Supercharging SPI with Stand-alone ECU
Turbo Mini Forums

Hi there, new to the forum and looking for a bit of advice. I’m hopefully about to become the owner of a 1996 Mini Sidewalk and fancy going down the supercharger route but want to do this in a somewhat staged manner and want to get a parts list going of things I’ll need to acquire. First thing on my list is ECU and fuelling situation including if applicable replacing the ignition system. I want to replace the “toilet bowl” fuel injection with something that will suit the eventual supercharger set up and the ECU with something more tuning friendly. I’m happy with DIY equipment, the first thing on my idea list was a Speeduino but need to find a suitable fuelling set up that it works with on the Siamese port, still need to do further reading on if this can also take over the ignition system or if something else can deal with that. So far, and this will probably be updated and edited throughout, the parts list currently stands at:-

Supercharger: Eaton M45 Unit with Rebuild kit and Vmaxscart integration kit

ECU: Speeduino or MS based unit

Additional Sensors: unknown at present

Ignition: possibly Speeduino, mega jolt probably

Fuelling: Cheap Weber style throttle body or MT07/RS660 motorcycle throttle body

As far the stage process I wish to follow I think the following is what would be best and give best incremental improvement:-
ECU>>Ignition>>Fuelling>>Supercharging

I’m happy with DIY solutions and scavenging or modifying components from other vehicles to get it to work. I want to do this as cost effectively as possible which is why I’m going to buy a second hand M45 and recon it myself, worst that happens is it goes back on eBay totally reconned for someone else. Just needing help with component choice and integration and the many problems that will come along the way. Cheers for your help.

Edited by gusrus on 2nd Apr, 2024.

So after a bit of brain storming I’ve come up with a potential solution to the fuelling and how I’m going to go about this with the upgrade path I have in mind. The first solution is cheap Weber type throttle bodies, with a manifold they’ll mate up to the SPi head and the aftermarket ECU will do all the controlling, the other option I like is the use of motorcycle throttle bodies, something from the new breed of parallel twins such as the MT-07, GSXR8, Aprilia RS660. They’re cheap, plentiful and I can design a manifold and adaptor plates to be manufactured from them to mate to the SPi head then another for the supercharger, still needs an aftermarket ECU, so this is a potential solution to what I’m looking at.

So after a bit of brain storming I’ve come up with a potential solution to the fuelling and how I’m going to go about this with the upgrade path I have in mind. The first solution is cheap Weber type throttle bodies, with a manifold they’ll mate up to the SPi head and the aftermarket ECU will do all the controlling, the other option I like is the use of motorcycle throttle bodies, something from the new breed of parallel twins such as the MT-07, GSXR8, Aprilia RS660. They’re cheap, plentiful and I can design a manifold and adaptor plates to be manufactured from them to mate to the SPi head then another for the supercharger, still needs an aftermarket ECU, so this is a potential solution to what I’m looking at.