Old thread-- but 1/2 relevent to my question---- what are the differences in what 996GT2 ECU does compared to 997 GT2 ECU ?
What extra functions are in 997 GT2?
Can anyone give me some insight please?

 

997's ecu sends out much more data via CANbus, so it's integration to 996 is difficult. I do not say impossible, but requires modifications.
997's ecu controls turbochargers ( ie. boost ) with a PWM signal where 996's ecu controls wastegates with alternating voltage. No PWM outputs in 996. CV control is similar (voltage based ) in both ones.
997 = Siemens, 996 = Bosch.

 

While Todd and Cynthia was here. I asked them about the differance between 996tt vs 997tt and they both almost same. Just few minor changes

 

Thx for reply.What happens with 996 when seperate(incar) boost control is used? Is that the same if used with 997?
Apart from more data from 997ECU-- what other functions does it perform that the 996 ECU is not doing?

 

Here's some minor changes..:

2.13 Engine management

The new 911 Turbo has a new engine
management system, ME 7.8.1. This is
based on the ME 7.8 system of the 911
Turbo (996) and the optimization measures
incorporated in the current 911
generation.

The ME 7.8 system features the following
familiar basic functions:
• Hot film air mass metering
• Static high-voltage ignition system with
individual ignition coils for each cylinder
• Sequential multipoint fuel injection
• Idling control via throttle valve
• Electronic throttle valve control
• Stereo lambda control with one
lambda sensor up- and down-line of
each catalytic converter
• VarioCam Plus control
(continuous adjustment)
• Knock control with automatic adjustment
of air/fuel mixture to compensate
for variations in fuel quality

The ME 7.8.1 system in the new 911
Turbo incorporates the following additional
features:
• Variable turbine geometry (VTG) control
• Exhaust gas temperature control to
protect the components of the variable
turbine geometry system via additional
temperature sensors in the turbine
housing
• On-board diagnostics via CAN bus
• Continuous lambda control
• Overboost control

9.3 Networking

Similarly to the current Boxster and
911 models, the high-speed networks
CAN bus (Controller Area Network) and
MOST bus (Media Orientated System
Transport) also enable the exchange of
data and information throughout the
vehicle in the new 911 Turbo. This networking
of the different control units
entails the following advantages:
• Engine management with high-speed
information exchange
• Coordination of the networked control
systems
• Joint transmission of digital audio and
control data in the area of audio/communication
(MOST bus)
• Reduced vehicle weight

*************************************************

911 Turbo (997)

Motronic Control Unit ME 7.8.1

The further-developed Motronic control unit ME 7.8.1 is
used worldwide. It is based on the ME 7.8 of the 911
Turbo (996) and the further development of the current
911 generation. The new Motronic control unit features a
processor speed of 40 MHz with a memory capacity of
1 MB.

Electronic Accelerator Pedal Unit

The 911 Turbo (997) is provided with an electronic accelerator
pedal unit from the current 911 (997) series.

DME Power Supply

The power supply of the DME control unit is the same as in
the current 911 (997) series. The assignment of the fuse
carrier, as well as relay carriers 1 and 2, can be found in
the circuit diagram on the PIWIS Tester.

Starting The Engine

In order to start the engine it is necessary, after the
ignition key has been identified, to fully depress the clutch
pedal (vehicles with manual gearbox) or the brake pedal
(Tiptronic vehicles). In Tiptronic vehicles, the selector lever
must additionally be set to either “P” or “N”.

CAN Networking

As in current (987/997) models, electronic networking in
the new 911 Turbo facilitates the exchange of data and
electronic information between the various control units
throughout the vehicle via the internal high-speed network,
the CAN bus (Controller Area Network).

CAN Communication For The Motronic Control Unit
(DME)

On the 911 Turbo (997), diagnosis of the DME control unit
is performed for the first time via CAN.
The DME control unit communicates with the
following control units via CAN:
• Gateway control unit
• Driver authorization control unit
• Tiptronic control unit
• PSM control unit
• PTM control unit
• Steering angle sensor
• Yaw velocity sensor
• Airbag control unit
• Air conditioning control unit

************************************************
Not to mention the ones found from studying wiring schematics. I did not find it sensible to change from ME7.8 to ME7.8.1, although I already had modified the car from ME7.2 to ME7.8..

 

Apologies-- my question was specifically related to GT2-- ie same base engines.

 

Thank you for clarifing that for me!

Also thanks everyone for giving us such instrumental discussion.

 

Yes, these have the same base engines: 996 turbo / 996 GT2 / 997.1 turbo / 997 GT2. 996 turbo/GT2 utilizes ME7.8 and 997 turbo/GT2 utilizes ME7.8.1.

 

996 turbo: You can use an EBC to control OEM N75 valve or install EBC's own electric valve. Or even use a MBC. To avoid CELs either ask your tuner to reprogram your ECU or keep N75's plug connected.

997 turbo: OEM VGTs are controlled by PWM signal, and only very few aftermarket units are capable of doing that. Is it even necessary is the question...ECU tune does it better. If going to old-school turbos then an EBC with it's own bits 'n' pieces is necessary. And CELs will pop up without programming.