BMW Transmission Tuning


Here at Darkside Developments, we offer the Transmission Tuning Software from xHP for our BMWs due to its quality and reliability. The amount of Research and Development that has gone into their software would be difficult to match by any other tuning company.

Since introduction of the ZF 6HP transmissions in BMW vehicles in the early 2000s, they remained a blackbox for Tuners and car enthusiasts worldwide. The ZF6HP units were used throughout the whole BMW range from the 1-series hatchbacks to the mighty Alpina B5 cars putting out around 500 bhp and 700 Nm of torque. While the hardware stays widely the same throughout all applications and is mainly divided in only 2 types (6HP19/21 and 6HP26/28), the software inside the controller makes it possible to adapt the transmission to every vehicle and mimic a wide range of driver styles. Smooth and comfy (some call it “sluggish”) in the Diesel applications, the same transmission in the Alpina B3/B5 come with a way more sportier touch and make it hard to believe that they are from the same breed. Tweaking a transmission is not only about getting quicker changes or holding more power. Few people are aware of how deeply an automatic transmission contributes to the overall driving experience. From crawling in traffic, town and city driving, to taking a vehicle to the drag strip or a race track, the TCU widely defines how the car feels. Like everyone drives different with a manual, the maps inside the TCU hide the secrets to tweak an automatic transmission to the liking of your customers, so that they can finally experience what BMW promised back then in the glossy brochure: Sheer driving pleasure!

The later 8-Speed Auto Models feature the ZF 8HP Gearbox, widely regarded as the best Automatic gearbox ever released, and found in various guises in vehicles such as the Bentley Continental GT, Dodge Challenger SRT Hellcat, Aston Martin Vanquish and even the Lamborghini Urus. It had its debut in the BMW 7 Series (F01) 760Li saloon fitted with the V12 engine, and since then each new BMW model in all Series down to the 1 Series, in both rear-wheel-drive and all-wheel-drive versions have been equipped with it. Most models feature the “Driving Experience Switch” (DEC) button to change the transmissions behaviour. Unfortunately, BMW did not use that possibility to its full extent on the normal line-up. xHP reprograms your transmission, so you can access all shift-programs the 8HP is capable of and adds other features, dependent on model.

335D Dyno
335D Dyno

6 Speed - ZF 6HP (EXX Chassis)


£250 + VAT £300 INC VAT

  • Optimised D Shift Points to facilitate sporty, yet economy style driving
  • Optimised Shift Strategy for up/downhill driving
  • Optimised Warmup Behaviour
  • Optimised Torque Converter Lockup in 1st/2nd/3rd gear
  • Lowered minimum RPM limit manual mode
  • Adapted Torque Limits for Tuned engines
  • Kickdown delete in Manual Mode
  • Gear Display in Dash in D/S/M Modes


£275 + VAT £330 INC VAT

  • Stage 1 plus the following:
  • Optimised D & S Shift points for better acceleration in part and full throttle situations
  • Firmer, sportier upshifts in D/S/M mode
  • Faster paddle response time
  • Raised Torque Limits for Tuned engines


£300 + VAT £360 INC VAT

  • Stage 1 & 2 plus the following:
  • Race-like upshifts with torque increase
  • Shift times approx. 50% faster in S/M Modes
  • Shift times approx. 25% faster in D Mode
  • True Manual mode (no automatic upshift in M mode)
  • Automatic Rev-Matching (Throttle – Blip) on Downshifts in S/M Modes
  • Even more raised Torque Limits for Tuned engines


£400 + VAT £480 INC VAT

  • Max. RPM: Custom shift points for WOT (Full Throttle). The Max. RPM can be setup separately for D, S and M mode, each with Kickdown being active or inactive. “Kickdown” refers to the Kickdown-Switch at the end of the throttle travel, drivers recognise as small threshold in the pedal.
  • Kickdown: Enable/disable usage of the Kickdown-Switch, separately for D, S and M modes. There are 3 settings: Default, On, Off. Default uses whatever is setup in the flashed Map. On and Off override the setting in the Map respectively. Please note, that “Kickdown Off” does NOT mean, the car won’t downshift anymore. Just the maximum speed for downshift in each gear, when full throttle is applied, will be lowered!
  • Gear Display: Customise the display of the current gear in the dash. Four settings are available: Default, Gear Display Off, Display Actual Gear, Display Target Gear. Default uses whatever is setup in the flashed Map. Off, turns the Display off. The Dash will show just the current mode, but not the current gear (except in manual). Display Actual Gear and Display Target Gear will show the current gear in all modes (D, S and M), but differ in terms of when the display switches to the next gear. “Display Actual Gear” will let the display switch, when the shift is fully processed, and the next gear already engaged by the trans. “Display Target Gear” will switch the display right at the beginning of the shift. Perception of drivers is different, in terms of what is the correct time for changing the gear-display in the dash.
  • Start in 2nd Gear at Standstill: Chose whether the transmission shifts down to 1st or 2nd gear at standstill. (in M-Mode)
  • Throttle Blips: Throttle Blips are used to rev-match the engine on downshifts. This function lets you setup the aggressiveness of downshift blips in manual mode. The main goal of rev-matching is to speed up downshifts by actively matching the Engine-RPM to the Target-RPM in the Target-Gear. This is done, by applying a short blip to the throttle during the transition phase between 2 gears. More audible and faster blips but can get uncomfortable. Less intense will lead to a slower but smoother rev-match. Please note, that this function does not support all vehicles/maps. Generally supported are N54/N55 vehicles. On other vehicles, these settings may not have any effect.
  • Custom Shift Points: Change all shift points in D and S mode to your personal liking. These are based on the current shift points which are then modified by a certain %. Exact RPMs are not possible.
  • Shift Speed in M-Mode: This panel lets you tune the Speed of each upshift in M-Mode! Positive values (slider to the right) mean SLOWER but more comfortable shifts. Negative values (slider to the left) mean SLOWER but smoother and therefore more comfortable shifts. For example, if you have the feeling that the 1-2 shift in M is too hard, pull the slider to the left, to make it smoother. You can experiment to find your optimal setting. There are no "dangerous" settings possible.
  • Lockout 6th Gear in S-Mode: Since launch of xHP this is an endless debate. Some customers want the trans to engage 6th Gear on Highway Speeds when using S-Mode, others don't and complain about the exact same thing. Most BMW do not use 6th Gear in S-Mode. That is the factory setup and is due to German Autobahn. Nothing more annoying than a transmission shifting back and forth between 5th and 6th Gear on steady 200km/h+ drives. On the other side, customers in other countries use S-Mode as Standard mode and complain about bad mileage on the highway. The standard maps mostly use 6th Gear in S-Mode, as most of our customer base does not have the pleasure of unlimited motorways. To end this struggle, customers can choose to lockout 6th Gear in S-Mode.

8 Speed - ZF 8HP (FXX & GXX Chassis)


£350 + VAT £420 INC VAT

  • Removed Torque Limits
  • Gear Display in D-Mode


£375 + VAT £450 INC VAT

  • Gear Display in D-Mode
  • Removed 3rd and 6th Gear Torque Limit
  • Raised Line-Pressure mapping for high-input torque
  • Reconfigured DEC Logic, with similar logic as in M-Cars (access to more shifting modes)
  • Even faster shifting in M/Sport+, absolutely instant paddle response
  • Recalibrated Shift-Points in D & S Mode to improve throttle response
  • No automatic upshifting in M/Sport+ setting
  • Transmission keeps the current set mode when DSC is turned off
  • Launch Control enabled (update of DSC, DME eventually necessary as well on some cars)
  • Retains full ECO Mode functionality including Coasting


£400 + VAT £480 INC VAT

Stage 2 plus:

  • Recalibrated S/Sport+ mode for Roll-Racing and Race-Track use. The transmission keeps the engine in the upper rev range all the time and shifts on the Race-Track like an experienced Racing-Driver.
  • All other modes are unaffected and are 100% suitable for daily use.


£500 + VAT £600 INC VAT

  • Custom Software parameters are TBC

Check Compatibility

Pick you car's details and see if you can flash your vehicle with the xHP Flashtool app!


  • Typecode (4th - 7th Digit of VIN) {{vehicle.typecode}}
  • Model {{vehicle.model}}
  • Engine {{vehicle.engine}}
  • Power {{vehicle.power}}
  • Drivetrain {{vehicle.drivetrain}}
  • Driverside {{vehicle.driverSide}}
  • Region {{vehicle.region}}
  • Support From {{vehicle.supportFrom}}
We're working on OTS Files for this vehicle right now. Please check back later!



Current Version: {{map.currentVersion}}


Q: May I return to stock at any time with xHP?

A: Yes. Please get in touch and we can book an appointment to flash your TCU back to stock.

Q: How do I check if my vehicle is supported?

A: Please check using the compatibility tool above, or if you are not sure get in touch with your VIN and we can check for compatibility.

Q: Do I need to do anything differently once you have flashed the Gearbox?

A: The TCU will need to re-learn your driving characteristics, the best way to do this is for the vehicle to be driven as if around town for the first 50 miles, coasting as much as possible. Then a further 50 miles very steady, with no hard acceleration or braking. Then you can build up speed. The gearbox will take 2 - 3 weeks to learn your driving characteristics.

Q: How about reliability, will I shorten the life of my transmission using xHP?

A: Stage 1 and Stage 2 setups won’t have any effect on the lifetime of transmission components. Not on the TCU, nor on the shafts or clutches. Keep in mind, that automatic transmissions are highly complicated units, with a few hundred components inside. Some of these components are designed to wear out (like clutches) through making use of them. Your driving style and proper maintenance have the biggest impact on the life-time of transmission components. Obey these simple rules:

  • Let your transmission warm up on each drive before applying heavy throttle. You will notice some amount of slip in the warm up phase, which is intentionally to heat up the oil inside. Basic Rule: Your transmission needs about the same time to heat up as your engine oil.
  • Don’t “pump-up” your vehicle on standing starts with brake/throttle applied at the same time
  • Flush/change your transmission oil regularly. (approx. every 50k – 75k miles) BMW does not want you to do it, but ZF wants you. Trust ZF, who have built this transmission.
  • S and M modes are designed to facilitate sporty and fun driving. Shift times are cut and clutches get applied more aggressive. Use these modes when necessary and not as standard. The TCU records the amount of time you spend in each mode. BMW uses this data to judge on warranty cases.

Q: I just flashed my transmission, but the shifts are bad.

A: Your transmission may behave weird, right after flash, e.g. starting in 3rd gear. This issue should clear within a few hundred meters of driving. The transmission has extensive adaption-algorithms, to keep shift quality in check over a full life time and even with heavily worn out clutches. The adaptions applied, are very sensitive to abrupt changes, as they operate in a narrow window. Therefore, shift quality can suffer in the first few hundred miles, after doing an oil-change, replacing transmission hardware, or changing the TCU software, like with xHP. Don’t over stress your transmission during this adaption phase. The best way to adapt your transmission, is just normal driving in D mode with lots of varying speeds and shifts. We DO NOT advise anybody to clear the adaption values to speed up the process. Depending on the current wear state of your transmission, this can lead to unwanted and permanent bad results.

Q: I’m using MHD. What Map version should I flash?

A: If you are using MHD N54, use the xHP setting inside MHD. If you are using MHD N55, use the Alpina setting.

Q: I have a custom Tune, respectively tune my ECU by myself. Anything to watch?

A: A lot of the maps in the TCU use the PPS (Pedal Position Sensor) as primary input. For example, the Shift point –Maps and the TCC (Torque Converter Clutch) Maps. Therefore, it is recommended, to use the stock throttle mapping. This gives you greater control over the transmission’s reactions. Having too much torque on very low throttle will lead to an undesirable shifting behaviour. This is not special to xHP. The same applies to the stock transmission software.

Q: I already have a Flash - Tune (COBB, custom Tune etc.) on my ECU (Engine). Do I need to uninstall it before using xHP?

A: No. xHP has no direct effect on your existing Engine tune.

Q: I’m running JB4, can I use xHP with it?

A: Yes, xHP will work on JB4 equipped cars, but you have to remove it before flash and install again. On our test cars setting JB4 to Map 0 was not enough, as JB4 was still disturbing communication to the TCU. This possibly depends on the JB4 revision you are using.

Q: Will xHP void my OEM or dealer warranty?

A: xHP changes the calibration file on your TCU. Like every other tune on your vehicle, this will very likely void your OEM or dealer warranty, depending on your Country and/or guarantee contract.

Q: Is the use of xHP visible to the OEM tester at the BMW dealer?

A: The flash procedure itself leaves no visible traces at any place in your car. An OEM tester will not be able to directly detect the use of xHP. However, xHP enables you to change certain parameters (like max. RPM for shift) above OEM limits. Hitting those limits during driving can lead to records in other ECUs, which then can be possibly interpreted by the dealer in case of warranty matters.

Q: I installed the Stage 3 Map on my vehicle, but it’s still not shifting as quick as seen in some YouTube Videos!

A: You very likely refer to videos with a 5-Series car with Sport Automatic Option. BMW uses the same transmission on these cars, but they trick human perception by changing the behaviour of the rev-counter. Dampening is removed and the needle jumps instantly to the target value, before the shift of the transmission is even completed. The shift itself is in fact slower compared to xHP Stage 3 Maps. This “Sport Option” is a handshake between the ECU and the TCU controller. xHP activates the sport mode in the TCU on all vehicles, but it depends on your ECU, if it has this mode built in from factory. For example, 335i N54 cars do not have it, whereas 135i and 335i N55 sport it. Diesel 3-Series do not have this mode at all.

Q: Will my car be still updateable by the dealer?

A: If a customer updates his car with ISTA by himself or ordered and update at the dealer, the xHP map will be replaced with the stock map. You can just flash this car again, at no cost. xHP Pro will automatically carry out a long flash on such a vehicle. (Install + Map flash)

Q: I’m having “Dynamic Drive” Errors after the flash and can’t clear them.

A: The BMW Dynamic Drive system is pretty picky, when there is no CAN Bus communication for some time. On every flash, the CAN Bus has to be shut down for all other units in the car, so you can use the whole bandwidth for the flash operation and maintain a stable flash. After all returning to normal, the BMW dynamic drive has to recalibrate and re-align the position on all 4 wheels. During this procedure the system is inactive and will throw all kind of fault messages. Those errors can’t be cleared manually, you just have to wait for the system, to settle in again, which can take some miles/time. (up to 1 hour of driving, dependent on road surface) If you want to speed that up and have the knowledge, you may also relearn the units through the known BMW Tools.

Q: You flashed an xHP Map on my Pre-LCI 5 or 6 Series car, but I don’t see the Gear-Display in D-Mode?

A: Most of the 5 and 6-Series cars (before Facelift) where equipped with a faulty dash software, which is unable to display a gear number in S-Mode. When S-Mode is engaged, most of these cars display a red gearbox-error sign in the dash. Therefore, the Gear-Display is not active in the xHP Maps for those cars. Unfortunately, there is no way of checking upfront, if a certain car is affected by that or not.