Hey Patricio, our governing RC body here in NZ only allows .21 engines in truggy. You can run a bigger motor (.25, .28, .30) if it is factory installed and purchased with the truggy as a standard motor, but you must also run the pull start or roto start etc if fitted.
Once you remove the standard motor it must be replaced with nothing bigger than a .21 for racing.
A lot of guys here run the GO 5 Ports in their truggies and find they have ample power. They hold their own against Ninja, OS and anything else that comes along in the truggy ranks.
We had a few guys running the .28 motor in truggy just socially, and the 5 Port was pretty even, except for economy where it had it all over the bigger .28