13 replies to this topic

[dme123]

Hi All
I have a '96 Mini Sprite SPi, and reading around the topic it appears that the Sprite is detuned to 50bhp versus 60bhp+ for the Cooper models. I was wondering if anyone here knew how this was achieved - I suspect it's just in software on the ECU, but don't really know. If it is just the ECU, does anyone know if a Cooper ECU can be installed to recover the extra power?

Also, my exhaust is in a sad state and rather than just replace it from the cat back I'm thinking about getting a Minispares Stage One kit - does this actually give any noticeable increase in power?

Regards,

Dave

[redhotmini]

a stage 1 kit would be worthwhile. with regards to the detuned bit, im not entirely sure how it was 'detuned' compared to the cooper, it may be more than just ecu mapping.

[spiguy]

a stage 1 kit would be worthwhile. with regards to the detuned bit, im not entirely sure how it was 'detuned' compared to the cooper, it may be more than just ecu mapping.

I'm sure I was told there were differences in the head, bigger valves maybe? Could be bol*ocks of course...

[captain kirk]

I would be interested to know the answer to this one.

[mrslaphead]

The coopers had a higher compression ratio. 10.0:1 instead of 9.4:1 for the non coopers

[DaveRob]

higher comp ratio and different cam are the main 2 as far as I know..... their are plenty of threads about upgrading performance on SPis.... as far as the ECU goes I think their are 2 versions.... basically a 1 plug and a 2 plug type..... my understanding is the ECU isnt the issue its the cam and comp ratio.

Hope this helps

Rob

[dme123]

Hi All
Thanks for the replies - I should have know it wouldn't be anything easy to deal with!

Thanks,

Dave

[Sprocket]

Common question and it has been covered MANY times before. The search button is your friend here. However, to make it easy. The cooper has a sportier cam, higher compression ratio, and an ECU to match with slightly richer full throttle fueling and an ignition advance table to suit the higher compression ratio. the only other differnce is the final drive is 3.2:1 rather than the non cooper 3.1:1

There are several versions of the ECU which can be broken down into two catagories, one plug and two plug. The two plug ECUs were only used on the early cooper. The one plug ECU, there are several versions used on both cooper and non cooper, some are coded for use with a coded factory fit alarm/ imobiliser and some are uncoded.

Changing just the ECU on a non cooper engine without any other modification will do nothing except maybe iterfere with the tune of the engine.

[rick.spi]

wow i never knew this

[KLAS]

over here in Germany there are 53HP SPi engines with 2 plug ecus, too.
like mine, from 1992

[jaydee]

Keep in mind the 'detuned' spi pistons have a different dish.

[Guess-Works.com]

I love the terminology "Detuned SPi Engine"

However incorrect it is..

By the same token my scoobie must be a de-tuned WRX rally imprezza

[jaydee]

I love the terminology "Detuned SPi Engine"

However incorrect it is..

By the same token my scoobie must be a de-tuned WRX rally imprezza

Yer thats why i wrote

'detuned' spi

[Sprocket]

Keep in mind the 'detuned' spi pistons have a different dish.

No they dont

The difference in compression ratio from the cooper to the non cooper is achieved with a different compression hight of the piston, not the dish, the dish is exactly the same, the lower compression piston is shorter