I don't remember if the Ripper or the Slasher is the SSC one but I'm assuming yours is the SSC version since your running the 15 on it.

First lets look at prop selection. I'm assuming your running the MAS blue prop if it's SSC which is an 8x3 I think. This is what you have to tune your motor to since its a spec prop for the class.

Next is your CG, if your CG is too nose heavy you'll be wasting a lot of efficiency just keeping it in the air. Try the balance point at 1/3 the chord of the wing mid span keeping the plane ever so slightly tail heavy. Just be a little careful on the sticks in case its snappy. With the fully symetrical wing you should have no problem flying it under control with that setup.

Also, make sure your ailerons are level with the horizontal stab or reflexed up 1/16th of an inch.

Tach your motor and post results. If your spinning over 14,000 you should be able to fly with no problem. The mousse can muffler is not legal for SSC, only for Open A which it seems like your not able to keep up with anyway.

NAES