JB4 and AFR help.

jkane92

Active Member
Mar 30, 2015
51
1
Hello all,

Spent most of this weekend logging on my JB4. So basically when I log my car when it's standard (map 0). AFR starts off around 14.5 and only drops to 14 at the red Line. Which I thought was a bit to lean. When I switch to map 2 the AFR drops to around 12.8 at the red Line meaning a richer mix. Anyone else have simular results?

Also I had a go with map 6. My target/requesting more boost than map 2 but the actual boost I'm getting is way under the target and also lower than map 2 was. Any ideas why?

If you could share your map 6 set ups and also logs that would be great.

Thank you
 

Nora2004

Active Member
Oct 15, 2017
176
80
Gotta remember this is a direct injection setup so they will run leaner than traditional port injection! First time I logged I was shocked at the AFR's! But your AFR's are perfectly normal, plus, if the jb4 detects it running too lean it will drop into map0!

Now, map2 is using the additive method of boost, so it will simply add say 5 psi into whatever the ECU wants! The stock map6 uses an absolute method, whatever value you input into the rpm increments it will try to hit, this is the better method, especially at this time of the year as you will get to take advantage of the cooler weather!

The ECU doesn't just try to hit requested boost values, it actually wants to hit torque targets, so if it can hit that torque target only using 22psi instead of the requested 25psi then it will! My logs are the same, my target value is always slightly higher than my actual!

As for the boost been lower, the stock map6 runs lower boost levels than map2, it comes this way as a clutch friendly option for the manual guys!

If it's a new unit you can mail your logs off to George at Burger tuning and he will help you setup map6!

Also if you haven't yet, get the firmware updated to the latest version, drop your Fuel Open Loop down to 50 and log map2 in either 3rd or 4th with TC fully off!
 

jkane92

Active Member
Mar 30, 2015
51
1
Gotta remember this is a direct injection setup so they will run leaner than traditional port injection! First time I logged I was shocked at the AFR's! But your AFR's are perfectly normal, plus, if the jb4 detects it running too lean it will drop into map0!

Now, map2 is using the additive method of boost, so it will simply add say 5 psi into whatever the ECU wants! The stock map6 uses an absolute method, whatever value you input into the rpm increments it will try to hit, this is the better method, especially at this time of the year as you will get to take advantage of the cooler weather!

The ECU doesn't just try to hit requested boost values, it actually wants to hit torque targets, so if it can hit that torque target only using 22psi instead of the requested 25psi then it will! My logs are the same, my target value is always slightly higher than my actual!

As for the boost been lower, the stock map6 runs lower boost levels than map2, it comes this way as a clutch friendly option for the manual guys!

If it's a new unit you can mail your logs off to George at Burger tuning and he will help you setup map6!

Also if you haven't yet, get the firmware updated to the latest version, drop your Fuel Open Loop down to 50 and log map2 in either 3rd or 4th with TC fully off!


Thank you for your detailed reply. I have the latest firmware installed.
I tried someone else's map 6 setting after checking over their logs. In summary they were targeting 20.5 psi and hitting that actual boost. Mine with the same set up is only achieving 17.5 psi.
Switch mine to map 2, it feels so much stronger and the logs confirm that. Ecu 13.3psi, Target 5.1psi, Boost 18.7psi.
?

One feature I do like about the JB4 is the Auto shift boost reducer. Before I was getting a turbo surge (about 24psi) when changing gear. Changing the value to 70 has completely stopped that.

I'm Tempted to just use below 10psi values for Map 6 so it stacks it on top of the ECU psi. My cupra is a 290 so I can imagine I can stack a little more on top of the ECU psi than say a 310 golf r as their ECU psi will higher be from factory.
Not sure how much I can push my car as it's stock except a large turbo elbow.
 

Nora2004

Active Member
Oct 15, 2017
176
80
Targeting 20.5 in map6 is still quite low, here is my current settings, Vwr elbow, Ramair intake hose, Ramair panel filter with stock airbox mods, V-Power,

1500 18
2000 19
2500 19
3000 21
3500 23
4000 24
4500 23
5000 23
5500 22
6000 21
6500 20
7000 19

I also have the boost redux set to 70, however I changed to help the timing pick up much faster on gear shifts, prior with the boost coming back so soon the timing would fall on its face!
 

Nora2004

Active Member
Oct 15, 2017
176
80
Just to add, going over your map2 logs from the N54 forum, at 4krpm your hitting 16.9 psi, mines hitting 21.7psi!

A well setup map6 will outperform map2 anyday!
 

jkane92

Active Member
Mar 30, 2015
51
1
Just to add, going over your map2 logs from the N54 forum, at 4krpm your hitting 16.9 psi, mines hitting 21.7psi!

A well setup map6 will outperform map2 anyday!



I'll give them settings a go and log it and see whats happening. Cheer for your help. I might be cheeky and as for one of your logs so I can compare. You ever had had problems running them boost settings?
Also whats your boost safety and fuel loop open to?
 

Nora2004

Active Member
Oct 15, 2017
176
80
Was trying to upload one but this forum won't allow it, shoot me your email addy over and I'll mail some from the summer and some from the winter over!

Never any issues at all, they were settings that me and George settled on back in August, this time of the year I could bump them up a bit, but it's fine as is, safe and powerful!
 

Nora2004

Active Member
Oct 15, 2017
176
80
Oh and boost safety is 26 and FOL is 50, had been running 45, but with the cooler weather the trims were rising a little higher than I wanted, back up to 50 and they are solid! Only downside is at the very end of 5th gear the JB will log a fuel pressure code, however this is just the ECU getting confused by the rail pressure it's seeing!
 

jkane92

Active Member
Mar 30, 2015
51
1
Oh and boost safety is 26 and FOL is 50, had been running 45, but with the cooler weather the trims were rising a little higher than I wanted, back up to 50 and they are solid! Only downside is at the very end of 5th gear the JB will log a fuel pressure code, however this is just the ECU getting confused by the rail pressure it's seeing!

I've private messaged you my email address. End of 5th gear haha was that on a private road in Mexico [B)]
 
Aug 5, 2020
3
0
Iv recently fitted a used jb4 to my pfl cupra290 DSG im being told i should be seeing more boost then i currently am, im hitting about 20psi somebody looked through my logs and can't understand why im only hitting 20psi car is stock running 99ron im new to this and dont really have a clue what im doing i dont wanna just keep adding boost on map6 if it isnt safe for the car I'll add a log of my map3 if anybody can shed any light or advise that would be great ?https://datazap.me/u/wezpeak93/map3?log=0&data=1
 

Zer0

Active Member
Jun 22, 2019
522
242
Iv recently fitted a used jb4 to my pfl cupra290 DSG im being told i should be seeing more boost then i currently am, im hitting about 20psi somebody looked through my logs and can't understand why im only hitting 20psi car is stock running 99ron im new to this and dont really have a clue what im doing i dont wanna just keep adding boost on map6 if it isnt safe for the car I'll add a log of my map3 if anybody can shed any light or advise that would be great ?https://datazap.me/u/wezpeak93/map3?log=0&data=1

Well I'm on my phone and can't check the logs properly but something is not right, those are pretty much stock boost figures. Your car is in map 2 btw but it doesn't matter, you should see peak boost of at least 24 psi on that map depending on temps and fuel.

Make sure all plugs are connected properly. AFR wire should tap the white wire on a newish Cupra (2019 or later IIRC) and the ODB2 plug must be connected otherwise JB4 unit is not active. FOL setting of 45 is correct for Cupra. Fuel bias should be set to 100 in all boxes and it is so that's good.

Also, make sure the firmware is correct. Grab the stable from group 60 - VAG Gen 3 here and install:


Once done do a run on map 2, 3 or 4, doesn't matter. Make sure you log. Gear in third, around 3500 rpm, foot to the floor but don't let it downshift to 2nd. If if does try again. Pull throughout 3rd and a bit into 4th. Post another log. Second gear log is sort of useless, car isn't pushed hard enough in that gear.

if you're not already a member sign up here and post the log as well, some very helpful guys:

 
Aug 5, 2020
3
0
Well I'm on my phone and can't check the logs properly but something is not right, those are pretty much stock boost figures. Your car is in map 2 btw but it doesn't matter, you should see peak boost of at least 24 psi on that map depending on temps and fuel.

Make sure all plugs are connected properly. AFR wire should tap the white wire on a newish Cupra (2019 or later IIRC) and the ODB2 plug must be connected otherwise JB4 unit is not active. FOL setting of 45 is correct for Cupra. Fuel bias should be set to 100 in all boxes and it is so that's good.

Also, make sure the firmware is correct. Grab the stable from group 60 - VAG Gen 3 here and install:


Once done do a run on map 2, 3 or 4, doesn't matter. Make sure you log. Gear in third, around 3500 rpm, foot to the floor but don't let it downshift to 2nd. If if does try again. Pull throughout 3rd and a bit into 4th. Post another log. Second gear log is sort of useless, car isn't pushed hard enough in that gear.

if you're not already a member sign up here and post the log as well, some very helpful guys:


Hey thanks for your reply! iv checked all connections everythings as should be, iv just done some logs i did a map0 log for comparison and in 3rd gear im getting upto 15psi of boost where as on map3 im getting peak of 20psi but as it changes into 4th boost rises to 24psi id upload the log but there is that much onit i think it will be usless tbh so I'll just upload the screenshots of both on here
Screenshot_20200806-211154_JB4 Mobile.jpg
Screenshot_20200806-211149_JB4 Mobile.jpg
 

Zer0

Active Member
Jun 22, 2019
522
242
Post log on datazap :)

On a third gear run ign_1 should climb steadily like step of stairs from 0 to 9 or 10. There are some corrections to on the cylinders but that's pretty normal on R / Cupra. Can't really tell from those graphs, sorry.
 
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