[TopG42]

I have had my racechip black on for a while now. Recently did a warranty claim for my idrive system because it was not responding to my app and since it was not engine related there was no issue. However I brought that story up to my friend and he warned me that the race chip causes engine knocking (I haven't really heard knocking though). Can anyone confirm that racechip could cause this? I always thought it only increased boost pressure and that anything with the engine was left as is. Plz educate me thanks

[Rdurty2]

Sure the possibility is always there but it can also happen when stock.

Bad tank of gas can cause it.

Running too high of a setting on the race chip can cause it.

[TopG42]

Originally Posted by Rdurty2

Sure the possibility is always there but it can also happen when stock.

Bad tank of gas can cause it.

Running too high of a setting on the race chip can cause it.

Thanks for the answer! But you could explain to me why the extra boost could lead to that? I run strictly 93 from Shell

[PNTDG42]

Originally Posted by TopG42

Thanks for the answer! But you could explain to me why the extra boost could lead to that? I run strictly 93 from Shell

I am not a BMW tuner but I can give a basic/vague run down.

Increasing the boost is to increase the airflow into the engine. Greater airflow needs additional fuel injected to meet the target air/fuel ratio. Additional timing retard can also be required as airflow/load increases.

Your engine control determines how much fuel to inject and when to fire the ignition by comparing data it receives from several sensors and referencing tables and algorithms that the software and calibration engineers have put in place.

These piggyback devices accomplish an increase in boost by hijacking some of these sensors to "fool" the engine control into adding more boost or by directly hijacking the wastegate itself. To determine how it is working you really only need to pay attention to where the wiring harness is interfacing.

When you manipulate additional boost like this, the engine control system is not aware of the increased boost, therefore it will not be properly referencing its targets or tables. The ignition and fuel injection will initially be operating as if you were still at the lower boost.

There are feedback compensations in place that will immediately do their best to correct for it. There are short and long term trim tables used to "remember" what amount of compensation was needed to reach the targets. Short term trims can start filling in immediately and then it basically starts to spill over into the long term trims when its clear that the compensation is required indefinitely. These trim tables ween you off from depending on feedback compensation as heavily, since the feedback is really intended to clean up and smooth everything out, and not so much intended to be the primary tuning strategy.

All that said, there are maximums and limits. How much fuel your stock fuel system can supply, limits to the compensations and trims, limits to how much heat your intercooler can shed, etc.

The piggyback system is allowing you to circumvent your first line of defense; overboost protection. With that out of the way, you are allowed easy access to finding the limits of all sorts of things. When you are running any systems close to its limits, you can find that the smallest change in environmental conditions or fuel quality etc can make or break what you are able to get away with.

Id recommend that you gain the capability to datalog and then you will be able to watch all these parameters and become familiar with what is normal and expected in your car, and compare with others, or possibly pay a BMW tuner to analyze your logs and let you know if your safe or playing with fire.

[TopG42]

Originally Posted by PNTDG42

I am not a BMW tuner but I can give a basic/vague run down.

Increasing the boost is to increase the airflow into the engine. Greater airflow needs additional fuel injected to meet the target air/fuel ratio. Additional timing retard can also be required as airflow/load increases.

Your engine control determines how much fuel to inject and when to fire the ignition by comparing data it receives from several sensors and referencing tables and algorithms that the software and calibration engineers have put in place.

These piggyback devices accomplish an increase in boost by hijacking some of these sensors to "fool" the engine control into adding more boost or by directly hijacking the wastegate itself. To determine how it is working you really only need to pay attention to where the wiring harness is interfacing.

When you manipulate additional boost like this, the engine control system is not aware of the increased boost, therefore it will not be properly referencing its targets or tables. The ignition and fuel injection will initially be operating as if you were still at the lower boost.

There are feedback compensations in place that will immediately do their best to correct for it. There are short and long term trim tables used to "remember" what amount of compensation was needed to reach the targets. Short term trims can start filling in immediately and then it basically starts to spill over into the long term trims when its clear that the compensation is required indefinitely. These trim tables ween you off from depending on feedback compensation as [...]

Thanks for that information! I initially bought it because I thought this was a set it and forget it type of mod but I should have done more research. Forgetting it in this situation might lead to issues, which I don't think the extra 20-30hp is worth. Just wish femto wasn't the only option for dme unlocks.

[PNTDG42]

Originally Posted by TopG42

Thanks for that information! I initially bought it because I thought this was a set it and forget it type of mod but I should have done more research. Forgetting it in this situation might lead to issues, which I don't think the extra 20-30hp is worth. Just wish femto wasn't the only option for dme unlocks.

If you aren’t going to use it in higher settings and really push it, it’s probably just fine. If you only use it for 20-30hp your logs are probably clean. There’s generally a decent amount of headroom built in to a factory turbocharged car

[mike@x-ph.com]

We might be complicating this more than we need to.

Can a tuner cause knocking? sure if its too aggressive for the mods and fuel

Does racechip cause knocking? no


if you use 91 octanes you can run up to map 5 with no issues
with 93 you can run map 6 or 7 although i recommend using E85 for map 7

Even if you run map 7 or 91 octane, the DME will lower the timing ignition. If it's too aggressive to protect your engine, you will lose some power, but it won't get to engine knocking.

[TopG42]

Originally Posted by mike@x-ph.com

We might be complicating this more than we need to.

Can a tuner cause knocking? sure if its too aggressive for the mods and fuel

Does racechip cause knocking? no


if you use 91 octanes you can run up to map 5 with no issues
with 93 you can run map 6 or 7 although i recommend using E85 for map 7

Even if you run map 7 or 91 octane, the DME will lower the timing ignition. If it's too aggressive to protect your engine, you will lose some power, but it won't get to engine knocking.

Hey Mike! Glad you responded. I wanted to know your input on racechip vs a dme unlock and a mhd or bm3 stage 2? Current mods on rn are my active autowerk downpipe and milltek exhaust. I am at the point where I do not care about warranty I just want more power. If its not even worth modding/tuning further I would rather just go m2 or rs3 but I went b58 because of the potential but I am itching for more more.

Edit: For running map 7 with e85 can I just mix it myself to achieve e30 or e50? Or do I need a flex fuel kit

[mike@x-ph.com]

Originally Posted by TopG42

Hey Mike! Glad you responded. I wanted to know your input on racechip vs a dme unlock and a mhd or bm3 stage 2? Current mods on rn are my active autowerk downpipe and milltek exhaust. I am at the point where I do not care about warranty I just want more power. If its not even worth modding/tuning further I would rather just go m2 or rs3 but I went b58 because of the potential but I am itching for more more.

Edit: For running map 7 with e85 can I just mix it myself to achieve e30 or e50? Or do I need a flex fuel kit

bm3 is the top choice

If you dont mind sending your DME to Finland, this should be a no-brainer.

If sending the DME is an issue, and you are only looking for a little power increase, the Racechip is an excellent option