[tbouchard991]

I'm not aware it was on social media when built. I am pulling together some images to tell the story during my ownership. Once I get to the point When I know the interior swap is about dome, I'll share a bunch then. I've posted on this forum a few times with this car.

There was this article posted back in ~2017

- Jim Herrold's S54 E46 Touring — ULTIMATE KLASSE

 

[tbouchard991]

The speedometer reads faster than actual speed. I’ve owned enough BMWs to know this is common to some extent, but we’re talking almost 10% faster at 80 mph. Is this likely some kind of coding issue related to the swap? Speaking of coding and diagnostics, this is my newest BMW and I don’t have any software or interface for anything beyond the E36. I need to research all my options there.

Check this thread out! Link

After studying M and non-M EEPROM files, here's what I found -- there is a function deliberately designed to increase the speed by a certain ratio. In the non-M, the displayed speed is the real speed + 5.7%. In the M3, the error is a massive 8.9% -- completely unacceptable IMO.

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Oops meant to edit my original post, apologies for double post!

 

[tbouchard991]

Speaking of experience,

I did retrofit a M3 Cluster in my 323iT, and I can confirm its about 8.9% ish off. (I confirmed this with my Uniden R7 w/ GPS Speed) and I corrected with @TerraPhantm link above. Its pretty much spot on now.

 

[tbouchard991]

You can certainly do as Thomas suggested with the coding, but on a modified cluster I always start by assuming the needle is in the wrong place. I'd be happy to add in the door LEDs as well, not to much trouble to do, but I guess we would also need to verify your cluster is coded to the car, is the mileage in it correct to the chassis?

This is true as-well! I had to move my temp gauge needle smidge after getting it back from getting rear door LED's added, since it wasn't reading correctly. However, Speaking of a cluster that has not been touched, its 8.9% off! 😂 Correcting it rather easy with BMWScanner to make it more accurate, its a bit ludicrous how much its off from factory.

 

[tbouchard991]

Was your car originally a sport? Most of the 17" Non-M wheels will clear the M3 brakes. If you have to buy something from scratch a 330 sport package front, style 68, will fit as well and are cheap.

I believe @cjhinpa runs style 68's for his winter wheels on his Wagon (looks great).