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Speed,Combat,Scale,Racing => Speed Talk => Topic started by: Dave Edwards on November 20, 2016, 04:47:50 PM

Title: Fox Speed Reference
Post by: Dave Edwards on November 20, 2016, 04:47:50 PM
Got my fox speed in the air and completed the mile from a standing start at the last Middlesex event - right about 87mph.  For the guys doing all the cool engine work, use this as a reference: box stock engine, 29%caster, 10%nitro fuel, 8x8apc prop, 5-10mph wind.

If I play with props and get a perfect run on a calm, cool day, probably good for 90+mph.
Title: Re: Fox Speed Reference
Post by: Motorman on November 20, 2016, 08:10:47 PM
What kind of airplane, profile Q rat or full blown pan job?


MM
Title: Re: Fox Speed Reference
Post by: Dave Edwards on November 21, 2016, 03:17:53 PM
Plane was made up specifically for fox race from the scraps lying around the shop..  Kind of a cross between a f2c from the 70s and a tqr.  Solid wing, full fuselage, pretty good aerodynamics, a bit heavy but flies great.
Title: Re: Fox Speed Reference
Post by: Al Ferraro on November 22, 2016, 08:26:54 AM
Dave's Fox Speed
Title: Re: Fox Speed Reference
Post by: Dave Edwards on November 23, 2016, 02:13:10 PM
So, just out of curiosity, has any one broken the 90mph mark (one mile from a standing start) with a stock Fox 35?  If so, what combination of props/fuel/planes did you use? Likely someone has a sleek fox racer that can do this.

The fastest modified fox 35 I have seen is 107mph, roughly a 20% improvement in speed.  If my math is correct (power goes as V^3) that means a 75% boost in power is required.
Title: Re: Fox Speed Reference
Post by: Paul Smith on November 24, 2016, 10:22:07 AM
87 MPH is the  best I've heard for stock engine.

I did 69 at The Brodak with a stock engine and a sport-type airplane.  I doubt that the airframe made up the whole 18 MPH.  Maybe the solidness of the pan made the engine run better.