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Some mods on a Z4M Roadster

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FD3S
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Some mods on a Z4M Roadster

Post by FD3S » Sat Sep 16, 2017 11:35 am

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.

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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.

Image

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:

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Vibra Mounts:

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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.

Image

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.

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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 :

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The king naked

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New clothes of the king

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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:

Image

After the tune MAHA Dyno - power at engine:

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After the tune Dynoject Dyno - power on the wheels with AFR Ratio:

Image

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: .

Image

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
Last edited by FD3S on Thu Sep 28, 2017 10:19 pm, edited 3 times in total.

D4dawg

Some mods on a Z4M Roadster

Post by D4dawg » Sat Sep 16, 2017 12:26 pm

:o :thumbsup:
Great list buddy and a great write up of before and after pro and cons

Enjoy the beast ,)

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buzyg
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Some mods on a Z4M Roadster

Post by buzyg » Sat Sep 16, 2017 12:43 pm

Great post. Not a modder myself but I enjoyed reading what you have done to your Zed. That air box is nice. 8) :thumbsup:
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TomK
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Some mods on a Z4M Roadster

Post by TomK » Sat Sep 16, 2017 12:45 pm

That's a good selection of mods there most of which I can attest to! I'm sure you're enjoying the car a lot more now with the CSL box, "the monster", good description :D . 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

I must say I'm surprised at your dyno chart a little. The drop from 7200 is severe and it should only just tail off at 7800. Where have you located the IAT? It might be worth trying to extend that somewhere out of the engine bay if you are dealing with very hot ambient temps.
I don't use the snorkel but then my box was made for the Z so the mouth opening goes into the circular rubber oem intake space below the slam panel. How far does the mouth in yours sit from this cold air intake hole? As you can see from my chart (albeit I have 288/280 cams so the uplift in the last 1000 rpm is more pronounced thatn standard) there is a nice linear curve.
I'm really surprised at the small overall gain from box as well, perhaps it's worth trying to tune it on the dyno a bit? When did you last do your valve clearances, I made considerably more having done them before this run.
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MC[IB], CSL airbox, Schrick 288/280 cams, 4.44FD, UUC SSK, SS race cat back, AP CP9660[F]/5144[R] brakes, Apex ARC-8 with AR-1 or PS5, KW ClubSport 2-way, Turner spherical arms, PMC uniball rtab, VB engine mounts, Rogue pulleys & RSMs, Tillett B6, half cage

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Some mods on a Z4M Roadster

Post by Beedub » Sat Sep 16, 2017 12:59 pm

Great post, great car, great owner!
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Some mods on a Z4M Roadster

Post by Mangozac » Sat Sep 16, 2017 1:34 pm

Very cool stuff! I would love a Karbonius airbox but I just can't justify the price :(

89k kms is very early for rod bearings on a Z4M unless the car is regularly thrashed. I can understand the peace of mind though ;)
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Some mods on a Z4M Roadster

Post by FD3S » Sat Sep 16, 2017 8:36 pm

Thank you very much guys for the good words. :oops:
I appreciate it.

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Some mods on a Z4M Roadster

Post by Adam D » Sat Sep 16, 2017 9:19 pm

Could the high rpm drop be due to using 95 octane fuel, the engine knock sensors could be pulling the timing back to protect itself.
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Some mods on a Z4M Roadster

Post by FD3S » Sat Sep 16, 2017 10:13 pm

TomK wrote: Sat Sep 16, 2017 12:45 pm That's a good selection of mods there most of which I can attest to! I'm sure you're enjoying the car a lot more now with the CSL box, "the monster", good description :D . 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

I must say I'm surprised at your dyno chart a little. The drop from 7200 is severe and it should only just tail off at 7800. Where have you located the IAT? It might be worth trying to extend that somewhere out of the engine bay if you are dealing with very hot ambient temps.
I don't use the snorkel but then my box was made for the Z so the mouth opening goes into the circular rubber oem intake space below the slam panel. How far does the mouth in yours sit from this cold air intake hole? As you can see from my chart (albeit I have 288/280 cams so the uplift in the last 1000 rpm is more pronounced thatn standard) there is a nice linear curve.
I'm really surprised at the small overall gain from box as well, perhaps it's worth trying to tune it on the dyno a bit? When did you last do your valve clearances, I made considerably more having done them before this run.
Tom hello. Thanks for your comments and your time.
That is true I enjoy the car much better now with the airbox and with immediate response of the throttle with the tune.
Your concerns seem right about the skid pads but I guess everything depends the way you hit the bumper. The skid pads may protect you from some hits though. My main concern about them is if there is a possibility to get detached at speed above 250 km... Because a failure at the place they stand hits the front tires directly... But I guess I am getting paranoid about it.

The clutch stop is easy and cheap mod. I have followed the comments of this thread http://www.zpost.com/forums/showthread. ... ght=clutch and also I have bought it from this link http://www.ebay.com/itm/230820559306?ss ... 1497.l2649 . I want to do also the CDV Delete at the next service.

Tbh your chart has put ghosts in my dreams. I have seen it some time ago, and I was expecting similar results. Not even close unfortunately.
I haven't thought about valve clearance neither the IAT location. Thanks for the recommendation.
Which airbox do you have? Also the hp you get is rwhp or engine power? Do you have aftermarket headers?
I will shot some photos tomorrow to see where my airbox stops.
My mechanic told me that cams is one solution to solve that but maybe I will loose power from the low rpms. However I am not ready mentally to do the cams.

My strategy will be the following:
1) Test during a night that the temperature drops, on an open road and check if that heat soak is cured or no.
2) If no, I will 3d scan the end part of the airbox and the circular rubber oem intake space and create and print a 3d model. The problem is that you can not do many things fas the space left for the snorkel is pretty tight.
3) I will put an Rpi Scoop, so it can catch more air in that tube.
4) Do the Valve clearance and relocation maybe for the IAT.
4) Pray to be solved this issue and dyno again once with hood open or closed with 100 octane petrol and maps. :D

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Some mods on a Z4M Roadster

Post by paulgs1000 » Sat Sep 16, 2017 10:17 pm

Interesting and honest assessment of your mods :thumbsup: Love the sound of that airbox; not surprised that your American muscle owners were impressed :lol: :thumbsup:
Thanks for posting :thumbsup:
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Some mods on a Z4M Roadster

Post by FD3S » Sat Sep 16, 2017 10:22 pm

Adam D wrote: Sat Sep 16, 2017 9:19 pm Could the high rpm drop be due to using 95 octane fuel, the engine knock sensors could be pulling the timing back to protect itself.
Adam thanks for the answer. Another friend told me that too. It is another hypothesis that I have to check. This stage of trial and error I hate it because I have unfortunately no time due of work and all those trials need a lot of time unfortunately....
paulgs1000 wrote: Sat Sep 16, 2017 10:17 pm Interesting and honest assessment of your mods :thumbsup: Love the sound of that airbox; not surprised that your American muscle owners were impressed :lol: :thumbsup:
Thanks for posting :thumbsup:
Glad that you liked it Paul.

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Some mods on a Z4M Roadster

Post by TomK » Sun Sep 17, 2017 7:20 pm

Adam D wrote: Sat Sep 16, 2017 9:19 pm Could the high rpm drop be due to using 95 octane fuel, the engine knock sensors could be pulling the timing back to protect itself.
I don't buy that as there are many charts of S54s in America creating maximum power at max revs (7800) as they should do according to BMW specs. They run less than 95 if I'm not mistaken?
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Some mods on a Z4M Roadster

Post by TomK » Sun Sep 17, 2017 8:24 pm

FD3S wrote: Sat Sep 16, 2017 10:13 pm
Tbh your chart has put ghosts in my dreams. I have seen it some time ago, and I was expecting similar results. Not even close unfortunately.
It should be. My last S54 with a CSL box gave a similar shape curve but had no fancy cams.
FD3S wrote: Sat Sep 16, 2017 10:13 pm All the runs made with powen button off, except the second run on the dynojet.
Bear in mind that the power/sport button only affects the throttle map and a dyno run is a full throttle affair, it will make no difference.
FD3S wrote: Sat Sep 16, 2017 10:13 pm
I haven't thought about valve clearance neither the IAT location. Thanks for the recommendation.
Well worth doing the valve clearances imo before trying to tune it, if they're out you'll be down on power for sure.
FD3S wrote: Sat Sep 16, 2017 10:13 pm
Which airbox do you have?
Goke
FD3S wrote: Sat Sep 16, 2017 10:13 pmAlso the hp you get is rwhp or engine power?
Corrected engine power, same as yours.
FD3S wrote: Sat Sep 16, 2017 10:13 pmDo you have aftermarket headers?
No, stock exhaust except the back box
FD3S wrote: Sat Sep 16, 2017 10:13 pmI will shot some photos tomorrow to see where my airbox stops.
here's mine
DSC_1921.JPG
DSC_1921.JPG (210.82 KiB) Viewed 3488 times
FD3S wrote: Sat Sep 16, 2017 10:13 pmMy mechanic told me that cams is one solution to solve that but maybe I will loose power from the low rpms. However I am not ready mentally to do the cams.
Adding cams is not the solution for your problem, pretty sure about that.
FD3S wrote: Sat Sep 16, 2017 10:13 pm My strategy will be the following:
1) Test during a night that the temperature drops, on an open road and check if that heat soak is cured or no.
Definitely get testing. Use something like Torque to monitor your IAT temp (which I think may be the cause of your issues). It should read something vaguely similar (like +5 or +10c) over the ambient temp. What kind of IAT are you using? It shouldn't be the genuine CSL one as that is different to the one required for alpha-n mapped cars like ours iirc.
FD3S wrote: Sat Sep 16, 2017 10:13 pm 2) If no, I will 3d scan the end part of the airbox and the circular rubber oem intake space and create and print a 3d model. The problem is that you can not do many things fas the space left for the snorkel is pretty tight.
I would have thought the mouth of your airbox would pull enough air through the OEM cold air feed even from 10 or so cm away that yours I guess is? Did you do a dyno run with the bonnet open, if there was no difference then surely the issue is not that of "not getting enough air into it"? Did you do a baseline run with your stock airbox?
FD3S wrote: Sat Sep 16, 2017 10:13 pm 3) I will put an Rpi Scoop, so it can catch more air in that tube.
I have one, haven't bothered fitting it yet... not convinced it will do anything.
FD3S wrote: Sat Sep 16, 2017 10:13 pm 4) Do the Valve clearance and relocation maybe for the IAT.
You could consider relocating the IAT to somewhere within the cold air feed IF the IAT is suffering heatsoak in it's current location (check with torque app or such as suggested earlier)

Good luck with it, but with this statement
FD3S wrote: Sat Sep 16, 2017 10:13 pm since my car rarely seen more than 5500 rpms
I'm not quite sure why you're going through all the bother of worrying about max power? :cry: Mine rarely sees less than 5.5k :D
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Some mods on a Z4M Roadster

Post by FD3S » Mon Sep 18, 2017 6:12 pm

Tom thanks for you detailed answer once again.
Last night I had to do around 250 km to make a business meeting. So late at night returning back home I give it a try with second and third gear all the way up to 8200 rpm. The problem it was obvious and the same thing happened. From 7100 rpm you could feel the drop of power. Also I have put filled the car with 100 octane gas.

Do you mention to monitor my engine with something like toque. What kind of obd port do you use with that app?
I will search to see if there is something similar for iOS devices.

I have taken a photo from the car at the garage to see where my airbox ends. Sorry guys for the dust it is after a trip the car.
During both dynos the car had open bonnet.

Image

Your suggestion about the relocation of the IAT sensor seams more and more logical.
Btw I have found this on Turner:
https://www.turnermotorsport.com/p-3917 ... n-harness/
Do you know it makes sense to buy it?


Also have taken a photo of the old bearings:
Image
Image

Now to answer you also why I bother with all that since i rarely push the car hard. The reason is that I want to have everything completed and perfect in my life and then to be able to forget them and find new endeavours. :D

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Some mods on a Z4M Roadster

Post by RedUn » Tue Sep 19, 2017 10:06 pm

There's a further piece you can buy to finish the box off which will move the intake closer to the feed pipe.

Its also got a much more aerodynamic shape to the inlet so I imagine that will help at high rpm, a straight edge like you've got won't be helping.

By the way, I've no idea how much the bell mouth shape will help but without a doubt it will help.

You can buy a genuine one from bmw but you will need to mess with the flap or karbonious sell a full carbon one that's nice 8)

Nice work on the car by the way :thumbsup:
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