996 C4S rear wheel drive conversion.
Discussion
I have read a bit on the web regards this but it all seems to be in the states. has anyone in the Uk converted a 996 C4S to rear wheel drive, if so which method did you use, simply removed the diffs and drive shaft to the front, or was it more involved?
How did it affect the drive of the car once completed?
Having been inspired by Richards CLR build i fancy doing a bit of work to mine, i'd like to maybe have a go at creating a "996 GTS" type car, wide bodied, rear wheel drive, alcantara, with a fair bit of weight removed as well.
Any experience with the rear wheel drive conversion would be greatly appreciated.
How did it affect the drive of the car once completed?
Having been inspired by Richards CLR build i fancy doing a bit of work to mine, i'd like to maybe have a go at creating a "996 GTS" type car, wide bodied, rear wheel drive, alcantara, with a fair bit of weight removed as well.
Any experience with the rear wheel drive conversion would be greatly appreciated.
Budflicker said:
I have read a bit on the web regards this but it all seems to be in the states. has anyone in the Uk converted a 996 C4S to rear wheel drive, if so which method did you use, simply removed the diffs and drive shaft to the front, or was it more involved?
How did it affect the drive of the car once completed?
Having been inspired by Richards CLR build i fancy doing a bit of work to mine, i'd like to maybe have a go at creating a "996 GTS" type car, wide bodied, rear wheel drive, alcantara, with a fair bit of weight removed as well.
Any experience with the rear wheel drive conversion would be greatly appreciated.
The removal of the front drive hardware should be the same for UK cars as for USA cars.How did it affect the drive of the car once completed?
Having been inspired by Richards CLR build i fancy doing a bit of work to mine, i'd like to maybe have a go at creating a "996 GTS" type car, wide bodied, rear wheel drive, alcantara, with a fair bit of weight removed as well.
Any experience with the rear wheel drive conversion would be greatly appreciated.
In case you haven't read these I will post some links to some threads on this subject.
https://www.6speedonline.com/forums/996-turbo-gt2/...
https://www.6speedonline.com/forums/996-turbo-gt2/...
For my Turbo I talked to a tech and he said/recommended replacing the stock front spindles with (IIRC) GT2 units but I'm not sure why.
Should my Turbo's front diff/viscous coupling go bad I'm removing the hardware rather than spend the money to have the front diff fixed/replaced.
Slightly old thread resurrection.....
I am going to be doing this in the new year on my 996 C4S and am part way through a conversion to the missing 2S in the line up but keeping that 4S look.
Having read most of the online information (some of which needs to be taken with a large pinch of salt) I have lined up 9E to perform the work for me including changing over the engine mounts for RSS ones at the same time. They have done 20-30 cars in the UK so far, mainly larger power turbos but the hardware is exactly the same.
There aren’t any issues with electronics. The overall weight saving is in the region of 80-85lbs which isn’t as much as perhaps you would expect but certainly not to be sniffed at.
Deleting the rear wiper, front spare wheel and all the associated bits has saved 20kg’s and a lithium battery another 16kg. Along with approx 40kg from the front drive shafts that will total 76kg which isn’t bad. I just swapped out some part worn bridgestones for MPSC2’s which also saved another 5kgs of rotating mass so we are at around 80kg which is about half the additional weight premium of a 4S vs 2. I plan to add a half cage back in (agency power) which will add back some weight.
The geo does need to be altered a bit according to 9E when doing this conversion however they didn’t reveal the secret sauce here for that. I already have a fast road setup with additional front camber but who knows what they will recommend.
It will be interesting to drive it once all the work is complete as my only unknown is how taking the weight out primarily from the front will alter the balance, it may alter the ride height a bit at the front by a few mm. This wouldn’t be an issue with adjustable suspension but I am on stocks stuff right now. I have 15mm H&R spacers all round and at the suggestion of 9E changed the tyres before suspension and dialled in a better geo which should go a long way to making things as I would like.
In my head at least I get the best of the looks and pure driving dynamics but we will see in reality if it lives up to expectations or whether more hardware changes are required such as adjustable suspension to be able to dial the setup in as needed.
I am going to be doing this in the new year on my 996 C4S and am part way through a conversion to the missing 2S in the line up but keeping that 4S look.
Having read most of the online information (some of which needs to be taken with a large pinch of salt) I have lined up 9E to perform the work for me including changing over the engine mounts for RSS ones at the same time. They have done 20-30 cars in the UK so far, mainly larger power turbos but the hardware is exactly the same.
There aren’t any issues with electronics. The overall weight saving is in the region of 80-85lbs which isn’t as much as perhaps you would expect but certainly not to be sniffed at.
Deleting the rear wiper, front spare wheel and all the associated bits has saved 20kg’s and a lithium battery another 16kg. Along with approx 40kg from the front drive shafts that will total 76kg which isn’t bad. I just swapped out some part worn bridgestones for MPSC2’s which also saved another 5kgs of rotating mass so we are at around 80kg which is about half the additional weight premium of a 4S vs 2. I plan to add a half cage back in (agency power) which will add back some weight.
The geo does need to be altered a bit according to 9E when doing this conversion however they didn’t reveal the secret sauce here for that. I already have a fast road setup with additional front camber but who knows what they will recommend.
It will be interesting to drive it once all the work is complete as my only unknown is how taking the weight out primarily from the front will alter the balance, it may alter the ride height a bit at the front by a few mm. This wouldn’t be an issue with adjustable suspension but I am on stocks stuff right now. I have 15mm H&R spacers all round and at the suggestion of 9E changed the tyres before suspension and dialled in a better geo which should go a long way to making things as I would like.
In my head at least I get the best of the looks and pure driving dynamics but we will see in reality if it lives up to expectations or whether more hardware changes are required such as adjustable suspension to be able to dial the setup in as needed.
This will be interesting to hear how it drives after the conversion.
As the thread op I haven't done mine yet, I have fitted RSS engine mounts which are excellent, also done centre console delete and a bit of alcantara inside.
I got side tracked and bought a Cayman R in the mean time so nodding the 996 has been on the back burner lately.
Look forward to hearing how it goes.
As the thread op I haven't done mine yet, I have fitted RSS engine mounts which are excellent, also done centre console delete and a bit of alcantara inside.
I got side tracked and bought a Cayman R in the mean time so nodding the 996 has been on the back burner lately.
Look forward to hearing how it goes.
Will post up when done in the new year.
Running std 225/295 for the cup2’s, partly because the wider sizes were incrementally so much more costly and partly because 9e said until the front diff is removed don’t mess too much with front tyre size. I figured I can run these in 4wd until the conversion and in the dry the fronts should muster at least as much grip as a less but wider tyre. I have been guilty before of putting too much tyre on a car and loosing some playfulness so I didn’t want to repeat. Plus 295 rear for 320 ponies must be up there near the top in width/hp ratios!
I just managed to get the bolt in half cage powder coated yellow this weekend and the handbrake, shifter, rear console lid and steering wheel off for an alcantara overhaul.
Many swear words on the handbrake used. Total swine to break the glue and prise the thing off.
Running std 225/295 for the cup2’s, partly because the wider sizes were incrementally so much more costly and partly because 9e said until the front diff is removed don’t mess too much with front tyre size. I figured I can run these in 4wd until the conversion and in the dry the fronts should muster at least as much grip as a less but wider tyre. I have been guilty before of putting too much tyre on a car and loosing some playfulness so I didn’t want to repeat. Plus 295 rear for 320 ponies must be up there near the top in width/hp ratios!
I just managed to get the bolt in half cage powder coated yellow this weekend and the handbrake, shifter, rear console lid and steering wheel off for an alcantara overhaul.
Many swear words on the handbrake used. Total swine to break the glue and prise the thing off.
I think you have a lot of tyre there. I switched to 17 on my 996. That means 205 front and 255 rear. I'm using old ps3 tyres which were basically free and are not even that well liked. My car still has way more grip than I can imagine. Sometimes I feel a bit of unwillingness to turn in but it will turn.
I'm assuming you want to work more or think more about how to control your car if you're ditching the front wheel drive but please tell us what made you decide to do this and how you think the car will change.
I've only had two 911's, a 997 c2s in 2005 and my current 1998 996 which I bought last year. The 997 didn't real feel rear engined but my current 996 definitely let's you know about the extra weight at the rear. The 997 I just drove like any car and could throw it round without any real thought. My 996 has a lot of mods to the suspension and is quite stiff. This may add to the experience but you definitely feel the car bobbing around at the back and it's difficult to explain the feel of the lighter front but I tell my none car friends it's like holding a pool que at the light end and then waving it round. Initially it doesn't want to turn but then once it's turning it's happy to or almost wants to turn more.
Can I ask about the light weight battery. Is this just plug and play. My car just lives outside on the street. I leave it for a week or two sometimes and then just jump in and go. Will a light weight battery work for me?
I'm assuming you want to work more or think more about how to control your car if you're ditching the front wheel drive but please tell us what made you decide to do this and how you think the car will change.
I've only had two 911's, a 997 c2s in 2005 and my current 1998 996 which I bought last year. The 997 didn't real feel rear engined but my current 996 definitely let's you know about the extra weight at the rear. The 997 I just drove like any car and could throw it round without any real thought. My 996 has a lot of mods to the suspension and is quite stiff. This may add to the experience but you definitely feel the car bobbing around at the back and it's difficult to explain the feel of the lighter front but I tell my none car friends it's like holding a pool que at the light end and then waving it round. Initially it doesn't want to turn but then once it's turning it's happy to or almost wants to turn more.
Can I ask about the light weight battery. Is this just plug and play. My car just lives outside on the street. I leave it for a week or two sometimes and then just jump in and go. Will a light weight battery work for me?
@Griffter - I don’t honestly know how 9e deal with that, they do this all the time on big power turbos so I assume it’s the same solution on c4s however I can’t answer the technical question but I can ask!
@ATM - I researched a fair bit lithium options and the difficulty is the amp hour (capacity) rating which essentially means how much juice they hold and therefore how long they will last before going flat. You can easily get the CCA (power) where it needs to be but capacity is often a compromise. Not an issue for me as it’s a weekend car in a garage on trickle most of the time. For you if left for extended time it could be more of a pain than a benefit. Odessey lighter than stock (but not as light as lithium) might be ok but I deemed the weight saving not enough really to warrant the cost.
@ATM - I researched a fair bit lithium options and the difficulty is the amp hour (capacity) rating which essentially means how much juice they hold and therefore how long they will last before going flat. You can easily get the CCA (power) where it needs to be but capacity is often a compromise. Not an issue for me as it’s a weekend car in a garage on trickle most of the time. For you if left for extended time it could be more of a pain than a benefit. Odessey lighter than stock (but not as light as lithium) might be ok but I deemed the weight saving not enough really to warrant the cost.
[quote=Spinner20]@Griffter - I don’t honestly know how 9e deal with that, they do this all the time on big power turbos so I assume it’s the same solution on c4s however I can’t answer the technical question but I can ask!
Thanks I’d be interested to know if you get the chance to enquire.
Thanks I’d be interested to know if you get the chance to enquire.
Short update.
Have spent the last couple of months doing and organising a whole host of non-mechanical things like getting an agency power roll cage sorted, retrimming a few interior bits, Momo wheel, some spacers etc and the car is currently with rpm having a check over and a few fluids changed etc
The 2wd conversion bottom line is that unless you have adjustable suspension to lower the front ride height it is recommended that you leave the front drive shafts bolted in place. This negates the reasonably large c35/40kg weight saving by removing them. They can however be removed at a later stage.
So ideally, for me at least, doing to rwd conversion would mean new suspension and corner weight at the same time which I am sure would be excellent. However this substantially ups the ticket price.
I am going to give it a few more months until the weather breaks before considering options again and in the mean time bed in the cup 2’s and get a feel for where the car is at before taking things further.
Ideally I would do a Hartech 3.9 with new suspension and 2wd conversion but that’s out of reach for now so I think I will enjoy it and see what happens!
Have spent the last couple of months doing and organising a whole host of non-mechanical things like getting an agency power roll cage sorted, retrimming a few interior bits, Momo wheel, some spacers etc and the car is currently with rpm having a check over and a few fluids changed etc
The 2wd conversion bottom line is that unless you have adjustable suspension to lower the front ride height it is recommended that you leave the front drive shafts bolted in place. This negates the reasonably large c35/40kg weight saving by removing them. They can however be removed at a later stage.
So ideally, for me at least, doing to rwd conversion would mean new suspension and corner weight at the same time which I am sure would be excellent. However this substantially ups the ticket price.
I am going to give it a few more months until the weather breaks before considering options again and in the mean time bed in the cup 2’s and get a feel for where the car is at before taking things further.
Ideally I would do a Hartech 3.9 with new suspension and 2wd conversion but that’s out of reach for now so I think I will enjoy it and see what happens!
2WD conversion done. Custom suspension setup next week.
Currently with the conversion car is c.80kg light but all from the front end. Clearly this messes with stock suspension which now had much large wheel arch gap at front and looks odd. However........
Drives beautiful. I found the steering a touch lighter but brimming with feedback. On like for like tarmac I can now feel road surface and other changes much more crisply.
Performance is more spritely and the best way to describe it is the same effect as taking a passenger out your car. It’s noticeable.
This will end up as a 996 GTS.
Currently with the conversion car is c.80kg light but all from the front end. Clearly this messes with stock suspension which now had much large wheel arch gap at front and looks odd. However........
Drives beautiful. I found the steering a touch lighter but brimming with feedback. On like for like tarmac I can now feel road surface and other changes much more crisply.
Performance is more spritely and the best way to describe it is the same effect as taking a passenger out your car. It’s noticeable.
This will end up as a 996 GTS.
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