Single Turbo Boostbox Tuning

chrisdfv

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Aug 29, 2017
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E90 335i
Interesting, since everything in them is someone else's work, namely my own.

Jake,
is the BRO table my only option to raise boost target in partial throttle scenarios? I get occasional overboost codes. I have my BRO table set to 80% in that portion of it but I'm running out of fuel scalar range. Do my torque request tables need to be set more aggressive?
 

Jake@MHD

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Nov 7, 2016
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Jake,
is the BRO table my only option to raise boost target in partial throttle scenarios? I get occasional overboost codes. I have my BRO table set to 80% in that portion of it but I'm running out of fuel scalar range. Do my torque request tables need to be set more aggressive?

No, I would leave BRO alone and up your driver torque request table in that throttle percent area until boost target there is very close to your spring pressure.
 
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chrisdfv

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Aug 29, 2017
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E90 335i
Haven't posted an update here in a while since I've had a broken auto trans for the longest.
I manual swapped last weekend and finished breaking in the clutch. Did some logging finally and it seems I have my PID time out issue figured out.
Boost is smooth now. No overboost, not PID time out. I ended up using stock D-factor table values, and it worked like charm.
https://datazap.me/u/cd919/mt-16-and-cruising-18?log=1&data=3-8-23-27-30-31&zoom=16-61
25112
 
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all4bspinnin

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Jun 12, 2017
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135i TT
Chris, changes are looking good. Have to tried making your load request the same value from about 3500 and on, then use wgdc base to bring boost up to target? Your current flash comes in somewhat linear. Better for traction but has a less aggressive hit.
 

chrisdfv

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Aug 29, 2017
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E90 335i
Chris, changes are looking good. Have to tried making your load request the same value from about 3500 and on, then use wgdc base to bring boost up to target? Your current flash comes in somewhat linear. Better for traction but has a less aggressive hit.

I like the linear powerband. My car hooks under all circumstances above 50 mph so I'm happy with that. I'm sure my 164k mi stock motor enjoys not having a big torque hit in the mid range.

Do you prefer to see boost target a little closer to actual? Probably safer, I just haven't bother messing with it since this tune runs so well.

What do you find yourself changing most on BB cars? P-factor Z values, or p-factor table breakpoints?
I'm helping my friend with his BB car, but it reacts totally different to the PID that works on my car, and I'm struggling with PID time out. :cry:
 
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all4bspinnin

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Jun 12, 2017
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135i TT
Have you tried running a flat 80 in the BRO? It works well on some single turbo cars. I dont really modify the PID breakpoints much. Theres definitely more than one way to go about it, but I tend to make small adjustments to the P factor, and find myself actually modifying d factor often. The main thing I try to dial in the most is the base wgdc table then go back and hit PID. Are you using rpm x sp? If so, try switching back over to the normal wgdc base / wgdc spool. 0 out pre control, the position tables, wgdc floor, wgdc dynamic, and just keep your P, I, D, and D multiplier tables. Set max wgdc to 100.

I also set the entire wgdc base table to 100 if spool mode is cutting off fairly early and its not scaled too far out on the maf req wgdc.

try starting off with 1M PID, 80 BRO, and then working on your wgdc base to bring load up.
 

noorj

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Jul 12, 2017
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'07 E90 335i
What’s the theory/idea behind an 80% boost request offset? Aren’t you just running artificially higher load values for a specific boost pressure
 

chrisdfv

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Aug 29, 2017
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E90 335i
Have you tried running a flat 80 in the BRO? It works well on some single turbo cars. I dont really modify the PID breakpoints much. Theres definitely more than one way to go about it, but I tend to make small adjustments to the P factor, and find myself actually modifying d factor often. The main thing I try to dial in the most is the base wgdc table then go back and hit PID. Are you using rpm x sp? If so, try switching back over to the normal wgdc base / wgdc spool. 0 out pre control, the position tables, wgdc floor, wgdc dynamic, and just keep your P, I, D, and D multiplier tables. Set max wgdc to 100.

I also set the entire wgdc base table to 100 if spool mode is cutting off fairly early and its not scaled too far out on the maf req wgdc.

try starting off with 1M PID, 80 BRO, and then working on your wgdc base to bring load up.


I had tried 80, 85, 90, and then stock BRO. Mainly was increasing because I was running out of fuel scalar range. I'm using rpm x sp, and I already have the tables you mentioned 0'd out.
Don't mac solenoids run out of resolution above 80ish %?

Oddly enough after messing with P-factor break points one more time, Now PID is working great...:laughing:
25460
 

Abacus38

Lieutenant
Nov 2, 2016
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2007 Ti Ag 335i
Update:

Using a flat 35% WGDC in my SP x RPM table I was able to target and hold 17 psi

https://datazap.me/u/cd919/log-1517959897?log=0&data=3-8-19-20-23-29-31

How ever took a log this morning in 3rd gear and got some throttle closure due to overshooting target. Going to lower values in that area of my table but at least now I have a starting point.

https://datazap.me/u/cd919/log-1518033364?log=0&data=2-3-4-5-7-8-23-26-29-31


When using the RPM vs boost setpoint method what tables are you using to tuned?

Are you just using WGDC(RPM X Setpoint) and P I D factor table?
 

Abacus38

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Nov 2, 2016
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Tampa/Orlando, FL
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2007 Ti Ag 335i
Thanks I definitely plan on coming in here. I just figured out scaling thing thanks to v8bait post. I'm almost done creating a base map for e85 however does anybody have the flexfuel boostbox xdf?

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):

View attachment 8182

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):

View attachment 8183

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.
 

chrisdfv

Corporal
Aug 29, 2017
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E90 335i
Thanks I definitely plan on coming in here. I just figured out scaling thing thanks to v8bait post. I'm almost done creating a base map for e85 however does anybody have the flexfuel boostbox xdf?

Nice, I use his 3 cell values as well. The flexfuel xdf should be available from github, but if it's no longer available, I can send it to you.
 

Abacus38

Lieutenant
Nov 2, 2016
643
385
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34
Tampa/Orlando, FL
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2007 Ti Ag 335i
Nice, I use his 3 cell values as well. The flexfuel xdf should be available from github, but if it's no longer available, I can send it to you.

I have that xdf but I was wondering if you have the one flex fuel xdf that has the 3 boost box toggles with it.
 

nahor

Specialist
Sep 15, 2017
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2010 BMW 135i Single Turbo
I have that xdf but I was wondering if you have the one flex fuel xdf that has the 3 boost box toggles with it.
Do you have the standard boost box XDF? If so that's all you need, you don't need a specific flex fuel one. Just switch to the boost box one, set the toggles, and switch back to the standard flex fuel one when you're done.

If you don't have the standard boost box XDF, just email Motiv and they'll send it to you.