SYDNEYGARRETT 6041
The Green Beast
165lbf dry
215lbf with afterburner
Jet A-1 with propane start. About 72 km/h so far at half boost. Build thread
DIY TURBOJET KARTS
BLOWTORCH
Turbochargers, kerosene, and questionable decisions.
Free tools, real build numbers and hard-won lessons for turning a shed turbocharger into a jet engine, and bolting it to a kart.
Static thrust, afterburner lit
215 lbf
Measured on a Garrett 6041 kart
70,000
rpm at full power900 °C
into the turbine+30–35%
thrust from the afterburner1 moving part
in the whole engine01
DO THE MATHS FIRST
Pick a turbo, a fuel and an afterburner temperature, and everything updates live. Checked against a real afterburning kart: nozzle sizes within 2 mm, afterburner gain spot on, dry thrust about 13% conservative.
Thrust and fuel
Compare turbo sizes
Each size at its preset airflow and pressure ratio, with your other settings.
DryAfterburner lit
Compare fuels
Same engine, same fuel in both burners. Thrust barely moves; consumption changes a lot.
Combustion chamber
From the inducer rules used by published builds, checked against your airflow. A first cut to build and tune from.
On the kart
How it's worked out
A simple jet cycle: the compressor squeezes and heats the air, fuel raises it to your turbine inlet temperature, the turbine takes out just enough to drive the compressor, and the leftover pressure pushes gas out the nozzle. The afterburner reheats that exhaust before the nozzle.
Assumes 95% mechanical efficiency, sea-level pressure and a nozzle sized for the flow. Presets are ballpark points for each size class; for real numbers read your turbo's compressor map and pick Custom. Afterburner figures assume the nozzle is sized for afterburner flow; a dry-sized nozzle chokes the engine when it lights.
Measure thrust on a load cell before trusting any number on the kart.
02
TOOLS AND GUIDES
TOOLCombustor sizer
Flame tube, casing and hole pattern from your inducer diameter.
TOOLFuel nozzle sizerNozzle ratings and pump pressure for your fuel flow. Set nozzle count and pressure in the main burner settings.
TOOLTurbo comparisonHow thrust changes from a GT28 all the way up to an HT60.
GUIDE, COMING SOONCombustion chambers
The 2 × and 6 × inducer rules, hole areas and materials.
GUIDE, COMING SOONLight it on propane
Change over to kerosene at about 350 °C EGT, then run.
GUIDE, COMING SOONAfterburners
Flame holders, pilot flames and hot streak ignition.
03
Build submissions open soon.THE GARAGE
AUSTRALIAAIRESEARCH
Brendon's jet kart
3.9 ininducer
65krpm max
Petrol with LPG start. About AU$1,600 all up. Instructables
AUSTRALIAHOLSET T4
Blowtorch kart
???lbf dry
???lbf with afterburner
Kerosene with propane start, salvaged aircraft combustion cans. Under construction.
04
BUILD LOG
A rusty Holset, a pair of salvaged aircraft combustion cans, and a plan. Every measurement, photo and mistake on the way to first light-off.
- 1Turbo sourced: single-entry T4 HolsetDONE
- 2Combustion cans found in the shedDONE
- 3Measure everything
- 4Thrust stand and first light-off
- 5On the kart, GPS-logged runs
READ THIS BEFORE YOU LIGHT ANYTHING
QUESTIONABLE DECISIONS, SENSIBLE PRECAUTIONS
These engines spin past 70,000 rpm, run at 900 °C and burn litres of fuel a minute.
- Stand out of line with the turbo. A failed wheel throws fragments sideways; put steel between it and people.
- Drain before every start. Pooled fuel ran Whittle's first engine away after the fuel was cut.
- Oil first, oil last. No oil pressure, no start; keep it flowing until the engine cools.
- Prove it on a thrust stand. Remote controls, extinguishers and ear protection before it goes near a kart.