Your motor and ECU will work perfectly fine together, until you start asking for more then around 85hp. If you are experiencing issues with your SPi, nearly all of the issues is due to other item, rather then the ECU. A really good idea would be to download one of the many "code reader" apps from both PC and mobile and buy/build yourself a cable to connect to the unique Rover 3-prong port.

As a long time SPi owner, I can tell you that these are great motors and can be super reliable and easy to live with...when taken care of. I am currently at the ceiling for the ECU and have thought about going the SC ECU route....but so glad I didn't. The biggest issue is that we are here and they are there and comms between have been said to be spotty at best. You also have to find someone that understand the software they are using on this end. Oh, and just so we are clear, non of these options are truly plug and play. Most that I have talked to said their cars either would not run or barely ran after install and before proper setup.

If you have not already, theminiforum.co.uk has a injection1specific section that is an amazing wealth of knowledge. You should check it out.

If your SPi is working OK now, don't bother. Claims by aftermarket manufacturers are often exaggerated.

I believe the ECU just delivers gas, doesn't make HP.

I see that there is a company in the UK that makes a nice computer for the Spi and I'm wondering if it would help my car gain hp. I have a few modifications including a Swiftune SW5 cam, milled head, lightened flywheel, header, K&N filter, 1.5 roller rockers. I'm not looking for crazy hp, just maybe to make all the mods work together better for the $1,000 the computer costs.

Looking for any opinions from anyone with experience on the computers. I should probably get a better cylinder head too. Thanks in advance.