icepilot

Hi guys!
I am about to receive my small Viper from X-treme Jets. Anton has flown it with the Wren 44 Gold and says it flies great
and that the 54 would be over the top. Has any of you built and flown this - I have only seen videos of the EDF version,
and a still picture of one flying with the 54. I am still wondering if it will be underpowered with the 44..

Any comments?

Thanks!

Tor

MNModels

Hello Tor,

I have flown the small viper with 54 size turbine. Picture on Xtreme website - Mercedes color. Just about perfect for me. I do not know much about mw44 gold, but the wing loading and fuel will be less than 54 size turbine.

Regards

Morne

icepilot

Thanks, Morne -
the 44 Gold is about 400 grammes lighter and need a lot less fuel (I have one liter in my Savex L-39 and it flies
for almost 9 minutes) so the wing loading will be much lower. How is the takeoff and vertical with the 54?

Tor

MNModels

Tor,

1 to 1 ratio. So take off 40m and unlimited vertical or.....at least 6 rolls up...

I think 44 will fly it like our old DF jets.... Will be perfect for scale flying...

Morne

siclick33

It might be worth clarifying which 54 size turbine you've used, Morne. Power outputs for even the 'standard' Wren 54s can vary quite considerably and may alter the 54/44 comparison.

icepilot

As far as I can see from the XJ website it's a Wren 54

siclick33

Mk 2,3,4,70,75, Supersport or 100?

Even assuming it is a 'proper' 54 (e.g. Mk 2,3 or 4) then that is a difference of several pounds thrust.

I'm not trying to be difficult but the type of 54 could make a huge difference to the performance.

Selleri

Love the colour scheme Tor, good choice! [8D]

MNModels

Hi,

6kg thrust meassured on load cell. Viper 6.3kg dry. It is EDF version converted to turbine. Spring air and wire oleos. The only problem is the size and space available for fuel tank. Maximum flight time 5 - 6 minutes. So i would imagine the 44 will benifit...

Morne

icepilot

Thanks, Sverrir - it's very clean and nice, and I have always liked blue and white.
Morne - if yours is 6.3 kg dry, then mine should come in at approx 5.5 kg - and with 4.5 kg thrust I guess I'm good to go!
That's the same weight ratio as my Savex L-39, and the 44 pushes that around at a nice clip..

Tor

Stobe777

My Feedback: (1)

The Wren MW54 and Supersport are no longer made. The Wren 75 & 100 are the new models with 75 and 100 N power respectively. I would assume the 75 would push the little Viper around just enough...

TP.

heraldoboldrin

what servos are you using? can send some pictures from the inside..

regards

Heraldo

MP3_tilaco

I have a Viper S with Super Bee, is a awesome plane but mine is over 8 kg dry [:-]

I use just Align DS-510M.