Tuning w/ N20 TMAP to see 22+ Boost
- Thread starter Jeffman
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- n20 tmap mboost
I am kind of confused with the whole N20 TMAP tuning. This is my understanding:
With the MHD Box checked, you are able to run the N20 map without having to do any other tuning changes. But you will not actually be using the map sensor to it's full advantage.
In order to use this sensor to it's full advantage, any load based tables will need to be changed accordingly.
Is this correct?
With the MHD Box checked, you are able to run the N20 map without having to do any other tuning changes. But you will not actually be using the map sensor to it's full advantage.
In order to use this sensor to it's full advantage, any load based tables will need to be changed accordingly.
Is this correct?
In order to use the sensor to its "full advantage" you need to use the 3 point map scaling and "scale" your tune at loads above the breakpoint. Usually that's 10psi or 145% load, so all loads above that are now equal to a higher boost pressure than before the scaling. Example is before scaling I would run 20psi = 195 load now load is around 170. So all of the calibration parameters (fuel, cams, ignition, etc) I was running at 195 load on the maps now need to be moved to the 170 load area. That's a very simplified explanation but the basic concept of the process
I hate to seem dumb or thick headed. But I'm stil slightly confused.
I understand how the sensor itself works and all. Typical "5v" sensors with two different ranges.
What I am still confused on is the tuning of the sensor, or when it is needed.
Is it imperative that you rescale all the load based tables when using the sensor and having the "n20 map sensor" checked in MHD? If this is the case, it leads me to my next question:
How does MHDs OTS tunes work when running the 3.5 bar sensor? Are all required tables rescaled automatically?
I understand how the sensor itself works and all. Typical "5v" sensors with two different ranges.
What I am still confused on is the tuning of the sensor, or when it is needed.
Is it imperative that you rescale all the load based tables when using the sensor and having the "n20 map sensor" checked in MHD? If this is the case, it leads me to my next question:
How does MHDs OTS tunes work when running the 3.5 bar sensor? Are all required tables rescaled automatically?
There are 2 different things going on here:
1 - checking the N20 option or setting the conversion manually in the bin allows the DME to read the 3.5 bar MAP slope correctly on an otherwise 2.5 bar MAP (stock) tune. It changes nothing in the tune and requires no changes other than setting the different MAP parameters.
2 - the 3.5 bar MAP reads up to 36psi, but the DME currently only goes to 22psi. If you want to actually run more than 22psi of boost (or 18.5psi on INA0S/DCT), you need to either use another controller (like JB4) or the built-in 3-column MAP scaling logic.
So, one part is to read over 22psi (3.5 bar MAP), the other part is to actually run over 22psi (3-column + re-tune to new boost vs. load changes). Without scaling or some other controller that allows running over 22psi, switching to a 3.5 bar MAP doesn't do anything except change resolution of the MAP itself.
If you do not rescale some of the load based tables when using the 3.5bar sensor - you might run boost at levels that you are not targeting.
Having read through the three pages of responses I felt many readers would have a difficult time getting to a straightforward answer to the OP's question. I'm going to try and boil this down a bit. There are three steps to getting MAXboost working:
First...
And here are the two maps in TunerPro for doing that:
I have it like this with n20 sensor
Next, you do this...
He's talking about the checkbox for the N20 3.5bar MAP sensor that's in the "Options" submenu during flashing.
That's why you can have the "2-cel" MAP conversion map zeroed out.
Then, last but not least, you need to make an adjustment to the "Logging Options". In the submenu for measurement units, you will also see a checkbox to activate MAXboost logging. Be sure that's checked.
Once you've done all three, your logs will be able to record boost values right up the ~37psi limit in the 3-cel MAP conversion table.
So, how well does this work?
I ran some tests on this question. And here are some graphs to show what I found. First is a comparison of readings collected through the two MAP conversion tables.
As you can see, the boost readings do read higher with the MAXboost scheme. But is that an inaccuracy? Our test car has a WMI controller by a company called Torqbyte. This controller has its own dedicated TMAP sensor, which receives boost signal from the manifold plenum. Because the Torqbyte software has a calibration feature, its readings for boost post throttle body are very accurate. Let's see how the MAXboost stacks up there.
Here is the Torqbyte's TMAP reading versus the MHD logger's value of "boost mean"
Again, it's reading a little high. But the "boost mean" value from the N20 TMAP sensor is a measurement from UPSTREAM of the throttle body. The Torqbyte sensor is reading manifold pressure. So the more fair comparison would be to the MHD value "Boost PSI". And here it is:
Pretty accurate, I'd say.
One other thing also talked about:
The DME's calculation for load DOES change with this modification. Here is the before/after:
Here is one last graph comparing the change in boost target values. As said above, the DME now calculates much higher boost targets for equivalent load requests.
Hope this helps.
Doug Harper
FrankenTurbo
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I didn't want to clutter the previous post so I'll separately post this graph showing the boost duty controls we had in place during this testing. All pulls were performed at a static 35% boost duty.
Hey Doug, thanks for the long post with tons of nonsense, your overuse of graphs, and as always...misinformation.
Everyone else, please ignore most of what he just babbled about, since it is wrong. Let me try and now clear this mess up.
MAXBoost... this is no longer a thing. This was the inline box that Ken was selling that would scale boost in hardware, prior to the scaling being done in custom logic code directly in the DME. There is no adjustment needed in logging options anymore either (again, this was only for the hardware MAXBoost device).
Current state:
- MHD auto detects if you are scaling boost using the 3-cell TMAP table and adjusts your logs accordingly.
- When using the N20 TMAP, you you have two options:
1. use the N20 checkbox or stock 2-cell TMAP conv. table, and have a max psi of 22.x (or 18.5 for DCT cars).
2. use the 3-cell TMAP table with supplied values and have about 35psi max
- When using the 3-cell TMAP table, BOTH the 2-cell table AND the N20 checkbox in MHD don't do anything. The 3-cell table (when used), forces additional logic to be written which overrides the 2-cell table. MHD proprietary stuff
- The current supplied 3-cell TMAP table values are slightly off (1-2psi high depending how much boost you run), and I will post corrected values once more testing is complete.
Boost vs. Boost mean:
- Boost mean is a direct rolling avg. of the TMAP voltage directly converted to PSI based on the 2-cell or 3-cell table, whichever you are using.
- Boost is a modeled value, based off of Boost Mean, but taking into account the DME internal model for airflow losses over the throttle body, etc. Therefore it will always be equal to or slightly lower than Boost Mean.
Everyone else, please ignore most of what he just babbled about, since it is wrong. Let me try and now clear this mess up.
MAXBoost... this is no longer a thing. This was the inline box that Ken was selling that would scale boost in hardware, prior to the scaling being done in custom logic code directly in the DME. There is no adjustment needed in logging options anymore either (again, this was only for the hardware MAXBoost device).
Current state:
- MHD auto detects if you are scaling boost using the 3-cell TMAP table and adjusts your logs accordingly.
- When using the N20 TMAP, you you have two options:
1. use the N20 checkbox or stock 2-cell TMAP conv. table, and have a max psi of 22.x (or 18.5 for DCT cars).
2. use the 3-cell TMAP table with supplied values and have about 35psi max
- When using the 3-cell TMAP table, BOTH the 2-cell table AND the N20 checkbox in MHD don't do anything. The 3-cell table (when used), forces additional logic to be written which overrides the 2-cell table. MHD proprietary stuff
- The current supplied 3-cell TMAP table values are slightly off (1-2psi high depending how much boost you run), and I will post corrected values once more testing is complete.
Boost vs. Boost mean:
- Boost mean is a direct rolling avg. of the TMAP voltage directly converted to PSI based on the 2-cell or 3-cell table, whichever you are using.
- Boost is a modeled value, based off of Boost Mean, but taking into account the DME internal model for airflow losses over the throttle body, etc. Therefore it will always be equal to or slightly lower than Boost Mean.
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Well, Jake, now I guess I know where you stand. It's a shame you don't have the professionalism to handle this via email, as I attempted to do last week.
So add Motiv to the "Team Vargas" lineup. Or is this just more of an unfocused hostility? Who knows. And I don't care.
I'm enjoying your clutch on our test car, though. So that's a happy!
Doug Harper
FrankenTurbo
So there is a 3psi diff between boost and boost mean assuming when you say mid 20s - it meant 25psi ?
I never got an email from you... must have been the other Jake (Hershorin), so I have no clue what you are talking about. Regardless, it doesn't take away from needing to correct the majority of what was written.
Jeff was a bit mixed up then I believe, as both Boost and Boost Mean will log above 22psi when using the 3-cell TMAP scaling + N20 sensor. They shouldn't have a 3psi difference at WOT either, if they do it's most likely because you are getting throttle closures.
I think I understand Jake's explanation of Boost and Boost mean. But consider my typical observations when logging:
Here is a recent log comparing Boost and Boost mean (E40-E50 fuel, N20 TMAP, stock turbos and stock exhaust, 3rd gear WOT).
https://datazap.me/u/jeffman/e40-e50-wgdc-30-75f-flat-first-two-wot?log=1&data=2-3-16
Note both Boost and Boost mean values track each other very nicely until I lift off the gas:
Boost (max) = 22.6 psi
Boost mean (max) = 23.5 psi
But when I lift off the gas at 6300 rpm, Boost mean spikes to 25.8 psi when the throttle closes and shortly thereafter drops to close to 0 psi; it never goes negative, which is consistent with charge pipe pressure where the N20 TMAP is located. In contrast, Boost doesn't spike on throttle closure, rather it immediately drops to -11.3 psi (vacuum), which is consistent with manifold pressure. These observations is why I correlated Boost mean measurements to the N20 TMAP in the charge pipe, and Boost measurements to the OEM TMAP in the manifold.
If I'm not making any sense let me know and I'll delete this post too.
Here is a recent log comparing Boost and Boost mean (E40-E50 fuel, N20 TMAP, stock turbos and stock exhaust, 3rd gear WOT).
https://datazap.me/u/jeffman/e40-e50-wgdc-30-75f-flat-first-two-wot?log=1&data=2-3-16
Note both Boost and Boost mean values track each other very nicely until I lift off the gas:
Boost (max) = 22.6 psi
Boost mean (max) = 23.5 psi
But when I lift off the gas at 6300 rpm, Boost mean spikes to 25.8 psi when the throttle closes and shortly thereafter drops to close to 0 psi; it never goes negative, which is consistent with charge pipe pressure where the N20 TMAP is located. In contrast, Boost doesn't spike on throttle closure, rather it immediately drops to -11.3 psi (vacuum), which is consistent with manifold pressure. These observations is why I correlated Boost mean measurements to the N20 TMAP in the charge pipe, and Boost measurements to the OEM TMAP in the manifold.
If I'm not making any sense let me know and I'll delete this post too.
You are correct. Boost mean is always TMAP. However, since "Boost" is calculated, the DME knows when the throttle is closed and it's model is then based off the MAP in the intake mani.
