[Jasinedward]

Morning!

I've recently decided to tune my 2024 M4 Comp Xdrive. I was planning on going with Paul. Since I'm doing this myself I have a few questions in regards to my process. I will be modding in stages.

1. Flexfuel sensor and tune.

2. Catless downpipe and xhp tune

3. Midpipe and the rest of the exhaust

4. Port Injection and Turbo upgrade

So for my first stage, I believe I will need the following:

-BM3 License
-Femto unlock
-Custom tune
-flexfuel sensor

Is there anything I am missing for this stage? I was planning on getting the BM3 flexfuel sensor to install at the fuel hat location. Is that the best option? There seems to be a few different flexfuel sensors to order.... how to I know I'm selecting the right one?

Thanks in advance!

[hotsauce_bukkake]

Originally Posted by Jasinedward

Morning!

I've recently decided to tune my 2024 M4 Comp Xdrive. I was planning on going with Paul. Since I'm doing this myself I have a few questions in regards to my process. I will be modding in stages.

1. Flexfuel sensor and tune.

2. Catless downpipe and xhp tune

3. Midpipe and the rest of the exhaust

4. Port Injection and Turbo upgrade

So for my first stage, I believe I will need the following:

-BM3 License
-Femto unlock
-Custom tune
-flexfuel sensor

Is there anything I am missing for this stage? I was planning on getting the BM3 flexfuel sensor to install at the fuel hat location. Is that the best option? There seems to be a few different flexfuel sensors to order.... how to I know I'm selecting the right one?

Thanks in advance!

Personally, I would include the downpipes and xhp tune in the first mod list as well. As for the fuel hat location for the flex fuel-- I went with the engine mount location for a couple of reasons:

1. You'll get a more accurate reading as it's reading the fuel closer to the HPFP supplying fuel to the injectors.

2. Engine bay mount ensures compatibility should you ever decide to upgrade the oem LPFP.

3. I didn't want to risk getting fuel smell inside the cabin of the car when disconnecting the fuel lines.

[Jasinedward]

I've had some quotes from some shops as well.... digging a bit deeper it seems like most don't offer custom tunes and rely on the canned tunes from the BM3 software.... How much of a different will a custom tune be from a canned BM3 tune with minimal mods?

[Schulminator]

Custom tune will be considerably more whp than canned BM3 tune. I estimate 60++ whp

[hotsauce_bukkake]

Originally Posted by Jasinedward

I've had some quotes from some shops as well.... digging a bit deeper it seems like most don't offer custom tunes and rely on the canned tunes from the BM3 software.... How much of a different will a custom tune be from a canned BM3 tune with minimal mods?

There are plenty of custom tuners writing custom tunes on BM3. Inside the app is a full list custom tuners for the platform. Custom tunes tend to run much cooler than the OTS maps as well. On ethanol, the stage 2 OTS map has gotten me over 600whp. I haven’t dyno’d it, but my clutch started slipping on that map so that’s what I’ve estimated ��

[Hendo741]

Originally Posted by hotsauce_bukkake

Personally, I would include the downpipes and xhp tune in the first mod list as well.

+1 for this. If you're going to pay for a custom tune, get the tune with DP installed. After that add PI when you do turbo upgrade and get retuned. Paying for tunes after every upgrade would be a waste of money imo.

[Matt@Evolve]

Originally Posted by Jasinedward

Morning!

I've recently decided to tune my 2024 M4 Comp Xdrive. I was planning on going with Paul. Since I'm doing this myself I have a few questions in regards to my process. I will be modding in stages.

1. Flexfuel sensor and tune.

2. Catless downpipe and xhp tune

3. Midpipe and the rest of the exhaust

4. Port Injection and Turbo upgrade

So for my first stage, I believe I will need the following:

-BM3 License
-Femto unlock
-Custom tune
-flexfuel sensor

Is there anything I am missing for this stage? I was planning on getting the BM3 flexfuel sensor to install at the fuel hat location. Is that the best option? There seems to be a few different flexfuel sensors to order.... how to I know I'm selecting the right one?

Thanks in advance!

This is quite similar to what we've done on our own G82 M4. Drop me a DM we can get you setup with parts and custom tuning

[mike@x-ph.com]

I'd wait on the custom tune, get all the parts first, and then do the custom tune.

Start with Femto, bm3, and bm3 flex fuel kit, get the basic modes, then turbo, then port injection, and lastly the custom map.

[Jasinedward]

Originally Posted by mike@x-ph.com

I'd wait on the custom tune, get all the parts first, and then do the custom tune.

Start with Femto, bm3, and bm3 flex fuel kit, get the basic modes, then turbo, then port injection, and lastly the custom map.

That’s what my plan was originally, but Paul Johnson tuning said they would make adjustments when I add the downpipe. It’ll be a while before I do port injection and turbos so I’ll be more than happy to buy a new tune when that stage happens.

[Abacus38]

Originally Posted by Jasinedward

Morning!

I've recently decided to tune my 2024 M4 Comp Xdrive. I was planning on going with Paul. Since I'm doing this myself I have a few questions in regards to my process. I will be modding in stages.

1. Flexfuel sensor and tune.

2. Catless downpipe and xhp tune

3. Midpipe and the rest of the exhaust

4. Port Injection and Turbo upgrade

So for my first stage, I believe I will need the following:

-BM3 License
-Femto unlock
-Custom tune
-flexfuel sensor

Is there anything I am missing for this stage? I was planning on getting the BM3 flexfuel sensor to install at the fuel hat location. Is that the best option? There seems to be a few different flexfuel sensors to order.... how to I know I'm selecting the right one?

Thanks in advance!

Bang for buck path for 9s pass 140mph+/ 5s 60-130mph
Fenmto unlock plus BM3 custom rom $1700
BM3 Flex sensor $599
BMC Drop Ins $125
Mad or Arm Catless downpipes $400
XHP Stage 3 $462
Custom tune $1000

Total 3,286 + labor

Labor for downpipes is about $600-700

Do the unlock first and install BM3. Then install all the part and get the custom tune.

[Mapper]

Originally Posted by hotsauce_bukkake

Personally, I would include the downpipes and xhp tune in the first mod list as well. As for the fuel hat location for the flex fuel-- I went with the engine mount location for a couple of reasons:

1. You'll get a more accurate reading as it's reading the fuel closer to the HPFP supplying fuel to the injectors.

I am trying to scenario play the idea you suggest. Yes, lets say you ran zero Ethanol - then hit up an E85 station and filled the tank... the sensor would start to show the E % which would differ from what is in the lines between the pump and the HPFP/Fuel Rails.
But how long until that fuel is circulated back to tank (returned) or used in the injectors - at which point (lets scenario play) if you had two sensors (one at LPFP Hat and one at HPFP) the readings would be the same before you even left the fueling station parking lot. I have a hard time believing this would matter. The other points are still valid, but is this particular reason even a concern?

[markoz28]

Originally Posted by Mapper

I am trying to scenario play the idea you suggest. Yes, lets say you ran zero Ethanol - then hit up an E85 station and filled the tank... the sensor would start to show the E % which would differ from what is in the lines between the pump and the HPFP/Fuel Rails.
But how long until that fuel is circulated back to tank (returned) or used in the injectors - at which point (lets scenario play) if you had two sensors (one at LPFP Hat and one at HPFP) the readings would be the same before you even left the fueling station parking lot. I have a hard time believing this would matter. The other points are still valid, but is this particular reason even a concern?

I would not rely 100% on the sensor reading right after fueling. I would allow for a couple of miles to have the fuel slosh and mix. For instance, when I fill up my sensor will read 44% and after a while bounce up to 50% and start to slowly drop to 48, 46, then 44 and sometimes 42. This is because the E and 93 are still mixing. After a couple of miles the percentage stays steady. At that point you can let her rip.

[hotsauce_bukkake]

Originally Posted by Mapper

I am trying to scenario play the idea you suggest. Yes, lets say you ran zero Ethanol - then hit up an E85 station and filled the tank... the sensor would start to show the E % which would differ from what is in the lines between the pump and the HPFP/Fuel Rails.
But how long until that fuel is circulated back to tank (returned) or used in the injectors - at which point (lets scenario play) if you had two sensors (one at LPFP Hat and one at HPFP) the readings would be the same before you even left the fueling station parking lot. I have a hard time believing this would matter. The other points are still valid, but is this particular reason even a concern?

I'm having a hard time tracking the point you're trying to make. In the "scenario" you suggest you're bringing in a second sensor to make your point, which is moot. Even if the placement of the sensor only makes the tiniest difference, it only makes sense the most accurate fuel reading will be as close to the injectors as possible. Even in the scenario you suggest, your sensor is not updated before you leave the parking lot. You have to drive a bit before the reading is accurate anyway.

At this point I'm kind of rambling because your message wasn't exactly clear. Sure, the accuracy difference is minimal, but I want my sensor to be reading fuel as close to combustion as possible. Of course, this is assuming you're not running a flex map.

[Mapper]

Originally Posted by markoz28

I would not rely 100% on the sensor reading right after fueling. I would allow for a couple of miles to have the fuel slosh and mix. For instance, when I fill up my sensor will read 44% and after a while bounce up to 50% and start to slowly drop to 48, 46, then 44 and sometimes 42. This is because the E and 93 are still mixing. After a couple of miles the percentage stays steady. At that point you can let her rip.

You are describing something separate to what I am inquiring about.
This is not talking about the fuel mixing in the tank. There is no sensor there. I am talking about the feed fuel line from the LPFP to the hpfp in which there is an option choose a sensor location of either on the output of the lpfp or in engine bay. The comment was made and a reason for placing up front in engine bay was to 'provide more accurate' reading. Does it? (is my question)

Which mounting would provide the best accuracy reading to tell the ECU what fuel is being burned?

[Mapper]

Originally Posted by hotsauce_bukkake

I'm having a hard time tracking the point you're trying to make. In the "scenario" you suggest you're bringing in a second sensor to make your point, which is moot. Even if the placement of the sensor only makes the tiniest difference, it only makes sense the most accurate fuel reading will be as close to the injectors as possible. Even in the scenario you suggest, your sensor is not updated before you leave the parking lot. You have to drive a bit before the reading is accurate anyway.

At this point I'm kind of rambling because your message wasn't exactly clear. Sure, the accuracy difference is minimal, but I want my sensor to be reading fuel as close to combustion as possible. Of course, this is assuming you're not running a flex map.

Sorry my question isn't clear. After re-reading I would agree.