TD03-based Twin Turbojet

[ABM]

Hello,

I'm planning on building a turbojet engine as a project. I currently have two Mitsubishi TD03 Turbos from an N54 BMW engine, but each of them is so small so I was thinking of combining their inlets and feeding their combined air to the same combustion chamber.

Compressor:

- Inducer dia 38mm

- Exducer dia 25mm

Turbine:

- Inducer dia not sure until I chop off the car's manifold, but seems very roughly like 25mm

- Exducer dia very roughly 35mm

I'm also assuming I would need to remove the wastegates and weld their ports shut or something? I haven't went into the main design or so yet, just want to ask y'all about the viability of using these turbos in a turbojet. Pics attached.

Thanks in advance!

(https://imgur.com/a/1PoGz8e)

[racket]

May I suggest you find a much larger turbo to use , this will give you a greater chance of success than using these turbos

Cheers
John

[ABM]

Thanks for he recommendation John! Time to rebuild that old Garrett T3/T4 I have lying around. ordering a rebuild kit today
-ABM

[racket]

The T3/4 units can have a missmatch of comp /turb sizes, you want the "hole out" turb exducer area 20% greater than the "hole in" comp inducer area otherwise you could have problems .

[ABM]

Yikes, in my case the comp inlet and turbine outlet areas are roughly equal and this is my only other turbo option. Would restricting the entrance to the compressor (with a nozzle/funnel etc) help alleviate the issues arising from the lack of expansion at turb side?

[racket]

You can try using it but be careful of your temperatures

[nicenozzle]

Aside from the fact that smaller turbos are much harder to work with for this, it would be very cool.
I've been working on a compound turbojet design where each compressor feeds the other sides combustion chamber, much like a twin turbo works in a car, causing a natural equilibrium among each turbine.

Basically like you're building 2 turbojets, just linking them together, might save you a bit of work on making everything perfect since they don't need to be exactly even to run the same.

Yes definitely weld the wastegates, sand down very well, need a clean even flow in each side