M130, ITBs, and MAP

[Herrubermensch]

Hi,

If you are wanting to us the Multi Throttle Tuning option, then I would advise upgrading your Firmware to one of the 1.11.0.x version, rather than remaining on the 1.10.0.x release as there has been some work done in the background on how this system works.

Mobne, if you have a stable MAP signal from your rail, that will give an accurate reference of Engine Load for the M1, then I see no issue with using VE mapping and your ITB's. Most ITB setups will not provide this and give a flat response to throttle position changes once the throttle position exceeds a fairly low number as the pressure on both sides of the throttle plates equalises to typically ambient pressure.

Stephen, I would greatly appreciate it if you would review and respond to my recent post in an older thread on essentially the same question. Thank you!

[Mobne]

The reason i like tps is because it’s so low volume of air so even if the signal is good and produce about -0.6bar vacuum it still goes fast up to 0 (100kpa) when you open them.

With tps I get a much larger and detailed tune compared to map.

I don’t know if you answered this but is it possible when you have a map sensor after throttle to tune the main fuel against tps and compensate the positive pressure from map signal? Or must it be done with the advancer method or is it just “better” when you don’t have stable map signal.

For some reason I like ve, it also gives you an idea if the injectors do what you specified them to. When I tested the estimated itb setup I get the feeling those fuel numbers is just an estimate and not related to ve at all.

If you could share a tune with this setup for a boosted with like 1 bar boost it would be great to se it as an example in the software as a complement to reading the guide.

[Stephen Dean]

I'll see if I can supply a tuned turbo Package, I have a couple but as they have been tuned by others I will need to gain permission to share.

[Mobne]

With the new tuning method for ITB, if i have a mapsensor connected and calibrated. Can i still have the sensor active for logging and other compensations or table axis? Or will it interfeer with the setup as we use estimated values in the tune.

Is there a tabled that can be used as starting point for boost compensation?

0kpa boost should be 0% trim, 100kpa boost should be 100% trim and 200kpa boost 200%? Is this the startingpoint? Or does it work in another way?

How would you do with an engine running say 3bar boost? The compensations maximum value is 200%.

[Mobne]

I'll see if I can supply a tuned turbo Package, I have a couple but as they have been tuned by others I will need to gain permission to share.

Anything?

[NathanB]

0kpa boost should be 0% trim, 100kpa boost should be 100% trim and 200kpa boost 200%? Is this the startingpoint? Or does it work in another way?

How would you do with an engine running say 3bar boost? The compensations maximum value is 200%.

I think you need to go back to some basic M1 fundamentals with this. The fuel model used in the GP packages is an efficiency model. This calculates the fuelling based on a series of items to determine engine load (air into cylinder):

- Engine efficiency (set to 100% as per CTN0036)
- Engine Displacement
- Number of Cylinders
- Pressure of air (this is why boost pressure relative is used as estimated manifold pressure = in man est main table is multiplied with (boost pressure + ambient pressure) )
- Charge temps and cooling
- Fuel vapour factors


Engine displacement and number of cylinders are constants. charge temps and fuel vapour factor are going to have smallish swings on a combination with an intercooler that is sufficently sized.

So if we have 70 at a point in the estimate table and we have 100kpa of boost and 100kpa ambient:

(70 x (100+100))/100 = 140

If we then have 200kpa of boost

(70 x (200+100))/100 = 210

If we have 300kpa of boost

(70 x (300+100))/100 = 280

Notice how this part of the calculation has increased with boost? The efficiency boost pressure compensation is meant for compensating the changes in engine efficency with the change in boost pressure, it is not for scaling the engine load. (remembering the effiency table is set to a single value of 100 as per CTN0036, so this value is getting scaled.)

The same applies with the airbox pressure comp - its not designed for ambient pressure changes (this is automatically calculated for) this comp is designed for allowing you to account for the changes in pumping efficiency in the engine.

On a turbocharged engine, if you have an inlet manifold pressure sensor calibrated, and your boost pressure sensor fails or faults, the engine will continue to run, however the engine load will not be calculated correctly. The reason the multi throttle tuning guide says to not have a manifold pressure sensor calibrated it because we cannot guarantee correct behaviour if other sensors (airbox/ambient/boost) go into fault or fail.