Trouble with fuel map

Give input on tuning as well as any tips and tricks you may have. Also feel free to share base mapping files for various engine types.
thethinkingman
Posts: 32
Joined: Mon Feb 15, 2016 3:51 pm
ECU Model: S40 Pro
Firmware Version: 34.0
Location: Dalgety Bay, Scotland

Re: Trouble with fuel map

Post by thethinkingman »

The default setting for pressure offset is 0.253 (if memory serves me right) would this be a suitable value for my 216kPa sensor?
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Trouble with fuel map

Post by Rob Stevens »

So, I think that is a 2 bar map sensor, so put 216 as the 'Pressure at 5v (100-600)kpa'
You need to adjust the pressure offset until the reading in 'real time display' shows what it is now without the engine running, this should be 99 or 100 kpa unless you live at the top of Ben Nevis! Where it will of course be less still.

Now you need to fill out the table that corrects for manifold (or ambient) pressure.
This can be found - Essential Map Settings/Set Manifold Pressure Compensation

Copy the settings shown for the sample map 'samturbo.map' This will give automatic fuelling during turbo spool up. You may wish to add ignition retard at high boost also (not shown on samturbo.map)

Follow my advice earlier of targeting 2 to 4 degrees ignition at idle and check this with a timing light to ensure your crank trigger is in the right place.

In Essential Map Settings/Set Map Columns. Do Not select 'Use map as load'

To help stabilise idle you may set ignition at 15deg at say 800 rpm and 0deg at 1200rpm this will force the engine to sit at around 1000rpm its a simple way of getting a strong idle if you have no idle control system. Something to try once you have a good idle at 4deg as outlined above.
thethinkingman
Posts: 32
Joined: Mon Feb 15, 2016 3:51 pm
ECU Model: S40 Pro
Firmware Version: 34.0
Location: Dalgety Bay, Scotland

Re: Trouble with fuel map

Post by thethinkingman »

Rob stevens, that is the clearest guide ive read yet! Thankyou.
One last thing though, Throttle stops. I loaded up another base map from a friend and i quickly ran the engine just to see if it was remotely close, in the Real time mapping page and with my foot totally OFF the accelerator, the engine was idling in column 7, so i then switched it off and went into Throttle stops to recalibrate the TPS, now fully closed is 0% and full open is 100%. It says in the manual that zero should actually be 15%, so do i recalibrate it again but screw the butterfly valve/blade open until it says 15% click ok then hold ot wide open to set WOT, followed lastly by via the throttle valve adjustment screw wind it back out?? I hope that makes sense
thethinkingman
Posts: 32
Joined: Mon Feb 15, 2016 3:51 pm
ECU Model: S40 Pro
Firmware Version: 34.0
Location: Dalgety Bay, Scotland

Re: Trouble with fuel map

Post by thethinkingman »

..you say copy settings from samturbo map but that appears to be for a 3 bar sensor as Row 20 is set to 300 kpa where as mine is a little over 2 bar.

So, the actual main maps lookup the compensation tables and determine fuel and timing?? If for example the main map was set to 10.00 ms fuel at row 10 and the comp map says +50% then overall we would see an injection duration of 15%
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Trouble with fuel map

Post by Rob Stevens »

..you say copy settings from samturbo map but that appears to be for a 3 bar sensor as Row 20 is set to 300 kpa where as mine is a little over 2 bar.

Don't worry about that, copy it over, its a straight line on a graph, the 3 bar is just a longer line.
50 kpa = -50%
100 kpa = 0%
150 kpa = 50%
200 kpa = 100%
300 kpa = 200%
500 kpa = 400%
etc.

So, the actual main maps lookup the compensation tables and determine fuel and timing?? If for example the main map was set to 10.00 ms fuel at row 10 and the comp map says +50% then overall we would see an injection duration of 15%

Yes - Exactly (but I think you intended to type 15ms fuel duration not 15% !!!!!?????) + any other compensations that may be active. i.e have a look at DTASwin air temp compensations (also in the manual) (set to standard) and copy these corrections over to your map, assuming your air temp sensor is in the boost the hotter it gets the less fuel it needs in an ideal world.

It says in the manual that zero should actually be 15%, so do i recalibrate it again but

No you are miss reading, what it says is the arbitrary number should be 15+ as defined in the 'set throttle stops' window. This screen shows you a picture of a butterfly with numbers, the closed position needs to be between 15 and 50, the fully open position over 200, these are not % they are just numbers the system uses. if you end up with 17 closed this = 0% and 248 fully open this = 100%
As mentioned before have the closed position whilst idling set to achieve 0% , this should jump to 1% soon as you brush the throttle.

It takes longer to type than doing it!
Getting there :0
Last edited by Rob Stevens on Wed Feb 24, 2016 2:42 am, edited 1 time in total.
thethinkingman
Posts: 32
Joined: Mon Feb 15, 2016 3:51 pm
ECU Model: S40 Pro
Firmware Version: 34.0
Location: Dalgety Bay, Scotland

Re: Trouble with fuel map

Post by thethinkingman »

Sorry, yes i meant ms rather than %
I understand what needs to happen with the stops now!
I just want things to be as clear as possible before i head out and actually have a go at the real thing. I am tempted to but a pot box from MEF motorsport to make it simpler to setup.
Are you telling me enter the comp values before actually trying to map it?
Once again i very much appreciate your help
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Trouble with fuel map

Post by Rob Stevens »

Yes, you must have the compensation values working always, it makes it automatic. When in dyno mode you can see the compensations that are active as they show the fuel (or ignition - red) corrections in blue by the sensor readings, i.e. Water 20 deg (in blue +20%)

The pot box is very useful but for use on the dyno, you can very quickly +/- 50% fuel but on the road you just can't hold it on a cell. It all happens far too quickly.

It might be an idea to disconnect the turbo boost pipe (but bung it up to prevent turbo over speed ) whilst you have a play at mapping, or perhaps jam the waste gate open. The build of the map is still relevant as the compensations are automatic. However don't rely on this, the main fuel map should reflect the true on boost situation.
thethinkingman
Posts: 32
Joined: Mon Feb 15, 2016 3:51 pm
ECU Model: S40 Pro
Firmware Version: 34.0
Location: Dalgety Bay, Scotland

Re: Trouble with fuel map

Post by thethinkingman »

Ive seen the blue/red compensations your talking about with the little bit of running ive done and i plan to do exactly what you said with the WG and your bang on about bunging it up to stop overspeed! I had a diesel that did that and it literally snapped the turbine shaft in 2!!
Well now i know what i know i will take it out next week and see if it doesnt blow up!
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