WasteGate DC Setup 101: Request.

[Sassimac]

Guys...

Is there a chance of a simplified WGDC setup "how to"...??

Thank you..!!!

[Steve @ VersaTune]

Look at your logs and set the BCS DC to the duty cycle seen in the logs when actual load = desired load. Desired load needs to be manually determined based on the requested load tables and the current rpm, gear, app, bat, baro, etc.

[Sassimac]

That simple..???

[Steve @ VersaTune]

Yes.

[Sassimac]

Ok.... I have done a General log, and it appears that the Absolute load and APP (not Relative PP) logs marry up quite well with the APP Requested Load Table. I setup the tables so the APP Requested table is the main player. So, I am OK here.

If I understand this correctly, it's just a matter of matching up the WGDC, RPM and APP log to fill in the WGDC table.

Is it best to go cell by cell, or in columns.?? How accurate should this table be, and what +/- factor is OK..???

Thanks..!!!

[Steve @ VersaTune]

Make sure that actual load = requested load.

You can start with columns and get more granular form there. In theory there are different DCs required for different requested loads when the throttle is at a fixed position.

[MPS2NV]

Look at your logs and set the BCS DC to the duty cycle seen in the logs when actual load = desired load. Desired load needs to be manually determined based on the requested load tables and the current rpm, gear, app, bat, baro, etc.

I have decided Im going to ask a question! Im not sure if its a good one or a stupid one :/

Steve, is there a formula to manually determine the desired load?

Thanks

[mituc]

Yes, there is, but you're not going to like it. ( http://obdcon.sourceforge.net/2010/06/a ... oad-value/ )

LOAD_ABS = [air mass (g / intake stroke)] / [1.184 (g / intake stroke) * cylinder displacement in litres]
Derivation:

air mass (g / intake stroke) = [total engine air mass (g/sec)] / [rpm (revs/min)* (1 min / 60 sec) * (1/2 # of cylinders (strokes / rev)],
LOAD_ABS = [air mass (g)/intake stroke] / [maximum air mass (g)/intake stroke at WOT@STP at 100% volumetric efficiency]

* 100%. Where:
— STP = Standard Temperature and Pressure = 25 °C, 29.92 in Hg (101.3 kPa) BARO, WOT = wide open throttle.

I mean, there's a formula for the absolute load and based on what you get now and the supporting mods on your car you set your "desired" load targets.

Here's the idea:
- if your wastegate duty cycle values are close you will still hit the load targets because the compensation tables will work for you;
- now, you take those actual BCS DC values you see in the log and overwrite yours from the tune.

There will always be small variations, but as long as your wastegate duty cycle values are close the ECU will need less time to adjust it (+ or -, depending on the weather, and so on).

The ideal way of determining the load values to put in your tune is to take a few logs when the ambient temperature is the average of the year. Where I live we have -35 to +42 Celsius so it's quite hard to do that (I usually consider the average of +10C to be still able to make the car move during hot summers and not to blow the engine during winter), but if the average temps in your area are more persistent over the year then you're lucky.

You also need to take into consideration the flow capabilities of your car in the weather you're using it in most. If you have a stock K04 and you live in South Africa you may never see more than like 235-240g/s (maybe only if you log at night of 2-4 hours before the sun rises). Pushing it too hard in therms of load/boost will not result in more power, because timing is also very important. So if you have a load of, say, 1.9 at 6000rpm but your timing values are around 5... the car will not make power, but will only cook your exhaust side of the engine (vales, cats, and so on).
So load (therefore airflow) is not everything.

[MPS2NV]

Your right, I dont like it! Haha I will keep reading your post and practice what your saying until I think Im getting close to a result I need to do MAF cals but Im very concerned about understanding tuning and getting boost levels under control/lower before driving to much. I carried out a general log in 3rd gear just to get a report of what events may be happening, this was after subtracting 10% wgdc from all but the 100% cells, the log shows the wgdc pretty much fall straight down to 0% from 28psi MAP and MAP continues to rise all the way to 37psi MAP until redline, not sure thats what I want to be happening!

[Steve @ VersaTune]

Requested load is the lowest value of all the requested load / load limit tables at your current rpm/app/baro assuming the ECU isn't pulling load due to injector duty cycle limit, traction control, excessive MAF volts, overboost, etc.