Hello guys,
It has been two years since I purchased my Z4 M Roadster so I thought it was time to renew our relationship by changing some things. Here are some things I would like to share them with you.
After a lot of research on the forum here and the zpost, I have seen all the possible modifications the car can have and decided to go slowly on the following list:
1) OEM New rod bearings.
Since I am the second owner and I wanted to have piece of mind, so I decided to change them at around 89.000 km.
Pros: Piece of mind - Priceless
Cons: None.
2) Bmw Stubby antenna.
I never could imagine that a so small piece could make such a beautiful difference.
Pros: The car looks better.
Cons: I think while driving in not urban areas it is more difficult to find good reception but nothing tragic.
3) Vibra Techniques engine mounts.
I selected the street version since I have read many good comments about them, so I thought they are the best solution for our car. To be honest the car feels more robust after installing them, but if I had the opportunity I would go to stock again, since the have small vibrations when the car starting and at gear change. Nothing loud but you can notice it.
While changing them I discovered that it was a good move since one of the OEM engine mounts have been cracked seriously.
Pros: Car I think feels more robust.
Cons: Vibration sound due to the metal nature of them.
Old One:
Vibra Mounts:
4) Clutch Stop .
Makes the shifting sorter and you can have more aggressive shifting.
Pros: Feels better the shifting.
Cons: My mechanic told me that maybe it will make the clutch to fail faster, but I do not feel something that could lead that way.
5) RPi skid pads.
The Rpi skid pads have been bought an a group buy through zpost. I hated haring my bumper making scratches on our crappy roads.
Pros: On a big hit the bumper will not brake easily
Cons: The skid pad doesn't cover exactly the front of the bumper so you will still get some scratches on the face of the bumper.
6) CSL Style Airbox from Karbonius.
I wanted something that would make the sound of this beatiful engine a little bit louder. However since I travel often with my car I didn't want something that would make a long trip undoable due of the loud sound. With CSL Airbox I think I made the right choice. The car has the same stock sound when you want, but if you kick the pedal then a monster comes out of it. Now about the sound of the Airbox I have heard good and bad things from different people. Personally for me it is perfect and I wish I could have the same sound with a SC kit as I think the SC as a future change.
The Karbonius airbox for me the way it is fabricated it is perfect. I am not a Carbon Fiber Specialist but also the my mechanic who owns a OE CSL airbox told me that it is the best quality non OE airbox he has seen.
Pros: Sound, sound and yes sound. Power.
Cons: Cost - Alpha N tuning required.
7) Epic Motorsports Tune
Well before going this way I have talked with private messages with a lot of forum members, who I have to thank them all for their time and their help on a newbie. I would like to thank Vanne, ga41, Bedub, asirvr4 and especially Nikitas_Z4mcoupe for their help.
Randy the owner of Epic, is a very helpful guy and it was the only one who answered my questions promptly and within a timely manner. This won my trust and I decided to go this way. Other tuning companies never answered me, so I prefer my money to go to someone who cares about them. I have not regret it since the car with the Alpha N tuning and the airbox is working like a charm. It is stronger than stock. You can feel the difference right away.
I haven't noticed any problems yet. I have tried my car ever on 43.5 Celsius and it was working fine with some small heat soaks as expected.
Here are some photos:
Back up stage - The coffee is needed while waiting for an hour :
The king naked
New clothes of the king
The tuning procedure is easy to do it since you buy all the necessary parts from Epic. I have done it myself. Tbh we had some issues with the driver to install the program on the PC but after changing a laptop it worked fine. Randy can give you maps for 93,95,98,100 octane maps. I have choose the 95. In the future I think I will go for the 100 octane since he told me that there is no problem if you put 95 octane gas and you have the 100 maps. Because the procedure to back up your ECU and uploading the next file takes around 2.5 hours, be sure that you have some battery charger plug in while you doing the procedure.
Vanne has build a very detailed post about the CSL Airbox installation that it was really helpful for me.
Before the tune and the CSL airbox I took my car on a dyno. You can see the before and after results here.
Before the tune:
After the tune MAHA Dyno - power at engine:
After the tune Dynoject Dyno - power on the wheels with AFR Ratio:
It was really cool that while waiting for my dyno, some guys from the local corvette club were doing live tuning to their beasts.
Those cars were able to take 50-55 hp, only with a software tune...
After hearing my tiny car on the dyno with the Airbox they were like :bow: :drinking: .
It worths to mention the following things:
My car except those changes is completely stock with Euro Headers. After the first dyno, before the modification, my tuner told me that the car had probably another program since the logs he have seen it was not the BMW Original files. All the runs have been done with 95 octane gas. All the runs made with powen button off, except the second run on the dynojet. The runs after the tune and the airbox have been done twice, since the MAHA dyno measures the power of the motor and the dynojet on wheels and could give me also Air Fuel Ratio that the tuner needed to see to tell me why the car drops after 7200 rpm.
The guys from both dyno's have told me that this is the strongest S54 car they have seen even from guys who have headers (except the guys who have SC). Also the one guy told me that the program is really good and the mechanic told me the same.
Randy expects that the car can go above 310-320 km/h now the speed limit is removed after seeing the dyno. I haven't tested this assumption, since my car rarely seen more than 5500 rpms, but I hope some day to verify it
Tbh I thought that I could get higher numbers from the dyno's but it is what it is.
My next steps is to find a way to correct the 7200 rpm drop. Randy says this is a heat soak and is happening due luck of air in the dynos and on the street it will be ok. I think this is happening because I have not bought the CSL snorkel extension and the airbox is not having enough air. What are your thoughts?
My thought was to scan the CSL Airbox and 3D Print an extension. After to provide it to a carbon fiber company to create a replica for that. I am talking with Karbonius to build a custom made snorkel for our cars, but I am not quite sure how this conversation will end.
I apologise if I have done any mistakes, since my English is not my native language.
I would like to close with a video that gives a slight taste of the CSL Airbox:
https://youtu.be/NDoNhiNBrxo
It has been two years since I purchased my Z4 M Roadster so I thought it was time to renew our relationship by changing some things. Here are some things I would like to share them with you.
After a lot of research on the forum here and the zpost, I have seen all the possible modifications the car can have and decided to go slowly on the following list:
1) OEM New rod bearings.
Since I am the second owner and I wanted to have piece of mind, so I decided to change them at around 89.000 km.
Pros: Piece of mind - Priceless
Cons: None.
2) Bmw Stubby antenna.
I never could imagine that a so small piece could make such a beautiful difference.
Pros: The car looks better.
Cons: I think while driving in not urban areas it is more difficult to find good reception but nothing tragic.
3) Vibra Techniques engine mounts.
I selected the street version since I have read many good comments about them, so I thought they are the best solution for our car. To be honest the car feels more robust after installing them, but if I had the opportunity I would go to stock again, since the have small vibrations when the car starting and at gear change. Nothing loud but you can notice it.
While changing them I discovered that it was a good move since one of the OEM engine mounts have been cracked seriously.
Pros: Car I think feels more robust.
Cons: Vibration sound due to the metal nature of them.
Old One:
Vibra Mounts:
4) Clutch Stop .
Makes the shifting sorter and you can have more aggressive shifting.
Pros: Feels better the shifting.
Cons: My mechanic told me that maybe it will make the clutch to fail faster, but I do not feel something that could lead that way.
5) RPi skid pads.
The Rpi skid pads have been bought an a group buy through zpost. I hated haring my bumper making scratches on our crappy roads.
Pros: On a big hit the bumper will not brake easily
Cons: The skid pad doesn't cover exactly the front of the bumper so you will still get some scratches on the face of the bumper.
6) CSL Style Airbox from Karbonius.
I wanted something that would make the sound of this beatiful engine a little bit louder. However since I travel often with my car I didn't want something that would make a long trip undoable due of the loud sound. With CSL Airbox I think I made the right choice. The car has the same stock sound when you want, but if you kick the pedal then a monster comes out of it. Now about the sound of the Airbox I have heard good and bad things from different people. Personally for me it is perfect and I wish I could have the same sound with a SC kit as I think the SC as a future change.
The Karbonius airbox for me the way it is fabricated it is perfect. I am not a Carbon Fiber Specialist but also the my mechanic who owns a OE CSL airbox told me that it is the best quality non OE airbox he has seen.
Pros: Sound, sound and yes sound. Power.
Cons: Cost - Alpha N tuning required.
7) Epic Motorsports Tune
Well before going this way I have talked with private messages with a lot of forum members, who I have to thank them all for their time and their help on a newbie. I would like to thank Vanne, ga41, Bedub, asirvr4 and especially Nikitas_Z4mcoupe for their help.
Randy the owner of Epic, is a very helpful guy and it was the only one who answered my questions promptly and within a timely manner. This won my trust and I decided to go this way. Other tuning companies never answered me, so I prefer my money to go to someone who cares about them. I have not regret it since the car with the Alpha N tuning and the airbox is working like a charm. It is stronger than stock. You can feel the difference right away.
I haven't noticed any problems yet. I have tried my car ever on 43.5 Celsius and it was working fine with some small heat soaks as expected.
Here are some photos:
Back up stage - The coffee is needed while waiting for an hour :
The king naked
New clothes of the king
The tuning procedure is easy to do it since you buy all the necessary parts from Epic. I have done it myself. Tbh we had some issues with the driver to install the program on the PC but after changing a laptop it worked fine. Randy can give you maps for 93,95,98,100 octane maps. I have choose the 95. In the future I think I will go for the 100 octane since he told me that there is no problem if you put 95 octane gas and you have the 100 maps. Because the procedure to back up your ECU and uploading the next file takes around 2.5 hours, be sure that you have some battery charger plug in while you doing the procedure.
Vanne has build a very detailed post about the CSL Airbox installation that it was really helpful for me.
Before the tune and the CSL airbox I took my car on a dyno. You can see the before and after results here.
Before the tune:
After the tune MAHA Dyno - power at engine:
After the tune Dynoject Dyno - power on the wheels with AFR Ratio:
It was really cool that while waiting for my dyno, some guys from the local corvette club were doing live tuning to their beasts.
Those cars were able to take 50-55 hp, only with a software tune...
After hearing my tiny car on the dyno with the Airbox they were like :bow: :drinking: .
It worths to mention the following things:
My car except those changes is completely stock with Euro Headers. After the first dyno, before the modification, my tuner told me that the car had probably another program since the logs he have seen it was not the BMW Original files. All the runs have been done with 95 octane gas. All the runs made with powen button off, except the second run on the dynojet. The runs after the tune and the airbox have been done twice, since the MAHA dyno measures the power of the motor and the dynojet on wheels and could give me also Air Fuel Ratio that the tuner needed to see to tell me why the car drops after 7200 rpm.
The guys from both dyno's have told me that this is the strongest S54 car they have seen even from guys who have headers (except the guys who have SC). Also the one guy told me that the program is really good and the mechanic told me the same.
Randy expects that the car can go above 310-320 km/h now the speed limit is removed after seeing the dyno. I haven't tested this assumption, since my car rarely seen more than 5500 rpms, but I hope some day to verify it
Tbh I thought that I could get higher numbers from the dyno's but it is what it is.
My next steps is to find a way to correct the 7200 rpm drop. Randy says this is a heat soak and is happening due luck of air in the dynos and on the street it will be ok. I think this is happening because I have not bought the CSL snorkel extension and the airbox is not having enough air. What are your thoughts?
My thought was to scan the CSL Airbox and 3D Print an extension. After to provide it to a carbon fiber company to create a replica for that. I am talking with Karbonius to build a custom made snorkel for our cars, but I am not quite sure how this conversation will end.
I apologise if I have done any mistakes, since my English is not my native language.
I would like to close with a video that gives a slight taste of the CSL Airbox:
https://youtu.be/NDoNhiNBrxo
. I have some skid plates but have been wary of fitting them as the roads are so bad and steep round where I am that I worry I'd rip them off the bumper if they snag on something? I'd also like to try the clutch stop one day, I guess that's fairly simple to do right? Did you buy one or use this method? http://www.m3forum.net/m3forum/showthread.php?t=179858
Mine rarely sees less than 5.5k 
