Convert C 4 box to C2
12-16-2015, 07:47 AM
#46
Three Wheelin'
I'm not getting this.. so essentially there is a clutch between the front and rear.. and this can be used to vary the amount of torque going to the front. As standard the centre diff is open so all the power sent it's way goes to the front. the clutch could then be activated by the PDAS but only to reduce power to the front.. unless the clutch is permanently open and the PDAS closes it but then I cant see how any power at all would go to the front under normal circumstances..
On the 964 they decided to put in a fixed permanent torque split using an epicyclic gearset which could then be adjusted by incrementally locking the input and outputs of the epicyclic together, using a clutch pack, taking the differential action out of the equation and leaving a 50/50 split.
There's some subtlety in "open" vs "LSD" vs "sends all the power" vs "torque split" - you can have an "open" differential, which allows the shafts either side to spin at different rates, which also applies a differential torque bias.
05-26-2016, 04:25 AM
#47
Three Wheelin'
Guys,
Just to let you know that with Redtek we have come up with a plug and play adaptor to lock the two shafts together. It is more complex than you would think and will have to be a two piece collar. I'm hoping to get the conversion done in mid/end June. I'm sure Nick will get a few made but as of now I have no idea on price. I have the C2 console for the gear change and the ABS with continue to work as is.
Unknowns is still that rear diff, very wary of trusting get the PDAS to operate it though in theory it should.. Because the priority of the PDAS is to eliminate any oversteer I'm not sure it would work properly so I think I'll use a mechanical LSD. According to Redtek one for a C2 should fit.
Just to let you know that with Redtek we have come up with a plug and play adaptor to lock the two shafts together. It is more complex than you would think and will have to be a two piece collar. I'm hoping to get the conversion done in mid/end June. I'm sure Nick will get a few made but as of now I have no idea on price. I have the C2 console for the gear change and the ABS with continue to work as is.
Unknowns is still that rear diff, very wary of trusting get the PDAS to operate it though in theory it should.. Because the priority of the PDAS is to eliminate any oversteer I'm not sure it would work properly so I think I'll use a mechanical LSD. According to Redtek one for a C2 should fit.
05-26-2016, 04:55 AM
#48
Three Wheelin'
What's the plan for the 4wd gubbins? Remove torque tube, front diff, front drive shafts, what about the front hubs?
I'd go plate lsd I think, as Nick says no reason a c2 plate diff won't drop in. The OS Giken Super Locker diff is cool if you can find someone to build it right for you it is rather pricey but then the porsche one isnt exactly cheap.
I'd go plate lsd I think, as Nick says no reason a c2 plate diff won't drop in. The OS Giken Super Locker diff is cool if you can find someone to build it right for you it is rather pricey but then the porsche one isnt exactly cheap.
05-26-2016, 05:19 AM
#49
Burning Brakes
Guys,
Just to let you know that with Redtek we have come up with a plug and play adaptor to lock the two shafts together. It is more complex than you would think and will have to be a two piece collar. I'm hoping to get the conversion done in mid/end June. I'm sure Nick will get a few made but as of now I have no idea on price. I have the C2 console for the gear change and the ABS with continue to work as is.
Unknowns is still that rear diff, very wary of trusting get the PDAS to operate it though in theory it should.. Because the priority of the PDAS is to eliminate any oversteer I'm not sure it would work properly so I think I'll use a mechanical LSD. According to Redtek one for a C2 should fit.
Just to let you know that with Redtek we have come up with a plug and play adaptor to lock the two shafts together. It is more complex than you would think and will have to be a two piece collar. I'm hoping to get the conversion done in mid/end June. I'm sure Nick will get a few made but as of now I have no idea on price. I have the C2 console for the gear change and the ABS with continue to work as is.
Unknowns is still that rear diff, very wary of trusting get the PDAS to operate it though in theory it should.. Because the priority of the PDAS is to eliminate any oversteer I'm not sure it would work properly so I think I'll use a mechanical LSD. According to Redtek one for a C2 should fit.
i`m highly interessted in this adaptor! if it`s available and not to expensive, i`m going to buy one!
I would re-wire a C2 ABS brain (300€ @ ebay). The car will even forget it has been a C4 previously :-)
Front Hubs can be satisfied with 30mins work on a lathe from the old driveshafts. Remove front dif, remove torque tube, install CAE (C2) shifter and you wont need to weld anything... with your named adaptor, it should be a 2 or 3 day effort to convert a C4 to C2. I already spoke with my mechanic some time about this job and we would leave the hydraulik activated rear diff as it is, but remove the PDAS valves and would do a manual valve from the pressure bomb to the rear-diff slave. With that, you can configure your diff-torque manually. Perfect would be, to use some kind of "sputnik - valves" like used in the lightweight 964 C4 to adjust from inside...
05-26-2016, 06:23 AM
#50
Three Wheelin'
What's the plan for the 4wd gubbins? Remove torque tube, front diff, front drive shafts, what about the front hubs?
I'd go plate lsd I think, as Nick says no reason a c2 plate diff won't drop in. The OS Giken Super Locker diff is cool if you can find someone to build it right for you it is rather pricey but then the porsche one isnt exactly cheap.
I'd go plate lsd I think, as Nick says no reason a c2 plate diff won't drop in. The OS Giken Super Locker diff is cool if you can find someone to build it right for you it is rather pricey but then the porsche one isnt exactly cheap.
05-26-2016, 06:26 AM
#51
Three Wheelin'
great news!
i`m highly interessted in this adaptor! if it`s available and not to expensive, i`m going to buy one!
I would re-wire a C2 ABS brain (300€ @ ebay). The car will even forget it has been a C4 previously :-)
Front Hubs can be satisfied with 30mins work on a lathe from the old driveshafts. Remove front dif, remove torque tube, install CAE (C2) shifter and you wont need to weld anything... with your named adaptor, it should be a 2 or 3 day effort to convert a C4 to C2. I already spoke with my mechanic some time about this job and we would leave the hydraulik activated rear diff as it is, but remove the PDAS valves and would do a manual valve from the pressure bomb to the rear-diff slave. With that, you can configure your diff-torque manually. Perfect would be, to use some kind of "sputnik - valves" like used in the lightweight 964 C4 to adjust from inside...
i`m highly interessted in this adaptor! if it`s available and not to expensive, i`m going to buy one!
I would re-wire a C2 ABS brain (300€ @ ebay). The car will even forget it has been a C4 previously :-)
Front Hubs can be satisfied with 30mins work on a lathe from the old driveshafts. Remove front dif, remove torque tube, install CAE (C2) shifter and you wont need to weld anything... with your named adaptor, it should be a 2 or 3 day effort to convert a C4 to C2. I already spoke with my mechanic some time about this job and we would leave the hydraulik activated rear diff as it is, but remove the PDAS valves and would do a manual valve from the pressure bomb to the rear-diff slave. With that, you can configure your diff-torque manually. Perfect would be, to use some kind of "sputnik - valves" like used in the lightweight 964 C4 to adjust from inside...
As for the ABS I don't think there is any need to mess with the brain. The PDAS won't know the 4 wheel drive is no longer working as long as the hydraulics are blanked off.. So the ABS should work fine as is.
The centre console does not need welding.. most now are just bolted in which saves the hassle of having to strip the interior.
Last edited by jack.pe; 05-26-2016 at 09:03 AM.
05-26-2016, 02:48 PM
#52
Burning Brakes
This is all a bit above my head.. What would fitting a manuka valve for the rear diff actually involve? What bits would have to be procured? If you can give me a bit more detail I'll talk it through with Redtek.
As for the ABS I don't think there is any need to mess with the brain. The PDAS won't know the 4 wheel drive is no longer working as long as the hydraulics are blanked off.. So the ABS should work fine as is.
The centre console does not need welding.. most now are just bolted in which saves the hassle of having to strip the interior.
As for the ABS I don't think there is any need to mess with the brain. The PDAS won't know the 4 wheel drive is no longer working as long as the hydraulics are blanked off.. So the ABS should work fine as is.
The centre console does not need welding.. most now are just bolted in which saves the hassle of having to strip the interior.
no problem with your solution, but with rewiring the ABS brain to a C2 brain, the car will forget it`s C4 origin. When converting to 2WD, i would prefer to make the car thinking it is a proper C2 ABS-wise... no problem to leave the car as it is.. but with a C2 brain, you can get rid of the middle-/rear diff valve block (solenoid)...
After that, you can do some playings with the rear diff. We have a limited diff in the G64.00 box that is hydraulic activated. We can re-use that but with a manual actuation. here, the C4-lightweight sputnik valves come to the table (in my mind). With that, you can modulate the pressure (from the bomb) to the limited-diff master by yourself... You can drive an open diff, you can lock it fully.. it`s up to you...
front hub is clear. We can reuse parts from the front drive-shafts...
shifter: you need the frame for the C2 conversion, that holds the shifter assembly. You can glue or you can weld this in. A friend of mine had a 64C4 conversion and there it was welded.. but, with the "new" CAE shifter (for C2 cars) you are instructed to cut out that frame in the installation instructions... If you combine the information, that you`ve to cut out a C2 shifter box for using the CAE shifter and the fact, that we need a kind of shifter-assembly box to have the OEM C2 shifter solution in the converted C4... it implies for me, that we can use the CAE shifter as a plug&play solution shifter-wise (you`ve to have a look to the CAE website.. with a picture it get clear what i mean... )
I`m looking excited to your final solution an your resumee, if the car is better as it was as a C4... because i realy love the C4.. But 70kg loss in wheight, less drive-train loss power-wise and a more agil handling are on the pro-side...
regards from munich
thilo
05-26-2016, 02:59 PM
#53
Three Wheelin'
hi Jack,
no problem with your solution, but with rewiring the ABS brain to a C2 brain, the car will forget it`s C4 origin. When converting to 2WD, i would prefer to make the car thinking it is a proper C2 ABS-wise... no problem to leave the car as it is.. but with a C2 brain, you can get rid of the middle-/rear diff valve block (solenoid)...
After that, you can do some playings with the rear diff. We have a limited diff in the G64.00 box that is hydraulic activated. We can re-use that but with a manual actuation. here, the C4-lightweight sputnik valves come to the table (in my mind). With that, you can modulate the pressure (from the bomb) to the limited-diff master by yourself... You can drive an open diff, you can lock it fully.. it`s up to you...
front hub is clear. We can reuse parts from the front drive-shafts...
shifter: you need the frame for the C2 conversion, that holds the shifter assembly. You can glue or you can weld this in. A friend of mine had a 64C4 conversion and there it was welded.. but, with the "new" CAE shifter (for C2 cars) you are instructed to cut out that frame in the installation instructions... If you combine the information, that you`ve to cut out a C2 shifter box for using the CAE shifter and the fact, that we need a kind of shifter-assembly box to have the OEM C2 shifter solution in the converted C4... it implies for me, that we can use the CAE shifter as a plug&play solution shifter-wise (you`ve to have a look to the CAE website.. with a picture it get clear what i mean... )
I`m looking excited to your final solution an your resumee, if the car is better as it was as a C4... because i realy love the C4.. But 70kg loss in wheight, less drive-train loss power-wise and a more agil handling are on the pro-side...
regards from munich
thilo
no problem with your solution, but with rewiring the ABS brain to a C2 brain, the car will forget it`s C4 origin. When converting to 2WD, i would prefer to make the car thinking it is a proper C2 ABS-wise... no problem to leave the car as it is.. but with a C2 brain, you can get rid of the middle-/rear diff valve block (solenoid)...
After that, you can do some playings with the rear diff. We have a limited diff in the G64.00 box that is hydraulic activated. We can re-use that but with a manual actuation. here, the C4-lightweight sputnik valves come to the table (in my mind). With that, you can modulate the pressure (from the bomb) to the limited-diff master by yourself... You can drive an open diff, you can lock it fully.. it`s up to you...
front hub is clear. We can reuse parts from the front drive-shafts...
shifter: you need the frame for the C2 conversion, that holds the shifter assembly. You can glue or you can weld this in. A friend of mine had a 64C4 conversion and there it was welded.. but, with the "new" CAE shifter (for C2 cars) you are instructed to cut out that frame in the installation instructions... If you combine the information, that you`ve to cut out a C2 shifter box for using the CAE shifter and the fact, that we need a kind of shifter-assembly box to have the OEM C2 shifter solution in the converted C4... it implies for me, that we can use the CAE shifter as a plug&play solution shifter-wise (you`ve to have a look to the CAE website.. with a picture it get clear what i mean... )
I`m looking excited to your final solution an your resumee, if the car is better as it was as a C4... because i realy love the C4.. But 70kg loss in wheight, less drive-train loss power-wise and a more agil handling are on the pro-side...
regards from munich
thilo
With regard to the console assembly that sits below the gearknob to support it the C2 item is still available new from Porsche. With the various grommets, shafts and so on it works out around £160. A lot for what it is but not thousands like the other aftermarket options..plus I want the strandard look. It can just be bolted in place and I know of at least 2 that have used this option.
Ok, it would be great to reuse the rear
Diff but I'm not sure that creating a mechanical actuator or spring to fit would really be that easy.. Or cheap?
05-26-2016, 04:01 PM
#54
Burning Brakes
Hi Thilo, ok then on the ABS brain. I'm leaving mine as is and it should be OK.
With regard to the console assembly that sits below the gearknob to support it the C2 item is still available new from Porsche. With the various grommets, shafts and so on it works out around £160. A lot for what it is but not thousands like the other aftermarket options..plus I want the strandard look. It can just be bolted in place and I know of at least 2 that have used this option.
Ok, it would be great to reuse the rear
Diff but I'm not sure that creating a mechanical actuator or spring to fit would really be that easy.. Or cheap?
With regard to the console assembly that sits below the gearknob to support it the C2 item is still available new from Porsche. With the various grommets, shafts and so on it works out around £160. A lot for what it is but not thousands like the other aftermarket options..plus I want the strandard look. It can just be bolted in place and I know of at least 2 that have used this option.
Ok, it would be great to reuse the rear
Diff but I'm not sure that creating a mechanical actuator or spring to fit would really be that easy.. Or cheap?
05-27-2016, 10:21 AM
#55
I'm not sure its been mentioned yet but you will also have to deal with the different gearbox front mount setups between C4 & C2. The C4 mount alone with no support from the torque tube etc is not adequate to support and maintain alignment of the front of the gearbox.
C4
C2
There is a 4wd to 2wd gearbox mount adapter available for the 6 spd 993 but not sure it would work on the shorter 5 speed 964 box:
http://fdmotorsports.net/993-turbo-c...n-trans-mount/
05-28-2016, 09:52 AM
#57
Burning Brakes
i`ll not do the convertion within this year. I`ve to move from munich to frankfurt during the summer and i`m in the process of planning/sourcing the overhaul parts for all bushings all around (wishbones, trailingarms, and all other rubber bushings) with unibal :-)
This is the next topic on my list for the upcomming winter. After that, we can speak about gearboxes...
06-05-2016, 10:21 AM
#59
Three Wheelin'
Thread Starter
Hi Guys,
Any news from Redteck ?
Thilo any progress on the LSD setting from the cabin ,
Gather some parts , ready to drop the box and engine, moving PS to the front , replacing engine tin work with FG and some other things...
thinking converting to C2 as everything would be out .
Cheers
Konstantin
Any news from Redteck ?
Thilo any progress on the LSD setting from the cabin ,
Gather some parts , ready to drop the box and engine, moving PS to the front , replacing engine tin work with FG and some other things...
thinking converting to C2 as everything would be out .
Cheers
Konstantin
06-05-2016, 01:47 PM
#60
Burning Brakes
Thilo any progress on the LSD setting from the cabin
I`ve to discuss the LDS - valve with my mechanic...
moving PS to the front ,