[jwzimm]

Hey all,

I had a question about how the JB4 handles boost control in the ISO configuration. I have the BMW PPK flash on my 2011 N55 which obviously ups the boost a bit. I know that ISO isolates the boost control from the DME and puts the JB4 fully in the drivers seat as it were.

My question is, does the JB4 simply pass through the control signals for boost in map 0 or does it run a "stock" map stored internally?

I ask this because if it is the latter then I would be seeing a detriment I think. The JB4 would be effectively de-tuning the car in map 0. I am also concerned with how it handles part throttle/low load conditions in this respect. I know most folks tune and run for WOT max power but most of the time we are not in that realm. I would hate for the JB4 to be holding the engine back from running the full PPK power levels in these conditions.

Any help/comments?

[jgoens]

Originally Posted by jwzimm

Hey all,

I had a question about how the JB4 handles boost control in the ISO configuration. I have the BMW PPK flash on my 2011 N55 which obviously ups the boost a bit. I know that ISO isolates the boost control from the DME and puts the JB4 fully in the drivers seat as it were.

My question is, does the JB4 simply pass through the control signals for boost in map 0 or does it run a "stock" map stored internally?

I ask this because if it is the latter then I would be seeing a detriment I think. The JB4 would be effectively de-tuning the car in map 0. I am also concerned with how it handles part throttle/low load conditions in this respect. I know most folks tune and run for WOT max power but most of the time we are not in that realm. I would hate for the JB4 to be holding the engine back from running the full PPK power levels in these conditions.

Any help/comments?

Good question.
Even though I don't even put it on map 0, having ppk, I would like to know that.

[weehe126]

That's is a good question and I think you are right. The way you can check this is to log map 4 as it is map 0 but with canbus logging. If you get more than 8 psi your PPK is still good in map 0.

[jwzimm]

I drove today with the JB4 uninstalled and I have to say, it feels better with the stock PPK tune only in everything but WOT. I really think that the JB4 runs a stock map it is programmed with so it effectively nullifies the PPK.

[jgoens]

Originally Posted by jwzimm

I drove today with the JB4 uninstalled and I have to say, it feels better with the stock PPK tune only in everything but WOT. I really think that the JB4 runs a stock map it is programmed with so it effectively nullifies the PPK.

I kind of think your right..when I had mine off last week for my wp repair it seemed to run pretty good...but I still put it back on..haha.

[jwzimm]

Originally Posted by jgoens

I kind of think your right..when I had mine off last week for my wp repair it seemed to run pretty good...but I still put it back on..haha.

I think mine is going to stay off. It always felt....nervous...with the JB4 on. Like it was straining at the leash all the time. It made me kind of uncomfortable driving it. With it back to OEM it feels much more predictable. The only drawback is the reduced maximum output.

Honestly, I think I may become addicted to the M3 S55 when I attend the upcoming UDE event.

[Mike@N54Tuning.com]

Originally Posted by weehe126

That's is a good question and I think you are right. The way you can check this is to log map 4 as it is map 0 but with canbus logging. If you get more than 8 psi your PPK is still good in map 0.

The JB4 will run stock boost levels on map0 and map4. So if you are flashed you will be running the flash boost.

Mike

[mike@x-ph.com]

Originally Posted by Mike@N54Tuning.com

The JB4 will run stock boost levels on map0 and map4. So if you are flashed you will be running the flash boost.

Mike

+1

[jwzimm]

Originally Posted by Mike@N54Tuning.com

The JB4 will run stock boost levels on map0 and map4. So if you are flashed you will be running the flash boost.

Mike

Okay, so to confirm, in Map 0 or Map 4 the JB4 will take whatever the DME commands for boost and pass it through to the control solenoid. That is good. Thanks for checking.

[mike@x-ph.com]

Originally Posted by jwzimm

Okay, so to confirm, in Map 0 or Map 4 the JB4 will take whatever the DME commands for boost and pass it through to the control solenoid. That is good. Thanks for checking.

Correct

[Mike@N54Tuning.com]

Originally Posted by jwzimm

Okay, so to confirm, in Map 0 or Map 4 the JB4 will take whatever the DME commands for boost and pass it through to the control solenoid. That is good. Thanks for checking.

yuppers

Mike

[jgoens]

Originally Posted by jwzimm

I think mine is going to stay off. It always felt....nervous...with the JB4 on. Like it was straining at the leash all the time. It made me kind of uncomfortable driving it. With it back to OEM it feels much more predictable. The only drawback is the reduced maximum output.

Honestly, I think I may become addicted to the M3 S55 when I attend the upcoming UDE event.

So, what are you going to do, sell the JB4? I get the nervous thing, like the car can be a bit jumpy, but the acceleration is definitely improved. Especially with some e85, the car sometimes feels like it's ready to take off on its own.

[jwzimm]

Probably. I am honestly toying with the idea of de-modding and selling to trade up to a 2015 M3.