PI controller pro's & Con's comparison: JB4 PI vs split 6

Terry@BMS

Sergeant
Platinum Vendor
Jan 23, 2017
462
379
50
We used to have a "reset to defaults" option. Was a total disaster. People run interface versions that are out of date and reload the wrong options, they add parts that suddenly default don't apply to and wonder why its not working, etc. It was worse than what we did now which was why we removed those and simply post the settings in the specific thread. Which largely works very well. I'd love to come up with some sort of an interface wizard that makes setup easier but it's already pretty easy. One of the strengths of the JB4 implemnentation is how flexible it is and with that will come some confusion

This AFR rich thing isn't an issue of default settings being wrong. He has a custom tuner working with him. The tuning does whatever the tuner tells it to do. The settings look reasonable other than when on PI and a BEF you set open loop to 0 which may have prevented AFR from going so rich. That said I don't think his tuner expected a 10:1 AFR short run to blow a motor.

The concern I have is if we know 10:1 AFR is likely to damage a motor then let's just failsafe on a 10:1 AFR. The real key to the JB4's success is the passive safety systems that go above and beyond what can be easily done flash only. It took me less time to add the 10:1 AFR safety logic than it did to write this reply. My general question to those of you who are tuners or do tuning, do you ever run or plan to run really rich tuning? If so we'll need a "disable" option for the safety.
 
Last edited:
  • Like
Reactions: Payam@BMS

bahn

Sergeant
Platinum Vendor
Nov 5, 2016
250
414
0
Iowa
I’ve made my engine blown because of PI. Terry , my tuner didn’t tell me to set fuel bias to 20 , did also not to set FOL to zero , and run in map 1 to verify the things , and he didn’t make me remind that fuel bias settings are applied in all maps. So once I went to the high way to do a log and evaluate the things , I was in map 1 and fuel bias settings were set in 75 and FOL was in 40. The car took an immediate action and misfire cylinder 1 code popped up and never gone. Once we opened the engine , we saw that all cylinders walls were washed and crappy with scratches. Can’t you take any precautions for such situations , I think Jb4 should not let the fuel bias settings apply in all maps :(
What index were the injectors?
 

luchocamp

Corporal
Dec 9, 2017
147
81
0
Ride
f30 335ix / e90 335xi
JB4 is great equipment. No benefit from AFR under 10.8 maybe failsafe to map 4 after that.
 

BreakMyBillfold

Specialist
Nov 18, 2016
81
34
0
AZ
With our off the shelf stuff on single turbo, the suggested JB4 PI values of 80, off the shelf E85_PI BEF, open loop set to 0, trims are generally very level and fuel pressure is maintained.
Terry, what is the hybrid turbos (Pure Stage 2 Hi-Flow, specifically) version of this BMS PI values summary? I'm using the off the shelf E85 PI BEF, and realized I don't have the correct starting values, such as FOL=0.
 

Terry@BMS

Sergeant
Platinum Vendor
Jan 23, 2017
462
379
50
Terry, what is the hybrid turbos (Pure Stage 2 Hi-Flow, specifically) version of this BMS PI values summary? I'm using the off the shelf E85 PI BEF, and realized I don't have the correct starting values, such as FOL=0.

It's easy, just set "fuel bias" all to 50 in the JB4 user adjustment page, load the E85 PI BEF, and you're off and running. IF you need any help just capture a JB4 log and post it to the n54tech support forum or email it in and we can ensure it's working right, provide tuning advice.
 

Maniac0908

Corporal
Mar 22, 2018
109
6
0
Ride
07 335xi
Ok, April 2019. I’m going single. Getting the precision raceworks pi, and making my own stage 3 LPFP. (Maybe stage 4 if I have the funds). What’s the best set up controller wise? I have jb4 with a custom bef. Should I use jb4 pi controller or spilt second? Do I need jobs switch? Does jb4 pi controller have the high power wire now so we can also have 2step? Thanns
 

Payam@BMS

Sergeant
Oct 27, 2016
412
265
25
33
Ok, April 2019. I’m going single. Getting the precision raceworks pi, and making my own stage 3 LPFP. (Maybe stage 4 if I have the funds). What’s the best set up controller wise? I have jb4 with a custom bef. Should I use jb4 pi controller or spilt second? Do I need jobs switch? Does jb4 pi controller have the high power wire now so we can also have 2step? Thanns

JB4 PI controller for sure. Everything is integrated into one, no need for a hobbs switch. The PI controller has a trigger for the secondary fuel pump.
Yes, you can use 2step as always.
 
  • Like
Reactions: Zhelyazkov

Max

New Member
May 24, 2019
2
0
0
Ride
xxx11xxx
@ Terry

Hi Terry, this discussion ist quite old, but I´ve one question on the log from [U]cebrailbakan[/U]. After a few seconds logging the trim value is going to 0. I have made a lot of loggings, but never had trims of 0. Do you have an idea?
 

Payam@BMS

Sergeant
Oct 27, 2016
412
265
25
33
@ Terry

Hi Terry, this discussion ist quite old, but I´ve one question on the log from [U]cebrailbakan[/U]. After a few seconds logging the trim value is going to 0. I have made a lot of loggings, but never had trims of 0. Do you have an idea?

Are you using the JB4 PI controller? If so, do you have a log so I can take a look?
More than likely you'll have to set open loop to 0 and lower your fuel bias settings.
 

Max

New Member
May 24, 2019
2
0
0
Ride
xxx11xxx
Are you using the JB4 PI controller? If so, do you have a log so I can take a look?
More than likely you'll have to set open loop to 0 and lower your fuel bias settings.
No, I‘m not using it, sorry. Behause I try to understand the JB4 as good as possible, I‘m interested how the trim value can be zero.
 

Payam@BMS

Sergeant
Oct 27, 2016
412
265
25
33
No, I‘m not using it, sorry. Behause I try to understand the JB4 as good as possible, I‘m interested how the trim value can be zero.

It's hard to identify without a log. I'd send one to your tuner and see what he says. More than likely you'll have to remap your AIC 6 PI controller if it's dumping too much fuel.