Tuning w/ N20 TMAP to see 22+ Boost

WOT808

Specialist
Aug 7, 2017
76
If PID goes flat to match your WGDC base table then that means PID has been under target for too long and has "timed out". To fix it, you can either lower load request or raise wgdc base
That was the common theme in the thread I posted about it. I've logged with boost ~1psi off target and still get PID drops after multi gear pulls. It doesn't happen 100% of the time but it happens. This does not happen if the tmap isn't scaled.

Seems like the 'PID timer' is a lot more sensitive with the tmap scaled. Looks like the timer will reset when you let off throttle / shift when running the RPM x SetPoint table. Without that table enabled, once the timer is 'out', you'll have to restart the car to get PID back.

Have you been successful targeting above 21?
 

Jeffman

Captain
Jan 7, 2017
1,405
@Jeffman, looks like you're having the PID drop issue with the TMAP scaled in the log posted on this page.
Have you found a way around it?
Aha! I remember looking at that last summer and thinking it was “weird”. Nope, never did anything about it. Got too busy this fall and winter and haven’t looked at it - too cold here the last few months in Chilly Philly. I’ll probably play around with it once it warms up a bit.
 

V8bait

Sergeant
Nov 2, 2016
456
Texas
I'm not here much but I'll share a few things I do to help. This is the 3-value I use (2-value is stock because it is ignored when using the 3-value):

upload_2018-1-18_9-22-36.png


I use different values than you guys seem to be, I recommend testing the N20 sensor to figure out your scale like I did. Targeting higher voltage and lower pressure helps correct the gauge some in theory (but be careful at the sensor limit so as not to overrun it), and moving the middle value left helps preserve sensor linearity, I graphed it a long time ago but looks like this (used to scale down to 1.6v but was a bit too far for some sensors/barometrics):

upload_2018-1-18_9-29-16.png


The values above were based on data-sheet values which I've found to be a bit misleading. For the N20 sensor the formula I use for absolute pressure is BOOST (ABSOLUTE) = 10.105*(VOLTAGE)+2.2758


I'll add, you can set the sensor 3rd value to like 4.2v / 36.6psi if you only want to target 30psi, and use the full 220 load range of the DME. I used to do this as it allows the DME to see the highest load, but it got annoying to set in every tune and required major changes again for people wanting to go over 30psi. But there's many ways you can set up the scaling once you understand what it's doing. I'll have to add this stuff the the spreadsheet I made I guess.
 
Last edited:

all4bspinnin

Corporal
Jun 12, 2017
155
https://datazap.me/u/m6keharr/2k-v16?log=1&data=3-6-23-30-31

I don't have logs uploaded of my flash with tapering boost target dropping pid. I guess I've never got target and actual close enough (under 1psi) to satisfy that 'timer' and not overshoot.
Looks like you've lowered the base wgdc table a pretty good amount and are relying on your PID to hit target. Personally, I do not prefer to tune this way. I like to get PID as close as possible to wgdc base. If WGDC PID and WGDC base are essentially the same line, actual load is just back of load request, and boost is not exceeding target and is without throttle closure then that's where I like to be.

I would raise your wgdc in your rpmxsetpoint table until it follows wgdc after pid as close as possible. I can almost guarantee the PID timeout will disappear.
 

all4bspinnin

Corporal
Jun 12, 2017
155
I'm not here much but I'll share a few things I do to help. This is the 3-value I use (2-value is stock because it is ignored when using the 3-value):

I use different values than you guys seem to be, I recommend testing the N20 sensor to figure out your scale like I did. Targeting higher voltage and lower pressure helps correct the gauge some in theory (but be careful at the sensor limit so as not to overrun it), and moving the middle value left helps preserve sensor linearity, I graphed it a long time ago but looks like this (used to scale down to 1.6v but was a bit too far for some sensors/barometrics):

The values above were based on data-sheet values which I've found to be a bit misleading. For the N20 sensor the formula I use for absolute pressure is BOOST (ABSOLUTE) = 10.105*(VOLTAGE)+2.2758

I'll add, you can set the sensor 3rd value to like 4.2v / 36.6psi if you only want to target 30psi, and use the full 220 load range of the DME. I used to do this as it allows the DME to see the highest load, but it got annoying to set in every tune and required major changes again for people wanting to go over 30psi. But there's many ways you can set up the scaling once you understand what it's doing. I'll have to add this stuff the the spreadsheet I made I guess.

Thank you very much for the info :)
 

Jeffman

Captain
Jan 7, 2017
1,405
Yes.


Yeah possibly. But can't go any higher as fuel scalars are already 1.50 (Max) in the WOT range. And STFTs not maxing out at 34 so I think I'm good for now.
But I am wondering why my fuel scalars are so high. Even on 93 Octane I need fuel scalars of at least 1.10 - 1.15 to avoid lean codes. This started about 5 years ago after I first tried E85. Now I'm wondering whether I need to replace the O2 sensors (original, 9 years old now at 63K miles) based on recent posts talking about O2 sensors becoming "lazy" at 100K miles (or possibly age-related like mine).
UPDATE: I just upgraded to six new Index 12 injectors. Previously had four original 10 year old index 5’s and two index 8’s from a warranty repair. STFT’s are now much lower with the improved fueling. So if your STFTs are creeping up and you’re on old injectors it may be time to upgrade.
 

shushikiary

Corporal
Jun 4, 2018
145
I've been reading around... trying to figure out what's going on with my N20 sensor. I always get 2ABC when its in. Ambient pressure reads 0.94 off of it, while stock is 1.64. This lines up with the math. IAT reports right. I cant figure out what is going on with why this isnt working (obviously I'm at altitude). I'm wondering if perhaps There is a min expected TMAP voltage and I'm below it or something.

It seems there is a min voltage value given by address 0x4C1DC in the IJEOS bin? Its a 16 bit floating point, conversion the same as for MAP Max Voltage. Maybe that's the key?
 
Last edited:

jyamona

Captain
Platinum Vendor
Nov 7, 2016
1,240
Philly
I've been reading around... trying to figure out what's going on with my N20 sensor. I always get 2ABC when its in. Ambient pressure reads 0.94 off of it, while stock is 1.64. This lines up with the math. IAT reports right. I cant figure out what is going on with why this isnt working (obviously I'm at altitude). I'm wondering if perhaps There is a min expected TMAP voltage and I'm below it or something.

It seems there is a min voltage value given by address 0x4C1DC in the IJEOS bin? Its a 16 bit floating point, conversion the same as for MAP Max Voltage. Maybe that's the key?
What is your altitude? I had to fix this for a few high alt people. That byte was not the fix
 

shushikiary

Corporal
Jun 4, 2018
145
What is your altitude? I had to fix this for a few high alt people. That byte was not the fix
I'm at 5280, but I will also be driving the car up to 12,000 sometimes too.

I found a post that does talk about a min TMAP voltage.... so it does exist! but its not in the xdf, and it sounds like its not at the address you described, so where is it in the IJEOS bin?
 
Last edited:

jyamona

Captain
Platinum Vendor
Nov 7, 2016
1,240
Philly
I'm at 5280, but I will also be driving the car up to 12,000 sometimes too.

I found a post that does talk about a min TMAP voltage.... so it does exist! but its not in the xdf, and it sounds like its not at the address you described, so where is it in the IJEOS bin?
I do not have the byte handy, I can look it up later unless @V8bait can beat me to posting it. I sent to him awhile ago and it fixed it for one of his mile high customers.
 

V8bait

Sergeant
Nov 2, 2016
456
Texas
I do not have the byte handy, I can look it up later unless @V8bait can beat me to posting it. I sent to him awhile ago and it fixed it for one of his mile high customers.
If the guy PM's me I'll get him them np, so far your addresses are spot on but I don't like to circulate things until I get your ok outside the guys I get good feedback from.
 

shushikiary

Corporal
Jun 4, 2018
145
To answer my own question, the spike there is related to cam lobe separation in the vanos intake vs exhaust moving warm. Was easiest to just adjust requested load to flatten it out.

This code is really starting to bother me having to clear the 2ABC 2-3 times a day, and I have to restart the engine each time so its doubling the load on my starter.
 

jyamona

Captain
Platinum Vendor
Nov 7, 2016
1,240
Philly
To answer my own question, the spike there is related to cam lobe separation in the vanos intake vs exhaust moving warm. Was easiest to just adjust requested load to flatten it out.

This code is really starting to bother me having to clear the 2ABC 2-3 times a day, and I have to restart the engine each time so its doubling the load on my starter.
Just to confirm, what is the text for 2ABC? I can send you this tomorrow.
 

shushikiary

Corporal
Jun 4, 2018
145
2ABC Charging pressure sensor, electrical.

From other posts I've seen it happens when the voltage from the TMAP is below the expected voltage and that IJEOS has a rather high min TMAP voltage. The sensor reports 0.94 volts for 12.2 psi ambient, which is likely below the min TMAP voltage value I suspect. So every time I start the car it throws 2ABC and 3100, clear them, restart, and then it runs great. Stock TMAP reports 1.64 volts or so for the same pressure, which lines up with the voltage to PSI curves for both sensors.

So its got to be the TMAP min voltage needing to be lowered. I already wrote 0.50 (in 16 bit floating point) to 0x4C1DC, but that doesnt fix it, so I think you're correct its not the location of the TMAP min voltage. (note this translates to 0x66 after the conversion, I also tried 0 which didnt work either. )

Thankyou very much for grabbing it, otherwise I'd have to live with this code for the rest of the cars life I suspect.
 
Last edited:

shushikiary

Corporal
Jun 4, 2018
145
Talking to wedge he said the 0x4C1DC was the right address for tmap min voltage on IJEOS, and that it was a 16 but float with the same conversion equation as the tmap max voltage. Even tried setting it to zero and that didn't fix the code either.

There might be a code disable for this code like many others though, maybe that's the way to finally fix this, I'm hoping to hear from Jake soon.

The stock value for 0x4C1DC was 1.03 volts or 0xD3
 
Thread starter Similar threads Forum Replies Date
S Advanced Tuning 0
Naldo12 Advanced Tuning 0
doublespaces Advanced Tuning 4
DCT_JAY Advanced Tuning 28
matreyia Advanced Tuning 17

Similar threads


Top