Shrike 40
 

OK all you speed crazies I've got a shrike 40 with an OS 46 SX with an Ultra thrust muffler turning a APC 9x7 prop around 17,500. My problem is its not fast enough to beat a pylon plane (Dodger) with a Jett 30 combat engine on it. Can isomeone help me by telling me what I can do to make my Shrike go faster. I would really appreciate any help. My Shrike is a built kit and not the ARF if that makes a difference.

Thanks Soinks

From what I've read it's the thick wing on the shrike that slows them down. I have a shrike 10 and I wish I had trimmed the ribs to make it thinner. But try a smaller prop with more pitch. Maybe an 8-8 or 8-9. that might help out a bit.

Stick the 46 on a viper 500

The Shrike is not really a speed airframe, it is a short coupled sport flier. It lends itself to overpowering, such as FIRE .61's in the .40 size and I think some crazy engines in the .10 size, but powering a Shrike .40 with a .46 isn't going to make it a rocketship. You're up against a killer engine in a pretty clean airframe. I suspect a 9x8 might be about the fastest prop on that .46 and airframe but really not sure. Now put a Jett .56LX or even a Sport Jett .50 on the front and things might turn out better.

Both SpeedBoy and Speedy Gonzalez have built fast Shrikes with thinner airfoils and minimum thickness fuselages. It wouldn't be that hard to work with the original "kit wood" to acheive the same results.
Settle on a 8% thick airfoil [about an inch thick at it's fattest point] and keep the front end of the model no larger than absolutely necessary to encase the engine and the equipment.
I favor the use of fiberglass to help acheive the slim look, but really clever woodmeisters have done pretty well without it.
The Harry Higley "yellow booklet" called "Master Modeling" shows how to develope patterns for tapered ribs. I wouldn't bother with that particular method, but only because it looks more difficult than using my "eyeball TLAR method".
A fairly sharp leading edge with an airfoil that grows gradually thicker to about the 35% chord line works. I use an arched piece of music wire to develope my patterns that my plastic French Curve templates don't accomodate.