Hi I was looking at the Thunder Tiger GP-61 motor to go in my new Twist 3D but what size prop would be a good one ?

I'm new to the 3D stuff, sorry if this has been asked already I could not find any post on the Thunder Tiger GP-61.

thanks for any help I may get Leesops

Try the APC 14x4 ...

Based on my experience with a TT-61 Pro, the 14x4 is probably too much.
My engine, running fuel with 10% nitro, works great with the APC 13x4W '3D Fun Fly' series.

If you relly wnat allot of pep for that engine try the 11.5x4 or 12x4 those props are great for it.