I'm currently in the process of upgrading my mini so I can get better performance and get higher horse power compared to the base Cooper S. I've been loosely following the suggested steps found on the mini mania webpage: [FONT=Calibri][SIZE=2][FONT=&quot]http://new.minimania.com/Mini_Cooper_Performance . Currently I'm on step 3
getting ready to move on to step 4. What I'm looking at is the DINAN clearance items and I'm getting ready to purchase upgraded fuel injectors and fuel regulator along with a new throttle body and ECU upgrade. However, according to the DINAN webpage I may be violating emissions controls if I install new fuel injectors. If this is true I won't go through with this plan. Since my mini is also my daily commuter car and not just a weekend track car that I take out for fun.
[/FONT][/SIZE][/FONT]

 

Well, you have intake, exhaust, and pulley. I would look at JCW injectors next and then a tune. I have the WMW quick-tune (I love it) and I know others with the JCW re-map from a Mini dealer. That pretty much covers the basic engine mods. Due to my limited wrenching experience I stopped there. Suspension came next for me and was just as good an upgrade as the speed mods when considering fun-factor. WMW sells the JCW injectors.

I would stay away from the ECU tune options listed on MiniMania. Surf this forum for the nightmare stories from those products. Also, it looks like the "new throttle body" they link to is just a stock replacement. The Detroit-Tuned bypass valve is a modified oem throttle body that will get rid of the yoyo you feel in the acceleration. Be careful trusting a single source when choosing your upgrades (including me). It will save you money in the long run. There's lots of info on this and other forums about what people have done and regretted.

good luck to you.

 

Fuel injectors and a tune would be a good next step for the engine. Do not worry about emission control issues with the injectors and tune. During a smog check no one will be able to tell you installed different injectors or tuned the ECU. You should still be well under the emission limits.
You do not need a fuel regulator or throttle body.

As Act 04 stated, after that spend money on suspension mods. High performance drivers training (track day) is also good.