[Update 03/09/15]: As of update 3.6 this method is obsolete, RR3 detects this file with a special signature in it. Removing it, improperly editing or placing a blank file with the same name will force close the app as a "critical file is missing". Time Travel is back though if you haven't noticed (at least for me). Scratch that, stopped after first use.
[Update 18/08/15]: Member of MRR 'Tin' has put out a warning that using this method now risks a permanent ban if FMEA can detect you (us) cheating the system. Use at your own risk. I haven't been banned yet because I mostly play offline to begin with. They probably can't detect anything while offline by speculation, but a risk is a risk.
I have an S4. Looks like the Devs put some new feature that automatically gives an "out of sync" message if you kill internet connection, leave game (whether it be force close or tabbing out) and return. I've tried countless varients of time travel which all resulted to null. No jump in time at all no matter what I do.
Time travel is dead on Android, for good or for bad.
However there is a solution. Maybe go to the topic "Save gold on repairs" and you can rejoice on something greater than time travel - the power to remove time.
Cars don't even deteriorate after races, thus no need to service!!!!
Forum URL Link: http://myrealracing.club/thread/11872/save-gold-on-repairs
[Thank you based Tin I owe you my life]
[Also read a bit further in the thread before you go to operate on the files]
After you have read a little from Tin's thread:
Make sure you force close Real Racing 3 before you remove the files - launch after finishing the edits. Savour that instance of beating the system - FMEA's game. I also would go with a suggestion by another member to nullify the "carrepair.repair" file by renaming, or simply removing or adding a character.
I will say though, I haven't seen a solution for negating the wait times of upgrades and bought cars (I have yet to test any of those with anything). I neutralised the "carupgrade.upgrade" file but it just removed the upgrade feature. Upon entering the upgrade tab of a vehicle you are faced with, well, nothing. Maybe a solution will come later.
Anyway this is a life saver. So far there are no problems or wierd glitches to be seen. I doubted this method since it was for a previous update but, well, it still works here with their new fancy overhauled update.
Be sure to rep+ Tim for this revolución. Without it I think I might have lost the will to live.
THANK YOU TIM
If anyone wants detailed instructions on how to do some magic (although it is fairly easy) I might put down the steps I took on my Galaxy S4 with screenshots. I don't know much of other devices besides Samsung's but the process should be similar for all Androids. I'll help if anyone desperately needs assistance.
