For an MPi, you may as well go straight for a hi-flow head. You can get one from the UK, or have a local shop do one for you. The stock head is pretty restrictive as far as heads go, but it is easy to get a large improvement in flow capability.

You can fit a larger bore throttle body, but you won't see a huge gain here - but you can modify yours to allow thr butterfly to open more very easily - but that won't help unless the head flows more...

The stock header / downpipe is not bad - probably the best "cast" version on any production mini, but an LCB and high-flow exhaust will also help.

After this - you are really limited... The stock engine management doesn't want to easily give up much more than 80hp in most circumstances.

As others have suggested, switching to a 3.1 diff ratio will make it feel way more pokey, but you will notice the increased RPM.

If you want to go much over 80hp, then I'd jump to the EFI kit from specialist components and stick a new cam in there with more lift and a little more duration. This last step will likely yeild a good 15, maybe 20hp over what you previously had - simply because it will allow all the other parts to work much more effectivly.

The next problem you'll have though, is working around the chocolate gears that they put into the MPi gearbox!

You can't adjust a Mini ECU. I think you would have to spend a ton of $ to get more power out of a MPI.

multi point injection was introduced mostly to cover emission demands and better fuel economy... tuning is straight forward and 85 or 90ish bhp is fair enough for street use.. plus u keep the same mileage

but the mini i have i believe is a multi injection car not a single

I've driven the same car Rick just mentioned, on a few longer trips.  It is a single point injection car, so less powerful than the MPI cars that came later.  It does have a lower final drive:  a 3.1, I think, as per the build for heavier cabriolet cars.

a supercharger would be a good upgrade if you know what you re doing...

I've only driven one SPI Mini 1275 on 12" wheels/tires and was I impressed with the performance and economy...did I say I was impressed.  It was a heavy Cabriolet model but moved right along on the I5 and I found the rev limiter during the MMW 2005 autocross at Altamont's 1/2 mile oval.  

FD change as Mur has suggested, lighter wheel/tire combination as also suggested but I would not begin messing with the MPI power unit.

6464/Jim-

But removing the catalytic converter from a late model MPI might foul up the emmission readings-

In Ontario all cars newer than a 1987 model needs an e-test as part of the current legislation-

BIG AL-

the cheapest and simplest mod would  be to remove the cat with a straight pipe. 

You are somewhat limited with the late model MPI's when it comes to tuning. I am not sure if our host sells it but Mini Sport were advertising a "claimed" 45% increase in power for their MPI stage 3 kit in this months Mini mag. A friend ported polished and skimmed his 2000 Mini head and removed the catalytic converter and the increse in power in that car was very noticeable even with the 2.76 FD. If you have them Sports Pack wheels are ridiculously heavy and all that mass saps a lot of power that is one of the reasons the 13" wheeled Mini's were slower than the 12" wheeled Mini's.

A 1998 mini from most markets in the world would have a tall-ish final drive.  The best improvement to the car from an economic perspective would be to go to a less tall final drive.  3.2:1 or 3.44:1 are options that would really make that car fly, and the 3.44:1 is so common it is just the work to change it over, they are common and inexpensive.

Reducing reciprocating mass is a good idea.  Light rims and tires are a good thing to consider.

As for the engine, there are a few people who have done a lot with the later injected minis, they will likely chime in on this thread.

As for me, an injected mini often is a better driver that many people's high performance 1380+ engines.  Smooth delivery, good power, good economy.  You can always buy another mini and build a crazy strong engine for endless tire squealing.

The advice on a logical progression for upgrading that I followed is thus:

 The A-Series engine is all about breathing. Virtually anything to improve volumetric efficiency is a good way to go.

A "Stage One kit" is the typical first step to improving performance. It usually consists of a low-restriction air cleaner, exhaust header and a way to increase fueling to match the increased intake and exhaust efficiency. A higher efficiency intake manifold is a good thing as well and may be included. Carbed cars use a Metro unit or aftermarket equivalent. Check our host's offerrings for both carbed and injected cars. These kits are easy to fit and are claimed to provide 10-15% power increase.

The next move would be an upgraded head and ignition. After that, a more aggressive camshaft, then overboring. I suppose that supercharging might fit in there somewhere as well.

Leaving the A-series for an engine swap opens up a whole new realm of options and possibilities.

I went from stock 998 to stage one kit, to carbed 1380 with stock head and dizzy to adding a Stage IV head and performance dizzy to Honda VTEC engine swap, to making the Honda AWD.

This topic has been addressed numerous times and I'm sure others will chime in, but how far you take this will depend on how far you want to go and how much you want to spend! Like the sign on the speed shop wall says "Speed costs money. How fast do you want to go?"

PS Welcome to the insanity!

hi there, just was woundering if anyone out there could help me decide witch route to go for. i have a 1275 1998 mini and i want to get the most power out of my engine for the most resonable price. someone has told me to change my head and others have told me to upgrade some engine parts. are there steps like should i do some minor stuff and then move to bigger upgrades are should i just do a major upgrade. with all said, what ever i decide to do i would like to do something that i will notice the power but not do any long term damage to my engine. please help