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-   -   Some performance numbers with 81" Sensenich (https://vansairforce.net/community/showthread.php?t=93175)

ronoc74 11-15-2012 04:31 PM

Some performance numbers with 81" Sensenich
 
We've tweaked the flow gauge parameter and corrected a static error, so now that I have accurate fuel flow and TAS within 1 knot at 140 kt, I can report some accurate numbers. I chose the 81" over the 79" to get good cruise performace with one P-mag, and it worked out very well. Australia doesn't have any high-altitude airports so reduced climb is ok.

Engine: Superior XP-IO-320-A1AC2
Ignition: 1 P-mag and 1 Slick mag
Prop: Sensenich 70CM7S9-0 (81)

Static RPM is about 2240. It will climb at 1700 fpm solo with full fuel.

Top speed at 8,500 ft (9,700 DA) leaned to 75 ROP is 172 kt TAS at 10gph. It hit 2640 rpm so I pulled it back after finding top speed.
LOP cruise 159 kt TAS at 7.1 gph WOT 2470 rpm.
LOP cruise at 9,400 (11,500 DA) returning from the solar eclipse was 150 kt TAS at 6.2 gph WOT 2350 rpm. I think the lean-mode EGTs in the photo aren't accurate but there was room to richen a bit.

It seems to have gained 3 - 5 kt since I removed the tiedown rings. I didn't realize they made that much drag.

I remember reading ages ago that the Superior XP engines have smoother intake ports which results in a couple of extra hp. YMMV.




Don 11-15-2012 05:24 PM

Thanks for the data points. When I get the VM1000 calibrated I'll post my results too.

alpinelakespilot2000 11-16-2012 11:26 AM

Interesting Connor. Thanks for sharing. I like seeing other peoples numbers (and EFIS screens) as I'm in the process, now that I've got all of my fairings on, of figuring out what my performance is.
Is it your engine or prop that forces you to keep your rpms down? (My Aerosport 0-320 has a 2700 rpm limit. However, given that my Catto prop is probably underpitched, I quickly push up to engine redline.)

pierre smith 11-16-2012 12:20 PM

I also give up around 9 knots in my -10. running LOP, as I notice your speed does as well.

ronoc74 11-16-2012 01:41 PM

Quote:

Originally Posted by alpinelakespilot2000 (Post 716931)
Interesting Connor. Thanks for sharing. I like seeing other peoples numbers (and EFIS screens) as I'm in the process, now that I've got all of my fairings on, of figuring out what my performance is.
Is it your engine or prop that forces you to keep your rpms down? (My Aerosport 0-320 has a 2700 rpm limit. However, given that my Catto prop is probably underpitched, I quickly push up to engine redline.)

It's my prop that has a 2600 rpm limit. There's harmonic vibration centered around 2700 rpm.

RV10inOz 11-16-2012 02:57 PM

Once again Vans book figures are accurate. The -9 is max speed 170 knots. With any 1-2 knot error in the static/ airspeed system, and Conor and I have chased it being accurate, to get book figures is always comforting.

The tie down rings were a big difference, we noticed it on the -10 as maybe 4 knots worth of drag :eek:

Pierre, maybe you are running too far LOP? Or are you comparing MAX speed to your LOP speed? We can discuss by PM so not to corrupt this thread.

Great pics Conor!

ronoc74 11-16-2012 09:49 PM

Quote:

Originally Posted by pierre smith (Post 716942)
I also give up around 9 knots in my -10. running LOP, as I notice your speed does as well.

Probably a little more because the rpm drops too, which can't be avoided.

pierre smith 11-17-2012 05:20 AM

Quote:

Originally Posted by RV10inOz (Post 716979)
Pierre, maybe you are running too far LOP? Or are you comparing MAX speed to your LOP speed? We can discuss by PM so not to corrupt this thread.

Great pics Conor!

Negative Oz, when I cruise ROP, I true 200 MPH or a little better, at 7,500'

Leaving the power exactly where it is, I turn the Dynon to "Lean" mode and watch the EGT's climb until peak, then the little boxes start appearing indicating degrees LOP. I stop at -50 and wait for the speed to stabilize, with the autopilot on and cruising perfectly level. I usually end up with 188 MPH TAS according to the Dynon 120, and now burning 11.7 GPH, instead of 15+

Best,

RV10inOz 11-18-2012 05:11 AM

I see similar numbers, but I wonder about the lean mode on the D120/180, it often varies a bit due to hysterisos in the probes.

A BMP and sneak back up to peak on the first to peak then back down 10-20 is usually about those fuel flows and speeds.

Pull out the tie down rings too! :eek:

eddieseve 11-19-2012 03:55 PM

Some interesting trip facts Cessnock to Atherton and back to see the Solar eclipse;

Route for trip up, 1 day;

Cessnock -> Scone -> Quirindi -> Moree -> Roma -> Shute Harbor -> Charters Towers -> Mareeba -> Atherton (with a few diversions for rain)

Route for trip back, 2 days with overnight in Coffs Harbor because of rain;

Atherton -> Mareeba -> Charters Towers -> Mackay -> Harvey Bay -> Coffs Harbor -> Williams Town -> Cessnock

Fuel Stops
Roma $174.58 81.65 litres
Shute Harbor $157.07 74.80 litres
Atherton $232.30 101.00 litres
Mackey $174.09 81.39 litres
Harvey Bay $174.17 74.80 litres
Coffs Harbor $147.90 66.27 litres
Cessnock $ 94.11 43.63 litres
----------------------------------
$1154.22 523.54 litres

Cost per person $577.11

Flight and Fuel Stats;

Total flight time 17.05 hours
Average Fuel consumption 30.7 litres per hour
Litres / 100 km 11 litres / 100 km
Fuel Cost per hour $67.70
Average cost per litre $2.20
Average Speed 148.56 knots
Oil consumption 1.5 quarts over 17.05 hours

Distance travelled 2533nm or 4692 kilometres
1283nm Up
1250nm Back

Cheers


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