MINI TURBO

On this page you will find information about Mini's with Turbo engines fitted. These are my own experiences, info from other Mini Turbo owners and technical information.

  First if you want to fit a MG Metro Turbo engine in a Mini, You have to make a gap in the bulkhead because you need some space for the Turbo that is fitted at the back of the engine. To fill the gap you need a bulkhead box, there is one fabricated bulkhead available at Avonbar Racing (ABR 028) or you make one by yourself. When the box is fitted there is some stiffening of the bulkhead recommended. If the engine is fitted, the top engine stabilizer is to short, make it longer or fit an adjustable engine stabilizer from KAD, there is some more engine noise with it but with the left and right threaded ends it is easy to adjust and it looks very nice too! On the under side of the engine to subframe, fit two engine stabilizers with polyurethane engine steady bushes.
If you plan to fit a new exhaust take the Maniflow LMD680 Mini Turbo Down pipe and the ABRLS023 Mini Turbo system (only available at Avonbar) this is a single box side exit, with 2" dia. I fitted this one and it fits very well and the sound is nice, because of the Turbo that works as a muffler a single box system gives the same noise level like a non turbo engine with a twin box system.

Technical Data: standard MG Metro Turbo engine

Engine number: 12HC16AA, from 1987 12HD26AA
Valve clearance: (Cold engine) In. . . 0.30 - 0.35
Ex.
 0.35 - 0.40
Spark Plug Gap 1.0 mm
Ignition timing (strobe) deg. at 1500 rev. (without vacuum)
centr. advance begin 0 +/- 1 at 900 revs (without vacuum)
centr. advance test 8.8 - 13.5 at 2360 revs (without vacuum)
centr. advance end 11 - 15.5 at 2880 revs (without vacuum)
max. advance 19 - 19.5 at 5600 revs (without vacuum)
vacuum adv. beg deg/mm Hg <x 1,33 = 1 mbar 0/5 - 35
vacuum adv. end  deg/mm Hg <x 1.33 = 1 mbar 22 - 26/170
Idle 880 - 930

The Engine

If you want to improve the standard Turbo Engine, I recommend fitting a dump-valve. There is a lag e.g. when You shift to the next gear, without dump valve the Turbo is building up pressure, but the throttle valve is closed so the Turbo stops itself because the pressure gives it some resistance. Now, if there is a dump valve in the system, the excess air pressure can go out when the dump valve opens. It is a great improvement!
The membrane from the dump valve needs vacuum; take it from the intake manifold.
Remove the standard Metro Turbo ECU if you want to give it more boost. The bleed setup as used normally to get more boost will not work good with the SU carburettor. You need a modified actuator to run on higher boost levels.
With these higher boost levels your minimal need is to have a cross pin diff!!!
This is my engine setup, and is rated at 158 bhp at the flywheel and 137 bhp at the wheels.

Key: CR = Compression Ratio

- Engine: 1293cc: +0.020 Omega pistons (lowered dish) for very low CR. (less than 8.0)
- Head: Habumini Turbo head with 35mm / 29mm valves, flowed and enlarged chambers for lower CR.
- Cam: Avonbar Turbo specially made by Piper Cams, fast road, smooth power and flexibility and also reduces the turbo lag
- Rockers: 1.7 lift full roller rockers
- Timing: adjustable belt drive timing gear
- Ignition: Habumini modified turbo ignition and sparks plugs are NGK
- Carburettor: Modified HIF44 Turbo 
- Flywheel: lightened ultra light flywheel & light steel backplate
- Gearbox: Jack Knight S/C C/R, - clutch: sintered clutch plate, grey race diaphragm
- F.D.: Jack Knight 3.9 semi s/c - drop gears: 1:1 Jack Knight s/c
- Diff: Sallisbury LSD
- Oil: Valvoline Racing 20W50 (Mineral Oil)