I had a GP for 2 years now, I wanna to power mod it, I read another thread saying the GP engine is different than JCW, if so, what did they improve in GP? I also want to know what power mods does GP use.

 

The engine and the turbo are the same as the standard JCW.

For mods the first thing I did to my GP and would recommend first is a Forge front mount intercooler. It will lower intake temps and give you noticeable gains.
http://www.waymotorworks.com/forge-a...r-s-turbo.html

 

I heard the gp has a higher compression than jcw? Is that true? If so isn't jcw engine has more benefits of tuning?

 

The compression is the same on the GP and JCW, which both run lower compression than the cooper S.

The main thing that is different on the GP engine wise is a different ECU tune from factory. This allows a higher output, 160kw compared to 155kw for the JCW. This applied in most world markets, but I think in the US the power output was the same?

 

The power is tuned slightly higher in the US also. ~207hp (JCW) vs. ~211 hp (GP2).

Edit for correct numbers

 

211 HP in the US (per MINI USA)

There are some revisions in the cooling system too. I believe the radiator is angled differently and the system operates full time on a special cycle to keep the motor cooler. I'll have to find that reference, it was from MotoringFile.

Here is the official US spec: http://www.motoringfile.com/2012/09/...-jcw-gp-specs/