F87Bimmerpost User: SeanWRT

THOR GTS TCU is a first of its kind and is groundbreaking for the M2 OG. And it deserves a separate review thread…Here it is.

Hi guys, last time I did anything to my M2 OG was the custom tuning for GP500 turbo on pump gas in 2018. Since then, I commute and rotate from 540Li, M2 and the M4C from my younger bro. I thought next time I upgrade anything, it would be a new ride (another topic…). However, a few days ago, I flashed the THOR GTS TCU that’s tailor made for the N55 M2, and also the full F87 Competition chassis coding (EPS/GHAS/DSC). I’ll try keep the below review ACCURATE if not short.

THOR GTS TCU for the N55 M2 – I’m saying this based on my familiarity with the M4C on GTS TCU that I had more than 10k miles on – I’m positive the THOR GTS TCU is NOT the OEM GTS adapted to OG M2, instead it looks much more like an update based on M2 N55 OEM TCU. Becuase the shifting strategy remains exactly unchanged from the N55 OEM, while OEM GTS should be vastly different in this regard and is clearly better in my opinion.

That being said THOR GTS is definitely a noticeable improvement over M2 OG TCU in many ways which I’ll break down as below:

1. Shifting Strategy: no change.
2. Shifting time: slightly improved (it is perceivable) in all modes, though M4C GTS TCU still feel a bit quicker to me.
3. Shifting delay: noticably improved, especially in comfort and Sport. This is the best part of the flash in my opinion.
   All OEM TCUs have built-in shifting delay in each driving mode, it’s quite annoying with the OG M2 which has a lot of it stock especially when TCU adapts and goes into the “cruise” drive style.
   With THOR the delay is significantly reduced, meaning a more responsive TCU that uses less time to decide a up or down shift. And it’s very noticeable especially on street and highway driving.
4. Clamp Pressure: not that human can sense.
5. Shifting Jerkiness:
   A lot of jerkiness with stock goes to “reluctance to upshift at low speed” and “violent downshift”.
   With less delay in shifting and quicker shifting time, the jerkiness get minimized.
   The comfort mode just goes to lower RPM more quickly, but when you’re on it, downshift is less hesitant and smoother. So that the car feels smoother and more powerful at the same time.
   In sport mode, RPM tend to less hang up high for too long on pedal lift, while downshift seems to be unchanged (it’s fine already stock to begin with), it now just becomes smoother.
   S+ mode feels no different other than being less violent. Probably due to quicker shift time. And I believe the acceleration improves with smoother shifting.

I’ll rate the THOR GTS 8 out of 10. Huge thanks to THOR for bring this to the N55 M2!

M2 Competiton OEM chassis Coding

EPS – it’s significantly lighter than M2 OG, but weight builds up very quickly as speed goes up. It takes some geting used to depending on where you come from. But I have quite a broad bandwidth, dealing with light steering car like 540 and my wife’s Lexus IS300. I quickly start to like the new EPS, because it just feel more effortless and makes the car more nimble at low speed which I’ve always exactly wanted.
Also, with less weight, I clearly see how the steering weight masks the lack of road feedback with modern M cars.

GHAS – No one can tell precisely by how much the new differential control improves the traction. Let’s believe it does…or not. Actually, I’m getting more flashing DSC lights out of more downshifts from the new TCU.

DSC/MDM – Coming from Euro MDM stock, I feel the new DSC is significantly less intrusive, to the point I thought DSC was fully off in my first few try. More fun, yes, but we have the DSC off for more “more fun” don’t we? I use S+ only for time attack. I’m not sure if lap time improves with the new DSC. I guess I’ll find it out some day at the BMW driving experience center when it’s open.

In the end, I’m keeping all the codings I did with THOR and yes I’d do them all again. Especially I like the TCU and EPS, though I’m hoping for further improvement on the TCU. Let’s hear your comments or reviews!

Thanks! Sean