kentb
Well Known Member
Today Oregon has great weather, so I took a day off from work and flew my plane.
I did performance testing and collected the following data:
Testing was done at 8000 pressure altitude. 100 degrees ROP. OAT 53 F degrees, full throttle.
"TAS Lite" is the TAS computed by my BMA EFIS Lite (G3).
rpm map TAS Lite FF
2690 22 160 10.3
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
150 129 146 210 180 309 166
rpm map TAS Lite FF
2600 22 158 9.7
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
151 233 188 349 149 128 165
rpm map TAS Lite FF
2550 22 158 9.5
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
154 124 149 224 178 311 166
rpm map TAS Lite FF
2500 22 159 9.2
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
181 322 146 208 153 99 162
rpm map TAS Lite FF
2400 21.9 154 8.8
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
157 94 144 194 177 318 162 74% pwr
rpm map TAS Lite FF
2300 152 8.2
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
173 319 143 208 158 78 158 70% pwr
rpm map TAS Lite FF
2200 22.3 149 7.6
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
166 54 135 170 162 293 155
rpm map TAS Lite FF
2100 22.4 147 8
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
164 300 135 200 149 85 152 richened to smooth engine
rpm map TAS Lite FF
2000 22.4 144 7.6
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
154 70 132 194 157 283 151
Now the questions:
I am surprised that running at 2690 (full prop) and 2600 were not faster then 2550. Why would this be? Did I make a mistake in my measurements?
Why would I start getting roughness at 2100 rpm?
Vans predicts 195 mph for 160hp engine. What do I need to do to see this number? Fly down low at full throttle?
When I did this testing I flew from 170 ft MSL to 8000 MSL at full throttle and on takeoff I was turning 2700 RPM and when I reached 8000 ft I was turning 2660 RPM. Is this to be expected? After leveling off I turn the prop up to full which was 2690 and then using my AFS2500 engine monitor found the peak EGT and the richened to 100 degrees.
As I tested with slower RPM I kept leaning to keep the same temp on the EGT. Is this the correct way to do this or should I refine peak EGT of each RPM setting?
Kent
I did performance testing and collected the following data:
Testing was done at 8000 pressure altitude. 100 degrees ROP. OAT 53 F degrees, full throttle.
"TAS Lite" is the TAS computed by my BMA EFIS Lite (G3).
rpm map TAS Lite FF
2690 22 160 10.3
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
150 129 146 210 180 309 166
rpm map TAS Lite FF
2600 22 158 9.7
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
151 233 188 349 149 128 165
rpm map TAS Lite FF
2550 22 158 9.5
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
154 124 149 224 178 311 166
rpm map TAS Lite FF
2500 22 159 9.2
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
181 322 146 208 153 99 162
rpm map TAS Lite FF
2400 21.9 154 8.8
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
157 94 144 194 177 318 162 74% pwr
rpm map TAS Lite FF
2300 152 8.2
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
173 319 143 208 158 78 158 70% pwr
rpm map TAS Lite FF
2200 22.3 149 7.6
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
166 54 135 170 162 293 155
rpm map TAS Lite FF
2100 22.4 147 8
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
164 300 135 200 149 85 152 richened to smooth engine
rpm map TAS Lite FF
2000 22.4 144 7.6
speed 1 Track 1 speed 2 Track 2 speed 3 Track 3 TAS
154 70 132 194 157 283 151
Now the questions:
I am surprised that running at 2690 (full prop) and 2600 were not faster then 2550. Why would this be? Did I make a mistake in my measurements?
Why would I start getting roughness at 2100 rpm?
Vans predicts 195 mph for 160hp engine. What do I need to do to see this number? Fly down low at full throttle?
When I did this testing I flew from 170 ft MSL to 8000 MSL at full throttle and on takeoff I was turning 2700 RPM and when I reached 8000 ft I was turning 2660 RPM. Is this to be expected? After leveling off I turn the prop up to full which was 2690 and then using my AFS2500 engine monitor found the peak EGT and the richened to 100 degrees.
As I tested with slower RPM I kept leaning to keep the same temp on the EGT. Is this the correct way to do this or should I refine peak EGT of each RPM setting?
Kent