Van's Air Force
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What performace are you getting?
- Thread starter kostanza
- Start date
eric.kallio
Well Known Member
numbers
There are a few threads in the archives that might help you. Also, if you post what you are seeing and what you have the target audience can give you numbers from similarly equipped planes.
Eric
There are a few threads in the archives that might help you. Also, if you post what you are seeing and what you have the target audience can give you numbers from similarly equipped planes.
Eric
MauleDriver
Well Known Member
Yesterday's flight...
Running 30 to 50 degs LOP @ 9,000, WOT, 2000 RPM, light with 2 people
149 to 155 knots
9.5 to 10 GPH
I don't mean to be ambiguous by using ranges but that's what I actually get... constant fluctuation.
I can definitely speed up by going richer. Prop setting has a significant effect on GPH, some lesser effect on speed.
My flight profile is generally WOT to cruise @ 8K+, descend to 5K before coming off the power a bit. After leaning at cruise, I don't touch the mixture until short final.
Running 30 to 50 degs LOP @ 9,000, WOT, 2000 RPM, light with 2 people
149 to 155 knots
9.5 to 10 GPH
I don't mean to be ambiguous by using ranges but that's what I actually get... constant fluctuation.
I can definitely speed up by going richer. Prop setting has a significant effect on GPH, some lesser effect on speed.
My flight profile is generally WOT to cruise @ 8K+, descend to 5K before coming off the power a bit. After leaning at cruise, I don't touch the mixture until short final.
ScottSchmidt
Well Known Member
Typical
Of course weight changes the speeds but I ran in a race in Three Forks, Montana and averaged 212mph running 2500 RPM and 24 inches (just me in the plane).
When it is just the two of us, running at 11,500ft at 2360 RPM ROP 165-170 kts TAS, and LOP 158-165 kts TAS. The speed really depends on how smooth it is.
I have 850 hours on my plane and have flown between 10,500 and 12,500 for most of it. I flightplan for 162 kts TAS (running LOP) and it is typically within a minute or two of my flight plan.
Check that your flaps are up against rear spar and that the ailerons match it. I even moved my ailerons up a little when I noticed that my ailerons were below the flaps in cruise flight.
Of course weight changes the speeds but I ran in a race in Three Forks, Montana and averaged 212mph running 2500 RPM and 24 inches (just me in the plane).
When it is just the two of us, running at 11,500ft at 2360 RPM ROP 165-170 kts TAS, and LOP 158-165 kts TAS. The speed really depends on how smooth it is.
I have 850 hours on my plane and have flown between 10,500 and 12,500 for most of it. I flightplan for 162 kts TAS (running LOP) and it is typically within a minute or two of my flight plan.
Check that your flaps are up against rear spar and that the ailerons match it. I even moved my ailerons up a little when I noticed that my ailerons were below the flaps in cruise flight.
RV10inOz
Well Known Member
Maul driver....the reason speed does not vary much with RPM when LOP is that HP is a function fuel flow, but when ROP it is a function of Mass Airflow. Have a good look at the APS/John Deakin graphs and you will see why 
I am with Scott, we have 600 hours and we are LOP all the time and I say 160+/-4 depending on level, temps, turbulence, and up in the FL's we find that we are usually around 157TAS on 35LPH compared to 40-41 down lower.
Now, as for your questions about your speed........which is really why you asked in the first place.
1. Have you installed all the fairings and wheel spats? If not...You should.
2.Have you done a 4 way GPS box test and compared this to your indicated TAS on your EFIS or one calculated from IAS etc. If not you need to do this.
3. Which kind of static port have you used?
The reason you need to know these things, and the reason I ask is that if you dig back through the records, I was baffled why we had the slowest RV10 in the world. I soon discovered we did not, it was like all the others, fast!
So it was all about static vents, I started experimenting by glueing a big rivet head like the Vans one over the static port disc, now I had the fastest RV10 in the world, but of course that was wrong.
This is my experimental static port below, and once I jagged it right....well It works so don't muck with it!!
By the way some on RV7's have been the same, a small fence in front of the port corrected big errors there too.
Now as you can imagine, this static error has a corresponding effect on your altimeter and encoder, so your Transponder is reporting false altitudes and your alimeter is too. I did some calculations based on 160 knots and whatever else I needed at the time and the error was around 140 feet. And Speed effects it, less error the slower you go.
I am with Scott, we have 600 hours and we are LOP all the time and I say 160+/-4 depending on level, temps, turbulence, and up in the FL's we find that we are usually around 157TAS on 35LPH compared to 40-41 down lower.
Now, as for your questions about your speed........which is really why you asked in the first place.
1. Have you installed all the fairings and wheel spats? If not...You should.
2.Have you done a 4 way GPS box test and compared this to your indicated TAS on your EFIS or one calculated from IAS etc. If not you need to do this.
3. Which kind of static port have you used?
The reason you need to know these things, and the reason I ask is that if you dig back through the records, I was baffled why we had the slowest RV10 in the world. I soon discovered we did not, it was like all the others, fast!
So it was all about static vents, I started experimenting by glueing a big rivet head like the Vans one over the static port disc, now I had the fastest RV10 in the world
, but of course that was wrong.This is my experimental static port below, and once I jagged it right....well It works so don't muck with it!!
By the way some on RV7's have been the same, a small fence in front of the port corrected big errors there too.
Now as you can imagine, this static error has a corresponding effect on your altimeter and encoder, so your Transponder is reporting false altitudes and your alimeter is too. I did some calculations based on 160 knots and whatever else I needed at the time and the error was around 140 feet. And Speed effects it, less error the slower you go.
