Ok i have been flying the DD for a yr now and i know it should scream!! I have flown it with these props 9/7 9/8 9/8.5 9/9 and would like to know if im not usen the right one or do i need to trim the pipe a little or what. im also using the OS header pipe that comes with the engine. is that good enough or not.

Thanks

Go to Pspec for a APC prop in the 7.4x8.2 range, some head and liner shims and play around with that. If you can come up with 20,000 or better that should be worth trying to fly.

The pipe is the one OS requires for the engine so assume its pre tuned.
Thanks

The advice I give is generalized. Dave at pspec will most likely have strong recommendations for this and that.

Ooh, yeah. Those engines are timed for 20k++. Those props are wayyyy too much load, unless as CP suggests the pipe could be tuned for those prop sizes, in which case you might be zipping around pretty good but the engine is impatiently tapping its foot waiting for you to let it rev. You're lugging it in other words. In Europe, for pure RC speed models, they run props as small as 6.5x10 on .45 DF engines.

First kick at the cat I would say trim an 8.8 x 8.0 APC pylon prop down to 8" diameter and get thte thing over 20k. I wouldn't recommend the 8x8 sport prop.

MJD

Piggy,
where can i find this pspec? Do they have a web site?
Thanks

Usually pspec works or Performance Specialties. Scroll down for the guy selling model plane pylon racing equipment.
Don't forget about Eliminator Props, Steve Wilk has 100 sizes over there and great prices for custom CF.

and no the pipe isnt pretuned, wait till you take a inch or more off the header then you might see it perk up, go to macspro.com and read their instructions on how to tune the pipe system, the df 46 should spin the 9x7 @20k rpm if the pipe is set right

Apc 7.4x8.25 on pipe will give you 24,500 Static - you can get from APC or Tower - like $15 as they are chopped Carbon.
This is what I run on my Miss Ashley

You should seek out Freakinfast as he has posted extensively about this engine and various prop combos on a delta which I think is a Dust- but they all look the same to me

Freakinfast is a wealth of knowledge and a good guy!

Rob, did those props just go up in price? IIRC, they were more like $10 from APC and if Pspec has them, more like $8........24,500 with that prop is A-OK!! [X(]

http://www.rcuniverse.com/forum/m_76..._1/key_/tm.htm

This link will help:
http://www.rcuniverse.com/forum/fb.asp?m=7645422 oops, I see Rob posted the same link.

Your pipe looks short if anything, so don't cut till you run the correct prop. Those small hub non pylon props(sport) are a bomb waiting to go off, luckily you had too much prop to reach the high rpm. You need APC carbon props!

Mac’s pipes and headers are what I use. The #1050 Quiet pipe, #1250 Muffled and the 1150 tuned (noisy) I have all tried and all work well!
To my biggest surprise the quiet pipe rendered the most speed, at least measured on the ground. The best average pipe setting was 9 ½� from center of piston to the large diameter on the pipe.
The highest speed measured was 24,500 RPM (on ground) spinning a APC carbon (LP 74825C) 7.4X 8.25 on Power Master 30%Heli fuel. K&B HP glow plugs

Have fun!

CP - or the props are so much more they just seem like $15.
Maybe it is 23,500 at launch on the ground - I don't tach it much more after FF gave me the code

Hey Rob, do you still fly the Ashely?

i just ordered the 7.4x8.25 carbon props from phils hobby shop. they are $10.oo a piece and $5.50 for shipping. atleast ill be able to try it out over the winter since its one big ski

Nick, see the info I left at the other thread.

Rob, yeh....are you giving Miss Asshley a good workout? [8D]

Rev-on Bro Brokenprop, don't forget to keep a fresh roll of toilet paper handy in the glove box........

Freakinfast's review of this engine hadn't soakened into my head good until this thread came out as a reminder. This engine might be the best kept secret in Extreme Speed. This level of performance and user friendliness is rare. From what I know, if the compression and pipe isn't set just right for the prop, it won't go as smoothly as his engine does. If the engine is fairly non-critical with the 7.4x8.2 prop, that's the key to having a set up that you can launch with a nice smoke trail and still have a screaming run. Besides having a fist full of $10 props, make sure your fuel is at least as oily as that Powermaster Helocopter fuel.

what kind of throws are you flying with Iam getting ready to fly mine thanks .

1/4" low rate 3/8" high rate on ele and
1/2" low rate 3/4" high rate on ail.
You will prob want to put expo on both
thats what i have on mine

Wonder what differences there are between the .46VRDF and the 46 VXDF, I picked a NIB .46VRDF at our local swap meet for 60$, the instructions say 2000 to 25000 RPm range.

From OS's website: "With advanced technology that allows it to produce 25% more power than the 46VR-DF, O.S.' new 46VX-DF is perfect for pilots of medium-size jets."

Personally, I don't think its quite that much difference. Maybe 10-15% at most.

I flew mine for the first time today I have a jett 50 with 9+9 prop this thing just pulls strait up. I was unable to get any fast flights in due to throttle servo concerns but will give it hell next weekend. Thanks for the help.

Right on!!! Glad i could help out.

So is this one as reliable as the other OS's, and good for a speed plane?

Hey guys flew the dust today and got good wide open flight it flew at 160 mph need to go faster. The specs are 2lbs 15oz jett 50 motor 9+9 prop 15% nitro. I fly at about 3000 feet elv. dint have take with me so I dont know the rpm any help would be great and is 185 to 190 possible with this combination. Thanks The Road Runner.