Z4 M40i incoming, looking for mods.

J

Jeroen

New member
My new toy is arriving soon and I want to start to modify it.
I would love to hear experience from you guys and any suggestions are very welcome.
My goal is to have a quick and controlable car for fast roadtrips with nice turnin feel en a few trackdays per year.

Engine
-femto unlock
-mhd stage 1 400hp-ish?
-air intake, which one?
-downpipe 200cell
-midpipe delete
-mhd stage 2 460-480hp-ish?

gearbox
-xhp software

suspension
-front upper brace
anything else?
- which coilover set for example? (Not to go low)

wheels
It comes with 19inch 799m wheels, but I gues they are heavy. Any lighter/lightweight wheels recommended?
If 18inch will improve the drivebility, please lett me know.

brakes
any recommendes mods? more bite from brakepads?

Anything else I need? :)
 
Jeroen said:
Yes, build 2022, but locked ecu.
And thanks, but I have been here for some time already. :)
Click to expand...

When I looked at it (M40i) ..the obvious things are the MHD stage 2 tune ..I think the FEMTO issued arrived later?

Particulate filter removal

xHP maybe

Based on other experience stock intake should be fine

xHP worked well on the DCT whaqt it would do on a 3rd generation XF 8HP box not sure

Braces I think would be a waste of time

IMHO
 
Welcome to the forum and good luck with your modifications. :thumbsup:

Don't forget we like to see photos!
 
The ACS is a tuning box only for cars without extra mods?
The ACS price of almost 5k is crazy.

I like to "build" it myself with the mhd route and I think I will be done at 3k with femto, mhd, downpipe and maybe the midpipe + intake.
 
I am also considering a box tune (as mine will be new delivered in April I do not want to unlock ECU and lose warranty). From research seems the Dahler box tune is a good option and cheaper than ACSchnitzer. Anyone have experience on this?
 
I always too scared to do these mods and I always have a warranty on my car. I believe they can detect box mods too? Also aren’t they just stock maps rather than custom maps?
 
ori said:
I always too scared to do these mods and I always have a warranty on my car. I believe they can detect box mods too? Also aren’t they just stock maps rather than custom maps?
Click to expand...
Modern BMWs..F series and later BMW tools can spot any / all ECU mods plus suspicious activity typically caused by tuning boxes..
 
My understanding was that if the tune box is disconnected (Dahler even has a plug in for this disconnect) then everything returns to normal ECU and original settings. Is that not the case?
 
MiguelM said:
My understanding was that if the tune box is disconnected (Dahler even has a plug in for this disconnect) then everything returns to normal ECU and original settings. Is that not the case?
Click to expand...
Modern car ECUs, because of a long history of folks either re-mapping or using tuning boxes logs all anomalies where values reported by sensors are either implausible or inconsistent with expected parameters..so incorrect correlations on say reported boost vs fuel burnt vs calculated torque or flagged. BMW and others now use AI type tools in their data centres that can remotely deduce what has happened..those logs are non volatile and no erasable.. hardly surprising engine designers are not dumb..incredible amount of smarts in modern engine ecus!
 
ouch ! there goes my plan down the drain... if I had any issues with the car they would then use this to invalidate the warranty.
I guess even a 300 cell downpipe would make the ECU log some inconsistent parameters...
Is there anything safe to mod that does not void warranty?
thanks
 
MiguelM said:
ouch ! there goes my plan down the drain... if I had any issues with the car they would then use this to invalidate the warranty.
I guess even a 300 cell downpipe would make the ECU log some inconsistent parameters...
Is there anything safe to mod that does not void warranty?
thanks
Click to expand...

I’m not sure a sports cat would flag or not..clearly the level of pollutants is higher ..I think later cars all have Nox sensors..

Given how far and how many sensors are used and now how much memory modern car ECUs have I wouldn’t want to offer any suggestions..

Of course ..just accept your warranty may be worthless and just do what you want to do and enjoy!

Part of the reason I spent a lot of time going with an E89 rather than a G29 was for that reason..

I guess I could have bought a 3 year old one but the colour choice was pretty poor..
 
B58 is solid. Me personally I don’t worry about the engine warranty, failures are extremely rare even when pushing high numbers

I own an x3 with the b58. 200 cel sports cat, OPF delete and bootmod3 stage 2. It’s fast and I’ve owned a lot of fast cars

I imagine this set up in a z4 with so much less weight and in an aerodynamic shape would be ridiculous. Do it!
 
  • Wow
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