Hi folks,

I'm starting to look at sizing my bypass for a TJT3000 I just received. I'm thinking an inner tailpipe (fed by the turbine exhaust and bypass) diameter of 3.25" is a reasonable size. Any opinions? I will also be using an outer pipe, feeding from the inside of the model, external to the bypass.

This will be for a scale or sport scale model, of about 25 lbs dry.

Thanks for any inputs. I posted on the tjt website, but I don't think the post went thru.

Hi Ron,
As fitted to my Aviation Design F16 - I would recommend an inlet diameter of 3 3/4" with an outlet diameter of 3 1/4". Overall pipe length is 28". Let me know what model you are installing the TJT3000 into, and I may be able to give optimized specific pipe dimensions for your application.
I would suggest with a bypass installed you should also install/cut naca style inlet vents just forward of turbine in the rear fo the inlet duct, (both sides) I can supply drawings/templates for correct size if required.
The reason for the naca vents is to draw additional cooling air into the fuz area for internal cooling and this will also help supply/draw some cool air between the inner and outer pipe walls lowering overall pipe temps...
We can also supply custom tailpipes/ bypasses for your model if required.

Ron let me know if you require any further pipe info?


Cheers-

Thanks Marty. I'll PM you.