I have a 360 F1, 45k miles, current clutch installed at 23k (full clutch kit only) before my ownership and showing 35% worn (65% remaining). I have a CS TCU fitted that was installed correctly by my tech and the car drives beautifully.... Occasionally I notice a very slight clutch drag when in gear and stopped always when the car is very hot. It’s very infrequent (3-4 times in the last 4K miles,12 months) and if I pull away again it may be ok at the next stop 2 minutes down the road. If I or the tech check the gearbox input shaft it usually isn’t turning but we’ve also never caught it dragging. I was questioning him whether this is just an adjustment issue but he suggested that the pressure plates get tired and with 5 years/21k on the clutch it will be reaching the end of it’s life and with even with full TO travel they can struggle to fully open the clutch. I totally trust him and he definitely isn’t trying to sell me a clutch unnecessarily (he’s always booked for months) but I’ve never heard of this before and it always seems to be friction plate wear signalling no the end. If it needs changing I’m fine with that but as it drives so well I’m reluctant to look at this unless absolutely necessary although I’m aware that a dragging clutch could damage the box if left alone. Although I think I’m far from there yet. WRT to PIS it’s 4.6 for what it’s worth and I’m pretty sure the first time it dragged we raised it from 4.6 to 4.7. I could swear it’s adjusted itself back but didn’t think there was any adaptations on PIS. Maybe my memory is failing.... Any thoughts?.......M
You could raise the pis to stop the creeping. As long as the clutch fully engages around 1400 1500 rpm you should be just fine.
There are many articles around about setting the PIS. The general consensus is to set the PIS at a point where there is not any noticeable creep with the car in gear on a level surface. One technique that my tech uses is to set the PIS level to a point where creep is just noticed. Then set it up one notch at a time until no creep. Setting up the PIS should be done when the car is fully warmed up If you set the PIS level when the clutch is cold then it is highly likely that as the parts expand with the temperature rise that the clutch will slightly drag at these elevated temperatures. If you noticed that after the car has fully warmed up that your clutch drags just bit, have the PIS raised one notch. If I am not mistaken I think one notch equals 1/10 of a millimeter Steve
Thanks for the responses and I understand the PIS can be increased. That was my thought too. It was just the comment that with a 6 year, 22k mile clutch it is likely to be a tired pressure plate that can cause the drag. It’s something I’ve never heard before. I think I will run the car and graph the clutch position to see it I can work out at what point the clutch moves from fully open through the bite point to fully closed..... Sent from my iPhone using Tapatalk
Most everyone believes it will. Certainly, if you notice that the car creeps a bit it should. Shifting to neutral is same as if you had a manual transmission with three pedals. Most drivers would recommend shifting a 3-pedal car to neutral while at long stops. On the F1 it not only should prolong clutch wear, but is also easier on the the clutch release bearing. Steve
On an F1 the clutch is open in neutral so no reduction in bearing wear. Like a manual with the clutch depressed. I’ve an update to my post I’ll make later but I’ve looked the clutch position at different times and think I’ve learnt something M Sent from my iPhone using Tapatalk
I had a bit of a look this afternoon with the xdiag kit. The current clutch closed position is 18.6 and the PIS is set at 4.6. I make it that the kiss point should be somewhere around 14 (if I’ve understood the operation correctly) and it will transmit increasing amounts of torque until fully closed at 18.6 In neutral the clutch position is around 10 and the gearbox input shaft isn’t rotating. The clutch must be fully open. Image Unavailable, Please Login When I select first the clutch closes slightly to 11.75. The gearbox shaft isn’t rotating but it can’t as it is locked by the gearbox. Image Unavailable, Please Login Same with reverse selected..... Image Unavailable, Please Login So when you select a gear the clutch closes slightly.....a sort of pre-start position waiting for a throttle input. This is where I’ve felt the drag but it is still 6.8 mm from fully closed (or 6.8 mm open if you prefer). Whilst driving it is hard to determine where the clutch is accurately as the refresh time on the datastream is about 1 second which isn’t fast enough to track it. I was trying to see how far the clutch opens beyond the kiss point during a change. Here are a few graphs of engine and gearbox primary speed (which are overlaid apart from during the changes) along with clutch position and selected gear. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login So what have I learnt? I struggle to see how the PIS is set in neutral by watching the gearbox primary, as the clutch closes slightly after a gear is selected and that would almost certainly cause drag when a gear is selected. On my car the clutch will open beyond the point where it’s been dragging so I expect a small PIS increase will stop the very infrequent creep I’ve seen. All of this assumes the clutch itself accurately follows the movement of the release bearing and the sensor is working properly. It would be good to understand how far the clutch opens during changes. Does it open to the kiss point or a few mm beyond? Looking at the portrait graph it is the latter as most changes appear to be around 6mm. If only I could set the PIS in decimals! M
