I get 6700 with a falcon 27x11 CF on a DA120 and it unloads to about 7250 in the air according to telemetry. That's at sea level with high humidity

Thought I'd contribute to the thread.

DLE55 Bowman ring, Falcon 23*8 prop, static ground RPM 1450 IDLE 72-7300 WOT. Unloads to 8200 RPM in the air telemetry confirmed.

This is the same on both my 30% planes.

Originally Posted by Muttdog

I get 6700 with a falcon 17x11 CF on a DA120 and it unloads to about 7250 in the air according to telemetry. That's at sea level with high humidity

Muttdog should that read 27 x 11?

Originally Posted by Jetpainter

Muttdog should that read 27 x 11?

Damn fingers! Yep 27x11

We are running 2 different DA-120's on Proflow cans and the falcon 27x11 and we are seeing 6860-6900 on the ground @ 1200 ft asl, redline 40:1 , 30 degrees Celsius

Gp 61 smooth pipe falcon 24x9 cf one gallon of fuel throught it 6900

GP 61 running a DA50 short header with homebuilt adapter and a MTW TD75K canister and a Falcon carbon fiber 24 X 9, 6800 at about 500ft with about 90 minutes of run time.

Originally Posted by Jetpainter

GP 61 running a DA50 short header with homebuilt adapter and a MTW TD75K canister, 6800 at about 500ft with about 90 minutes of run time.

Attachment 667961

What prop are you running?

Originally Posted by HELLFIRE

What prop are you running?

Sorry I guess that would help, Falcon Carbon Fiber 24 x 9. I edited my previous post.

I just a did a ton of prop testing again on my EF 104 as I installed a pair of ES composites pipes on a DA-120. They are butter smooth on transition.



Falcon 27x11, 7200 rpm

Mejzlik 28x12, 6550 rpm

Mejzlik 29x10evo, 6350 rpm

Biela 29x10, 6300 rpm

Mejzlik 26x10THx3, 6800 rpm

Biela 27x10x3, 6100 rpm


By far the 27x11 is my pick. Instant response and wonderful power. The 28x12 is faster.

The 29x10evo is for my 110 yak and works super well in that airframe.

The 3 blades are just for noise abatement. The 26x10TH is still loud. The Biela is quiet, but is heavy and spool up suffers. I am going to try a 27x12TH this weekend to see if it good for speed and IMAC.

DA-170, KS1090 pipes
Xoar PJE 32x3dB

6510rpm after two tanks 95 octane gas 50:1 Motul 800 oil

CRRC55 GFii stock mufflers
600 feet ASL
Xoar 23x8
Lucas 2 stroke semi synthetic 40:1
91 Octane Gas
7030 rpm
Idles at 1250

3 Gallons of gas through the engine

ZDZ80RV
( ZDZ 80 RV [NOT the RV-J aka as Super, but the standard RV] )
Was around 6800~ on OEM old ring at 130 psi compression

Now 9/12/2014 with brand new Bowman ring, not broke in, first run on the front lawn to tune, it was new starting at 142psi compression, and using 100 octane Sunoco race car fuel and a 25x10 Xoar = 6700.

But after the ring finishes breaking in during the next week or two, i will test again with both the 25x10 & 26x10 Xoar props that i have..... more to follow....
I will test the final max prop RPM once the ring seating has peaked, by finding when the compression peaks and stops climbing, meaning, once the ring is 100% seated and sealed and shaped to the cylinder wall, the compression will peak. It is currently at 157 psi after 5 flights and maybe 3/4 of a gallon. So i assume it is close to being completed.

Brand new engine on dle exhaust 6580 RPM

DLE 120 and Falcon 27x11