Prototype Fuel Injection Conversion

[mab01uk]

This may be of interest to some and was originally posted on TMF:-
http://www.theminiforum.co.uk/forums/to ... onversion/

Developing a prototype electronic fuel injection control unit (ECU) for a 1098cc Mini
http://www.just-technology.co.uk/?page= ... nt_145#145

[ianh1968]

I've had enough of SU carburettors! They work great on standard engines but when you're into modifying as I am,
they become a real hinderance as they can't be tuned properly without changing the metering needle
and to select the right needle, you really need a rolling road session.
So decided to fit a fuel injection system to my Mini 1275GT (which has a 1098 engine at the moment)
that can be adapted and tuned without the expense of a rolling road.

It was difficult to get repeatable results however, and this made tuning a bit more hit-and-miss than expected.
This is partly due to the coarseness of the narrow band Lambda sensor and difficulty in holding a steady
RPM / load long enough to get a sufficient number of samples.

This really illustrates why a rolling road is essential for precise tuning.

I also need to investigate a wideband Lambda sensor in a future update.

The chap that created this is clearly very talented, but really needs to make up his mind
why he did all this. The stated purpose was that the system could be adapted and tuned
without the expense of a rolling road.

However, in his parting shot, he states that everything is a bit "hit-and-miss", and that
a rolling road is essential for precise tuning. There is a section in the Vizard book
that featured a fuel injection system that produced a gain of MINUS 10 bhp compared
to a carb setup. Modern/fancy/electronic does not always mean better, especially if
you are not going to set things up accurately... Because there are no before/after
figures, we have no idea if the performance was any better after the modifications!

... and I thought that all this "mixture calibration" stuff could be accurately established
by using the "one-shot plug-chop" method! (Either that, or you can poke your finger
up your backside and if it comes out "light brown", the mixture is just about right, and
if it comes out "smelly", it isn't...).

Ian

[Oldskoolbaby]

I've had enough of SU carburettors! They work great on standard engines but when you're into modifying as I am,
they become a real hinderance as they can't be tuned properly without changing the metering needle
and to select the right needle, you really need a rolling road session.
So decided to fit a fuel injection system to my Mini 1275GT (which has a 1098 engine at the moment)
that can be adapted and tuned without the expense of a rolling road.

It was difficult to get repeatable results however, and this made tuning a bit more hit-and-miss than expected.
This is partly due to the coarseness of the narrow band Lambda sensor and difficulty in holding a steady
RPM / load long enough to get a sufficient number of samples.

This really illustrates why a rolling road is essential for precise tuning.

I also need to investigate a wideband Lambda sensor in a future update.

The chap that created this is clearly very talented, but really needs to make up his mind
why he did all this. The stated purpose was that the system could be adapted and tuned
without the expense of a rolling road.

However, in his parting shot, he states that everything is a bit "hit-and-miss", and that
a rolling road is essential for precise tuning. There is a section in the Vizard book
that featured a fuel injection system that produced a gain of MINUS 10 bhp compared
to a carb setup. Modern/fancy/electronic does not always mean better, especially if
you are not going to set things up accurately... Because there are no before/after
figures, we have no idea if the performance was any better after the modifications!

... and I thought that all this "mixture calibration" stuff could be accurately established
by using the "one-shot plug-chop" method! (Either that, or you can poke your finger
up your backside and if it comes out "light brown", the mixture is just about right, and
if it comes out "smelly", it isn't...).

Ian

I tend to disagree. Live mapping a car can be equally as accurate as strapping it to a rolling road. The only thing you won't have at the end of it is a power graph. But why would you "need" a graph when a laptop on a passengers lap will show where more or less fuel is needed or the ignition needs adjusting.

[David Reid]

I've had enough of SU carburettors! They work great on standard engines but when you're into modifying as I am,
they become a real hinderance as they can't be tuned properly without changing the metering needle
and to select the right needle, you really need a rolling road session.
So decided to fit a fuel injection system to my Mini 1275GT (which has a 1098 engine at the moment)
that can be adapted and tuned without the expense of a rolling road.

It was difficult to get repeatable results however, and this made tuning a bit more hit-and-miss than expected.
This is partly due to the coarseness of the narrow band Lambda sensor and difficulty in holding a steady
RPM / load long enough to get a sufficient number of samples.

This really illustrates why a rolling road is essential for precise tuning.

I also need to investigate a wideband Lambda sensor in a future update.

The chap that created this is clearly very talented, but really needs to make up his mind
why he did all this. The stated purpose was that the system could be adapted and tuned
without the expense of a rolling road.

However, in his parting shot, he states that everything is a bit "hit-and-miss", and that
a rolling road is essential for precise tuning. There is a section in the Vizard book
that featured a fuel injection system that produced a gain of MINUS 10 bhp compared
to a carb setup. Modern/fancy/electronic does not always mean better, especially if
you are not going to set things up accurately... Because there are no before/after
figures, we have no idea if the performance was any better after the modifications!

... and I thought that all this "mixture calibration" stuff could be accurately established
by using the "one-shot plug-chop" method! (Either that, or you can poke your finger
up your backside and if it comes out "light brown", the mixture is just about right, and
if it comes out "smelly", it isn't...).

Ian

I tend to disagree. Live mapping a car can be equally as accurate as strapping it to a rolling road. The only thing you won't have at the end of it is a power graph. But why would you "need" a graph when a laptop on a passengers lap will show where more or less fuel is needed or the ignition needs adjusting.

I am going to disagree, fuelling is easy to do "live", but ignition timing, unless you advance all the way to the audible limit you have no idea if you have reached MBT.

On any dyno you can measure the effect of every degree of timing.

[JohnA]

Why do people spend time and money building an engine then don't want to put it on a rolling road to get the best out of it ?

[Richspec]

Why do people spend time and money building an engine then don't want to put it on a rolling road to get the best out of it ?

cos they don't know any better or theres no rolling road nearby that understands minis and are too lazy to travel

edited to add:

what happened to your rollers John?
I'm sure I've asked before but cant remember the answer

[gs.davies]

There's an awful lot of owners on TMF and some of the Facebook groups that don't want to do anything properly despite sinking significant amounts of time, energy and cash into their projects..!

[Spider]

I'm not going to knock this guy or his project, he strikes me as being one clever bloke and a great project.

Why do people spend time and money building an engine then don't want to put it on a rolling road to get the best out of it ?

One BIG problem we face in these parts is while there are quite a number of such facilities available to us, none of the operators know how to use them and / or have zero interest in our cars as a project, it's only the quick buck to them. Often they'll come off the rollers no better then they went on or only slightly better, while much of the gains yet to be realised.

[Richspec]

its getting that way here too, if its not a rechip or modern ecu they cant really help, no one keeps any weber stock so you have to take your own parts to swap in / out.

[Cables]

I must be lucky as we have a guy not a million miles away, who is just as happy playing with SU's and Webers on old stuff, as tuning big power skylines.
Plus he keeps a decent stock of Weber/SU parts in, and if he doesnt have it knows exactly what bits you would need.

[ianh1968]

<SNIP>we have a guy not a million miles away,
who is just as happy playing with SU's and Webers on old stuff

Your profile does not state your location...
Where are you? (??? You may want to update your profile ???)

Ian

[Cables]

Sorry im in Crewe in Cheshire, at the aforementioned garage, is in AB Garages in Hawarden on the Welsh/English boarder.
I think a few on hear may already use him.