Just recently put the 15% craven speed pulley onto my 2005 MINI. I really like the instant power gain, best bang for the buck. Going in the middle of June to get it tuned because it is running a little rich right now.

 

If anything it should be running lean compared to when it was stock. You're adding more air to the mixture. Not that I wouldn't recommend getting a tune, but maybe do an intake and exhaust prior to the tune to round out the package a bit more. Larger injectors wouldn't hurt either at that point.

 

I already have a CAI and borla exhaust, ithose were the first mods I had to add, does yours ever backfire?, my mini is backfiring like crazy and I am pretty sure it messed up my exhaust

 

The 2005 is programmed to "poot", a mini backfire....made louder bt an aftermarket exaust....some love it...but many thought their cars were not running right....mini later removed this audio feature from later software....
You car will run LEANER with you mods....same amount of fuel....more air.

 

yeah i was reading that they had done that when they made my MINI but this is no little "poot" haha. It got way worse after i put the pulley on it. Guess ill figure something out