[DallySingh]

Hi all,

I'm collecting my Z4 M40i in 2 weeks and was interested in tuning it but would like some feedback and opinions.

Firstly, I'm from the UK which means our Z4's are only 340bhp / 0-60 in 4.4 seconds as opposed to the US counterpart which are 382bhp / 0 - 60 in 3.8 seconds.

Does anyone know how the EU version is limited? Is it simply software or is it an engine modification?

So, I'm looking to tune mine but don't know whether to go down the Racechip or BM3 route.

- If I go BM3, can I avoid voiding the warranty by flashing the stock map back when taking the car back to the dealers?

- Would a remap push the Z4 close to the 400bhp mark? On the Racechip website the GTS Black claims an additional 76bhp.

- If it does push it close to 400bhp, would that make the 0-60 quicker than the US counterpart?

- Besides the obvious differences between BM3 & Racechip (Full flash vs Piggyback), what are the main differences between the two when it comes to performance?

- How obvious if the difference in performance from stock to remapped?

Thanks guys.

[BEAR-AvHistory]

Europe has switched over to a new, stricter, testing procedure for emissions called the Worldwide Harmonized Light Vehicle Test Procedure (WLTP).

Its believed this is a software item, as I am in the US have not looked to see if anyone was offering a euro tune. Why not email BMS & ask them?

Back in the day was looking for a tune for the then unique 2011 335IS & became a tester for BMS developing one for the car by asking the question. BMS has a tune for the US version its the same as the normal B58 tune. They sell world wide & might be interested in looking into a euro version for the Z4.

[z4monster]

I was trying to decide between MHD and the Racechip tuning. I decided against MHD as it requires a bench unlock for the DME to allow it to be tuned. I decided to go with Racechip as it's removable and untraceable. I have to say it's definitely quicker and feels more punchy even at low revs. The 0-60 is so fierce it's truly unbelievable.

[DallySingh]

Originally Posted by z4monster

I was trying to decide between MHD and the Racechip tuning. I decided against MHD as it requires a bench unlock for the DME to allow it to be tuned. I decided to go with Racechip as it's removable and untraceable. I have to say it's definitely quicker and feels more punchy even at low revs. The 0-60 is so fierce it's truly unbelievable.

Hi, sorry but what do you mean by bench unlocking the DME?

I was under the impression that with BM3 it was literally; hook your laptop up via the ODB port and flash away.

Am I missing something?

[chowser51]

newer bmw's need the dme to be unlocked before tuning.

any tune or chip is detectable if they look hard enough so technically warranty might be voided.

it's a pay to play system.

my plan is to ask the bm3 people if they'll bench unlock my next car if i drive it to them before buying a tune. they're only six hours away.

[Flying Clog]

No experience of Racechip on a BMW

But did have a Racechip GTS for my Mini JCW and it was great.
Better acceleration, more mid range and a measured 265hp at the wheels.

Will look to get a chip for my Z4 next year.

[Joe240]

I had the stage 2 BM3 flash on my z4 and got used to the power. Night and day from stock and power throughout the revs. Unfortunately, the remote software update hit and flashed it back to stock. Car was noticeably slower again.

Unfortunately, this meant it had the latest firmware and new encryption so OBD unlock was out of the question. I waited a month to see if it would be cracked, during which time I put my B58 JB4 (piggyback like Racechip) and while it was faster again, it was noticeably falling flat in the higher revs. I hated it so much that I sent my DME to PTF for bench unlock this past Monday, got it back on Friday (Florida to Canada and back) and flashed stage 2 again.

Car pulls hard again throughout the revs. Truly missed the power. Addictive is an understatement. I drive in sport+ and manual shift every drive. With JB4 in 8th cruising at 60mph, floor it and it noticeably took time to build boost and put me back in the seat. BM3 flash is an instant pull (still building boost, but stronger pull without boost).

[DallySingh]

Originally Posted by Joe240

I had the stage 2 BM3 flash on my z4 and got used to the power. Night and day from stock and power throughout the revs. Unfortunately, the remote software update hit and flashed it back to stock. Car was noticeably slower again.

Unfortunately, this meant it had the latest firmware and new encryption so OBD unlock was out of the question. I waited a month to see if it would be cracked, during which time I put my B58 JB4 (piggyback like Racechip) and while it was faster again, it was noticeably falling flat in the higher revs. I hated it so much that I sent my DME to PTF for bench unlock this past Monday, got it back on Friday (Florida to Canada and back) and flashed stage 2 again.

Car pulls hard again throughout the revs. Truly missed the power. Addictive is an understatement. I drive in sport+ and manual shift every drive. With JB4 in 8th cruising at 60mph, floor it and it noticeably took time to build boost and put me back in the seat. BM3 flash is an instant pull (still building boost, but stronger pull without boost).

Can you not unlock the DME using BM3? This is the only bit I don't understand. All these video's on YouTube of guys remapping using BM3; how are they unlocking their DME's?

I was under the impression all you required was BM3 and it took care of everything.

[chowser51]

Newer BMWs have updated software which relock the DME and it can't be undone via just the software app. That's why people are having the DME's bench unlocked before flashing. This seems to be affecting G series and up. I haven't heard of anyone with an Fxx needing bench unlock recently.

[Joe240]

Originally Posted by DallySingh

Can you not unlock the DME using BM3? This is the only bit I don't understand. All these video's on YouTube of guys remapping using BM3; how are they unlocking their DME's?

I was under the impression all you required was BM3 and it took care of everything.

Starting at the November 2019 software update (there are a few after this update as well) BMW implemented a new encryption that tuners have not cracked yet. Because of this, unlocking the DME through the OBD port with a 2019.11 or newer software revision is not available at this time. They require a bench unlock.

I had a previous revision and was able to use the OBD unlock through BM3 initially (my car was delivered April 2019). Once it performed the remote software update, it installed the 2019.11 software with the new encryption, so I needed to remove the DME and have it bench unlocked. DME removal in the B58 is 100x easier than it is for the N55 so I wasn't too upset about having to bench unlock.