M44 Wiki

From page 16, post #308, tuners rejoice thread: You cannot really correlate load(7.97ms) to PSI.

You will just need to start raising the values a little at a time and seeing how that affects your boost. I would first start by playing around with WOT(Wide Open Throttle)(easiest). All this requires is tuning the 70% row. Since 70% is the highest the TPS position on the map that would be WOT throttle. You also have to look at TPS angle for WOT detection. This map just tells the ECU what % throttle will we go into WOT mode? If you look at it you can see that it is mostly 60%. So from 60-3000rpm if your TPS is above or equal to 60% then it will go into WOT mode. When in WOT mode this will add the WOT enrichment values to the fuel calculation.

Before playing with anything I suggest having an accurate boost guage and a Wideband Guage as the ABSOLUTE MINIMUM. While tuning WOT keep an eye on the AFR(i would try to stay around the low 12's) and if anything gets too lean or you hear any pings/knocks get off the throttle immediately and note the RPM at which it happened. Then go back and either try adding fuel(to WOT enrichment if you are doing a WOT pull, else to VE Part load if you are doing part load tuning/anything under WOT), pulling a bit of timing(again without knowing your MAF reading/ load reading this will be quite hard, but you can try taking a guess by using the RPM you hear ping at, then using that as a lookup in the boost map and seeing what load value you have in that table and you can use that to find the load value in the ignition table) or reducing your boost. Remember to change only one variable at a time so you can see the affects of what you are doing.

        If you are having trouble increasing your boost and you dont seem to be seeing anymore boost, you may want to take a look at Max duty cycle for boost solenoid. This is a map that is TPS vs RPM. Basically this map is just the max the BCS/TCV can work so you dont overboost. It is kind of a safeguard. As you can see in the lower RPM's the max duty cycle is about 30%. Towards the higher load / rpm it is around 90-99% which will allow the car to boost much more. I dont recommend messing too much with this map, the values seem to be pretty good stock. By raising the duty cycle in lower RPM high tps area you really risk connecting rod damage. Last but not least. If you can log load(using a vagcom or elm327) and ever go above the end of a table (8.02) it will continue using that slot. EX. I have a large 50 trim turbo and by 4500RPM WOT my MAF is maxed which would most likely correlate to over 8.02MS of load. This means that i were to tune the ignition/fuel i would need to tune the 8.02ms column all the way across.

        RECAP: First step, accurate boost guage and afr guage. I suggest having something to datalog afr, rpm, maf and ign adv at the minimum. Start with WOT tuning as this is the easiest approach(since tuning part load on the street would require holding the car at a steady rpm/load which is extremely hard). If you find any issues with your new boost value, try adding fuel, pulling ign or reducing boost if neither of those work. If you max your MAF / go over the max load on the table (8.02) use that column to tune. If your finding you cannot reach desired boost and keep increasing requested load and you dont see any changes try playing around with max duty for boost control solenoid. Remember dont go too crazy on this map! You risk bending rods at low RPM high TPS.

       In conclusion, M4.4 boost control algorithm is pretty solid. But for people who are looking more to set specific boost and specific RPM / tps a electronic boost controller is probably the best option and a hell of a lot easier to tune as you can set PSI. Then after that all that is left to do is adjust fuel and ign. But again datalogging will greatly help. Hope everyone has benefited from this and can start tuning their own cars with this info. If anyone is interested i can try and go into some more detail tomorrow about part load tuning. This will be useful when easing into the throttle up to WOT to try and control traction issues that may arise without going stupid lean and blowing up your motor. Again this is more complex and will require some data logging tools, which i will be more than happy to go into detail about! As always I assume no responsibility for what happens to your car if you tune incorrectly. Be safe and changes things a little at a time.. Happy tuning!

For more precise mapping of the TCV Pilot refer to this post: #4904 Mar 07 2015 Razorx


Drive while trying to "touch" as much cells of the TCV pilot table.

If you play back your log in the history table, please select history average.

Paste this data into my Excel sheet. As well as the other requested values. This is documented in the sheet.

Of course their will be some pollution in the history table. You have to use your intelligence to correct these values.

The sheet calculates the new TCV pilot table.

This pollution is caused by situations where the turbo is spinning down.

Another way to avoid this pollution is to only play back the parts where the turbo is spinning up. The history table only remembers the parts you play back.

To my experience you can have a good TCV Pilot map in three iterations.

The reason for such a fast result is that the algorithm I used is converging.

Adaptive Knock - to disable whilst tuning, set

☀"Motor temperature threshold for adaptive knock control" to 175

refer to discussion on page 233

LDR P-part only hack: modified LDR control routine locks I-part (integrator of the PID logic) at zero to prevent silly under/overshoot of the boost control duty cycle value, This also prevents the P-part (proportional component of the PID logic) from going positive, only allowing negative correction.

To set this up, set up your duty cycle map as you like it, do some data logging, then build the target load map to match the curve of your duty cycle map. Then, if load exceeds the target, say because it's winter and the air is now denser or whatever running condition you have generates more load than you expect, the duty cycle will be reduced somewhat to target the load setpoint. So, in essence the target load map turns into a (loose) "max load" map, and the system runs fully off the duty cycle map unless target load is exceeded.

Note that without the integrator, the correction range of the proportional component is fairly limited, so don't expect it to prevent large amounts of boost overshoot, but it will help you build a map combination that results in fairly stable target load without all the nastiness of boost over/undershoot due to the rudimentary integrator logic.

Table PLDRN "LDR P-part" defines the amount of correction based on RPM range: higher values in that table cause the P-part to deviate more for a given system deviation (difference between actual and max load). Increase for more aggressive correction, decrease for less aggressive correction. Toying with the duty cycle, max load, and PLDRN maps will be neccessary...