After overhauling a 5HP18 and doing some more neat modifications on the car, it's time to go for some bigger projects. In the future I will want to fit a BMW 4.0 V8 or 4.4 V8. The 5HP18 has a factory limit of 310Nm. It can just barely take a 3.0 V8.

The 4.0 was always delivered with a 5HP30 gearbox (560Nm max.) and the 4.4 was delivered with a 5HP30 in the first year before the intermediate 5HP24 (440 max.) was released.

A 5HP30 will be a direct fit into my car and a 4.0 transmission mount + drive-shaft will take care of the rest. Fitting a 5HP30 basically finishes the transmission-to-wheels part of a bigger engine swap and will give me a 560Nm box to handle a "little" 300Nm engine.

Since the 5HP18 and 5HP30 are both fully electronic, I will need to do some electrical work aswell. The 5HP30 EGS/AGS module is identical to the 5HP18 module regarding size, shape and pin layout. The wiring down to the transmission is different as the 5HP30 has a totally different valvebody. The BMW Wiring Diagram System already showed me how I will have to change certain wires at certain connectors to ensure the proper signals are transferred back and forth. I foresee no real problem here.

The car is not equipped with the anti-theft mechanism where EGS/AGS and DME have to be linked software-wise. So far, so good. I think I have this transmission swap properly on paper.

The problem that I can not fix however, is that the 5HP30 will have to apply shift times and shift pressures based on the torque/RPM curve of my 3.0 V8. The EGS/AGS will be programmed to shift based ona 4.0 torque/RPM curve.

Reason why I think this is a problem, is that if I would simply hook up the 5HP30, assuming all wires have been rewired correctly, it will time its shifts and pressures based on the throttle body sensor position and the Nm it expects to receive from a 4.0. Since it will receive far less Nm from a 3.0, it will possibly apply too much pressure.

Can anyone tell me if the data for the load profile is stored on the EPROM in the EGS/AGS? If so, I would have to load the engine load data of the 3.0 onto the 5HP30 EPROM so that it's shifting and solenoid actuation is the same as with a 4.0 but now based on a 3.0 load profile.

Can anyone with DME/DDE chiptuning or mapping in general tell me what these programmed variables look like?

Hope to hear from you guys. Once I start working on a 5HP30, the pictures and videos will be online.