GSJames

We have a fun and competitive little Q-25 series going here in North Texas, mostly due to the untiring efforts of Gene Hodges and Gary Alphin. (THANKS guys!) Some of us are just now venturing into the realm of building everything from scratch and have been cooperating with each other and teaching each other tips and techniques instead of flying those ARF things. However, to ensure that we share our hard earned knowledge, one of our group, who shall remain nameless, but his initials are Jim Pope, AMA L-85, NMPRA #85, has decided to "spill the beans" and give ALL of our speed secrets to the Contest Director in question (Gary Alphin) in hopes of helping him be a more competitive racer. Here is the letter that we sent... Keep smiling.


Gary A;

On second thought and after expensive research by the crack WAMS Q-25 Racing Team and consulting with our staff aerodynamic engineer Gary James, we have come up with more speed secrets that you should use. And Gary J. please feel free to add to any additional tricks that will help Gary A’s racing effort.


1. There’s no need to vacuum bag the cores. Just wrap the bare cores with Sara Wrap. I recommend that you double-ply the center of the wing. Use ¼ inch lag bolts to attach the wing to the fuselage. Use the ones with the hex head, not those cheapie square headed ones.

2. Use lead based house paint on the fuselage (two or three coats).

3. Use a 11/7 prop and don’t forget to cut one inch off of the left tip so it’s easier to turn around the right pylon.. Balancing the prop is a waste of time.

4. Use fuel containing 0% nitro-methane and about 40% castor oil. Your engine should last forever.

5. Eliminate ailerons altogether. The rudder will be adequate to make turns and should be as large as possible to eliminate the possibility of Portuguese roll (the opposite of Dutch Roll). .

6. The minimum weight of 3lbs, 4ozs is not desirable. You should add sufficient weight to meet an even 5 pound minimum so you can survive a midair crash or collision with a pylon.

7. Balance the plane at 4 inches back from the leading edge so your racer will be more responsive to elevator control inputs.

8. Add 5 ounces to the left wing tip so it will hang down nicely during a pylon turn.

9. Use 4 inch Du Bro wheels; the big fat ones that eliminate landing bouncing problems. Of course you may not have landing problems if you balance the airplane at 4 inches.

10. To avoid cuts, always allow as much leeway as possible when making pylon turns, but be sure to make your turns before the airplane disappears over the horizon.

11. Use re-bar for push rods. This should be strong enough and help meet the 5lb weight.

12. The 10 inch chord is a joke. Build your wings with a 13 inch chord and the 4 inch balance point will work quite well.

13. And don’t forget to have an elevator throw of 90 degrees.


Good luck, go fast and turn right!!!!

vicman

My Feedback: (10)

Gary,
Hush man! Don't let the Carolina guys in on all the speed tips at once.[>:]

GSJames

I was going to suggest that since the CL Speed guys often use single-bladed props that Gary A take a 16-12 prop and cut off one blade. That would make it an 8-6 and thus be legal for the Q-25 class. Right???

HighPlains

My Feedback: (1)

Well unfortunately the speed secret of leaving one blade on the ground is no longer legal in pylon. I was racing Formula One at a contest up in Washington state back in the 80's. During the engine start-up as I was tuning the engine for a heat, a part of one blade left the prop at around 22K on the tach. The engine picked up another 1000 rpm, and much to my caller and my surprise did not vibrate much worse than the normal ST X-40. So rather than take a zero, I decided to go ahead and fly the heat.

That airplane had always been a dog, but with the modified blade and a half prop, it ran the course 4 seconds faster than the plane's best time. That prop got removed after the heat to be studied away from inquiring eyes.

Unfortunately, a bit later I told another buddy about the "experiment". He promptly submitted it as a rule change that both blades had to be of equal size. Which was fine, since I already had a number of rules in the books that were written after other "experiments". I may hold the record there.

BobHH

My Feedback: (18)

Well Gary, I'll throw in one suggestion for you guys running the OS .25 FX. The rule books state that you must use the stock muffler, but nothing about changing out the muffler bearings. I've found that going to the high speed ceramic muffler bearings combined with the Hobby Zone OMG long cold glow plug will allow a good 22K to 23.5K RPM with the APC 8x6 prop!

Also, you can fine tune your engine on the flight line by needling to max rpm, back off 500 rpm. Ever so lightly rotate the plane where the prop just touches the pavement enough to trim the prop to the desired RPM. This may take a few tries until you get the hang of it.

Bob Harris

GSJames

Thanks Bob! I was going to suggest the use of high temperature, modified graphite muffler bearings from the local hot rod shop, but I'll switch to the ceramic. I've used the flight line, prop diameter modification procedure several times so far, and have seen several other guys use it as well. I wonder why they all seem to change the prop after the heat, I guess they are trying to disguise the modified prop... Unfortunately, some of the courses we run have grass runways and it's more difficult to modify the prop diameter without leaving a tell-tale puff of dirt and grass clippings during the procedure. Maybe if I position the launcher/holder between the airplane and the starting judge. I'll also suggest your impressive rare earth magnet on the outside of the crankcase method. Since it doesn't actually "modify" the engine, I'm sure that it would be legal... I'll pass all these suggestions along to the Contest Director...

BobHH

My Feedback: (18)

OK here’s a real one that the notorious John Gibson was using on the first BuckShot prototype. In years past John was a vivid competitor/designer/builder in Super Kart racing winning many championships along the way. He has this keen eye on reducing turbulence at strategic areas of the racing cart frame. After close examination of the BuckShot he installed this 10 mil plastic sheet with holes punched in it. His first heat times were dang near 424 numbers with only an OS .25FX for power. After much protest he was made to remove it by the CD!!

Bob Harris

GSJames

Seriously this time, I can't help but wonder why he didn't just recess the hold down strap into the surface of the wing in the first place. Of course, if it was actually protruding, I'd want to cover it with tape too.

vicman

My Feedback: (10)

I saw Bob lighten the engine by shedding the plane on turn two one time.

Duane-RCU

My Feedback: (5)

Great Gary, after I've quit racing and sold everything, NOW you give out the real speed secrets! I might have won some with these tips.

GSJames

Duane, WHADDYA MEAN THAT YOU'VE QUIT AND SOLD EVERYTHING !!! YOU CAN'T DO THAT!!! WE NEED YA'! [][][:@][]

BobHH

My Feedback: (18)

Well Vic, I’ve have developed a ARF BuckShot to be produced in China. Take a look at this prototype. It breaks down for ease of shipping. Just a little CA and you are ready to race!!

Bob Harris

vicman

My Feedback: (10)

I've got a yellow one just like it

Duane-RCU

My Feedback: (5)

I just figured I'd stir ya up a little! But I am selling the Shoestring and the LR1, and some other planes, but keeping all the Q25 stuff. The conventional tailed Viper needs to make it to another race, now that I got the power up a little. Wait till April??? Really???