Make My Mini Faster
Discussion
I have a 1994 1275cc Mini Cooper
And I want to know the best way to get more out of the engine??
Plus I thought this might make good conversation...
I have a bit of cash stashed away but not enough to swap out to say a 1380 or R1 motor bike engine... like I have seen
Any thoughts....
Thanks Monkey
And I want to know the best way to get more out of the engine??
Plus I thought this might make good conversation...
I have a bit of cash stashed away but not enough to swap out to say a 1380 or R1 motor bike engine... like I have seen
Any thoughts....
Thanks Monkey
Hi Monkey
Is it a carb engine?
if so the worlds your oyster! first step is whats known as a stage 1 kit, basically an uprated exhaust and new seperate inlet and exhaust manifolds. Id recommend a Fletcher system ive got one on one of my minis and its got a really nice rumble to it. id also recommend getting a K&N element for the standard airbox, lots of folk fit the pancake or cone filters but all it does really is make a load more noise, you can drill out the standard airbox in places to let more air flow through.
Then next stage up then is an uprated cylinder head, loads of suppliers for these, some better than others, personal recommendation would be morspeed or MED, from what ive used and what others i know recommend. this will improve power by a bit, then next step after that would be a cam, ive used the swiftune SW5 in the past and its a great driveable cam. fitting the cam will require the engine out however.
so that would be a decent start, cost would be about 200 quid for the stage 1 kit, say 2-300 for a head and then im not sure how much the cam us nowadays.
once you have decided to go for some uprated bits, get a rolling road tune done after fitting them at a specialist, it will make sure you are getting all the benefit of your mods!
Is it a carb engine?
if so the worlds your oyster! first step is whats known as a stage 1 kit, basically an uprated exhaust and new seperate inlet and exhaust manifolds. Id recommend a Fletcher system ive got one on one of my minis and its got a really nice rumble to it. id also recommend getting a K&N element for the standard airbox, lots of folk fit the pancake or cone filters but all it does really is make a load more noise, you can drill out the standard airbox in places to let more air flow through.
Then next stage up then is an uprated cylinder head, loads of suppliers for these, some better than others, personal recommendation would be morspeed or MED, from what ive used and what others i know recommend. this will improve power by a bit, then next step after that would be a cam, ive used the swiftune SW5 in the past and its a great driveable cam. fitting the cam will require the engine out however.
so that would be a decent start, cost would be about 200 quid for the stage 1 kit, say 2-300 for a head and then im not sure how much the cam us nowadays.
once you have decided to go for some uprated bits, get a rolling road tune done after fitting them at a specialist, it will make sure you are getting all the benefit of your mods!
Edited by chrisj_abz on Friday 11th September 22:05
VTEC engine it?, if you have the time and money, very reliable and bloody quick. Probably better than a bike engine in some ways. A few issues ago in miniworld there was a white VTEC engined mini, think the whole project cost him about 9K.
Heres the video: http://www.miniworld.co.uk/video/Roger_Dunns_Vtec_...
Heres the video: http://www.miniworld.co.uk/video/Roger_Dunns_Vtec_...
cater_racer said:
That's good advice Rufus, I'm taking a road going (historic rally mini) on track later this month, so spare wheel, jack, and bag of spares will all stay behind in the motorhome. Thanks for the reminder 
Sounds like fun Don't run with too much fuel in either (especially if you've got twin tanks) as it acts like a huge pendulum at the rear (oversteer is not good in a mini). Keep your right foot on it through the turns
Let us know how you go on!
Don't take too much notice of all this 'Stage this, that and the other'. It is all fairly meaningless sales 'puff' by those trying to sell packaged 'kits' of go-faster bits (sorry if that sounds cynical).
In real terms, the biggest thing that limits performance in a Mini is the cylinder head. Get a decent gas-flowed head with MG Metro-sized valves (35.5 mm in and 30.5 mm ex) and you have the basis of a half-decent engine. If you look at the combustion chambers of a late unleaded head you'll see big steps around the valve seats, a very rough surface finish, the intrusion of the valve-guide bosses into the inlet (and exhaust) tracts and the partial shrouding around the valves, all of which limits it's ability to flow mixture in efficiently.
If you get a better head, probably with a slightly higher compression ratio, an improved inlet manifold and exhaust manifold, and get that set-up properly you will see a noticeable improvement. Hotter cam, better back box, lightened flywheel, etc, etc, can all then follow as you can afford them and when you can get the engine out and in pieces.
Also, make sure your exhaust is the same diameter from the end of the manifold right to the final outlet point. I see these Minis with extra-large final pipes, or even twin pipes from the back box. These cause the gas to slow down and it's pressure to increase, thus causing back-pressure which loses power (it's called 'Bernoulli's Theorem, for those interested). A 1.75" internal diameter pipe is the right size for all 'big-bore' (that's all except for 998 and 850) engines.
In real terms, the biggest thing that limits performance in a Mini is the cylinder head. Get a decent gas-flowed head with MG Metro-sized valves (35.5 mm in and 30.5 mm ex) and you have the basis of a half-decent engine. If you look at the combustion chambers of a late unleaded head you'll see big steps around the valve seats, a very rough surface finish, the intrusion of the valve-guide bosses into the inlet (and exhaust) tracts and the partial shrouding around the valves, all of which limits it's ability to flow mixture in efficiently.
If you get a better head, probably with a slightly higher compression ratio, an improved inlet manifold and exhaust manifold, and get that set-up properly you will see a noticeable improvement. Hotter cam, better back box, lightened flywheel, etc, etc, can all then follow as you can afford them and when you can get the engine out and in pieces.
Also, make sure your exhaust is the same diameter from the end of the manifold right to the final outlet point. I see these Minis with extra-large final pipes, or even twin pipes from the back box. These cause the gas to slow down and it's pressure to increase, thus causing back-pressure which loses power (it's called 'Bernoulli's Theorem, for those interested). A 1.75" internal diameter pipe is the right size for all 'big-bore' (that's all except for 998 and 850) engines.
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