13 replies to this topic

[Tomm]

Hello TMF,

 

I am looking for some help from those of you who are a little more experienced than myself when it comes to SPI engines and the tuning of them. I have searched through here and google but I have not found exactly what I am after.

 

I have had Turbo minis, 16V minis, and they have been tonnes of fun but I am hoping to try my hand at a modified SPI now. 80hp was enough to put a smile on my face.

 

I have two questions here.

 

Firstly, how can i best get some more power out of my SPI?

 

What does the SPi respond to the best? My thoughts would be an LCB, Decat and exhaust system. I assume I would be best pairing this with an aftermarket air filter to help the breathing process.

 

Could anyone advise any products? My initial thoughts are Specalist Components LCB (it has the Lamba Bosses) Fletcher Link pipe and rear system.

 

Could anyone make any recommendations on this? Air filters, what are the best flowing ones for the SPI?

 

Can the standard SPI ECU be mapped? If so how well does it map? I have read on here that the SPI ECU does not respond well to tuning but Sprocket on here has managed to get 100bhp out of an SPI ECU.

 

I realise MegaSquirt is very affordable now and having dealt with the Megajolt it is a format I am briefly familiar with but I am unsure if this will be suitable for the SPI or if it will even be a worthwhile investment to get some more power out of the car.

 

With basic modifications will I see much of a power increase? My initial thoughts are No but I would be happily proved wrong.

 

Question 2.

 

As i said earlier, Sprocket on here ran 100bhp on the SPI ECU.

 

For me to reach the figure of say 80hp what sort of components am I going to be looking at? Is it a matter of a modified head, larger displacement bottom end 1330 or so, lairy cam, uprated injector and so on?

 

I would like to gauge the costs on such a build, I can then put it in perspective against the other options and try to weigh up what works best for me.

 

Sprockets 100bhp on SPI ECU thread here

 

http://www.theminiforum.co.uk/forums/topic/45702-its-official-100bhp-single-point-injection-mini-on-the-standard-ecu/

Cheers.
 

[megamini_jb]

Will be following with interest.

Was going to ask this soon myself.

[Richie83]

Will be following with interest.

Was going to ask this soon myself.

+1 

[FlyingScot]

In part answer to parts of your questions

No the standard MEMS cannot be mapped.
The SPI ECU referred to by Sprocket wasn't necessarily one which originally came from a mini.
There is a article here about SPi tuning http://minispares.co...3f-b562210c9155

FS

[Tomm]

Thanks for that link Flying Scott, it proved to be very interesting but as per usual with me, the more I read and understand the more questions I have.

 

 

In answer to the exhaust and manifold I read this.

 

The standard injection Cat is very efficient - both from a 'cleaning up emissions' point of view and from a 'non-restrictive' one.

 

We have found the Cat to cost only a couple of horses right at the top end of the rpm band on modified engines developing more than 104-ish bhp. Junking the Cat is therefore pointless unless absolute maximum power is sought.

I see this as there is not any real power gains to be had in terms of Manifold, Exhaust and De-cat's on lesser powered cars.

 

 

In reference to what the standard ECU can cope with, going with this...

 

As far as we have gone, the standard ECU copes with up to the 'GSi'-level tuning (Modified head, high lift rockers, replacement air filter element, rear exhaust section, etc.) offered by a number of the specialists.

 

Which I read as (please correct me if I am wrong as I am learning here) that the standard ECU will cope with a mild power increase over standard although this is the first reference I have heard of "GSI" tuning. Which then brings me onto this.

 

The limiting factor, as stressed previously, is the ECU. Beyond the aforementioned GSi type kits, further modifications net no further power output. Well, may be the odd one or two, but not significant gains. From all the combined efforts of myself and Swiftune Racing the most we've seen is 85bhp. And that is despite going further with mods to intake manifold, throttle body and air cleaner, adjustable fuel pressure regulators, complete replacement exhaust systems, current specific camshafts and higher ratio rockers (over the 1.5s). The best average is 82-83bhp. The worst was 78.4. Standard the injection engines give a quoted 63.

 

Does that go to suggest that I could go with a "Gsi" tuning package, try and develop a figure of around 80hp and still run this on a standard, unmodified SPi ECU. Anything any further will require an aftermarket ECU.

 

Throughout the whole article there is talk of development in the area of a "Plug and Play" ECU, ready to plug in on the existing loom and be suitable for the range of MPi and SPi engines. I did get very excited when I got to the bottom of that article and read

 

My advice is to be patient. The ECU we are after is currently being reliability tested on a standard MPi here in the UK right now. And we're looking at a customer purchase cost of around £350…

 

9 Years later I have not heard of anything, so I guess that will not be happening?

 

I know that specialist components does offer a SPI plug and Play Typhoon ECU which plugs into the standard wiring and has a base map for the 1275 SPI so should plug straight in and start straight up.

 

http://www.twinkam.c...aid=SC0127.001

 

I have not heard anything about this kit, like owner reviews, how much more we can expect to get out of the car in terms of power increases and so on. I guess the other pending problem would be finding someone to map it. I am sure SC could offer some help but Norfolk is quite a way to go for some people.

 

Standard ECU up to around 80bhp any more than that and you will need an aftermarket ECU. Fair assessment?

[minisilverbullet]

Answering your first post. 

 

I assume you have a cooper ECU?

 

My cooper Spi ( 45000 miles) with fresh plugs, LCB, rc40 exhaust, K&n filter got 73 bhp on minisports rolling road.  Accurate i don't know but pretty decent improvement i think. 

 

My ECU is of being repaired at the moment. and instead of having it repaired i flirted with the the idea of the SC ECU, in the end i could not justify the price. As on top of it you would need to modify your head or buy new

 

modified head = 500 (approx)

rockers = 180

SC Spi throttle body kit  including ECU- 1000

remap and tune - ? 

= I think I would be looking at around 2 grand, maybe the car would make around 95BHp (pure guess?) 

[Tomm]

Thanks for your reply Mr Silver bullet.

No mine is on a standard non-cooper SPI ECU.

Your point is most certainly valid and it is my main reason for starting this thread. I would be happy if I can brake the 80bhp barrier. When you weigh up the costs of going to the extent of a mappable ECU, head, rockers, cam, so on you end up in a territory that makes you reconsider your options.

Would I fork out £2,000 for 95HP, not at all, especially when you weigh up the other options out there (turbo, 16v head conversion, 16V engine conversion)and that's what I was trying to gauge from this thread.

I would be exceptionally pleased with 73bhp

[minisilverbullet]

Exactly my thought

The coopers have higher compression and different ecus, maybe that is something to research as a cheap first step.

I have also looked at the sc 7port head. Costs around 3k, can be used directly on the existing bottom end. Probably add around 25bhp. Plus future possibilities to upgrade the bottom end.

[psmini]

Following this thread with interest! I've looked at having my engine rebored with a different cam and a head but I reckon I'll be looking at circa £2500-3k for a drive away engine (I'm not mechanically minded). Think I'm going to go for the minispares SPI tuning kit with roller tip rockers for my Mayfair, looks to be good value for money and I've always found the quality of their kit pretty good.

[dbcool20]

Hey guys.

Another option if you want a more affordable (than the SC) and mappable ECU for the SPI is the "Ultimate Mini Squirt ECU" or "UMS". It was developed by some german guys.

Its a programable Plug-N-Play ECU which uses all the standard SPI sensors and wiring loom. you can then use programs like Tuner Studio MS to alter the fuel and ignition maps Or have real time display of the values etc... . Its a fairly decent ECU and works pretty good. I bought one a few years back, but unfortunately i have barely got to drive the car since then and not played with it much yet.

As for the price i know it was fairly cheaper than the SC typhoon ECU and stuff, but unfortunately I really can't remember exactly as it was quite a while back. Here is a link for More info on this UMS ECU:

http://www.m1n1.de/h..._classic_m.html

 

Cheers hope this helps your quest for BHP 

[FlyingScot]

You can tune SPI like any others minis with a number of caveats 1) Cam profile is crucial; wild profiles mean high emissions 2) free flowing exhausts ae good but watch the position of the lambda sensor boss as some positions lead to misreading the exhaust gases from only a couple of cylinders. 3) The head and the ECU on Cooper SPi and standard SPi are not the same Cooper has a higher CR and the ECU fuelling rate of change is quicker (AFAIK).

4) If you go for higher compression and Cooper ECU make sure it is either an early one without immobiliser or you have the matching immobiliser, key fob or the way to match them up.

 

My point about Sprockets build being not necessarily a mini SPI ECU is simply that several ECU exist for Rover cars with different software (Metro GTA, Rover 820 etc) and I am fairly sure it was one of these that was used to achieve the stated 100bhp from comments made in his various threads and he did not directly give the details (higher fuel pressure for example) but did comment that the fuelling was rich for most of the lower rev curve)

 

A nice free flowing Cooper SPi type set up should give you what you want, have a read around there are people who have built something similar who I hope will chip in.

 

FS

[Chopper69]

Hi all, I've just had the following done to my mayfair SPi -
block now 1293cc
Sage 3 head
1.5 rockers
Lightened and balanced flywheel
re ground nitro carburised crankshaft
Duplex timinggear and chains
Sw5 cam

I'm 200 miles into running it in,will let you know bhp figures when run in.......
I'm expecting around the 80 mark.

Edited by Chopper69, 25 July 2014 - 04:58 PM.

[Richie83]

Hi all, I've just had the following done to my mayfair SPi -
block now 1293cc
Sage 3 head
1.5 rockers
Lightened and balanced flywheel
re ground nitro carburised crankshaft
Duplex timinggear and chains
Sw5 cam

I'm 200 miles into running it in,will let you know bhp figures when run in.......
I'm expecting around the 80 mark.

sounds good. How does if drive?

[Chopper69]

I thought i'd have to put a please pass running in sign on the parcel shelf, but no need as its quicker now using limited revs than before with the whole rev range!!!
Running sweet at the moment.