SUPRA ULTIMATE B58 JB4 GUIDE AND LOG REVIEW (V1)

[Frosty]

I will be ordering the JB4 today. I'm getting the option fuel pressure connector as well. As of right now I am stock other than a drop in AFE filter.
Does anyone knows if the version that was designed for the manuals come preloaded?

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[ColonelAdama]

I will be ordering the JB4 today. I'm getting the option fuel pressure connector as well. As of right now I am stock other than a drop in AFE filter.
Does anyone knows if the version that was designed for the manuals come preloaded?

Not sure, but it is 3-4 minutes to flash the new firmware

 

[ColonelAdama]

Cool news coming soon again. Terry and I (and @RyanA90 ) have been busy developing an actual "MT mode" this week. It is activated by setting autoshift boost redux to 0, since that feature is not used on MT cars. Unreleased firmware only right now.

A fundamental function of the JB4's EWG connection is the boost PID. Allows JB4 to directly control boost levels, rather than spoof the sensor and let the car raise WGDC/boost.

As a refresher:

• PID Output = boost_error (boost vs. boost target) * Internal Mapping * PID Gain (see wastegate tuning)
• WGDC = FF + PID Output

So you can figure PID output = WGDC - FF.


The PID boost target for MT mode is 80% of DME boost target, rather than the ~95% it is for AT cars. This achieves the "underboosting" that MTs have needed but with the JB4 PID actually working with us, rather than against us (by pushing boost too high and causing MT stutters)

There is no "underboosting" method for MTs after this is finished, since it will already be built in to the JB4's MT mode.

You will attempt to fit the FF curve to the duty curve just like any other wastegate control JB4 car:
https://www.jb4tech.com/forum/model...g-review-ab/4229-jb4-duty-bias-ff-tuning-info

Confusing, but there will be results (and hopefully the new firmware available) soon.

*pic: new firmware, PID response goes negative when the underboost margin is reduced (arrow 1). PID can't correct enough, dme_bt drops and boost stutters (arrow 2)*

More work to do here, but already I can tell it makes tuning easier.

 

[Bug2th]

Cool news coming soon again. Terry and I (and @RyanA90 ) have been busy developing an actual "MT mode" this week. It is activated by setting autoshift boost redux to 0, since that feature is not used on MT cars. Unreleased firmware only right now.

A fundamental function of the JB4's EWG connection is the boost PID. Allows JB4 to directly control boost levels, rather than spoof the sensor and let the car raise WGDC/boost.

As a refresher:

So you can figure PID output = WGDC - FF.


The PID boost target for MT mode is 80% of DME boost target, rather than the ~95% it is for AT cars. This achieves the "underboosting" that MTs have needed but with the JB4 PID actually working with us, rather than against us (by pushing boost too high and causing MT stutters)

There is no "underboosting" method for MTs after this is finished, since it will already be built in to the JB4's MT mode.

You will attempt to fit the FF curve to the duty curve just like any other wastegate control JB4 car:
https://www.jb4tech.com/forum/model...g-review-ab/4229-jb4-duty-bias-ff-tuning-info

Confusing, but there will be results (and hopefully the new firmware available) soon.

*pic: new firmware, PID response goes negative when the underboost margin is reduced (arrow 1). PID can't correct enough, dme_bt drops and boost stutters (arrow 2)*

More work to do here, but already I can tell it makes tuning easier.

Will there be any advantages for autos with this fw?

 

[djf]

See if this helps the stutter. It applies to all maps, not just 6.

duty_15	duty_20	duty_25	duty_30	duty_35	duty_40	duty_45	duty_50	duty_55	duty_60	duty_65	duty_70
45​	45​	45​	45​	45​	45​	45​	50​	50​	50​	50​	50​

Thank you for all that you do! I’ll plug these in tomorrow and let you know how it runs

 

[RyanA90]

Cool news coming soon again. Terry and I (and @RyanA90 ) have been busy developing an actual "MT mode" this week. It is activated by setting autoshift boost redux to 0, since that feature is not used on MT cars. Unreleased firmware only right now.

A fundamental function of the JB4's EWG connection is the boost PID. Allows JB4 to directly control boost levels, rather than spoof the sensor and let the car raise WGDC/boost.

As a refresher:

So you can figure PID output = WGDC - FF.


The PID boost target for MT mode is 80% of DME boost target, rather than the ~95% it is for AT cars. This achieves the "underboosting" that MTs have needed but with the JB4 PID actually working with us, rather than against us (by pushing boost too high and causing MT stutters)

There is no "underboosting" method for MTs after this is finished, since it will already be built in to the JB4's MT mode.

You will attempt to fit the FF curve to the duty curve just like any other wastegate control JB4 car:
https://www.jb4tech.com/forum/model...g-review-ab/4229-jb4-duty-bias-ff-tuning-info

Confusing, but there will be results (and hopefully the new firmware available) soon.

*pic: new firmware, PID response goes negative when the underboost margin is reduced (arrow 1). PID can't correct enough, dme_bt drops and boost stutters (arrow 2)*

More work to do here, but already I can tell it makes tuning easier.

Major game changer for the MT (and AT) boys!

 

[ColonelAdama]

Will there be any advantages for autos with this fw?

Yeah it could potentially help. AT cars need a positive PID response (wgdc>ff) to not have throttle closures.

In other words, AT cars like a little underboosting to avoid throttle closures, but an MT needs it to be drivable.

 

[Frosty]

Not sure, but it is 3-4 minutes to flash the new firmware

Thanks you. Just got the jb4 in the mail. According to BM I have the latest board, with fp control and firmware. I guess it doesn't hurt to verify.

 

[Fuji808]

per BMS.....if you run ethanol mixture exceeding 25%, the new circuit board with fp upgrade is recommended.

otherwise, just upgrade firmware to 158 platform.

 

[Naijaboy]

Long time lurker here with the MT and just wanted to say thanks @ColonelAdama and others for starting this thread. I just purchased the JB4 with the FP control although I dont plan on running ethanol at this time. I still have to install my AA catted downpipe and will most likely install the JB4 at the same time. Looking forward to the firmware update that will most likely my life easier.

 

[MeanOldBill]

@ColonelAdama please take a look at the following map 6 and map4 runs at e40
any recommendations appreciated. Please and Thank you!
map 4:
https://datazap.me/u/palmerw/log-1734568393?log=0&data=1-4

map 6:
https://datazap.me/u/palmerw/log-1734568440?log=0&data=1-4

 

[FLtrackdays]

@ColonelAdama please take a look at the following map 6 and map4 runs at e40
any recommendations appreciated. Please and Thank you!
map 4:
https://datazap.me/u/palmerw/log-1734568393?log=0&data=1-4

map 6:
https://datazap.me/u/palmerw/log-1734568440?log=0&data=1-4

Let us know how it goes Mean Bill ?

I want to send the Colonel my mega log of my wife driving on track. Hopefully he’ll see something he can tweak and I can use it w/out going into limp mode ? Will definitely owe the Colonel more than a cup of coffee at the next cars & coffee event up in Greenville. When I finally get around to visiting TBR ? and that beautiful city again. The BMW test center is close to him as well. Talk about ideal location!!

 

[Frosty]

@ColonelAdama
Do you mind reviewing my first log(s)?
Map 1 and 2 on stock other than drop in filter
https://datazap.me/u/nocturnal/log-1734807802?log=0&data=1-4

 

[Frosty]

Terry asked me to update the firmware to P158 and add 6 cyl timing to 140. Now the car noses over like 3-4 times during the pull. It looks like it's overboosting with drastic throttle closures. Log below:
https://datazap.me/u/nocturnal/log-1734825647?log=0&data=1-2-3-4-9-11-18

 

[Frosty]

Terry made me move to Map4 with FF30. The car pulls much cleaner and feels stronger too. Still feel some throttle closing? I used to tune with a Microsquirt and Holley EFI, but these cars are different. I sent the log to Terry as well. Log below:
https://datazap.me/u/nocturnal/log-1734829190?log=0&data=1-3-4-9-11&zoom=0-62&mark=29-41

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