ORIGINAL: NOVAflier
I have a few questions, I just acquired a .60 size that I am installing a Saito 100, Cline System, and a 15 x 6 prop. My main concern is with the CG. Where would be a good place to start the CG for beginner/intermediate 3d? I have heard that the suggested location from GP is not that great for 3D..
Also, is it necessary to open a hole in the front of the cowl for cooling?
Yes you'll need that hole in the front to cool the Saito. Engines get hot and without airflow they can detonate.
The recommened 4.75" cg is very conservative and the plane doesn't 3D all that well there. If you've flown 3D before I'd start at around 5.5". Maybe work your way back after you have a feel for the plane. Mine is around 6.25" and it 3D's really well, but the knife edge coupling is worse than ever. I've mixed some of it out with my 9C, but it's not perfect by any means.