fuel pump, 15% pulley, cai, stock intercooler?, r56 calipers, and a new clutch (makes a clattering noise rn). Please give feedback and brands you would recommend (and a bunch of supporting mods I prob missed), you guys definitely have a lot more experience than me

 

First - get it back to a good reliable state. Not sure of your diy skills. Upper and lower motor mounts ( there are 3 mounts ), pass side upper mount is fluid filled - a tar like substance on the outside means it is done for. Lower mount does get soft over time. Sertpentine belt and tensioner ( and idler bearing ). FCP euro has a lot for that. Do you have any service engine codes, or is the light on? There is a bunch more stuff, but we can start here.

 

If you have a clattering noise when using the clutch its probably a broken dual mass flywheel.

I'm with @noodlesandsam , R50/53 Minis need extra attention in the gaskets and orings area. The engines are strong but very prone to losing oil in various places. So check and replace the crank and camshaft position sensor orings, the oil filter housing gasket, the oil pan and valve gaskets and the dipstick tube oring.

If you change the pulley also make sure to service the supercharger with fresh oil and replace the water pump as well as it will be spinning at higher rpms since its bolted to the back of the supercharger.

 

Here's an example: My MC40 has 380cc injectors, CAI, 15% pulley, colder plugs, stock intercooler, face-lift ECU, one-ball exhaust and a tune. It pulled 193.50hp at the wheel on the dyno and that equates to approx. 220hp at the crank (using a 15% loss factor). Since I don't track it I probably would go with a 17% pulley next time for a bit more boost. It's a blast to drive and totally reliable.

 

So…. I have an 05 with Auto. Dinan CAI, Dinan pulley, UUC catback exhaust. Colder plugs. Also bypassed trans heat exchanger to a true external cooler. No idea what the hp #s are, but it’s a blast.