11 replies to this topic

[Mini'92]

Hi

I am interested in getting a bit more from the standard engine setup. I have a K&N, Play mini back box but thats about it.

Was wondering what you experts could suggest? or should i rip out the crappy injection system and get a big carb on there?


Cheers

[Bungle]

you could go for one of blueminis heads but thats about it unless you replace the ecu or go to carbs

[chairchild]

the most you can do to an SPI is:

overbore to 1380
ported head with bigger valves
ported inlet manifold
52mm TB
Maniflow LCB exhaust manifold
K&N replacement air filter, in modified airbox

and all the usual bottom-end stuff like lightening and balancing does the usual wonders :wink:


Also, to modify the SPI airbox is VERY simple, and takes all of 2 minutes:
Remove airbox (2 screws, one air pipe, and a sensor clip) Then unclip the top of the filter housing.
Now take out the filter, and get a K&N replacement one
also, in the centre of the airbox, you'll see a lighter shade of plastic, making up a rather annoying restriction all the way round the inlet. Twist the 3 plastic tabs with a pair of pliers, and it pops right out! (MPI drivers dont have this luxury, and have to use a dremel to cut theirs out)


the "annoying" ring of plastic in the centre was put there by Rover, so if someone took the airbox apart, and a stone/etc got in there, the stone wouldn't be able to get into the inlet and destroy your engine. but it also has the side effect of blocking half of your potential airflow!




Beyond that, you'll need a reprpgammable ECU, and a custom injection setup - big bucks!

[PikeyMini]

sounds expensive! ?

[piransurfer]

Chairchild

That airbox modification sounds so good, I'm going to try it before work tomorrow!!

[mini_miniman]

chairchild tried you mod to the air box you where right only 2 mins work for a considerable amount of throttle response more aswell as a bit of umph! nice one

[Mini'92]

hey

does the modified air box provide better air flow than the k&n i have sitting on top??

Also can anyone recommend anywhere i might purchase exhaust/inlet manifolds? performance heads?? etc

also what is a 52mm TB??

thanks again.

[The Roadie]

Get a K&N 57i induction kit - WAAAAAAAAAPPPPPPPP. Then you can keep your standard airbox for long trips or cold weather like me.
Tip - buy a new air inlet temperature sensor for the K&N. They are only £24 and its not wirth the risk of butchering the airbox to get it out as it will probabl take the insert with it.

Also the ECU apprently "learns" from the increased airflow and colder air. I have now dropped from £20 a week in petrol to £15 a week. I go from Cheadle Hulme to Macclesfield, about 12 miles every day and back again.

As previous people have said, there isn't much more than a capacity increase and the "GSi" kit for them.
Still good mind, but you still get the smooth injection running, and the ability to start in the cold lol!

HANG ON - when my fuel pump broke, we had a pump for an R8 series Rover 214. Single Point injection one (1989-1994 I think).
It whines inside the tank as it was a bit of a dodgy fit, but it must slightly overfuel my car, its a bit quicker.

[chairchild]

glad to hear it worked well for you miniman!

For the ported inlets, and heads, I'd say send yours off to Morspeed http://www.morspeed.co.uk/

He ports injection inlets for around the £20 mark, and his Stg3 heads are a VERY reasonable price! :wink:


a 52mm TB, stands for a 52mm diameter throttle body (the bit that holds the butterfly) Standard SPI TB is only 42mm, and what they do, is remove the butterfly and spindle, bore it out to the bigger size, then refit the spindle, and fit a bigger butterfly - just makes the most of your newly ported head and manifold :wink:


As for the manifold, I'd have to say give www.minispares.co.uk a try, they've got reasonable prices on most parts. Also, if you have a welder, dont buy the injection manifold - just buy the carb one (about £20 cheaper) and just drill the hole for the lambda sensor, and weld on the right sized nut to screw it into!!



also, the temp sender easily comes out witha spanner, they're only "nipped-up tight" with a spanner when they're put in, which is sometimes loose enough for them to fall out of their own accord!

But the 57i style of K&N filter is inferior to a well modded airbox, with a replacement element. The airbox's simply allow better linear airflow - but the 57i's DO sound nice with your foot to the floor!

[AlexM]

Also, if you have a welder, dont buy the injection manifold - just buy the carb one (about £20 cheaper) and just drill the hole for the lambda sensor, and weld on the right sized nut to screw it into!!

I just bought the injection manifold, to be honest that sounds like a lot of hassle, id just avoid all that and spend £20 more.

[Sprocket]

a 52mm TB, stands for a 52mm diameter throttle body (the bit that holds the butterfly) Standard SPI TB is only 42mm, and what they do, is remove the butterfly and spindle, bore it out to the bigger size, then refit the spindle, and fit a bigger butterfly - just makes the most of your newly ported head and manifold :wink:

Never heard this before, sure you're not getting confused with th TPI (Twin Point Injection). It is not the lack of air the SPI (Single Point Injection ( also known as TBI, Throttle Body Injection) suffers from to neccesitate a bigger throttle body but rather its the Injector that is too small running out of squirt on a 1293cc with a 276 cam and big valve head, ported manifold and lcb causing pistons to melt at full load full throttle

[chairchild]

Well I've only heard of it being done a few times to an SPI - and the owners have all reported improved throttle response, and a noticeable improvement on the "butt-dyno" :wink:

and if the injector gets maxed out (which is strange, since Morspeed have sold several highly tuned 1380 units, and haven't had any complaints AFAIK) then all you have to do is put a 1mm washer in the pressure regulator to bump up the pressure, and therefore the fuelling