Supercharged ECU/Transmission into N/A car - swap complete
#1
09-04-2017, 04:34 AM
Supercharged ECU/Transmission into N/A car - swap complete
A little history: some time ago I added the supercharger and all related components into my 1997 XK8. This worked out fine despite high compression ratio of the N/A 4.0 engine. After some tweaking with the MAF sensor I made the N/A ECU work with the higher flow SC injectors (340cc or so) and provide the safe and steady 10.5/1 AFR at full throttle. This is covered in this thread:
https://www.jaguarforums.com/forum/x...ed-xk8-127904/
After a year I decided I want more power, which meant more boost. For this purpose I found the low mileage 2002 SC engine and ordered Andre Vos Twin Screw Kit. The initial plan was to use the stock engine electronics. Due to higher air flow I intended to use the 550cc injectors, which would in theory provide enough fuel for any reasonable level of power for my setup. But when everything was put together and I started experimenting with making everything work correctly I understood that the stock ECU could not handle these 550cc injectors. Seems like 550cc VS stock 215cc was just to much for the ECU no matter what I tried to do with the MAF signal - AFR was always rich at idle and too lean in motion even with the fuel trims within reasonable values (+-5%). I even tried to use the SC 340cc injectors - this worked much better, but this setup was getting maxed out at 4000 RPM, after that the ECU was just cutting fuel out like a rev limiter. I needed another solution and the best bet seemed to be the SC ECU which is proved to work well with the 550cc injectors. The ECU and TCU work together and this leads to the need of swapping the entire set together with the tranny.
This is where the main story begins. After long process of studying various Jaguar tech guides and electric diagrams I understood that there is not so much overall difference between N/A and SC setups. The majority of modules which are unique to each setup have the same pinout (not true for the TCU - completely different devices). For example, the difference between the SC and N/A ECU interface is that there are some extra pins in the wiring looms for additional components like 2nd fuel pump and IAT2 sensor. In case of instrument packs, the units are different in terms of software, but the pinouts match completely. So I decided not to change the vehicle wiring but to adapt the stock wiring to the task. I bought the SC underbonnet wiring loom from the wrecked XKR and took the SC TCU socket and the socket to the transmission itself. Also I took the socket form the N/A TCU to make the adapter which plugs into the tranny socket of the stock wiring loom to get power, ground and CAN bus connections without cutting any wires. These sockets are shown at the pictures below. Also, the next picture shows the comparison between the N/A Bosch and SC Siemens TCU.
Another difference in S/C and N/A setup is the source of information about the gear selector position for the TCU/ECU/Body Proccessor. SC uses only the linear switch at the selector, which translates all the positions to all the modules, while the N/A uses the separate Neutral switch at the selector and the rotary switch at the tranny housing. To get everything working I made my own wiring from the linear switch to all other modules which were in stock form connected to the rotary switch/neutral switch. The socket for linear switch is 12 pin 040 Multilock series which can be easily bought online.
The list of the electrical components I changed is: ECU, TCU, Inst Pack, ABS module (that's because my early 1997 ABS module was not compatible with the 1999 ECU/TCU which resulted in lack of speedometer and gearshifting because the CAN bus was not receiving the information form wheel speed sensors). All other modules (body processor, security module, key transponder module and so on) are left unchanged and communicate with the SC ECU without any problem.
The mechanical part of the task was not difficult. The SC Mercedes tranny bolts right on to the engine block. Interestingly, this tranny is much lighter and shorter than the N/A ZF unit although it is told to be much stronger.
One problem I had to solve was that there were no bolt places in the underbody to fit the Merc tranny rear mount, it had to be closer to the front of the car:
To get this solved I made the thick steel extension plate:
Also the propshafts are different - the N/A is shorter and has no center bearing:
One more thing: the SC tranny cooling lines have different radiator connectors, which can be solved using the adapters (M18 to M20):
Overall, this whole task was not so difficult as it seemed. At least not "almost impossible" like it is usually said to be. Needless to say, I am very happy to have the bulletproof tranny which is ready for any power output achievable with Jaguar's 4.0 engine.
https://www.jaguarforums.com/forum/x...ed-xk8-127904/
After a year I decided I want more power, which meant more boost. For this purpose I found the low mileage 2002 SC engine and ordered Andre Vos Twin Screw Kit. The initial plan was to use the stock engine electronics. Due to higher air flow I intended to use the 550cc injectors, which would in theory provide enough fuel for any reasonable level of power for my setup. But when everything was put together and I started experimenting with making everything work correctly I understood that the stock ECU could not handle these 550cc injectors. Seems like 550cc VS stock 215cc was just to much for the ECU no matter what I tried to do with the MAF signal - AFR was always rich at idle and too lean in motion even with the fuel trims within reasonable values (+-5%). I even tried to use the SC 340cc injectors - this worked much better, but this setup was getting maxed out at 4000 RPM, after that the ECU was just cutting fuel out like a rev limiter. I needed another solution and the best bet seemed to be the SC ECU which is proved to work well with the 550cc injectors. The ECU and TCU work together and this leads to the need of swapping the entire set together with the tranny.
This is where the main story begins. After long process of studying various Jaguar tech guides and electric diagrams I understood that there is not so much overall difference between N/A and SC setups. The majority of modules which are unique to each setup have the same pinout (not true for the TCU - completely different devices). For example, the difference between the SC and N/A ECU interface is that there are some extra pins in the wiring looms for additional components like 2nd fuel pump and IAT2 sensor. In case of instrument packs, the units are different in terms of software, but the pinouts match completely. So I decided not to change the vehicle wiring but to adapt the stock wiring to the task. I bought the SC underbonnet wiring loom from the wrecked XKR and took the SC TCU socket and the socket to the transmission itself. Also I took the socket form the N/A TCU to make the adapter which plugs into the tranny socket of the stock wiring loom to get power, ground and CAN bus connections without cutting any wires. These sockets are shown at the pictures below. Also, the next picture shows the comparison between the N/A Bosch and SC Siemens TCU.
Another difference in S/C and N/A setup is the source of information about the gear selector position for the TCU/ECU/Body Proccessor. SC uses only the linear switch at the selector, which translates all the positions to all the modules, while the N/A uses the separate Neutral switch at the selector and the rotary switch at the tranny housing. To get everything working I made my own wiring from the linear switch to all other modules which were in stock form connected to the rotary switch/neutral switch. The socket for linear switch is 12 pin 040 Multilock series which can be easily bought online.
The list of the electrical components I changed is: ECU, TCU, Inst Pack, ABS module (that's because my early 1997 ABS module was not compatible with the 1999 ECU/TCU which resulted in lack of speedometer and gearshifting because the CAN bus was not receiving the information form wheel speed sensors). All other modules (body processor, security module, key transponder module and so on) are left unchanged and communicate with the SC ECU without any problem.
The mechanical part of the task was not difficult. The SC Mercedes tranny bolts right on to the engine block. Interestingly, this tranny is much lighter and shorter than the N/A ZF unit although it is told to be much stronger.
One problem I had to solve was that there were no bolt places in the underbody to fit the Merc tranny rear mount, it had to be closer to the front of the car:
To get this solved I made the thick steel extension plate:
Also the propshafts are different - the N/A is shorter and has no center bearing:
One more thing: the SC tranny cooling lines have different radiator connectors, which can be solved using the adapters (M18 to M20):
Overall, this whole task was not so difficult as it seemed. At least not "almost impossible" like it is usually said to be. Needless to say, I am very happy to have the bulletproof tranny which is ready for any power output achievable with Jaguar's 4.0 engine.
#2
09-05-2017, 02:04 AM
Veteran Member
#3
09-05-2017, 02:37 AM
Staggering.....
The post is so well described and accompanied by relevant pictures that, despite reading it 10 times and the brain still refusing to get to grips with the the technical stuff, by the time we reached different length prop shafts I was thinking "I've got a quiet weekend, I'll do this to mine......"
I'm staggered by the knowledge and skill levels that exist in this forum. The bar just went up a bit again!!
The post is so well described and accompanied by relevant pictures that, despite reading it 10 times and the brain still refusing to get to grips with the the technical stuff, by the time we reached different length prop shafts I was thinking "I've got a quiet weekend, I'll do this to mine......"
I'm staggered by the knowledge and skill levels that exist in this forum. The bar just went up a bit again!!
#4
09-05-2017, 03:38 PM
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#5
09-06-2017, 03:03 AM
Thank You all for nice words,
One more thing I forgot to mention is that the stock N/A catalytic converters will not fit once the ZF tranny is swapped for the 722.6 because the Merc unit is a bit too wide for them at its bellhousing. Since the ROW AJ26 ECUs (both N/A and SC) do not use the downstream O2 sensors, I thought it was a nice chance to order some stainless catless downpipes which look better, weight a ton less and add some growl to the stock exhaust system:
One more thing I forgot to mention is that the stock N/A catalytic converters will not fit once the ZF tranny is swapped for the 722.6 because the Merc unit is a bit too wide for them at its bellhousing. Since the ROW AJ26 ECUs (both N/A and SC) do not use the downstream O2 sensors, I thought it was a nice chance to order some stainless catless downpipes which look better, weight a ton less and add some growl to the stock exhaust system: