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Tuning JB4 Technical Info, Discussion, Issues

Y0UKN0WITSCHRIS

Well-Known Member
Mar 6, 2018
1,067
1,045
113
27
Right-click while hovering over the blue “Download” button and copy the link. You can then use a URL shortener like v.gd or paste the full link here.
No download button pops up all it shows what appears to be a bar graph underneath of the files name and it fills about a eighth of the bar and that’s it. Trying to upload a pic but no matter what I do the site still says the file is too large :rolleyes:
 

Y0UKN0WITSCHRIS

Well-Known Member
Mar 6, 2018
1,067
1,045
113
27
Thank you again !
@Y0UKN0WITSCHRIS

How are your IAT's so low? You're holding a WHOLE lot of boost on the high end, 16.7psi at 5980rpm is awesome! I bet the car feels insanely strong. I can't get mine to hold over 13.
Oh she feels good lol and I have nothing more than the mods listed above. I may have got a good batch of Gas. There’s one Sunoco in my area that seems to get better quality fuel than the others but you pay a premium 20+ Cents more for their fuel.
 
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Abesy

New Member
May 1, 2019
18
19
3
Australia
I had my JB4 abruptly drop back to Map0 from Map3 on a 4th gear pull on the weekend. I have only ran Map2 but thought I would try Map3 for a couple of pulls. The default boost safety should be 24psi according to the App. Logs show 22psi but the timestamp capture on the app is pathetic. Got the fuel harness adapter this week so I will try work out a better custom map. Still learning a lot playing around with the JB4 and reading through all the info out there...
 

NVegas

Member
Jul 4, 2019
79
53
18
Las Vegas
Does anyone else log ECU_PSI on their JB4? If I increase my boost target, the value for ECU_PSI just drops lower and lower. I am noticing that the values I put in for map6 dont really seem to matter that much. It seems like the ECU is still managing to overpower the JB4 with torque limiting.

I have a couple logs that can show that wether I set the jb4 to add 2psi up top, or 8psi up top, I end up with the same amount of boost, often less boost the higher I try to go. For example, map 3 adds about 5psi on top, my last log on that map shows almost 16psi at 5k, and a hair over 12psi at 6k. With map6 set to add 7 psi, with multiple logs, my best run has 15psi at 5k, and 10.5psi at 6k.

Has anyone else experienced this? Would perhaps disconnecting the battery for some time help this issue?
 
Last edited:

kln55

Member
Apr 18, 2019
19
35
13
USA
Anybody using the USB cable able to keep the cable connected and close up the enclosure? Seems the serial port end is too big to fit and the plugged up hole is too small for the USB cord diameter.
 

R Veloster N

Well-Known Member
Mar 5, 2019
6,158
4,552
113
Rocky Mountains, US
Anybody know what map I should run on my vn I have downpipe,intake
Welcome to the forum and have fun. Please read the forum rules here;

You'll want to introduce yourself to the forum here;
Make sure you utilize the search engine at the top center left for any topics of interest and discussions. There's a plethora of information to glean thru on the forum and using the search engine will help you find it quickly.

Not every mapping is the same. Map selection is dependant upon you; separate modifications, altitude and ambient conditions and which performs the best for your individual conditions. It's trial and error method but you'll need to tailor your map to hose specifications listed above. Utilize the data logger in the app to help make those determinations.:)
 

Daveledo30

New Member
Apr 16, 2020
5
1
3
Plantation fl
Anyone here having problems with there jb4 on the veloster n I installed mine last week Thursday and have had nothing but problems since doesnt wanna stay in map 0 and also the car hiccups also even turns off sometimes app also freezes I've tried updating firmware and double checking connections but dont know what else to do really thinking about returning it at this point dont know what else to do?