Easystern

Hi Guy's

i had a nice Sunday with my first attempt to get some real speed data of my Laser Arrow.
setup is a 50 weston uk with a custom build 50 webra piston/liner, custom crank and custom housing .
muffler is a baffled genesis pipe

actually it was a weston 50 T1(for aerobatic planes) not the high revving V1, but after a total rod failure i had to rebuild the engine and did my own port work.


first Log is with 8x8 APC and second log with 9x7 APC and 145 MPH (233kmph) top speed at 20100 RPM.
Red is air speed in kmph , Black is RPM , Blue is engine temp in Celsius and purple attitude in meters.

Michael

mk1spitfire

Nice, great motor and plane combo!!!!!!!!!

Easystern

I forgot to mention
it is measured air speed , not ground speed measured with a pitot tube .
ground speed must be around 155 mph at this day, in one direction .

System is a data recorder/logger from SM Modellbau germany in the near future i will ad a gps data recorder from Wintec ( WBT-201) to get real ground speed .
michael

mk1spitfire

which is quicker the magnum or laser?

What speed did you get with magnum? was that a V1 engine??? prop?

Easystern

I dont have a logger in the magnum yet, but it will come, it has the stock V1.
the laser arrow is in the beginning of testing and not perfect dialed in ,i feel more speed with the right prop and tuned pipe and manifold lenght.
it jumps hard into resonance at around 16000 , the exhaust port timing is very high compared to the V1 stock liner ,i have to work with a 9x8 9x9 9x10 prop and a shorter manifold to get the resonace point close to 20000.

the laser with this setup must be good for 160 to 165 and my magnum for 170 to 180 .
the magnums out of the box and good tuned do 165 , measured at the german speed cup.
the laser is a shoebox compared to the magnum


next time i will test with the 9x8 and shorter pipe, i keep you updated with the log's in the next days.
right now we have stormy weather here like neworleens and i have to wait for a nice day.
michael

mk1spitfire

Your mission is get 200mph out the magnum!!!!!!!!

Easystern

161 MPH
Hello Together,
last weekend i had some time to go out for some speed runs with my laser arrow and an 9x8 apc on the weston.
i made 3 attempts to get it in the air, the first and the last was a bad starting crash with lots of luck for the laser.
the cause was i added some lead to the rear to get the cg right and trimmed up a little.
at the start with full throttle it made a full loop and did land on our security fens behind me .

the second flight was right and it revved up to 20100 rpm after a dive and 161 mph speed,that's not bad for that powered violin case .the other pas was 157 mph at 20000 rpm.

i hope we will get a nice october to go out for flying and more testing.

the SM logger gear is great and works fine with tha free logger program from the net. www.logview.info

have fun
michael

PS mk1spitfire , with a little work on the weston magnum it will make 200 mph , i will work on it next spring