GT3 gearbox - cooling it down
07-02-2013, 03:58 PM
#31
Rennlist Member
I agree with Peter's description of the symptoms, additionally I recently have the problem with the reverse gear being stuck (parking on slight slope after tracking, I put the car in reverse to avoid using handbrake). I don't think the synchro is involved here since I hardly ever use reverse? (by the way when I say stuck, I mean really having to pull as if you want to tear it away!). Rarely a problem when doing a lap (occasionally 4th to 3rd).
Next day, zero residual, completely gone.
07-02-2013, 04:02 PM
#32
Rennlist Member
Am I right that with a high clamp PP combined with high grip slicks it will likely be less forgiving if you do a money shift?
I have not done it yet, but with Toyo's and these clutches some have gotten away with going to 2nd instead of 4th..
I have not done it yet, but with Toyo's and these clutches some have gotten away with going to 2nd instead of 4th..
07-02-2013, 04:12 PM
#33
That's correct. The clutch in this case acts like a 'fuse' avoiding catastrophic failure. One more reason why Porsche goes PDK, to eliminate driver error at least in this case.
07-03-2013, 01:35 PM
#38
Nordschleife Master
PDK's are known for overheating their clutches too.
Interesting discussion here. I think you guys may be on to something. I don't take my head outside of the gearbox very often so much of what is being said here is news to me.
As was mentioned previously, I've never heard of this problem on high powered GT2s, which suggests that maybe something has changed more than just the part numbers. The friction of the clutch disc does seem a likely culprit.
The other thing that I wondered about last night after I read through this is the LWFW. I wonder about the flywheel acting as a heat sink. If the flywheel is lighter and thinner, maybe it is in part to blame? Less mass and less material to absorb the heat from the clutch? Just thinking out loud here. Regardless, it does sound like you GT3 owners do have a clutch assembly issue to figure out because in addition to wearing out those parts, this problem increases the wear on the things inside of your gearbox, primarily your synchros.
Might be time to start dumping the factory clutch and flywheel assemblies and delving into the aftermarket for them.
Interesting discussion here. I think you guys may be on to something. I don't take my head outside of the gearbox very often so much of what is being said here is news to me.
As was mentioned previously, I've never heard of this problem on high powered GT2s, which suggests that maybe something has changed more than just the part numbers. The friction of the clutch disc does seem a likely culprit.
The other thing that I wondered about last night after I read through this is the LWFW. I wonder about the flywheel acting as a heat sink. If the flywheel is lighter and thinner, maybe it is in part to blame? Less mass and less material to absorb the heat from the clutch? Just thinking out loud here. Regardless, it does sound like you GT3 owners do have a clutch assembly issue to figure out because in addition to wearing out those parts, this problem increases the wear on the things inside of your gearbox, primarily your synchros.
Might be time to start dumping the factory clutch and flywheel assemblies and delving into the aftermarket for them.
07-03-2013, 01:47 PM
#40
Matt,
I would say that pressure plate is one of my theories, as with the high temps caused by the friction, is possibly distorting the 'springs' not allowing a complete de-clutch. Again, no proof yet, just thoughts.
I would say that pressure plate is one of my theories, as with the high temps caused by the friction, is possibly distorting the 'springs' not allowing a complete de-clutch. Again, no proof yet, just thoughts.
07-03-2013, 01:50 PM
#41
There are a few aftermarket options that work well, I will stick to Sachs or Tilton as I personally never had success with others.
Another issue is a lot of the guys are not ready to deal with compromise, which is minimal if any with the unsprung HD Sachs kit, or not yet ready to dump 6.5K on a Carbon tilton which if not used correctly will also require maintenance due to wear on the multi carbon discs.
Another issue is a lot of the guys are not ready to deal with compromise, which is minimal if any with the unsprung HD Sachs kit, or not yet ready to dump 6.5K on a Carbon tilton which if not used correctly will also require maintenance due to wear on the multi carbon discs.
07-03-2013, 01:58 PM
#43
Rennlist Member
If it is the lwf(9 lb) that's causing the issue wonder if someone just put the 6rs lwf(11 lb) pp/clutch disc and see if that holds up. Don't think anyone wants to put a dual mass fw in their rs. 6rs should bolt rt in. Mike
