BMS VW GTI JB4 info thread

[shortyb]

Just go to datazap.me and create an account. Upload the csv file the jb4 spits out.

Fantastic!

 

[Diggs24]

It looks like he is diesel because the boost falls off sharply at ~4000.

No Jb4 for diesel. Also, click pedal and you can see it isn't 100 which would be WOT. Just 2 incomplete runs. Can't get good results from them.

 

[rc pete]

Are you asking why I didn't go flash tune route? Work at a large VW/Audi dealer and seen what happens when folks come in with flashed ECUs. The look on the faces of especially the Audi owners when they are told their warranties are cancelled is priceless. I have enough friends with E888 platform that would buy my JB4 when time to turn in the car comes.

No I was asking if you are flashed. I see now no.

Im trying to go without a flash, and see how far I can go.

Thanks

 

[euroadb]

JB4 with IS38

So am I correct in thinking that it's possible to run the GTI with an IS38 with only a JB4 and no tune? I thought I might have seen that somewhere, but not sure..

Anyway, can someone explain to me how this is possible? I was always under the impression that a tune was mandatory when you changed your turbo. Would the car theoretically run with just a turbo swap and no software change whatsoever? How is the JB4 able to accommodate the IS38? Just wanna wrap my mind around how the car behaves with a turbo swap with stock ECU, and what parameters need to be adjusted to accommodate the turbo, whether it's a reflash, or just a JB4, or both.

I have a JB4 and have been considering the possibility of IS38 in the future.

 

[Diggs24]

The ECU is very smart, but the boost map is still set to run an IS20. The ECU will target boost and lambda and hit them no problem. Car will be faster (as the turbo has more volume and can make more power at same amount of boost) but since it will be assuming there is an IS20 it will taper boost more aggressively towards redline. Thus you are not maximizing the IS38. Compare an R log and a GTI log ECU boost readings and you can see it.

 

[euroadb]

The ECU is very smart, but the boost map is still set to run an IS20. The ECU will target boost and lambda and hit them no problem. Car will be faster (as the turbo has more volume and can make more power at same amount of boost) but since it will be assuming there is an IS20 it will taper boost more aggressively towards redline. Thus you are not maximizing the IS38. Compare an R log and a GTI log ECU boost readings and you can see it.

Gotcha. So if I get an IS38 in the future, will I have to reflash my JB4 to IS38 (Golf R) firmware? Or is there a special firmware for GTI IS38? Or is this something that's gonna have to be tweaked in Map 6 settings with my stock firmware?

 

[Diggs24]

Gotcha. So if I get an IS38 in the future, will I have to reflash my JB4 to IS38 (Golf R) firmware? Or is there a special firmware for GTI IS38? Or is this something that's gonna have to be tweaked in Map 6 settings with my stock firmware?

No, we all use the same device and firmware. I would work with George to start a new safe base map and go from there. You have to remember that 20psi on IS38 at 3000 rpm is more torque than 20psi at 3000rpm IS20. Lots of low end torque is what breaks rods and other components (especially clutches). You will probably run less boost at lower rpms but more towards redline.

 

[euroadb]

No, we all use the same device and firmware. I would work with George to start a new safe base map and go from there. You have to remember that 20psi on IS38 at 3000 rpm is more torque than 20psi at 3000rpm IS20. Lots of low end torque is what breaks rods and other components (especially clutches). You will probably run less boost at lower rpms but more towards redline.

I'm sure the functions of the firmware are the same, but the preset maps must be different at least for different turbos, since BMS offers different JB4's for different turbos. So I figured a reflash to Golf R firmware and map 1 or map 2 and I would be good to go at least as a starting point? Unless the internals of the GTI aren't up to snuff to handle the full Golf R map/tune?

 

[Diggs24]

I'm sure the functions of the firmware are the same, but the preset maps must be different at least for different turbos, since BMS offers different JB4's for different turbos. So I figured a reflash to Golf R firmware and map 1 or map 2 and I would be good to go at least as a starting point? Unless the internals of the GTI aren't up to snuff to handle the full Golf R map/tune?

Map1 is map1 regardless of car. The JB4s are all the same.

 

[euroadb]

Map1 is map1 regardless of car. The JB4s are all the same.

Then why does BMS have more than one SKU for their JB4 lineup? There's a Group 1, Group 2, Group 3 and so on for the different engines/turbo combinations. Furthermore, if they really are all the same, does this mean I can just bolt on the IS38 with map 2 and be good to go?

Or does it work something like this?
IS20 ECU + IS20 + JB4 = fine
IS38 ECU + IS38 + JB4 = fine
IS20 ECU + IS38 + JB4 = map 6 / further tuning required to compensate for the "mismatch"

 

[soflo-nochi]

I know I might get torn apart for this but... with a USP cat less Downpipe, will the JB4 correct the CEL or will I need to purchase a spacer?


--2017 MK7 GTI PP Autobahn

 

[russiankid]

Then why does BMS have more than one SKU for their JB4 lineup? There's a Group 1, Group 2, Group 3 and so on for the different engines/turbo combinations. Furthermore, if they really are all the same, does this mean I can just bolt on the IS38 with map 2 and be good to go?

Or does it work something like this?
IS20 ECU + IS20 + JB4 = fine
IS38 ECU + IS38 + JB4 = fine
IS20 ECU + IS38 + JB4 = map 6 / further tuning required to compensate for the "mismatch"

I am pretty sure the JB4 reads the ECU and can determine the software. Also, JB4 is a piggy back that uses the stock parameters, so it adjusts to what the ECU is trying to do.

 

[Diggs24]

Then why does BMS have more than one SKU for their JB4 lineup? There's a Group 1, Group 2, Group 3 and so on for the different engines/turbo combinations. Furthermore, if they really are all the same, does this mean I can just bolt on the IS38 with map 2 and be good to go?

Or does it work something like this?
IS20 ECU + IS20 + JB4 = fine
IS38 ECU + IS38 + JB4 = fine
IS20 ECU + IS38 + JB4 = map 6 / further tuning required to compensate for the "mismatch"

I think they do that for tracking purposes. See who is buying the unit for what car. I assure you it is the same thing.

No, I wouldn't bolt it on and go straight to map2. I'd bolt it on and go to map6 and ask George to recommend a starter map6.

IS20 ECU + IS38 + JB4 = map 6 / further tuning required to compensate for the "mismatch"

This ^.

 

[euroadb]

I know I might get torn apart for this but... with a USP cat less Downpipe, will the JB4 correct the CEL or will I need to purchase a spacer?

You can have the JB4 clear all codes, but not just the CEL for the O2 sensor. I would just get the spacer and use it right away.

I think they do that for tracking purposes. See who is buying the unit for what car. I assure you it is the same thing.

No, I wouldn't bolt it on and go straight to map2. I'd bolt it on and go to map6 and ask George to recommend a starter map6.

IS20 ECU + IS38 + JB4 = map 6 / further tuning required to compensate for the "mismatch"

This ^.

Gotcha okay that helps a lot.

 

[Chozer]

Help me understand the Max Boost 1st and Max Boost 2nd settings.

I am running Map 6 absolute.
I have left the Max Boost 1st and Max Boost 2nd at the default 0. Does this mean they are just using stock ECU boost in these two gears?


I see from the first post it mentions 17 for first and 19 for second etc.

So I am unsure if I am supposed to leave these at 0 or set them to 17 and 19.