Thread: BMW N57 8hp to TD5 Auto adapter kit

I have read this thread from start to finish and I have a question that might have been covered, so apologies if this is the case.

How does the 8 sped get the 2 vital pieces of info that is required?

These being road speed and throttle position.

Originally Posted by d2dave

I have read this thread from start to finish and I have a question that might have been covered, so apologies if this is the case.

How does the 8 sped get the 2 vital pieces of info that is required?

These being road speed and throttle position.

Good question, one I have asked for more information from both HTG and MW Machines (who did the D2 8HP in the video).

So basically I am looking at three documents, one the LUCAS-EM TD5 pin outs, two the GearboxCU pin outs and three the HTG pin outs.

The D2 has a limited Canbus which to MY understanding is only on the LUCASEM to the Auto.

currently the Can Hi and Can low from the LUCAS-EM(Pin A32 and Pin A35) goes to the GearboxCU (Pin 16 and Pin 44), these are obviously going to be taken out and connected to the HTG Can pin outs

The pinouts for LUCAS-EM have the TP sensors (B12, B14, B26, B36) and Vehicle Speed (B13), there are no corresponding pinouts on the GearboxCU

My understanding is that the Canbus has this information carried for the 4HP as there are no pinouts for these in the GearboxCU

Land Rover Workshop Service and Repair Manuals > Discovery II (LT) V8-4.6L (2003) > Transmission and Drivetrain | Transmission Control Systems | Relays and Modules - Transmission and Drivetrain | Relays and Modules - A/T | Control Module, A/T | Component Information | Diagrams (workshop-manuals.com)

ZF 8HP wiring diagrams for HTG IO CAN – HTG tuning (htg-tuning.com)

Lucas TD5 (nanocom-diagnostics.com)


So basically it looks like I take out the pinouts from the gearboxCU and connect them to the HTG along with the

1. power
2. output speed sensors
3. lamp out puts for the sport and mode

Exactly how, yes it is true, I don't know!

As to the adaption of the 8HP with the TD5 -

This is an excerpt from the Rimmer Brothers website regarding the D2, just the automatic info. It does mention the CANbus as above.

Advanced Transmission
The new optional automatic transmission available on all New Discovery models - the ZF4HP22EH - featured a sophisticated electronic control system, with a variety of special features to enhance the driving experience on and off road. Electronic control gives more precise and consistent gear change points. The Transmission Control Unit (TCU) also communicated with the power unit ECM using a high speed "CANbus" link to effect a momentary torque reduction at the point of ratio change, resulting in a smoother change. Land Rover engineers invested a great deal of development time in making sure that the power unit and the automatic transmission worked together effectively as one unit. This meant, for example, that when the engine management system adjusted the fuelling to compensate for high altitude conditions, the transmission control likewise adjusted the shift strategy to suit. In addition to a normal gear shift mode, controlled via the conventional P, R, N, D, and 3, 2, 1 selector positions in either high or low range, the driver also had the choice of two alternative mode selections. If the mode selection button was pressed while the road-going high range was in use, a ‘Sport’ mode was selected, which made more use of available engine power, changing up at higher revs, and changing down more readily. When low range was in use, usually for more difficult off road conditions, the mode selector button brought in ‘Manual’ mode, which closely emulated a manual transmission, allowing a selected gear (e.g. 3, 2 or 1) to be held without shifting almost regardless of speed, assisting driver control. In this mode the only situation under which a downshift would then occur would be at very low speed, to avoid stalling the engine.

The point made regarding the momentary torque reduction is able to be controlled on the BMW GCU of the 8HP by the xHP Flashtool - this is the programming tool that HTG told me off - 8-Speed ZF - Flash Settings - rbttuning - Confluence - where this can done to maintain boost pressure.

Have been going over POTENTIAL options for the install and how to mount the gearbox. Have not had any luck on the replies from the companies who have done the conversion to the D2.

Lawrence from the first 8HP in a D2 got back to me as to having to move the gearbox back but no information other than the LT230 was tight to the chassis limitations as can be seen in the vid. I had already thought the solution here was to use the discbrake type handbrake arrangement if it went too far.

The 8HP has mounts at the transfer box end as far as I can ascertain, vertical. My thoughts are to buy another D2 GB chassis rail and attach this bascially under the transfer box adaptor


GB CHassis mount.jpg

And then use an off the shelf product such as the one below
ZF Mount 1.jpg

or this HPR 8HP B57 TRANSMISSION MOUNT KIT – 8speed AU

Sure this will require drilling, a lot of drilling bolts holes in the chassis as well as the chassis rail but this may also act as a gearbox protector with the plastic sump on the 8HP.

Have been having a lot of fun learning about CANbus and the wiring for the HTG CAN Io.

CANBus, the simplest way of understanding this is, taking the Engine ECU and GCU as the demonstration, they send packets of information which in each includes the pertinent identifier such as RPM, MAP etc. and the value of this such as for RPM - 2500rpm. In a more modern iteration with many systems such as HVAC, ABS, etc. on the same CANBus, they would also be receiving every packet of information on the CANBus with most of the packets of information irrelevant and therefore are simply ignored. There is a lot of information in each of the packets of information to ensure data integrity, and this is done under a Standard for CANBus Communication.

OBDI relies on this standard to be able to communicate via the ports, of course the need to know what the Pertinent Identifiers is why there are differences between manufactures but the packet of information's are configured in the same way - there has been an upgrade to the standard to allow for more identifiers due to the increasing complexity in cars and the number of systems, especially when you look at all the safety equipment and electrification of processes.

So in the D2 with the single CANBus from Engine to Gearbox only information between the two systems and each packet of information is read and pertinent to each. If the D2 was made today, the SLABS and BCU etc. would be on the CANBus and their information available to both the Engine and Gearbox but not being relevant, ignored. As they communicate over this CANBus there are only two lines, the High and Low, if other systems were on the CANBus they would have another set going off to the next system on the CANBus.

As a case in point, the gearshift console with all the indicators would today have an ICU and a CANBus connector (two wires) and a packet of information would be sent from the gearbox to the console with the required light to be lit - there are 7 wires from the GearboxEU to the Shift Console for this function now and this probably would continue to the dashboard via another set of two wires.

HTG CAN IO
All the inputs from the D2 are into the connector to the HTG unit, such as power, EngineECU, flywheel etc. In a more modern car, there are other systems that may require information from the gearbox, ABS ETC etc. which may be on a separate CANBus and this is why you see there are extra available CANBus IO's on the HTG connector.

HTG-IO-CAN-pinout-1024x576.jpg

The connector to the Gearbox basically only contains two sets of High LOW CANBus wiring the power lines and a wake up (ignition) lead.


GEAR POSITION DISPLAY
There are a multitude of Gear Displays which are able to communicate with the Gearbox via CANBus, this will be set of HI LOW wires and power of course for the display into the input connector of the HTG CAN 3 or CAN 4 slots.


NO EXPERT but I hope it gives some help to the others who have not had to think or learn about this before!!!

Should note, Paddle Shifters if used / wanted are connected by way of CANBus, so again it is an easy integration.

Looks like it will not be until next year to get this the 8HP installed.

Hello,
We have a little delay with IO CAN shipment.
Product is ready but we have a little delay with case’s for HTG IO CAN. I was assured by production department that we will be able to ship all order at the latest 14.12.2023.
Thank you for your patience.
Best regards,
Robert Lesisz

Have been searching hoping to find a 2" round gear display, unfortunately the only ones found are designed to use a mechanical linkage on the gearbox and not the CANBus.

The idea was to simply replace my EGT and Psi gauges with a combined one (do have the SAAS one purchased years ago before the Darkside turbo setup but this only reads to 30psi) and include the round gearbox display.

guages.jpg

Also want GREEN, not asking much, but did find a green display made by PCS which are used here by Marx and others in Aus, they use red displays and do not have the green but they are available, ex states at only a minor saving.

[ATTACH]187964[/ATTACH


gds5030big.jpg

The display is two inches high so it will fit within the enclosure with a bit of blanking off and right in front of me on top of the dash. The connection is direct CANBus, Hi, Low and power.