Double clutch or Single clutch?
07-11-2018, 01:49 AM
#31
Drifting
Did you just make that up based on one example? I know that clutches can last a long time if operated well but everyone I’ve always talked to still considers them a wear item. I feel like the dealership would know considering they change them out on a regular basis, unless you think they’re randomly replacing perfectly good clutches for no reason.
07-11-2018, 02:59 AM
#32
Drifting
Early cars had hand crank levers
sticking out the front hood for a means to crank up the engine to start
Astronauts used drink Tang
and so is double clutching part of history, unless your are still driving
a piece of history or a truck around
likely no need
sticking out the front hood for a means to crank up the engine to start
Astronauts used drink Tang
and so is double clutching part of history, unless your are still driving
a piece of history or a truck around
likely no need
Last edited by R.Deacon; 07-11-2018 at 03:52 AM.
07-11-2018, 03:23 AM
#33
Rennlist Member
Also, this business about clutches lasting the lifetime of the car is more about the driver than anything else. Brakes often have wear correlated as well. Wait until the last minute to brake hard at every stoplight, and your brakes will wear much faster. It only takes 10 mins to destroy of clutch if you want to.
07-11-2018, 09:50 AM
#34
This. Also, I’ll point out the double clutching achieves the transmission input shaft spin-up twice when in fact rev marching achieves it once and faster. You can clutch once, rev match, then shift, achieving much of the benefit of double clutching by single-clutching.
07-11-2018, 09:59 AM
#35
Rennlist Member
EDIT: FYI - the gears in the transmission are actually always engaged, in all gears, spinning at the time whenever the driver wheels are spinning. Or when the engine is on and the clutch is released (even in neutral).
07-11-2018, 11:44 AM
#36
Drifting
This. Also, I’ll point out the double clutching achieves the transmission input shaft spin-up twice when in fact rev marching achieves it once and faster. You can clutch once, rev match, then shift, achieving much of the benefit of double clutching by single-clutching.
Also, this business about clutches lasting the lifetime of the car is more about the driver than anything else. Brakes often have wear correlated as well. Wait until the last minute to brake hard at every stoplight, and your brakes will wear much faster. It only takes 10 mins to destroy of clutch if you want to.
07-11-2018, 01:06 PM
#37
Still, even if the clutch is designed to last 200k miles when operated correctly and my dealership was highly underestimating their expected lifespam, I wouldn’t consider that the life of the car.
Thanks to this thread, if I’m a passenger and the driver downshifts without double-clutching, I may no longer be thinking “they’re going to wear their transmission out” however I’ll still be thinking “they don’t know how to drive stick”. I don’t care if that just makes me an old geezer that doesn’t realize it’s not necessary anymore.
Thanks to this thread, if I’m a passenger and the driver downshifts without double-clutching, I may no longer be thinking “they’re going to wear their transmission out” however I’ll still be thinking “they don’t know how to drive stick”. I don’t care if that just makes me an old geezer that doesn’t realize it’s not necessary anymore.
07-11-2018, 01:22 PM
#38
Drifting
Still, even if the clutch is designed to last 200k miles when operated correctly and my dealership was highly underestimating their expected lifespam, I wouldn’t consider that the life of the car.
Thanks to this thread, if I’m a passenger and the driver downshifts without double-clutching, I may no longer be thinking “they’re going to wear their transmission out” however I’ll still be thinking “they don’t know how to drive stick”. I don’t care if that just makes me an old geezer that doesn’t realize it’s not necessary anymore.
Thanks to this thread, if I’m a passenger and the driver downshifts without double-clutching, I may no longer be thinking “they’re going to wear their transmission out” however I’ll still be thinking “they don’t know how to drive stick”. I don’t care if that just makes me an old geezer that doesn’t realize it’s not necessary anymore.
Who would really waste time double clutching in a "race car"? You're trying to shave off seconds. And if people on this forum agonize over milliseconds in shift times between a PDK and manual, but now it's toooootally no problem to throw the car into neutral, let out the clutch, and then shift again... for each and every gear change? Such a strange bunch we are. Synchros were invented to people wouldn't have to do this nonsense.
07-11-2018, 01:26 PM
#39
Yeah, you're an old geezer Who would really waste time double clutching in a "race car"? You're trying to shave off seconds. And if people on this forum agonize over milliseconds in shift times between a PDK and manual, but now it's toooootally no problem to throw the car into neutral, let out the clutch, and then shift again... for each and every gear change? Such a strange bunch we are.
Who would really waste time double clutching in a "race car"? You're trying to shave off seconds. And if people on this forum agonize over milliseconds in shift times between a PDK and manual, but now it's toooootally no problem to throw the car into neutral, let out the clutch, and then shift again... for each and every gear change? Such a strange bunch we are.
07-11-2018, 02:18 PM
#40
Three Wheelin'
There's no need whatsoever to double clutch unless you have a 1942 packard. Here's why:
1) there are 3 different things potentially spinning at different speeds that you have to "match" in a trans: engine, input shaft and output shaft.
2) the output shaft is connected to the rear wheels and is "hardwired" - you can't change its speed.
3) the engine spins at whatever RPMs - you change the speed with the gas pedal when the clutch is in.
4) the input shaft is connected to the output shaft by the gear lever and it's connected to the engine by the clutch.
When you push in the clutch, the IP shaft is no longer connected to the engine. If you leave trans in gear, the IP shaft continues to spin because it's connect to the OP shaft. When you shift into neutral, it isn't connected to anything and slows down due to inertia. It's by itself. When you shift into a higher or lower gear, the synchros (think ring and cone) match the input shaft speed to the output shaft speed. Prior to 50 years ago, you had to double clutch because without synchros the gear teeth of IP and OP were at different speeds, so you would tear up the gears by trying to jam them together. You could solve this problem by letting the clutch out in neutral and reconnecting the IP to the engine, which would allow you to spin the IP faster and match the IP-OP gear speeds. Double clutching kept you from tearing up the gears as they tried to mesh at different speeds.
You aren't going to tear up/grind the gears now because the synchros match the IP-OP speeds, and trying to extend the life of your synchros is silly. They aren't under load when the clutch is in, so all they are doing is spinning up a free-wheeling IP shaft (a couple pounds maybe?). In fact, if we are going to engage in 10 sigma overthinking and you believe the 2lb freewheeling IP inertia is going to wear things out, you will probably wear out the clutch faster by doubling the number of times it has to create friction with the flywheel (this argument is admittedly equivalently silly).
besides, we all know that real men triple clutch
1) there are 3 different things potentially spinning at different speeds that you have to "match" in a trans: engine, input shaft and output shaft.
2) the output shaft is connected to the rear wheels and is "hardwired" - you can't change its speed.
3) the engine spins at whatever RPMs - you change the speed with the gas pedal when the clutch is in.
4) the input shaft is connected to the output shaft by the gear lever and it's connected to the engine by the clutch.
When you push in the clutch, the IP shaft is no longer connected to the engine. If you leave trans in gear, the IP shaft continues to spin because it's connect to the OP shaft. When you shift into neutral, it isn't connected to anything and slows down due to inertia. It's by itself. When you shift into a higher or lower gear, the synchros (think ring and cone) match the input shaft speed to the output shaft speed. Prior to 50 years ago, you had to double clutch because without synchros the gear teeth of IP and OP were at different speeds, so you would tear up the gears by trying to jam them together. You could solve this problem by letting the clutch out in neutral and reconnecting the IP to the engine, which would allow you to spin the IP faster and match the IP-OP gear speeds. Double clutching kept you from tearing up the gears as they tried to mesh at different speeds.
You aren't going to tear up/grind the gears now because the synchros match the IP-OP speeds, and trying to extend the life of your synchros is silly. They aren't under load when the clutch is in, so all they are doing is spinning up a free-wheeling IP shaft (a couple pounds maybe?). In fact, if we are going to engage in 10 sigma overthinking and you believe the 2lb freewheeling IP inertia is going to wear things out, you will probably wear out the clutch faster by doubling the number of times it has to create friction with the flywheel (this argument is admittedly equivalently silly).
besides, we all know that real men triple clutch
07-11-2018, 02:25 PM
#41
RL Community Team
Rennlist Member
Rennlist Member
There's no need whatsoever to double clutch unless you have a 1942 packard. Here's why:
1) there are 3 different things potentially spinning at different speeds that you have to "match" in a trans: engine, input shaft and output shaft.
2) the output shaft is connected to the rear wheels and is "hardwired" - you can't change its speed.
3) the engine spins at whatever RPMs - you change the speed with the gas pedal when the clutch is in.
4) the input shaft is connected to the output shaft by the gear lever and it's connected to the engine by the clutch.
When you push in the clutch, the IP shaft is no longer connected to the engine. If you leave trans in gear, the IP shaft continues to spin because it's connect to the OP shaft. When you shift into neutral, it isn't connected to anything and slows down due to inertia. It's by itself. When you shift into a higher or lower gear, the synchros (think ring and cone) match the input shaft speed to the output shaft speed. Prior to 50 years ago, you had to double clutch because without synchros the gear teeth of IP and OP were at different speeds, so you would tear up the gears by trying to jam them together. You could solve this problem by letting the clutch out in neutral and reconnecting the IP to the engine, which would allow you to spin the IP faster and match the IP-OP gear speeds. Double clutching kept you from tearing up the gears as they tried to mesh at different speeds.
You aren't going to tear up/grind the gears now because the synchros match the IP-OP speeds, and trying to extend the life of your synchros is silly. They aren't under load when the clutch is in, so all they are doing is spinning up a free-wheeling IP shaft (a couple pounds maybe?). In fact, if we are going to engage in 10 sigma overthinking and you believe the 2lb freewheeling IP inertia is going to wear things out, you will probably wear out the clutch faster by doubling the number of times it has to create friction with the flywheel (this argument is admittedly equivalently silly).
besides, we all know that real men PDK
1) there are 3 different things potentially spinning at different speeds that you have to "match" in a trans: engine, input shaft and output shaft.
2) the output shaft is connected to the rear wheels and is "hardwired" - you can't change its speed.
3) the engine spins at whatever RPMs - you change the speed with the gas pedal when the clutch is in.
4) the input shaft is connected to the output shaft by the gear lever and it's connected to the engine by the clutch.
When you push in the clutch, the IP shaft is no longer connected to the engine. If you leave trans in gear, the IP shaft continues to spin because it's connect to the OP shaft. When you shift into neutral, it isn't connected to anything and slows down due to inertia. It's by itself. When you shift into a higher or lower gear, the synchros (think ring and cone) match the input shaft speed to the output shaft speed. Prior to 50 years ago, you had to double clutch because without synchros the gear teeth of IP and OP were at different speeds, so you would tear up the gears by trying to jam them together. You could solve this problem by letting the clutch out in neutral and reconnecting the IP to the engine, which would allow you to spin the IP faster and match the IP-OP gear speeds. Double clutching kept you from tearing up the gears as they tried to mesh at different speeds.
You aren't going to tear up/grind the gears now because the synchros match the IP-OP speeds, and trying to extend the life of your synchros is silly. They aren't under load when the clutch is in, so all they are doing is spinning up a free-wheeling IP shaft (a couple pounds maybe?). In fact, if we are going to engage in 10 sigma overthinking and you believe the 2lb freewheeling IP inertia is going to wear things out, you will probably wear out the clutch faster by doubling the number of times it has to create friction with the flywheel (this argument is admittedly equivalently silly).
besides, we all know that real men PDK
07-11-2018, 02:41 PM
#42
This is awesome, it used to be that real drivers had to drive a manual and now not only do you have to have a 3 pedal car but also double clutch, all to be a "Better" driver, awesome. Next it'll have to be mounted on the steering column "3 in the Tree for me!"
07-11-2018, 02:42 PM
#43
Drifting
There's no need whatsoever to double clutch unless you have a 1942 packard. Here's why:
1) there are 3 different things potentially spinning at different speeds that you have to "match" in a trans: engine, input shaft and output shaft.
2) the output shaft is connected to the rear wheels and is "hardwired" - you can't change its speed.
3) the engine spins at whatever RPMs - you change the speed with the gas pedal when the clutch is in.
4) the input shaft is connected to the output shaft by the gear lever and it's connected to the engine by the clutch.
When you push in the clutch, the IP shaft is no longer connected to the engine. If you leave trans in gear, the IP shaft continues to spin because it's connect to the OP shaft. When you shift into neutral, it isn't connected to anything and slows down due to inertia. It's by itself. When you shift into a higher or lower gear, the synchros (think ring and cone) match the input shaft speed to the output shaft speed. Prior to 50 years ago, you had to double clutch because without synchros the gear teeth of IP and OP were at different speeds, so you would tear up the gears by trying to jam them together. You could solve this problem by letting the clutch out in neutral and reconnecting the IP to the engine, which would allow you to spin the IP faster and match the IP-OP gear speeds. Double clutching kept you from tearing up the gears as they tried to mesh at different speeds.
You aren't going to tear up/grind the gears now because the synchros match the IP-OP speeds, and trying to extend the life of your synchros is silly. They aren't under load when the clutch is in, so all they are doing is spinning up a free-wheeling IP shaft (a couple pounds maybe?). In fact, if we are going to engage in 10 sigma overthinking and you believe the 2lb freewheeling IP inertia is going to wear things out, you will probably wear out the clutch faster by doubling the number of times it has to create friction with the flywheel (this argument is admittedly equivalently silly).
besides, we all know that real men triple clutch
1) there are 3 different things potentially spinning at different speeds that you have to "match" in a trans: engine, input shaft and output shaft.
2) the output shaft is connected to the rear wheels and is "hardwired" - you can't change its speed.
3) the engine spins at whatever RPMs - you change the speed with the gas pedal when the clutch is in.
4) the input shaft is connected to the output shaft by the gear lever and it's connected to the engine by the clutch.
When you push in the clutch, the IP shaft is no longer connected to the engine. If you leave trans in gear, the IP shaft continues to spin because it's connect to the OP shaft. When you shift into neutral, it isn't connected to anything and slows down due to inertia. It's by itself. When you shift into a higher or lower gear, the synchros (think ring and cone) match the input shaft speed to the output shaft speed. Prior to 50 years ago, you had to double clutch because without synchros the gear teeth of IP and OP were at different speeds, so you would tear up the gears by trying to jam them together. You could solve this problem by letting the clutch out in neutral and reconnecting the IP to the engine, which would allow you to spin the IP faster and match the IP-OP gear speeds. Double clutching kept you from tearing up the gears as they tried to mesh at different speeds.
You aren't going to tear up/grind the gears now because the synchros match the IP-OP speeds, and trying to extend the life of your synchros is silly. They aren't under load when the clutch is in, so all they are doing is spinning up a free-wheeling IP shaft (a couple pounds maybe?). In fact, if we are going to engage in 10 sigma overthinking and you believe the 2lb freewheeling IP inertia is going to wear things out, you will probably wear out the clutch faster by doubling the number of times it has to create friction with the flywheel (this argument is admittedly equivalently silly).
besides, we all know that real men triple clutch
07-11-2018, 03:06 PM
#44
Three Wheelin'
actually, real drivers use drum brakes, magneto ignition and turn on their high beams with a button on the floor.