First of all i would like to inform you that if you were in my situation like i was, unable to use my phone for an amount of time (2 weeks in my case) because you flashed a wrong room to your device ZTE Racer 2 than you are in the right place.
In order to recover your Zte all you need is a sd-card for it, and a card reader or another phone connected to pc i order to have access to that sd card too add some data to it.
Ok so here are the basic steps:
1.First download this http://www.4shared.c...stock_rom.html?
Now all you have to do is to extract the archive into your pc.
So basically you will have update.zip and stock_rom.zip
2.Copy the update.zip file into your sd card root folder
Now create a folder on your sd card name it lets say roomfolder and copy the Stock_rom.zip file there and rename it to update.zip (very important to have this name)
3. Insert the card into your Zte racer 2 and make sure you have some battery left on it (also disconnect the usb cable from your pc if you have it connected)
4. Power up your phone by pressing Power button+volume down at the same time, wait a couple of seconds and than after the screen changes a logo with and android and a warning sign appears.
5.After you get that android logo press both volume top+volume down at same time and notice some options are available there, you need to select apply sdcard:update.zip. After you select that a custom boot app will be launched.
6.Select wipe all data/factory reset and wipe cache partition from there to remove corrupt flashed room.
7.After that chose install zip from sd card and again press install zip from sd card .At this point you must find the folder that your created (i named it roomfolder) and click on that update.zip file.
8.At this point the installation of the room begins wait a couple of minutes until is complete and reboot your smartphone
AND ENJOY your ZTE again.
NOTE: the first time you will power up it , it might take some while just have patience.
My stock rom was something like ro.cosmote.zteracer2 now it says
This tutorial was based on weeks of reading forums on internet so i want to thank the persons who published those files to the internet.