GT2 master/slave conversion
05-19-2017, 12:35 PM
#16
I too have some problems with going from stand-still in sport mode. If I'm not really careful in balancing throttle and clutch I get this awkward jerky motion. I can't even imagine how it would be with an aggressive tune. Admittedly, I may not be a trained racing driver but I've been driving manual cars for 20+ years and have had the car for over 3 years. I'll probably do the GT2-slave conversion eventually but if I knew it would take care of this issue I'd do it like yesterday.
05-19-2017, 12:38 PM
#17
Just out of curiosity, why is it a GT3 spring with the GT2 slave? Wouldn't the GT2 spring be appropriate? (Or are they effectively the same, but the GT3 part is cheaper because it's not a GT2?)
Edit: I'm almost hoping my clutch will fail sometime soon so I can do this (along with a Sachs 2.5)!
Edit: I'm almost hoping my clutch will fail sometime soon so I can do this (along with a Sachs 2.5)!
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dak996 (05-22-2022)
05-19-2017, 02:59 PM
#18
Instructor
Thread Starter
All of these changes to improve clutch feel/response has me thinking...
I've only had the car for a few months and around 1k miles, I don't drive it often, but I still don't think I have a good feel for the clutch, does this mean I am not alone with this experience? I've been driving manual cars for 10+ years, admittingly not in cars this powerful...
And forget some stop and go in sport mode, the throttle is so touchy and if you hit one little bump it either upsets throttle input or clutch engagement and I feel like I'm just learning to drive a manual.
Oh and the clutch accumulator was changed by the dealer prior to sale because of a stiff clutch, per the invoice, I never drove it before it was fixed.
Do others have the same experience and are these clutch changes to address some of these issues?
I've only had the car for a few months and around 1k miles, I don't drive it often, but I still don't think I have a good feel for the clutch, does this mean I am not alone with this experience? I've been driving manual cars for 10+ years, admittingly not in cars this powerful...
And forget some stop and go in sport mode, the throttle is so touchy and if you hit one little bump it either upsets throttle input or clutch engagement and I feel like I'm just learning to drive a manual.
Oh and the clutch accumulator was changed by the dealer prior to sale because of a stiff clutch, per the invoice, I never drove it before it was fixed.
Do others have the same experience and are these clutch changes to address some of these issues?
I had that more severely in sport mode and occasionally in normal. Comparing the two, I think I've figured out where the inconsistency comes from. In my humble opinion...
With the stock clutch the initial engagement point is fairly consistent, but full engagement is much closer towards the end of the clutch travel than one would expect. So what I found was if I was getting 'sloppy' I'd get the initial clutch bite, release the clutch to about 3/4 or 4/5 of the way out (at which point it 'felt' like it was fully engaged because the car was moving along with a good amount of pull) and the last bit of travel I would let go faster, because modulating the clutch to the very last 10th's of an inch is a PITA. The problem is that even at 3/4 to 4/5 the clutch must not be fully engaged and I was still riding it so when I released that last 1/4 to 1/5 of travel quickly it would feel like I was dropping the clutch. It basically requires a lot more muscle memory/practice/thought for the proper throttle/clutch modulation.
What I'm noticing with the conversion is that the bite point is again fairly consistent. However, full engagement happens very quickly from the point of initial bite and the last few inches of clutch pedal travel is essentially dead space. So if I get lazy and quickly release the rest of the way I don't notice anything because there really is nothing more happening from that point on. Again my humble opinion based completely on what it feels like to me, those of you who know more about the actual physics and mechanics of what is going on feel free to chime in.
05-19-2017, 03:12 PM
#19
I had that more severely in sport mode and occasionally in normal. Comparing the two, I think I've figured out where the inconsistency comes from. In my humble opinion...
With the stock clutch the initial engagement point is fairly consistent, but full engagement is much closer towards the end of the clutch travel than one would expect. So what I found was if I was getting 'sloppy' I'd get the initial clutch bite, release the clutch to about 3/4 or 4/5 of the way out (at which point it 'felt' like it was fully engaged because the car was moving along with a good amount of pull) and the last bit of travel I would let go faster, because modulating the clutch to the very last 10th's of an inch is a PITA. The problem is that even at 3/4 to 4/5 the clutch must not be fully engaged and I was still riding it so when I released that last 1/4 to 1/5 of travel quickly it would feel like I was dropping the clutch. It basically requires a lot more muscle memory/practice/thought for the proper throttle/clutch modulation.
What I'm noticing with the conversion is that the bite point is again fairly consistent. However, full engagement happens very quickly from the point of initial bite and the last few inches of clutch pedal travel is essentially dead space. So if I get lazy and quickly release the rest of the way I don't notice anything because there really is nothing more happening from that point on. Again my humble opinion based completely on what it feels like to me, those of you who know more about the actual physics and mechanics of what is going on feel free to chime in.
With the stock clutch the initial engagement point is fairly consistent, but full engagement is much closer towards the end of the clutch travel than one would expect. So what I found was if I was getting 'sloppy' I'd get the initial clutch bite, release the clutch to about 3/4 or 4/5 of the way out (at which point it 'felt' like it was fully engaged because the car was moving along with a good amount of pull) and the last bit of travel I would let go faster, because modulating the clutch to the very last 10th's of an inch is a PITA. The problem is that even at 3/4 to 4/5 the clutch must not be fully engaged and I was still riding it so when I released that last 1/4 to 1/5 of travel quickly it would feel like I was dropping the clutch. It basically requires a lot more muscle memory/practice/thought for the proper throttle/clutch modulation.
What I'm noticing with the conversion is that the bite point is again fairly consistent. However, full engagement happens very quickly from the point of initial bite and the last few inches of clutch pedal travel is essentially dead space. So if I get lazy and quickly release the rest of the way I don't notice anything because there really is nothing more happening from that point on. Again my humble opinion based completely on what it feels like to me, those of you who know more about the actual physics and mechanics of what is going on feel free to chime in.
05-19-2017, 03:18 PM
#20
Instructor
Thread Starter
Not at all. The stock clutch really isn't a 'problem'. What happens in most cases is the stock clutch slave cylinder starts to go and you get the general symptoms of low fluid in the power steering reservoir (they're connected), overflow of the reservoir located in the frunk, unable to depress clutch, etc. It's not an uncommon problem in these cars so the options are GT2 conversion because its an upgrade while you're at it or go back to OEM and risk it happening again.
05-19-2017, 03:21 PM
#21
Not at all. The stock clutch really isn't a 'problem'. What happens in most cases is the stock clutch slave cylinder starts to go and you get the general symptoms of low fluid in the power steering reservoir (they're connected), overflow of the reservoir located in the frunk, unable to depress clutch, etc. It's not an uncommon problem in these cars so the options are GT2 conversion because its an upgrade while you're at it or go back to OEM and risk it happening again.
Guess I just need some more seat time!
05-19-2017, 06:13 PM
#22
Instructor
Thread Starter
. There are plenty of other more desirable mods in my opinion.
06-02-2017, 03:26 PM
#24
Rennlist Member
BBI makes a clutch slave upgrade that's a drop-in replacement for the OEM part. You save on labour, and it might be more foolproof and/or more cost-effective if your shop isn't used to doing the GT2 conversions. Costs more than the OEM GT2 parts though, so in the end it comes out about the same, and should have very similar results. (I've got one on order right now!)
The GT3 assist spring isn't strictly necessary, but it's generally recommended. Apparently the pedal becomes very stiff without it. Once I get mine installed next week I'll report back...
The GT3 assist spring isn't strictly necessary, but it's generally recommended. Apparently the pedal becomes very stiff without it. Once I get mine installed next week I'll report back...
06-02-2017, 07:15 PM
#26
Rennlist Member
You could always try it with the stock spring at first, then upgrade if it feels too stiff.
06-05-2017, 09:16 AM
#27
Instructor
Thread Starter
Definitely would recommend the spring, I use mine as a semi dd (2-3 days) and it's significantly stiffer than stock.
06-05-2017, 04:53 PM
#29
06-05-2017, 07:28 PM
#30
The BBi kit preserves the way the factory power steering and clutch reservoir work whereas the EVOMS kit (and GT2 OEM) separate the power steering and clutch reservoir systems. The BBi is an in-house made piece, appearing to be very high quality. The EVOMS basically uses all factory parts except for the slave mounting bracket. If you choose to go 100% OEM, you need to have a couple holes tapped on your factory trans casing, I believe.
The BBi kit is pretty much just the slave, whereas the EVOMS kit comes with the slave, clutch helper spring, necessary bracket, etc.
Regardless of which kit you use, the GT3/GT2 clutch assist spring will help reduce the force required to depress the clutch pedal. While some claim the BBi setup requires less effort than the EVOMS or GT2 OEM conversion, it appears like the difference is pretty minimal.
All of the above is based upon what I have read/heard (and therefore may not be fully accurate) - so feel free to fact check!
The BBi kit is pretty much just the slave, whereas the EVOMS kit comes with the slave, clutch helper spring, necessary bracket, etc.
Regardless of which kit you use, the GT3/GT2 clutch assist spring will help reduce the force required to depress the clutch pedal. While some claim the BBi setup requires less effort than the EVOMS or GT2 OEM conversion, it appears like the difference is pretty minimal.
All of the above is based upon what I have read/heard (and therefore may not be fully accurate) - so feel free to fact check!