Level R Singleplayer Hack?

Hi there,
can anybody tell me if there is a hack for level r? i dont mean for the online mode, but for the singleplayer challenges ... they are not really serversided i think ... there must be a posibility to get infinite time or something ... can anybody help?

I'm not a genius in cheat engine but at least i know that the time is recorded client-side and sent to the server. So if anyone knows to work with cheat engine, it should be an easy task :D