21 replies to this topic

[joel93]

so do yopu think i should buy an lcb, stage 3head for now
and cams when i get some money.
does this sound like a plan?

thanks again mate..

[minisilverbullet]

I am thinking you should do a quick rolling road session, find out what the engine is producing now. and take it from there

My SPI with a minisport 'stage 1' kit made 73 bhp. So with that I couldnt justify a stage 3 kit, only to reach and extra 10 bhp for around a 1000 quid

[joel93]

but mine isn't a cooper so only hade 50bhp standard.
if i want the standerd bhp what wears and losses power ?

ill fit an lcb and go to rolling road how much it cost.
im hoping for 55bhp with stage 1 kit

[RayBoogs]

Sometimes your not always best getting a stage kit, you can sometimes get better heads off ebay which will give you just as good results, i think its the mg metro head that is supposed to be pretty good, cant remember which one exactly. But if you have the money there is nothing wrong with a stage 3 kit.

Also the standard SPi manifold is already an LCB I believe (correct me if I'm wrong) and there is no point in replacing unless it is knackered.

You also talk about roller rockers, these are good but can as said lose power down low (and they arent just bolt on, you need to take the head off and replace the head gasket) but if they are used with a good road cam like the SW5-07 (which is just about the best cam you can get for your needs) they can be good, on the subject of cams, this is where the SPi loses most of its power, the cam is pretty poor and you will see the most results when replacing this, but it will need an engine out.

Now the ECU as has been said it is limited to round about 90bhp possibly more, but as you get towards this it is also the injector size that will let you down and will not be able to supply enough fuel so you will need a larger one, also do not convert to carbs, as well as the issues with emissions and regulations, Injection is a lot better, especially when you get to the realms of mappable ignition it is far superior.

For me the best first mods to do would be "stage 1" ie air filter, decent CAT back maniflow exhaust system (1.75") and a set of new plugs etc. Then a good cam and head, and maybe put the roller rockers with the cam, you can also look at 7 or 8 port heads with mappable ignition if you want to take it to the extreme

Also have a look-see here >>> http://www.theminifo...showtopic=79995 <<<

HTH

Jack

Edited by RayBoogs, 10 February 2011 - 07:31 PM.

[yellowjb]

Hi mate...jus thought I'd let you know what I have just done to my "L"reg cooper spi...
First off fitted miniplay s/s exhaust/LCB/de-cat & did try K&N clamp on filter(although was quicker with this filter I found too noisy so got K&N panel filter in modified std air box now.) This was all ok & sounded great (not too loud!) but like you I wanted more...
so after thinking about it for ages I thought ******** to it & bought the minisport ported & flowed big vlave stage 3 head & a set of 1.5 roller rockers, & what do I think now I have fitted it all a couple of weeks ago . . . . . . . . . Brilliant!!! I say it drives now like a true cooper should! - seems to be plenty & "torqy" - which is 1 thing I was a bit concerned over as this is my daily driver so still wanted it "driveable" & not all "lumpy" but also what I am assuming is down to the roller rockers is what feels like a cam fitted with now a power band coming on somewhere over 3500rpm - Just BRILLIANT - doit doit! I agonised over the money for ages but stuff it don't regret spending a penny!! Just so much fun to drive now...a real difference...
Hope this may of helped??
Cheers
Ja

[Hamstein]

Hmmm, Interesting!
I have also been toying with the idea of putting a little more 'chunk in the trunk' of my 95 mayfair spi.

I've got to have the engine out to fix my crunchy second gear soon, and might as well give it the once over and fiddle with it whilst it's out.
I'm not really bothered about ultimate power, so a quick change of head and rockers,etc, for a reasonable increase would be fine for me.

Are the stage'd heads a simple drop on option for a standard spi?
As most tuning seems to dwell on the coopers, which have a higher compression ratio than my lowly model, are the heads machined for this, hence raising my ratio? or does it just stay as standard? Does this even matter? .....and if it does, will the standard non cooper ECU cope?

Surely the roller bit of the rockers only affect the wear on the valve stems, rather than performance, its the 1.5 bit which makes the difference, rollers or not!?

A few questions there I know, various opinions would be appreciated!

[RayBoogs]

I'm pretty sure you can just plonk the head on torque it up and it'll be fine.

Yes you are right in saying that its the ratio that helps with power, you can get 1.3 1.5 and 1.7 ratio roller rockers, the 1.3 are pretty much just for reducing wear and allowing it to rev more and more "smoothly", the 1.5 are for fast road and 1.7 mainly for race engines.

Although if you have the engine out I would highly recommend you change the camshaft as this is the worst part of the SPi engine, best choice for Cam is probably the sw5-07, good torque cam for low down power, or there are the kent MD274 and MD274SP, the SP is a scatter pattern cam, so you won't see the benifits of this low down but it will kick in higher up the revs.

and yes your ecu should be fine until about 90bhp

HTH Jack