Everyone that I fly with has been asking me how fast my plane is. I have finally put a GPS unit in my plane to get an idea of what it's doing.
I did 4 flights today. Running a Graphen 1400 MA 4S battery 75 C discharge.
1St. flight 151 MPH with a APC 4.75 x 5.5 prop.
2nd flight 141 MPH with a 5.2x5.2 graupner prop.
3rd flight 158 MPH with APC 4.75 x 5.5 prop.
4th flight 181 MPH with APC 4.75 x 5.5 prop.
Not sure how accurate this GPS unit really is, but I like that 181 MPH number.
I think it's time to move up to a 6S battery.