Tuning w/ N20 TMAP to see 22+ Boost

P33P33

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Apr 3, 2017
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BMW 335i n54 e93
Thanks Jake for the explanation. That was great. I was under the impression that 27 psi was the limit for the DCT and you couldn't change the the third cell PSI value and that's why I was changing the second cell value to change slope of the line to get headroom for DCT cars. Now it makes sense and by setting the third value to 33.26PSI you are only sensor limited which is great. I think there's bunch of others who didn't think of changing the third value to get full range of the sensor.
 

JohnDaviz

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Jan 6, 2019
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Sometimes i am stupid but often being dumb adds up to full retard mode.

So i have a DCT. So i will apply the values in my cells and need to scale with a divisor of 3 from above 10psi.

So does this mean:
Load 157 is 12PSI on stock. So 2PSI has to be scaled with 3 on N20 which results in 10psi+(2psi*3)= 16PSI?
 

P33P33

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Apr 3, 2017
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BMW 335i n54 e93
Sometimes i am stupid but often being dumb adds up to full retard mode.

So i have a DCT. So i will apply the values in my cells and need to scale with a divisor of 3 from above 10psi.

So does this mean:
Load 157 is 12PSI on stock. So 2PSI has to be scaled with 3 on N20 which results in 10psi+(2psi*3)= 16PSI?

Already did some tests and load axis stays the same because you aren't changing the sensor but merely stretching the scaling. So rough example would be that 10 psi boost equals around 150 load so you scale the area from 150 to 220 load(2nd and 3rd cell). if you have used the generic values before and now you start using the "DCT" values Jake provided load stays pretty much the same. Boost setpoint and maf calculations do change and basically means your WGDC base table needs attention.

So in the pictures below is very rough estimation what happens. Point here is that the load stays the same whether you use non DCT scaling or DCT scaling but boost setpoint and MAF calculations will change to lower values.


30071
30072
30073
 
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JohnDaviz

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Don´t get me wrong. I am on stock MAP sensor.

My example was the transition from stock sensor to N20 sensor.

I understood that i have to re-scale my map based on this division factor of 3 that was shown by jake.

On your picture is see Load actual 167.1 and boost of 25.7psi.
On Stock Sensor a Load of 167.1 results in boost of 13.74psi

So your scaling factor is higher than 3 between stock sensor scaling and n20 re-scaled.
 

P33P33

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Apr 3, 2017
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BMW 335i n54 e93
Sorry, thought you already had n20 sensor and you have been using the generic MHD 3-cell scaling(non-DCT). I wouldn't be too hung up on what my log shows for load vs. boost. That's why I wrote up there very rough estimate so people would see the difference. So I have made my initial load axis changes in the past and now all the changes I made for this new "DCT scaling" was WGDC base table adjustments because with the same actual boost ECU is seeing a little bit lower boost (boost setpoint) and that's why I was underboosting a bit.
I believe divisor 3 works if you start from scratch changing to n20 sensor. I haven't got the time to play with those numbers yet.
 

Jake@MHD

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So your scaling factor is higher than 3 between stock sensor scaling and n20 re-scaled.

The "scaling factor" is not meant to apply to requested or actual load because load comes from a very complex DME calculation of VE, estimated intake manifold pressure after flow calcs over the throttle, intake temp, ambient temp, etc.

T scaling factor I described above is simply to convert tmap boost the DME "sees" vs. what it actually is at the N20 sensor. You can follow @P33P33 rough guidelines for what load it will be, but will need to test / log / tweak.
 

Jake@MHD

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Just wanted to update this thread, now that MBoost code has been fixed, everyone can use the same scaling values with no issue:

0.5V @ 7.30809 psi
2.15876V @ 24.7psi
4.543146V @ 37.2psi

This requires of course setting the single cell boost ceiling to 1.5. Going to edit my original post as well.