I ran a 10 x 6 on my arrow I think and 11x6 is too much
took the flywheel off and baffle out the muffler to really woke it up
also glue the tail on and add some epoxy fillets around the firewall
I also added a secound aileron servo and set it up with flaps really slows the landings down
It really was a fast plane after the mods until I violated the laws of physics and shared the same airspace as my son-in-laws Alpha
I lost that one and re-kitted her