Do you ever use a clutch with seq. gearbox?

[Trk-el-son]

I know that for standing starts, using clutch is the fastest, but apart from that particular use, do people use clutch when driving, say, a GT car with paddle shifters?

Thanks! (-from a racing newb, trying to educate himself. 😁)

EDIT: Removed a part that created a debate about something that was not really relevant. It is still here in the quotes, but let’s just leave it.

 

[Vule]

I, for example, use the clutch for saving fuel. Going down a long hill with good speed, I press the clutch for coasting without engine braking.

If you are using the clutch like that, you are doing the opposite of saving fuel. Modern engines don't use any fuel while engine braking, so don't use the clutch, just find a gear that you are comfortable with doing the downhill and leave it at that.

As for GT7, I use the clutch because I use manual H pattern shifter when racing offline (for some cars, of course, when I equip them with the manual transmission). In any other case it won't have any effect on the game.

 

[MatskiMonk]

a GT car with paddle shifters?

If the car has a racing transmission the clutch doesn't work anyway.

About the only other useful application for the clutch outside of how you operate the H-pattern, is for clutch kick.

 

[S-car-Go]

You do not want to be coasting out of gear in a racing car. Adjust the fuel map and short shift going up the box if you are that fuel critical in the game. If your racing in real life your team manager should not let you run out of fuel out on track that's an inexcusable mistake.
In a road car coasting down a hill let's say could be construed as a loss of control of your vehicle and theoretically land you in trouble with the police and your insurance company if you pranged it. Did someone say due care and attention?

 

[Trk-el-son]

If you are using the clutch like that, you are doing the opposite of saving fuel. Modern engines don't use any fuel while engine braking, so don't use the clutch, just find a gear that you are comfortable with doing the downhill and leave it at that.

As for GT7, I use the clutch because I use manual H pattern shifter when racing offline (for some cars, of course, when I equip them with the manual transmission). In any other case it won't have any effect on the game.

Ok. My logic is, that a motor in gear will be performing (light) braking, and therefore will not roll nearly as far downhill as the car with the gear disengaged. This equals a further distance travelled only with the help of gravity, therefore fuel saved.

 

[Famine]

I, for example, use the clutch for saving fuel. Going down a long hill with good speed, I press the clutch for coasting without engine braking.

That uses more fuel than leaving it in gear. With the wheels driving the engine, the fuel injectors shut off - resulting in no fuel consumption. If you disengage the wheels from the engine (in neutral or by pressing the clutch pedal), the engine requires fuel to prevent from stalling.

It also reduces the control you have over your vehicle, and increases your stopping distance should you need to brake in an emergency (while already going downhill...).

 

[Meythia]

This equals a further distance travelled only with the help of gravity, therefore fuel saved.

Depending on the age of the car the engine will not burn fuel while IN gear and keeping in motion, whereas when you engange the clutch the engine needs to burn fuel to keep its minimum revolutions.
This should be installed in cars no older than 1980 or around that time.

Also when not using engine braking, you increase wear on the the brakes, and it might be a legal case as pointed out earlier.

 

[Trk-el-son]

In a road car coasting down a hill let's say could be construed as a loss of control of your vehicle and theoretically land you in trouble with the police and your insurance company if you pranged it. Did someone say due care and attention?

Loss of control?
Right foot ready to take action on brake or gas, left foot on the clutch, left hand on the wheel, right hand ready to engage correct gear. More or less the exact situation you are in, mid gear shift. I have quite a hard time spotting the control loss.

Depending on the age of the car the engine will not burn fuel while IN gear and keeping in motion, whereas when you engange the clutch the engine needs to burn fuel to keep its minimum revolutions.
This should be installed in cars no older than 1980 or around that time.

Also when not using engine braking, you increase wear on the the brakes, and it might be a legal case as pointed out earlier.

I did not say I was not engne braking. When needing to slow down, I engage the motor in what gear is needed.

Anyway, I am sorry this sidetracked. Mostly I just wanted to know, if there is a use for clutch (outside standing start) in race cars.

 

[TumeK5]

We're diving into one deep rabbit hole...

 

[Mafio]

If you disengage the wheels from the engine (in neutral or by pressing the clutch pedal), the engine requires fuel to prevent from stalling.

Maybe Im misunderstanding this but as someone who drives a manual everyday IRL, its the opposite. If you press the clutch or put it in neutral, the engine just idles. Yes it still requires fuel but it kind of sounds like you're implying the driver has to do something to get the engine fuel. Now, if one leaves it in gear and let the car roll, eventually it will stall out.

 

[Famine]

Maybe Im misunderstanding this but as someone who drives a manual everyday IRL, its the opposite. If you press the clutch or put it in neutral, the engine just idles. Yes it still requires fuel but it kind of sounds like you're implying the driver has to do something to get the engine fuel. Now, if one leaves it in gear and let the car roll, eventually it will stall out.

No.

When rolling downhill, per the example given, a fuel-injected petrol, manual car uses no fuel at all if it's in gear; the wheels drive the engine and the injectors shut off. If the engine is disengaged from the wheels - by being in neutral or with the clutch pedal pressed - it uses fuel; the injectors have to provide fuel to drive the engine.

I also drive a manual car, not that it would matter if I didn't because this is how they work regardless.

 

[P-Courty]

Brilliant channel to watch and learn about all kinds on car related content.

This explains with a real life experiment on coasting.

FYI coast in gear, more efficient and safer.

 

[Keef]

I know that for standing starts, using clutch is the fastest, but apart from that particular use, do people use clutch when driving, say, a GT car with paddle shifters?

Thanks! (-from a racing newb, trying to educate himself. 😁)

EDIT: Removed a part that created a debate about something that was not really relevant. It is still here in the quotes, but let’s just leave it.

This thread has devolved into people trying to understand how fuel and air mix to create boom so let's go back to your original question:

It depends.

Sequential technology has evolved quite a bit over the years. The first real modern ones appeared in the 90s but even those were much less advanced than current transmissions. First of all, they were fully mechanical and typically used a manual lever. The gears were selected sequentially by pulling the stick backward to shift up or pushing it forward to shift down (directions chosen to coincide with the g-forces the driver was experiencing thus making it easier to shift). But most of them still had to use the clutch fairly often due to the lack of electronic controls.

Typically on these older transmissions, the driver had to use the clutch on every downshift. The engine didn't have any automatic rev-matching electronics, so to downshift the driver had to quickly clutch, rev the throttle, and bang the gear. It only took a split second but that was the operation. Usually they offered flat-throttle upshifting though since it was easy enough to either brute-forced the engine to pull its revs down, or to install a switch to cut throttle momentarily while the shifter or clutch was in use. In some cases the driver would have to let off the throttle just a little bit during upshifts to reduce tension in the driveline to allow the shift to happen (you can do similar things in a manual transmission without using the clutch). See this Viper GTS-R where you can see the driver really driving the car especially on downshifts, using all three feet to clutch, brake, and hell-toe.



Eventually these tranmissions gained more electronics and tied the engine and transmission together. Nowadays, almost all cars have fully electronic shifting with no mechanical linkage at all, fully electronic rev-matching and clutching, etc. They only use the clutch to start and stop the car, however many cars also have some form of stall protection like F1 to prevent engine damage when they spin.

So the real big difference is that an old sequential manual was still a manual, just easier to use. Modern flappy paddles are exactly that, flappy paddles with no mechanical link to the transmission at all. Talk about easy mode.