TailTouch

My Feedback: (54)

Peak 9500 RPM with APC 15x4W prop.

Fuel: YS 20/20

Location: Philadelphia suburbs..
Temp: 88 F

Engine is broken in and has more than a gallon thru it. Stock H9 Plug.

dirtdr

same apc 15-4W prop
XP 25% sport fuel
70f
2150 ft elevation
9700 peak
engine has 20 gals of fuel through her

flipstart

Have a Saito 91 with about a gallon and half of Wildcat 15% run through on test stand. Now running at 9700 max with APC 15/6. Flipstart

windsheer

Had my Saito for 4yrs. APC 14X6 with 15% Wild Cat peek 10500.

seanychen

My Feedback: (4)

30% Heli fuel, APC 15x4W: 10200 rpm

Richard D Bahmann aka/Wrongway

My Feedback: (42)

Engine bought used, dont know how many gallons thru, estimate at least 2 or more.

Master 14X8K 4 Stroke prop
Wild Cat 15%
Sea Level. 70 degrees
Peak 9100

Got it in a Sig Astro Hog 7lb 13 oz dry, prop is ripping the air on the full throttle vertical uplines. Plane has good vertical. Does anybody know at what rpm the engine makes the best torque? What kind of airframes are you's hauling with the 15X4 and 15X6 and how is the performance?

seanychen

My Feedback: (4)

Hello,

I'd say the torque peaks out at around 10k, swinging 15x4 or 14x6. I think 15x6 is a bit much load for it, so is 14x8. Not saying the engine won't swing it. It just won't get into its peak torque rpm.

I have the Saito 91 w/ APC 15x4W on a 7-lb. Delta Vortex. It actually torque rolls rather well w/ plenty of pull-out power. TR'ing a Delta Vortex is a handful though, I'll tell you that.

I also have the same setup on a 6-lb. Funtana 40. It's more power than it needs, as this setup generates about 11 lb. of static thrust.

Richard D Bahmann aka/Wrongway

My Feedback: (42)

Thanks Sean, will try the 15-4 after checking the prop /ground clearance. My Astro Hog has conventional gear and a tendency to nose over when taxing out...just dont like the prop strikes as a general rule..

Richard

Jack Hyde

My Feedback: (1)

Sean,
Did you measure the 11 lbs thrust you posted or is it an estimate, computed, WAG? I am trying to calibrate a computation and am looking for data.

seanychen

My Feedback: (4)

I actually have measured it with digital force gauge 15x4W @ 9800 rpm. It said 10 lb. So using 30% nitro w/ 400 more rpm, I'd say boost about 1 lb.

14x4W @ 10500 rpm measured 9.5 lb, for reference.

Richard D Bahmann aka/Wrongway

My Feedback: (42)

New Readings, Master Airscrew 14X6 (K series) 70 degrees, sea level, 15% Omega 4 Stroke Fuel ...

9200 RPM
9.3 Lbs thrust (digital fish scale)

Note in post # 6 the prop was a Master 14X6 and not the 4 stroke K series. Re checked with digital scale same temp. The master 14X6 has rounded tips and seems slightly less wide as the same in K series. Both Masters were the black glass filled props.

9000 RPM
9 lbs thrust on the digital scale.

Will do an update with the APC 15X4 on digital scale as soon as I can get one from hoby store which is out of stock.

Richard

saitofreak

APC 14x6, 10% Coolpower, sea-level, 15degC air temp, 45min run-in: 10300 RPM

jharkin

My Feedback: (2)

APC 15x4W - peak about 9450. Will idle down to 1800-2200.

S&W 15% fuel, 80F near sea level.
Engine has about 3-4 gallons run time.