[mgc9991]

I was looking at flash tunes like bootmod3 and MHD at first, but realized that they mess with the ECU and leave a permanent trace for dealers to see. So I am now looking at a chip like RaceChip or maybe JB4.

1. Does RaceChip leave behind a permanent trace on the ECU like flashes?

2. They say they can make 350hp for the base chip (435i xDrive), can anyone confirm this?

[n55david]

They can still tell by the ecu logging peak numbers.. so just get bootmod3 or mhd.. it wont matter

[ronanz]

Originally Posted by Phantom10R

They can still tell bye the ecu logging peak numbers.. so just get bootmod3 or mhd.. it wont matter

This ^^

ALL data are stored on DME/TCM (boost, over-boost, rpm, fuel pressure, timing, AFR, TQ...)

.

[mike@x-ph.com]

Originally Posted by mportd.f32

I was looking at flash tunes like bootmod3 and MHD at first, but realized that they mess with the ECU and leave a permanent trace for dealers to see. So I am now looking at a chip like RaceChip or maybe JB4.

1. Does RaceChip leave behind a permanent trace on the ECU like flashes?

2. They say they can make 350hp for the base chip (435i xDrive), can anyone confirm this?

1- JB4 and Racehips are easier to hide. A simple dealership check cannot tell the car had a piggyback. That being said, if for whatever reason they decide to dig deeper (highly unlikely), they can tell that some parameters are off and can blame it on tuning.

2- Sounds reasonable. I recommend the Jb4, its the best piggyback on the market

[Fuel-It!]

Most good piggybacks won't leave a trace behind!

https://www.burgertuning.com/pages/faq

[Munchi435i]

Originally Posted by Fuel-It!

Most good piggybacks won't leave a trace behind!

https://www.burgertuning.com/pages/faq

Any parameters outside OEM spec will be recorded by the DME so yes even a piggyback will leave a trace of modification.

[Fuel-It!]

Originally Posted by Munchi435i

Any parameters outside OEM spec will be recorded by the DME so yes even a piggyback will leave a trace of modification.

That's why it's important the piggyback is well designed as keep all logged parameters within factory specification. It needs to be that way for them to work properly anyway.

[Munchi435i]

Originally Posted by Fuel-It!

That's why it's important the piggyback is well designed as keep all logged parameters within factory specification. It needs to be that way for them to work properly anyway.

So your saying that although a piggyback will increase boost and other parameters, it will show no increases to the DME?

[Fuel-It!]

Originally Posted by Munchi435i

So your saying that although a piggyback will increase boost and other parameters, it will show no increases to the DME?

Yes that is how they have to be designed to work. If the DME knows it's making more power or boost than factory it goes in to limp mode.

[thejeremyman9]

Originally Posted by Munchi435i

So your saying that although a piggyback will increase boost and other parameters, it will show no increases to the DME?

Yeah, that's basically how the piggybacks works. For example on the super basic JB+, it just adds "X" lbs of boost over stock by intercepting the signal and telling the DME it is running less boost than it actually is, so it increases boost to compensate. When the DME thinks it is running Y lbs, there is actually X+Y. Not ideal because the DME has to rely on its closed loop control to compensate for the extra boost (since it doesnt know how much it is actually running).

JB4 is the same idea but more sophisticated in the sense that it is controlling other engine parameters to make up for the extra boost, but the concept of tricking the DME so that the DME thinks everything is within the stock tune parameters is the same.

[Munchi435i]

Originally Posted by thejeremyman9

Yeah, that's basically how the piggybacks works. For example on the super basic JB+, it just adds "X" lbs of boost over stock by intercepting the signal and telling the DME it is running less boost than it actually is, so it increases boost to compensate. When the DME thinks it is running Y lbs, there is actually X+Y. Not ideal because the DME has to rely on its closed loop control to compensate for the extra boost (since it doesnt know how much it is actually running).

JB4 is the same idea but more sophisticated in the sense that it is controlling other engine parameters to make up for the extra boost, but the concept of tricking the DME so that the DME thinks everything is within the stock tune parameters is the same.

Now that makes more sense than just the blanket statement I was given.

[mgc9991]

Thanks for all the help. So do you think RaceChip would be a good option? JB4 is more for bolt ons and I don't really plan on doing any bolt ons.

[n55david]

Any map pressures over the stock range will be logged in the DME, if they really want to know they will. There was a guy here who had a JB4 on his car and the dealer knew based on the saved data in the DME but they let him slide.

[Fuel-It!]

Originally Posted by mportd.f32

Thanks for all the help. So do you think RaceChip would be a good option? JB4 is more for bolt ons and I don't really plan on doing any bolt ons.

I don't suggest RaceChip at all, do the JB+ if you want really simple and inexpensive or JB4. The JB4 is just so much better even for factory cars and not much more expensive most people go right to that. It also has a lot better resale value than any of the other options down the road so actually winds up being cheaper in the long run.

[Fuel-It!]

Originally Posted by Phantom10R

Any map pressures over the stock range will be logged in the DME, if they really want to know they will. There was a guy here who had a JB4 on his car and the dealer knew based on the saved data in the DME but they let him slide.

Hate to repeat myself the but the DME only ever sees FACTORY boost pressures with a JB4 or other properly designed system. Dealer was either pulling his chain or saw scratch marks on the factory connectors and was guessing he tuned it.