MS1-Extra and MS2-Extra

Basic's to getting Started -- Offline Tuning -- Live Tuning

AutoTune -- Finalising the VE Table -- Final Settings in MegaTune

Important Note: Adjustments made in MegaTune are only sent to the ECU if you press the "TAB Button" on your keyboard after making the change!! (This doesn't apply when tuning the maps in 3D mode) In order to keep changes ensure you select BURN TO ECU, this then sends the adjustments into the permanent memory of the ECU! I find the best method to make adjustments is to alter the value then press the TAB Button, this ensures they are sent. If the change is OK click BURN TO ECU, check it has been sent by clicking FETCH FROM ECU. You'll soon get the hang of it :o)

 

Basics to getting Started

It is important to understand that if the engine doesn't start or fire at all then it is NOT the VE Table (fuel map) that needs tuning, so don't go off and adjust that as yet. The ONLY fuel that goes into the engine during cranking is set by the Cranking PW, so if it doesn't fire you will need to look at the Cranking. Once it fires and the RPM goes above approx 300RPM then the VE table is used by the ECU. Start with this check list:

• Always check timing at cranking before getting too carried away with fuel. If the sparks don't come at the right time then it won't start, so check its firing with a strobe at approx. 10deg BTDC during cranking. If it doesn't, fix that first by checking/adjusting the Trigger Angle in Spark Settings, twisting the dizzy, checking alignment of crank / cam sensors, etc.

• Check that you have an RPM reading during cranking on the MegaTune screen, it needs to be reasonably steady and around 150-300RPM, if you have no RPM reading then you have a trigger problem, the ECU is not seeing your hall sensor or VR sensor, etc. If this is the case then you need to check your wiring to the VR or hall sensor (the red cable in the screen wire is the signal, the blue or black is the ground, do NOT connect these together!). If using a VR sensor you may have to adjust the potentiometers inside the MS ECU, see http://www.extraefi.co.uk/vr_setup.htm for instructions. If you have a hall sensor it needs a 5V or 12V ignition supply, you will need to check what type of sensor you have and see how it was wired in the original setup.

•• If using a VR sensor ensure it is wired up the correct way around, it does matter! If your not getting a good RPM read out despite altering the potentiometers in the ECU, try swapping the cables over from the VR sensor if your unsure which is the signal output.

• Check you get a PW reading on the MegaTune screen, this should be wrougly the same as you've set in Cranking Settings. If you get a PW of ZERO then you may have the throttle pot wired up wrong. The ECU goes into Flood Clear Mode when youve got your foot flat on the accelerator to clear a flooded condition, this means it adds NO fuel.

•• For MS1-Extra if the TPS is OK but you still get a PW of ZERO then check the setting for TPS for Flood Clear aren't set too low in More Cranking Settings .

•• For MS2-Extra simply calibrate the throttle sensor by going into Tools - Calibrate TPS with the engine ECU connected. Click on GET CURRENT for closed then fully open throttle (obviously not with engine running) and it will calibrate it for your TPS.

• If you need to open the accelerator during cranking (foot on throttle a little) and then it starts you are adding too much fuel during cranking as you are letting in more air to weaken the mixture with your foot. So reduce the Cranking PW time at the relevant temp setting.

• If it doesn't fire despite what you do with the throttle it will probably need more fuel, only add a little at a time, 0.2mS increments.

• Ensure the ECU still has power when cranking, I've seen an ECU wired up to the radio supply, this is usually switched off during cranking so the ECU has no power, obviously it will never start like this!! The dials in MegaTune will go blank "--" if the power is lost to the MS ECU.

It is a good idea to set the Priming Pulse to ZERO whilst tuning, the Priming Pulse adds a little amount of fuel to prime and bleed the injectors on power up. This can soon flood the engine whilst you are tuning as you will turn the ignition on and off a lot!

If you are starting the engine for the first time then it is recommended to adjust the REQ_FUEL (in the Engine Constants page) to richen or lean the engine until it is warm, an increase in REQ_FUEL richens the mixture across the whole map, a decrease in it leans the mixture. (NOTE: Press the TAB button and then press BURN TO ECU to force your settings into the ECU) We recommend using the REQ_FUEL because you can then re-tune you VE table to keep it all smooth for a good starting point, if you adjusted the VE table to keep it running then the chances are your idle areas would be either very high or very low compared to the rest of the map. Once you have the engine warm you can set the REQ_FUEL back to the calculated or original value, BUT you then will need to reset your VE table to compensate. (Basically the REQ_FUEL increases/decreases fuel over the entire map, so when you reset it you will need to change the VE table so the same amount of fuel is added) To do this, ensure the ECU is powered up but engine is not running. Remember what the REQ_FUEL value is for a reasonable idle (in other words what the value ended up being while you were adjusting it to get it to run OK for the first time), then change the REQ_FUEL back to where it should. Next go to the VE Table and select "TOOLS - VE Specific - Reset ReqFuel" and set the Current ReqFuel value to the value you remembered from earlier and the New ReqFuel value to the calculated or original value. When it asks you to burn select YES, this will then adjust the whole VE table, in the case below the VE values will increase to compensate fro a decrease in REQ_FUEL, so you should end up with a good smooth map to start tuning from.

Once you have the idle tuned when warm dont touch it again while the engine is cold. Only adjust the Warmup Enrichments to get a nice idle / running engine when the engine is cold. This enrichment is basically additional fueing thats added ontop of the fuel map (VE Table) to richen the mixture when the engine is cold. 100% would mean it uses the fuel map, 110% means it adds 10% to the fuel map, etc. So next time you start it from cold get ready on the warmup enrichments page.

Please Note: If you have lo-impedance injectors (less than 4 Ohms) , after getting a good idle you need to adjust the PWM duty cycle on the Constants Page in MegaTune down in 1% increments until you notice a change in idle quality (be sure to hit the "send to ECU" button each time you change the value). This is the point where the current limit is too much and the injectors are not being held fully open. Then move the value back up 3 - 5% (for example, if the idle falters at 45%, then put in a number of 48% to 50%). Move on to adjusting the time threshold. Lower the time threshold by 0.1 milliseconds at a time until the idle quality deteriorates. Then increase it 0.3 ms.

Don't start driving until you have a good stable idle, it isn't very safe to drive a car which won't idle. Adjust the fuel map once the engine is warm to get a strong idle, you should use the Live Mapping theory below to get a smooth idle, it will probably be a little rich, don't worry too much to start with. At idle a small change in the VE value can change the mixture a lot in some cases, so take time to adjust this and give it time to react.

Tuning the VE Table Off-line

The MS will naturally datalog the inputs from TPS, O2, Coolant Temp and the Air temp sensor. It also datalogs the fuel Pulse Width, Dwell, Spark Advance, etc, etc, etc, there are in excess of 20 seperate streams of data that MS1-Extra logs (MS2-Extra logs even more) onto a laptop whilst it's running the datalogger. To do this you need MegaTune running and select File -- Datalogging -- Record or ALT-LThe default file name is a time/date stamp. Once you select SAVE it starts datalogging a file with all the above parameters being logged. The bottom right corner of MegaTune shows LOGGING highlighted in black.

 

Before datalogging; • Turn the Accel Enrichment off, by setting the thresholds to an excessive amount, e.g. MAPdot 3000 or TPSdot to 20V/Sec in the Accel Wizard. • Turn EGO Correction ON when using MegaLogViewer, see HERE for more on how to set up the O2 correction (EGO). • Ensure the engine is up to operating temperature before logging, this ensures you only tune the VE table and no additions are thrown into the mix.

After you've run the analyser the VE table will have several red numbers, these are the values that have been changed by the analyser. Basically it looks at the AFR for the points of the VE table in the datalog and decides how much to change them depending on the average value of the AFR in the datalog. Click on Accept New Table and then EXIT.Save the msq (Save MSQ As) and then close MegaLogViewer. Turn the MS ECU back on and open the new msq file in MegaTune, Burn it to the ECU and your ready for another datalogging session. It is highly advisable to start at low loads and revs, do several logs and only move on to next rpm range slowly when the changes become small in the analyser.

Tuning the VE Table Live

This is by far the best method of tuning, but it does take 2 people to do it, one to drive, the other to operate the laptop.
Ensure the engine is up to operating temperature before starting tuning the VE table so that there are no warmup enrichments added to the mix. Also turn the accel enrichments off by setting the MAPdot to 2500KPa and TPSdot to 25V/S so that all your tuning is the VE. I always turn the EGO correction off so that theres no correction going on, to do this goto Basic Settings -- Exhaust Gas Settings and set the Controller Step Size to ZERO. Now all your going to tune is the table, the corrections can be turned on again later once the table is tuned.A lambda sensor is critical to tune any engine unless your a real expert! A wideband lambda will make life so much easier too.Start by driving slowly, keeping load low and engine speed low untill your happy that all is OK then move upwards. To tune the VE table live there are a couple of options. The best way is to use the 3D display (MegaTune Tuning -- VE Table) and drive to each cross point tuning as you go, this will need a driver and a passenger!! The green blob is where the engine is on the map and the cross hair (RED) is where you are tuning, so use the arrow keys to go to the points you want to tune. Use the AFR gauge in the left side of the screen to see what the mixture is doing and increase or decrease the points where the green blob is to get the AFR correct. To increase the value (richen) press the "Q" button to slowly increment it or the "E" button to increase the value by 5. Like wise the "W" button decreases it and "R" leans it off by 5 in one go. By gradually driving and tuning the points you will soon get a feel for what is needed. Its impossible to tune all the points, as its unlikely youll drive at light throttle at 6000rpm, etc, so you will have to estimate the table at some of the points. The table should slowly increase in value as you go up the KPa scale and also increase in value as the RPM increases, it may fall off slightly as you pass the maximum torque point.

If you start off and you find your having to drastically change the values then it may be better to pull over and adjust the entire table in the same direction before going too far. So say you've had to add 10-20 to the first few points, you will find the entire map will probably need the same doing before you can fine tune it.To do this pull over and close the 3D table down, and open the VE Table in Basic Setting -- Fuel VE Table1
As the engine should have already been tuned for a good idle leave that part alone for now. All we need to alter is the parts where you feel were a long way, so if cruising at 2000RPM was nearly OK but as soon as you went up the load a little it went weak you will need to increase the table all the way across the rev range but only above crusing KPa. To do this move the mouse cursor to the start of where you want to alter (e.g. 100KPa - 600RPM) and hold the left mouse key down, drag across the VE table and a box will appear. Position the box so it is all the way across the RPM range above the crusing KPa.

Now we have the area to increase highlighted and a box appears in the right corner which we can use to change the highlighted area. In this case we want to add say 20 to the area, so we will enter 20 in the box and hit the "+" on the screen. Equally we could decrease it by 20 by pressing the "-" or times it by say 1.05 or what ever. The "=" would set all the highlighted range to 20 in our example. It is important to note that untill you "BURN TABLE" the changes you make will be lost if you turn the MS ECU off, so select File -- Burn to ECU every so often or "ALT - B"The AFR your looking for will be different for each enine, but as a general rule of thumb 14.7 AFR is the most efficient mixture and is used for cruising, overrun can be a weak mixture but you may experience some poping through the exhaust if you go too lean. Max power is usually produced at around 12.5-13 AFR, a turbo engine may need 11.5 to cool the valves, etc. I tend to aim for 13-12.5AFR above 80KPa when tuning a NA engine.

Auto Tune

Auto-tune is a feature inside MegaTune that can check your EGO correction and alter the fuel map. It can be found under Tools in the Tuning VE Table section. Although many people have had a lot of success with this feature and I'm sure I will be shot for saying this, I don't think this is something you should get too carried away with as it can tend to create some pretty bad maps if it's not used correctly. I feel it's main purpose is to fine tune a map that is almost there. The trouble I've found with it, is there's little way of knowing whats been changed whilst you drive. It will only tune the area you are driving at so the fuel map could end up being very lumpy due to the tuning being altered where driven and no changes else where. Looking at the map you would never know what areas had been changed so you wouldn't know where to smooth off, etc. I recommend staying clear of this unless you really know what your doing. It's not an answer to tuning by driving up and down the road running autotune.

Finalising your VE Table

Once you've done a few datalogs and run them through the analiser or your done some live tuning, you will probably notice the map has only been tuned where you drive, so the low KPa areas of 5000+RPM would not have been changed and some other areas may have been missed. This is because you dont drive there, but to keep the map lookin good it is a good idea to look at it every-so-often during tuning and smooth it out a little if theres large lumps or if it leaving small numbers next to large ones. To do this simply look either at the VE Table in Basic Settings or in the 3D graph. If you look at the VE table above, youll see a smooth increase in value as the RPM increases and as the KPa increases, this is how it should be, if you have anything like below it may be that the values around the large numbers need increasing and that value may need decreaseing as it is probably compensating for too small values around it.

In th example the numbers no longer increase with KPa like they should and theres a couple of large numbers next to numbers a lot smaller, this isn't right. Start by smoothing out the numbers around it and re-tune those points, ensure your Accel enrichments are off, etc. Don't be too worried by this, the example is an extreme just to show you what to look for.

Once the VE table looks good and the car is driveable start turning on the EGO correction and Accel Enrichments. Start with small amounts of additional fuel, maybe at the bottom 0.2mS -- 0.8mS -- 1.4mS and at the top 1.8mS. It can be surprising how little fuel is needed for Accel once the VE Table is tuned.

Final Settings in MegaTune

Once the VE table (fuel map) is tuned you can now turn a few things back on in MegaTune to complete your installation.

• Acceleration Enrichments (AE):

Set the thresholds up for either TPSdot (Change in TPS Voltage/Sec) or MAPdot (Change in MAP/Sec) so that the AE cuts in when you push the throttle down fast, this usually creates a lean moment where the fuel is stripped from the intake walls due to a sudden change in pressure. The AE is used to add fuel to fill in the hole where it goes lean. Most people tend to find MAPdot is the best settings unless its a highly strung motor that revs extreamly quickly, then TPSdot is better. Most manufactorures use TPSdot, so try both. Start with the lower values at the bottom and the higher values at the top of the tables. I've found the below settings are a very good starting point, the lowest value should be quite small. The Accel Time shouldn't ever go over 1.0S, usually 0.4 - 0.7S is fine.

The End Pulsewidth (Decay mode) is a great way to taper the AE down with time, usually this is set to 0.0mS, in MS1 it can be found under AccelDecel Mode, where as for MS2-Extra it is in the Acceleration Wizard.

• EGO Correction (lambda/O2 sensor):

This is used by the ECU to correct or fine tune the VE table whilst the engine is running. It is not to compensate for a bad fuel map! The Controller Authority shouldn't be set above 10% (this is how much it will alter the fuel map by), use the settings below to start you off if you have a narrow band. If you don't have a sensor then set the Controller Steps to ZERO..

•• If using a narrow band lambda sensor (99% of cars have these) then the EGO feedback will simply only tell the ECU that it is rich or lean of 14.7AFR, so the EGO correction can only be used for cruising loads. Don't fool yourself that your sensor will tell you anything more than that, it wont.

•• If using a Wideband then the sensor tells the ECU the actual AFR over the whole spectrum. So the EGO correction can then use a AFR table to target different AFRs at different loads. 12.5-13 produces max power and 14.7 is the most efficient (cruising loads)

For more on EGO correction, please see HERE

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