high power Xray t3 help please!

[git-r]

Hi all,

Ive been gradually upping power in my t3 '12 and seem to have hit a ceiling with how much power the standard car can take

It seems the back belt can't take the power and keeps stripping after sustained use (10 mins).

touch wood everything else seems to be holding up ok but I don't want to have to keep replacing the back belt.

Anyone had similar experience and found any fixes? Could I get a stronger belt? Am I running the belt too tight or too lose?

Thanks in advance