Installing a Metro Turbo engine and gearbox in to a Mini
Intro
Any questions or comments then mail me at DervScenicMan@Hotmail.com
I decided to change the engine in my mini to a Metro turbo unit in October 1999, I wanted more power, less noise and no loss of reliability. Some would argue that the turbo motor would only give me one of these! I have listed all the resources I found useful at the bottom of the page.
Anyway lets cut to the chase!
Components
See the link at the bottom of this page for pictures of the various components.
Before we get down to the nitty gritty here's a brief overview of the main components followed by how the standard turbo installation works.
Description
To cut a long story short (see www.geocities.com/MotorCity/Downs/6626/eraturbo.htm) the boost pressure needed to be restricted at low RPM to prolong gearbox life, this is how it was done....
The hot exhaust gasses produced by the engine drive a turbine which generates (boost) pressure in the induction system, the 'dump valve spring' limits the maximum boost. In the case of the Metro there are actually two levels of boost 4.5 psi below 3500rpm (ish) and 7 psi from 3500 rpm upwards, as I said the dump valve spring limits the boost pressure and the Metro is fitted with a spring which gives about 7 psi. It's operation is all very simple (in theory) the boost generated is 'measured', the pressure in the inlet system 'pushes' against the dump valve when the dump valve spring can't resist the pressure any more the valve opens and bleeds off the excess pressure. So you already now how to increase the boost pressure (use a stiffer spring). The boost is restricted by bleeding pressure from the system by means of the 'Boost control solenoid valve' when this valve is open it effectively restricts boost pressure to about 4.5 psi. When the ECU detects the RPM has gone above the predetermined level it closes the solenoid, this obviously stops air escaping from the system therefore increasing pressure in the plenum chamber and in turn increase the boost level.
Options
They are a few different ways of tackling the conversion I won't (can't) cover them all but here are the most popular options.
I have decided to manually switch (junk the ECU) between the two levels of boost so for normal day-to-day driving I will have the lower levels but when I'm out on the country lanes I can press the fun button and have the higher level right through the rev range!
click here for the wiring diagram. (it's very big mind)
The other option is to keep the ECU and wire everything in as standard.
Cooling
Click here to see how I connected up my cooling system
Parts List
Here's a list of bits I had to get for the conversion
Fuel system setup
Links and thanks!
While investigating the subject I found it quite difficult to get the more detailed information I needed, the mini-list which I have been a member of for a few years was fairly useful, the alt.autos.minis was slightly more so but the resource that generated the most help was the Mini Spares Register (www.drive.to/minispares) maintained by Rich Huzzey of Cardiff Mini Club and who is also a 'contributor' in Mini World (I don't know where he gets all the time!) The MSR put me in touch with about fifteen people who had converted their minis using the Metro Turbo powerplant, the most useful was Keith Barnes (VERY helpful chap who would like to thank Adrain Dodds) whose mini you can see in the January 1999 issue of Mini Magazine, Oliver Stone also deserves thanks and his web site also has some nice pictures.
Good pictures of the ERA engine bay, with plenty of info too.
