[spxxx]

I figured I'd lay out the basics and hopefully this will get stickied for anyone looking to begin tuning their N54.

You have 3 options when it comes to tuning your car:

1. Flash ONLY (Cobb, MHD, etc) - a new file (bin) is written over your car's stock DME which controls boost, fueling, ignition advance, EVERYTHING is controlled by this flash file. Any changes to your boost levels (wgdc/PID), fueling used, etc will require you to re flash your car with a new map. Cost: MHD: ~$250 with all cables and modules + a map / Cobb: $500?

2. Piggyback ONLY (JB4, Procede, etc) - The stock flash is kept on the car and the piggyback intercepts signals from the DME such as AFR, Ignition, boost, etc and manipulates these signals (lies to the Dme) to increase boost, modify AFR (slightly) adjust ignition (slightly) but at the end of the day, the DME still contains the stock table values intended for use with pump gas at boost levels of 8psi. Used JB4: $400ish

3. Piggyback Stacked (ex. JB4 w/ a Backend Flash by MHD, BB flash or Cobb) - In this situation the Piggyback is basically acting as a very advanced electronic boost controller, meth controller, and safety net. This is basically the same as running MHD/cobb except the JB4 is controlling your boost. You flash a map using MHD, Cobb, BB flash onto the DME which will then control the AFR, fueling, ignition advance, vanos, etc and the JB4 controls the wastegates that in turn control boost. In this setup, your DME sees true boost (load) levels, you can accurately define the AFR, fuel scalar and ignition advance for your fuel's Octane level and desired power levels. Piggyback: $400 + MHD: $250ish

PLEASE READ THIS BEFORE STARTING A NEW THREAD TITLED "WHICH TUNE IS BEST FOR MY NEW 2007 E92 335i" LOL - hope this helps...

[_ink]

Good explanation as these questions continually pop up.

I would take it a step further and describe the JB4/Flash combo for the following (FAQ) topics:

-When you say the JB4 is an advanced boost controller, why/how?
- If the JB4 is controlling boost, how does the DME see true attributes?
- Load Targets, what are the differences/benefits in your above 3 categories?

There will probably be more FAQ points, but great start!

[BQTuning]

Originally Posted by spxxx

3. Piggyback Stacked (ex. JB4 w/ a Backend Flash by MHD, BB flash or Cobb) - In this situation the Piggyback is basically acting as a very advanced electronic boost controller, meth controller, and safety net. This is basically the same as running MHD/cobb except the JB4 is controlling your boost. You flash a map using MHD, Cobb, BB flash onto the DME which will then control the AFR, fueling, ignition advance, vanos, etc and the JB4 controls the wastegates that in turn control boost. In this setup, your DME sees true boost levels, you can accurately define the AFR, fuel scalar and ignition advance for your fuel's Octane level and desired power levels. Piggyback: $400 + MHD: $250ish

This......Perhaps I haven't been keeping up much as I should about the development of the JB4 but as far as I am aware of the DME never sees true boost when the JB4 is controlling boost. The DME sees significantly lower boost than actual boost that ONLY the JB4 is able see so it (the JB4) can maintain controlling boost properly

Here is an example, the DME limit of seeing boost is 22.6 PSI, but the JB4 is controlling and produces boost levels wayyy above this. It doesnt matter what TMAP sensor you have installed the DME will not see more than 22.6 PSI

You might want to follow up with Terry on this cause I dont this its correct

[spxxx]

Originally Posted by BuraQ

This......Perhaps I haven't been keeping up much as I should about the development of the JB4 but as far as I am aware of the DME never sees true boost when the JB4 is controlling boost. The DME sees significantly lower boost than actual boost that ONLY the JB4 is able see so it (the JB4) can maintain controlling boost properly

Here is an example, the DME limit of seeing boost is 22.6 PSI, but the JB4 is controlling and produces boost levels wayyy above this. It doesnt matter what TMAP sensor you have installed the DME will not see more than 22.6 PSI

You might want to follow up with Terry on this cause I dont this its correct

With settings 4-2 the DME will see true boost up to a certain threshold, will reach out to Terry and get a more definitive answer. Everyone, please add info and I'll update the first post but I mostly wanted to post info for total noobs, not people trying to find tube their stacked setup.

True load (which the jb4 does report to the DME) is a more important measure anyways @buraq for tuning purposes.

Thanks!