[Nezil]

Originally Posted by CantComplain

Hi Guys-

A little (completely) off topic here, but I have a question about BM3 I was hoping some users could shed some light on. I have a MY17 6MT, currently with FS catted DP. I don't intend to upgrade the intercooler, or charge pipes or anything else. Strictly for street use, so should not be an issue with high IATs. I'm looking at BM3 Stage 2.

So my question basically revolves around usability of the BM3 apps, both mobile and PC. I'm a computer guy by profession and a car enthusiast by nature, but all of the settings, configurations, tuning parameters, etc., seem a little daunting. Is it the type of thing that can easily be figured out with a little trial and error? How much tolerance for the "and error" side of things is there? And does each flash count against the 60 total allowed--is that still a thing? And will I throw the "modified ECU" OBD error that could get me flagged at the dealer?

In the past when I've hesitated on this type of stuff but eventually plunged in it's been fine, I was just wondering where this lies on the spectrum. And is there any demo I can play around with? Getting to see how it worked would really help put my mind at ease. I'm also interested in removing the cold start and want to confirm that's there with BM3.

Any help greatly appreciated.

As you said, it is off topic, so I'll point you to a post I made that might answer a lot of your question: http://f87.bimmerpost.com/forums/sho....php?t=1492908

Regarding warranty... If you flash your DME, you should expect that your drivetrain warranty is gone.

Before you visit your dealer, you can flash back to stock and lock the DME again, and they may not notice that you'd had a tune, but if you try to make a claim, they might dig deeper and find out.

The other thing to consider is that any bolt ons that you have, if they don't invalidate the warranty directly, are a red flag that you might have flashed a tune.

I'm obviously hoping that I never need the drivetrain warranty, and I'm planning on flashing back to stock and locking before visiting the dealer. I'm probably even going to go to the trouble of removing the bolt ons that I have (Sport Cat DP, FMIC, Boost & Charge Pipes) before I take my car in. I'm not doing that to 'fool' the dealer so that I can make a drivetrain claim, I'm doing it so that I don't get red flagged in case I need to make any other unrelated claims.

With all this being said, with the exception of the early diff recall, these cars now have a few years of use, and there have been very few issues. Even owners with big modifications like port injection and upgraded turbos pushing 500whp haven't had issues with the drivetrain yet. Remember that the gearbox and differential are the same parts in the M3 / M4 GTS, and our cars have less power and torque than those.