65 replies to this topic

[Northernpower]

That's very useful thankyou. What kind of pressure pump are we talking about. 50 psi?
Also I cant get the calculator to work?

I've edited the link, it should now work. As far as the fuel pump pressure is concerned the SC kit is designed to be regulated to 3.5 bar so you're looking for a pump with a greater delivery. If you're using a mini fuel tank the MPI (not SPI) is sufficient. If you're running a different type of pump don't forget a quality inline filter between the tank and the pump. Of equal importance is the feed from the pump to the injection rail. Regardless of whether you place the regulator in the boot or the engine compartment you need to use a quality fuel line and given the poor quality of some of the flexible lines out there a rigid line (copper) is the best bet. If you haven't wired it up yet don't forget the SC ECU controls the fuel pump earth not the live feed.

[IronmanG]

Thanks for that. It's a pickup so I will be going swirl pot and SC supplied pump filter and regulator.
Thanks for the heads up rgds earth!

[Wazzah]

In my opinion the SC ECU is a downgrade due to a lack of true load sensing capability.

The lack of a MAP sensor means that the fuel map needs to be exactly spot on for all throttle openings at each 500rpm step in the map table.

No amount of rolling road time can ever get this exactly right.

For a fast road mini the lack of this third dimension of Vacuum/ Load sensing and subsequent map correction is absolutely necessary.

I have run the SC gear for the last 18 months side by side with MEMS.

12 months of that was with a laptop by my side.

I've lost count of how many times I've swapped back and forth.

I have receipts for 9 manifold gaskets!!

As mentioned earlier on in this thread someone raised the possibility of the short inlet tract of the SC gear (minisport manifold) and it's lack of fuel mixing capability.

I believe this to be an absolute truth for a road going car.

I can get my car screaming with the SC gear on track days but it is undriveable on the road using those maps.

I can turn my car into a torque master with the SC gear but it will backfire at cruising speeds with the lightest loads.

Just plugging MEMS back in makes it a pleasure to drive with the best compromise in all operating conditions.

I'm currently running the Minisport manifold with a Rover SPI throttle body taken out to 45mm and it is good but could be better.

Hesitates below 2000 rpm and can't handle big throttle openings and runs out of fuel flat out in top gear.

I have one gasket left and am tempted to fit a flowed SPI manifold that I have ready to go.

I understand others in this post have higher outputs than mine but the common theme is the inability of an SC delta to cover all operating conditions.

[mini13]

Ok so whats stopping you fitting a MAP sensor and moving from Apha-N to Speed density mapping?

[Mini_Martin]

Mr Power your an absolute legend !! I’ve just plumed in my details.
1330cc, 120hp, 4 injectors, 0.5 BSFC and 80% duty cycle = 196cc so my 220cc injectors are plenty. Thanks mate.

Stevegrabba I took your advice after installing the 220cc injectors I multiplied the hole fuel map by 1.5 and it fired straight up! And it held idle beautifully. It has transformed the car ie I can actually take it for a drive now.
Steve thanks for starting this thread I can’t tell you how much it has helped me.

Just as a side note for anyone who is reading. When changing the map, after every change, don’t forget to press save!! LoL. It took me an hour to figure that out hahaha.

It’s time for me to finally run the engine in and shake the car down before I hit the rolling road.
Thanks again everyone for all your help.

Edited by Mini_Martin, 28 September 2020 - 09:20 PM.

[IronmanG]

Well done Mini Martin! Keep me informed of how the rolling road goes and any further developments !

[Mini_Martin]

Will do G

Gave it a small run out up and down the road and n Sunday and the heater valve for on top of the head blow off!!

All fixed now, on Thursday I ran it about 10 miles. so far so good. I’m going to sort the steering and geometry. And try to drive it round for 2 or 3 hundred miles just to brake the engine in slowly.

Hopefully get on the rollers at the end of the month.

[Grobster]

@Mini_Martin.... It was a pleasure to help you out.  I created the thread under my brothers log in  I'm Andy Grabba, he's Steve Grabba.

 

I eventually sold my 7 porter around 2 years ago.  I made vast improvements on the car from when I first started working on it, however never got beyond being maybe 80% satisfied with how it ran compared to my other and prior fast road mini's.

 

Then one evening I got a phone call from a very well respected mini tuner with experience and credibility going back to at least the mid 1980's.  I was given a brief about why and how, they really did not rate the SC Billet head for various reasons.  Whilst it had fantastic port flow capability and potential, at the vast majority of the drivable rpm range the fuelling mixture actual flow rate was far below optimum and far below such a rate that would give any consistency of fuel ratio's and values. 

 

Pretty similar to how putting a full race 12G940 head on a std 1275 would get it running, but never get it really running well because it would be a miss match of 'potential versus optimum'.

 

Would I use another SC 7 port Billet head?

....yes I would, but only on a large capacity build of 1380cc or greater, and I'd probably kit it with a bespoke manifold to accommodate 4xHS4 SU's, or twin HIF44's.  Why?....so I could ditch all the air temp, oil temp, barometric temp, oil temp fuelling correction values.  As you may note with the SC package and ECU, if you drive in the shaded side of the road for anything more than approx 30 seconds, this also screws with the fuelling values.  For example, If I headed up the to the top of the North Yorkshire Moors on the shaded side of the road it ran like a dog as the various correction values listed all started to change and already sensitive fuelling mix.  All messing that we can all do without, and carbs never seem to need.

 

Hope you are sorted now!

[Turbo Phil]

That’s interesting to hear but certainly not what I’ve found from the flowbench testing I’ve done with mine.
Referring solely to big bore heads, the SC billet head ports are quite conservative in size, certainly when compared to other 7 port heads widely available and compared to a modified 5 port.
They flow very well, but certainly not at the expense of velocity, which is much stronger than a worked 5 port head. This higher velocity if anything should promote better mixture as fuel is less likely to drop out of suspension. The higher velocity also improves VE thus increasing torque.

Phil.

Edited by Turbo Phil, 14 September 2021 - 01:23 PM.

[sonscar]

In my (limited) experience if the fuelling trims so badly affect the running then I would question the calibration and tuning of them.Properly tuned efi should be seamless and totally repeatable in its operation.Setting the trims is time consuming and one can easily affect the other so revisiting is often needed.I have no experience with the ECU in question.I run two elderly Megasquirt equipped cars.Just my experience and others will uncountably know more.Steve..

[IronmanG]

In my (limited) experience if the fuelling trims so badly affect the running then I would question the calibration and tuning of them.Properly tuned efi should be seamless and totally repeatable in its operation.Setting the trims is time consuming and one can easily affect the other so revisiting is often needed.I have no experience with the ECU in question.I run two elderly Megasquirt equipped cars.Just my experience and others will uncountably know more.Steve..

Is it the particular ECU that SC use that's the problem rather than the head itself you think?

[Northernpower]

In my (limited) experience if the fuelling trims so badly affect the running then I would question the calibration and tuning of them.Properly tuned efi should be seamless and totally repeatable in its operation.Setting the trims is time consuming and one can easily affect the other so revisiting is often needed.I have no experience with the ECU in question.I run two elderly Megasquirt equipped cars.Just my experience and others will uncountably know more.Steve..

Is it the particular ECU that SC use that's the problem rather than the head itself you think?

I my experience it's the ECU. SC have put a lot of work into the head but haven't matched it with a quality modern ECU. It takes a lot of time to program it and the guy tuning it could lose the will to live before it's finally finished. I would buy everything off SC other than the ECU and put a more efficient ECU on it.

[sonscar]

I,being an older non tech person fitted efi to my MGB(think large bore mini)and chose Megasquirt because it was very cheap.It was then "experimental" and there were next to no instructions and I had to learn lots of basic things and made many mistakes.One thing that stood me in good stead was to turn off all the embellishments leaving only fuel and ignition tables.Everything else relies on their accuracy.Change only one thing at a time.Save your maps.
A dyno person has to be familiar with the ECU and its tuning programming and to adjust everything could be weeks work,eg you only get one cold start per day and then it may be _20 to+30 degrees it will need calibrating for.
The ECU is not intelligent,it looks at the sensor data and does exactly what you have told it to do.Efi is time consuming to get right but very rewarding to master.I do not think the SC ECU is bad,merely missold and misunderstood.
Just my 2 pennoth.
Bearing in mind this was late 1990s I asked a local shop if they tuned Megasquirt?His reply..No they are a cheap system fitted by cheapskates very badly to really crappy cars,those who did not fit this category did not need to bring it to him and those who could not do it thought with an hour or twos work would get it fixed.Sweeping generalisations aside the game has truly marched on.Steve..

[Northernpower]

I do not think the SC ECU is bad,merely missold and misunderstood.
Just my 2 pennoth.
Sweeping generalisations aside the game has truly marched on.Steve..

That's exactly the point, the game has moved on, so, accepting its time consuming to fully program an ECU, the problem with the SC one is, its not user friendly and requires multiple inputs for changes when there are plenty of others on the market which enable the changes to be made much quicker. Because of this tuners are more reluctant to spend time fine tuning the setup. Just my personal experience of more than one SC installation.

Edited by Northernpower, 15 September 2021 - 11:35 AM.

[sonikk4]

This is why as and when funds allow I will be going Haltech.

I will go with the original supplied ECU to start with, and then once the engine is in the car and finances are in a better place going Haltech.

It’s bizarre considering how much money we have spent with SC that they cannot supply uswith a more user friendly ecu??