[DOCTOR.Y]

Hi guys,

Anyone can answer my concern?

I have read from many sources saying that JB4 plays with sensors and remap boost, fuel and timing etc. However, since it only requires a simple installation without a "hit and try" style tuning, I don`t understand how can those pre-written maps work perfectly with each car`s condition?

[Rob_BMW_PNW]

Off the shelf maps were made as a one size fits all, it will work for a majority a huge majority of cars.
JB4 sucks anyways, you said it yourself it plays with sensors, hijacks the signal and tricks it
Base/OTS maps have been in the community forever

[JETmn]

That is exactly how the JB4 works, it changes the signals to the ECU that the sensors are providing. Now that isn't really a bad thing. The JB4 has been proven to work well for years. It changes the boost signal to give you the extra boost pressure and with flex fuel wires it can also up your fuel pressure. The on the fly changes to maps and easy adaptation to ethanol mixes are great too. MHD is right around the corner and that is what the Cobb should have been, but they gave us the shaft.

The JB4 maps that are stock are on the conservative side, the map 5 can do some learning of the boost curve based on knock on your car. It works pretty well. If you just want a modest boost in power that is easy to obtain, the JB4 is a great way to go.

[DOCTOR.Y]

I just want a moderate upgrade of power, say at JB4 map1 level (380hp crankcase according to official announcement) because car doesn`t equip other supporting mods.

JB4`s maps are pre-written and therefore it is "one size fits all", this makes me feel worried about the compatibility and engine wear.

[mike@x-ph.com]

Originally Posted by Eric_Y

I just want a moderate upgrade of power, say at JB4 map1 level (380hp crankcase according to official announcement) because car doesn`t equip other supporting mods.

JB4`s maps are pre-written and therefore it is "one size fits all", this makes me feel worried about the compatibility and engine wear.

I think you misunderstood the one size fits all statement.

It means the Jb4 will work on any car with any mods and any fuel. Not the same map though.

Map 1 is for stock cars
map2 is for cars with catless downpipes
etc...

Thousands of users have been running these maps for year without any problems, they are proven to be safe and you can make sure yourself by datalogging your car.

If you want to stay on the safe side, just run map 1 at all times.

[DOCTOR.Y]

Originally Posted by mike@x-ph.com

I think you misunderstood the one size fits all statement.

It means the Jb4 will work on any car with any mods and any fuel. Not the same map though.

Map 1 is for stock cars
map2 is for cars with catless downpipes
etc...

Thousands of users have been running these maps for year without any problems, they are proven to be safe and you can make sure yourself by datalogging your car.

If you want to stay on the safe side, just run map 1 at all times.

Hi Mike,

Let me explain my concern in another way:

There are two stock 335i which have exactly same configuration. However the ownership history of car A is different from car B and therefore the (mechanical) conditions of two cars should somehow behave differently. Now if both cars install JB4 and run same map (say map1), they must react differently to the same map.

If all stock cars can run same map regardless of its mechanical condition, then when it comes to ECU flash, why do people have to remap each car according to its own log, rather than simply load a 'pre-written map' to every car (like JB4 style). From here I drew a conclusion that each car needs a customised tune. I`m new to tuning world, but that logic should make some sense.

[Mike@N54Tuning.com]

Originally Posted by Eric_Y

Hi Mike,

Let me explain my concern in another way:

There are two stock 335i which have exactly same configuration. However the ownership history of car A is different from car B and therefore the (mechanical) conditions of two cars should somehow behave differently. Now if both cars install JB4 and run same map (say map1), they must react differently to the same map.

If all stock cars can run same map regardless of its mechanical condition, then when it comes to ECU flash, why do people have to remap each car according to its own log, rather than simply load a 'pre-written map' to every car (like JB4 style). From here I drew a conclusion that each car needs a customised tune. I`m new to tuning world, but that logic should make some sense.

The JB4 is not your typical piggyback system. It connects to the CANbus system and reads in tons of vehicle data. AFR, timing, fuel trims, wastegate dutycycle, intake temps, oil temps, etc, etc, and it self tunes itself your specific vehicles condition. That's why custom tuning is not needed with the JB4.

Mike

[mike@x-ph.com]

Originally Posted by Eric_Y

Hi Mike,

Let me explain my concern in another way:

There are two stock 335i which have exactly same configuration. However the ownership history of car A is different from car B and therefore the (mechanical) conditions of two cars should somehow behave differently. Now if both cars install JB4 and run same map (say map1), they must react differently to the same map.

If all stock cars can run same map regardless of its mechanical condition, then when it comes to ECU flash, why do people have to remap each car according to its own log, rather than simply load a 'pre-written map' to every car (like JB4 style). From here I drew a conclusion that each car needs a customised tune. I`m new to tuning world, but that logic should make some sense.

Jb4 has access to the Canbus, it monitors timing, boost, AFR, fuel,etc... If your car is not handling the extra power well, JB4 will go back to stock map and let you know what needs to be changed in order to handle the extra power

[DOCTOR.Y]

Much more clear now

[JETmn]

Originally Posted by Eric_Y

Hi Mike,

Let me explain my concern in another way:

There are two stock 335i which have exactly same configuration. However the ownership history of car A is different from car B and therefore the (mechanical) conditions of two cars should somehow behave differently. Now if both cars install JB4 and run same map (say map1), they must react differently to the same map.

If all stock cars can run same map regardless of its mechanical condition, then when it comes to ECU flash, why do people have to remap each car according to its own log, rather than simply load a 'pre-written map' to every car (like JB4 style). From here I drew a conclusion that each car needs a customised tune. I`m new to tuning world, but that logic should make some sense.

To add a little more, map 1 and map 2 are pretty safe maps that all cars should be able to run with the correct mods and fuel that is listed. Where you usually see the custom maps is guys getting more aggressive than those maps, so they are using custom maps to try and get some more power out of it knowing they are getting close to the edge of what is safe. That is why they need to run logs more often to make sure they are getting in to unsafe territory.

[DOCTOR.Y]

Originally Posted by JETmn

To add a little more, map 1 and map 2 are pretty safe maps that all cars should be able to run with the correct mods and fuel that is listed. Where you usually see the custom maps is guys getting more aggressive than those maps, so they are using custom maps to try and get some more power out of it knowing they are getting close to the edge of what is safe. That is why they need to run logs more often to make sure they are getting in to unsafe territory.

Ok, so a custom map is only needed when pushing car to the edge of safety, nothing to do with the smoothness of the power delivery?

[Dhillon92]

I think you misunderstand the term maps regarding the jb4, these maps are only referring to control adjustments on the jb4, they arent actual maps that are flashed to the ecu.

A "custom map" is usually a full flash(no jb4) or a backend flash (which is a flash that works WITH a jb4) to adjust specific things that a jb4 cant via its hijacking and CANbus controls.

A custom flash isnt only needed when pushing the car to "edge of safety," some may argue a full flash is safer than a piggyback, but thats a whole different discussion.

From my experience, the only things that jb4 maps change, are target boost, the algorhythms for rest of the values are pretty much the same in all the maps (excluding 3, cause meth control).

Unless ofcourse youre referring to map 6, which is just another "map" where you input the target boost manually. This is only beneficial to aftermarket turbos, because all the other maps taper boost target in the higher rpms where the stock turbo isnt capable.

Hope this helps, like Mike said, the jb4 uses all the values it can read to optimize the chosen map for your vehicle, which in a sense means it is custom for your mods and configuration.

[MHD Tuning]

Originally Posted by Eric_Y

I just want a moderate upgrade of power, say at JB4 map1 level (380hp crankcase according to official announcement) because car doesn`t equip other supporting mods.

JB4`s maps are pre-written and therefore it is "one size fits all", this makes me feel worried about the compatibility and engine wear.

380 crank HP would be nowhere near a safe moderate tune on a stock E series N55. It's actually about the max effort for stock turbo and requires 93aki fuel at least if not more. Part of this optimistic power level is also due to running quite lean, which is fine on 300-320hp but not for a 380hp tune based on increasing only the boost.