here's what i did
1) i am using [ROM] [UNOFFICIAL] [LINARO 4.8.3] [DUAL-SIM] [APP2SD] CyanogenMod 11 [Update 20140813] here's the link >> http://forum.xda-developers.com/gala...od-11-t2827007
2) i installed an evolution kernal v1.8.1 here's the link >>>> http://forum.xda-developers.com/show....php?t=2564504 this kernal can overclock the CPU to 1600mhz
3) after that i have enabled developer options and tweaked the performance and overclocked the CPU to 1600mhz and in memory management option "Allow purging of assets" see the screenshot
4) I installed Ram manager pro and set its option to hard multitasking see the screenshot
5) I have also used GL to SD to move the game data to SD card (my SD card is class 10 sandisk) however it is not necessary even if the game is in phone memory it runs pretty well..
6) DONE NFS MostWanted is running soo smoothly and no crashes at all (it is recommended to close the mobile data while playing the game however its not necessary) i played it for 4-5 hrs till now and reached till MostWanted 7
Thanks to the respective developers for their Rom's, kernals and Mods......