Sorry, didnt mean to diss anyone.

I didnt see Stu's explaination above so I dont need to go into full detail
as he has done the hard work.

Generally the equation I use ( I have simplified it so you can all follow)

A=RPM/60
calculate crank rotations per second

B=1/A
calculate 1 rev time in seconds

C=B*2
allow for 2 crank cycles

D=C*1000
convert to milliseconds

E=D * 0.90
only use 90% duty cycle (or what even you deem correct)

The value in E is the final maximum allowable injection time in millisconds.


=============================


When talking about SEQUENTIAL injection as on cossies....

Fuel injection point (I.E the crank rotation degrees an injector starts to inject)
is generally only critical at low speeds as you inject MOST of the fuel on a CLOSED
inlet valve just before it begins to open.
The reason is, 1, it cools the valve and 2, the inrush of air mixes the fuel
better than
injecting the whole lot while filling the cylinder.
This applies to low loads and low rpm's only generally.
So its NOT just injection duration thats critical but WHEN it injects.
This is because the slow moving air at low rpm will cause the fuel to drop
out or the mixture if not kept moving.
However, at high rpm, (above >2500 rpm usually) the injection point is advanced
as the average air speed does not change much mixing the air/fuel better.
(on a cossie usually about +90 degrees every 1000 rpm till 5500 rpm)

So you can see, the map is NOT the only thing that matters.

At high rpm and/or high loads, the timing of the inlet valve becomes LESS
critical as generally all fuel in the inlet port will get into the cylinder and
is mixed nicely due to the high speeds and squish effect of the cylinder design.

===============================================

Ok, now back to Dannys original "problem" with the S8.

He complained about getting error code 31.

This error is set when the available fuel time based on the current rpm
is exceeded. The error code also cuts the power to the injectors to prevent
the engine melting. The reason is the map is telling the injectors to open
MORE than the time available. This means there COULD be NOT enough
fuel to match the air, the result - melt down.
I have set this to a figure of 95% of the injection duty cycle in the ecu
software that CANNOT be changed by the mapper only me.
This is a safety feature and therefore protects the user and myself from
destroyed engines and all the sh*t that may go with it.

On Dannys car, he has 8 injectors and a turbo that spools up faster than
ima taking the piss out of me

There may be a possible scenario where the ecu software estimates the rate
of rise of the rpm and may be prematurely causing this fault.
Rather this way than the reverse from an engine safety point of view.
I have been unable to reproduce the fault on my engine simulator YET.


Danny,
Could you please tell me exactly at what rpm this fault occurs
and what boost you think it happens at.?????
You did tell me by email but have lost all my emails since then in a
hard disk crash.