To small or big turbine?

[kanbus]

Hi i'm Jens. I'm from Denmark and have always had a big interest in engines and electronics. I've had a small electronics lab where I lived before but i had to pack it up when I moved together with my girlfriend.
But as luck will have it I have a workshop available at work and even more luckily they have supplied me with two turbo's that was written off from our Warehouse.
I have lurked the forum the past months and i'm impressed by the knowledge and all the cool projects you guys have made. now I want one myself.

The goal I have is to first have a working gas generator, make noise, burning lots of fuel.
Second (if money, time and availability of parts awllow) drive a free power turbine. What I will end up powering is still up for debate.

The one turbo is a twin scroll I think is from a CAT c15 engine.
The specs is as follows:
Comp inducer - ø63mm
Comp scroll A/R - 0.57
Turb exducer - Ca. ø63mm
Turb scroll A/R - 0.74

So the cons are as I see it it's a twin scroll and theturbine is way small. it's maybe a tad to big for my liking.

The other is an unknown switcher turbo.
The specs is as follows:

Comp inducer - ø59mm

Comp scroll A/R - unknown
Turb exducer - Ca. ø70mm

Turb scroll A/R - unknown,  but it's fat.

Is it correct of me to assume i could use the bigger turbo and maybe bleed air from the compressor to mitigate surging? maybe use this air to drive something in the future. maybe a small generator to charge batteries and power pumps etc.

The smaller turbo seems more manageble for me as a start though. But the area of the turbine exducer is 41% larger than comp. inducer.
Is my assumption correct that pressure in my combuster will be low and effeciency will suffer?

What turbo would you choose to best suit my goals?
Best regards.
Jens

[kanbus]

I forgot to ask if there is a way to find more info on my specific turbos like max rpm and turbine inlet temp?

I can’t make the oem of any of the units.
I’ll try to upload some pictures later today.

[racket]

Hi Jens

Use the smaller turbo , you'll have less problems , and it'll produce more thrust than the larger one

Max rpm is based on the quality of the turbo , if its of unknown heritage then we need to keep tip speed of the comp exducer to under 440m/s and your turb outlet temps to ~600deg C

Cheers
John

[kanbus]

Thats what I'll do. thanks.

Here's some images. I could only find little info on the cartridge and the writing on the turbo is to hard for me to read to make anything out of it.
It's an old unit, but not some random one from china. But i gues materiel science has come a long way since this turbo was made.

[racket]

Hi Jens

That is an old unit , so keep to those modest pressures and temperatures .

Cheers
John