GT2 Slave Conversion Opinion
#46
12-15-2019 | 07:38 AM
Registered User
Joined: Mar 2009
Posts: 249
From: NYC
Rep Power: 27
IMHO (and I am sure I will get some flak for this) this has to be one of the most useless modifications that people do to their 996TTs. My accumulator and slave cylinder went south and I looked into the GT2 conversion at my race shop and they laughed. I track my car occasionally and drive it a bit (has 38k miles now on my 2001) and while the clutch has no feel and is light I have never stalled it and just adapted. I guess to each their own but to invest this much time and money into something that imparts a feel that is stiffer and just as annoying on the opposite end of the spectrum is silly. Again, bring on the flak!
#47
12-15-2019 | 08:21 AM
Registered User
Joined: Aug 2005
Posts: 729
From: Bend, OR
Rep Power: 101
I went the BBI route. Cost me about 1,100$ in parts (new slave, new front reservoir cap indicating brake fluid contents instead of Pentosin, DOT 4 fluid , new purple spring for clutch pedal) and did the work myself. Yeah - it's a pain getting on top of the transmission, but worth the investment of money and time.
For those of you interested in the process, these are some of the instructions one of the BBI people (non native English speaker) sent me :
With the combination of parts you got it would be best to first flush the OE system free of Pentosin.
Flush the system - can use a power bleeder - push the clutch in with a block of wood (this evacuates all the fluid from the master cylinder), and push through 4 liters of Dot 4. if you want to flush some through the master cylinder, don't push it in and out with the bleeder pressurized, its likely to cause damage...release the pressure, then pump and keep the reservoir topped up.
You would then install the new master cylinder. Pelican has a wealth of online resources for maintenance items and this is a good write up on replacing that unit.
https://www.pelicanparts.com/techart...eplacement.htm
With regards to the clutch helper spring - its pretty straight forward.
When the spring is compressed there should be a place to put a pin through it to secure it from expanding out again. On one end there is a hex bolt to secure it. Remove that and slide out the assembly.
For the Slave Cylinder:
You can use standard instructions part of the way.
https://www.rmeuropean.com/porsche-9...placement.aspx
Installing the new slave cylinder - zip tie the rubber boot onto the actuation rod, then stretch the boot out so it was able press back into the cylinder, keeping the rod seated in the cylinder and not loose. This makes it way easier to position the rod into the clutch fork. Also, make sure the allen key screw on the slave block is tight before installing.
Align the slave cylinder with mounting holes, ensure that the rod is positioned correctly relative to the fork.
Put the bolt in the hole furthest from clutch, at the slave bleed nipple end, and position your hand so you can push on the end of the cylinder while holding the bolt in place (with palm of your hand). push slow and steady (about 0.5in), and ensure the cylinder is lined up, if the rod is at an angle you won`t likely be able to push the cylinder. Get it finger tight, then put in the other bolt. You should be able to tell if the rod is still in the fork when you start to tighten the two bolts - there should be a fair bit of tension in the cylinder, pushing back towards you - if the cylinder is loose on the bolts, the rod slipped off the fork.
Connect the lines
Tighten the two bolts, and then bleed the system (the bleeder is 8mm - you`ll need a short wrench) - i used another 2 liters of DOT4 for this, again, while pumping the clutch to work out any stuff, etc in the lines. it may take a few bleeds to get good resistance in the clutch pedal and not have to pull it back up by hand.
Bleed the system properly, namely: connect the bleed bottle to the nipple, have the clutch pressed in with a board propped up to the seat, fill the reservoir with dot 4 and pump up the power-bleeder to 10psi, crack the bleed valve and push a liter or two of dot 4 through the system total. Stop every 200mL, close the bleed nipple, release the pressure on the power-bleeder, then bring the clutch pedal back up fully, pump it a few times by hand (without the power-bleeder pressurized), then push the clutched back in with a block of wood, apply 10psi with the power-bleeder and then crack the bleed nipple again.
Raise the engine back up and tighten the engine mount nuts, reconnect the axle, and reinstall the airbox, then lower the car to test the clutch by running the car and pumping the clutch - try to engage 1st - VERY gently as it feels WAY different and has a totally different engagement point than the old system If it doesn`t go in gear it probably means you have air in the lines - raise it up and bleed it again. if the pedal doesn`t return after pushing it in, pump it a quite a few times by hand until it gets resistance, then rebleed if its not actuating the clutch still (can`t get it in gear).
If it works, raise the car back up, fit the hoses, brackets, under trays back where they belong and button it all back up.
Note: the power steering system doesn`t need to be bleed manually, simply run the car and turn the steering lock to lock a few times and it will work the air out.
For those of you interested in the process, these are some of the instructions one of the BBI people (non native English speaker) sent me :
With the combination of parts you got it would be best to first flush the OE system free of Pentosin.
Flush the system - can use a power bleeder - push the clutch in with a block of wood (this evacuates all the fluid from the master cylinder), and push through 4 liters of Dot 4. if you want to flush some through the master cylinder, don't push it in and out with the bleeder pressurized, its likely to cause damage...release the pressure, then pump and keep the reservoir topped up.
You would then install the new master cylinder. Pelican has a wealth of online resources for maintenance items and this is a good write up on replacing that unit.
https://www.pelicanparts.com/techart...eplacement.htm
With regards to the clutch helper spring - its pretty straight forward.
When the spring is compressed there should be a place to put a pin through it to secure it from expanding out again. On one end there is a hex bolt to secure it. Remove that and slide out the assembly.
For the Slave Cylinder:
You can use standard instructions part of the way.
https://www.rmeuropean.com/porsche-9...placement.aspx
Installing the new slave cylinder - zip tie the rubber boot onto the actuation rod, then stretch the boot out so it was able press back into the cylinder, keeping the rod seated in the cylinder and not loose. This makes it way easier to position the rod into the clutch fork. Also, make sure the allen key screw on the slave block is tight before installing.
Align the slave cylinder with mounting holes, ensure that the rod is positioned correctly relative to the fork.
Put the bolt in the hole furthest from clutch, at the slave bleed nipple end, and position your hand so you can push on the end of the cylinder while holding the bolt in place (with palm of your hand). push slow and steady (about 0.5in), and ensure the cylinder is lined up, if the rod is at an angle you won`t likely be able to push the cylinder. Get it finger tight, then put in the other bolt. You should be able to tell if the rod is still in the fork when you start to tighten the two bolts - there should be a fair bit of tension in the cylinder, pushing back towards you - if the cylinder is loose on the bolts, the rod slipped off the fork.
Connect the lines
Tighten the two bolts, and then bleed the system (the bleeder is 8mm - you`ll need a short wrench) - i used another 2 liters of DOT4 for this, again, while pumping the clutch to work out any stuff, etc in the lines. it may take a few bleeds to get good resistance in the clutch pedal and not have to pull it back up by hand.
Bleed the system properly, namely: connect the bleed bottle to the nipple, have the clutch pressed in with a board propped up to the seat, fill the reservoir with dot 4 and pump up the power-bleeder to 10psi, crack the bleed valve and push a liter or two of dot 4 through the system total. Stop every 200mL, close the bleed nipple, release the pressure on the power-bleeder, then bring the clutch pedal back up fully, pump it a few times by hand (without the power-bleeder pressurized), then push the clutched back in with a block of wood, apply 10psi with the power-bleeder and then crack the bleed nipple again.
Raise the engine back up and tighten the engine mount nuts, reconnect the axle, and reinstall the airbox, then lower the car to test the clutch by running the car and pumping the clutch - try to engage 1st - VERY gently as it feels WAY different and has a totally different engagement point than the old system If it doesn`t go in gear it probably means you have air in the lines - raise it up and bleed it again. if the pedal doesn`t return after pushing it in, pump it a quite a few times by hand until it gets resistance, then rebleed if its not actuating the clutch still (can`t get it in gear).
If it works, raise the car back up, fit the hoses, brackets, under trays back where they belong and button it all back up.
Note: the power steering system doesn`t need to be bleed manually, simply run the car and turn the steering lock to lock a few times and it will work the air out.
Last edited by Yves; 12-15-2019 at 08:24 AM.
Thread
Thread Starter
Forum
Replies
Last Post
Carbon
996 Turbo / GT2
23
06-14-2012 05:13 AM
drhenrock
996 Turbo / GT2
18
12-25-2010 04:28 AM
