Cayman GT4 hill brake assist

[Vetteran]

Having acquired my car in France (manuals in French), I have learnt the hard way (sort of) to get the hang of using an electric handbrake with a manual shift. In order to avoid the dreaded roll back when stopped on a hill: put car into neutral, apply electric handbrake and IMPORTANT take foot off footbrake and trust handbrake to hold car. When ready to go select first gear and press accelerator. If, as I was doing you apply the handbrake but keep your foot on the footbrake, when you move your foot off the brake and onto the accelerator the car momentarily rolls back causing you to quickly put your foot back on the brake. In the meantime the car's hill assist system, sensing your desire to move forward, has released the handbrake so that when you try to move off again you roll back (handbrake disengaged). On a steep hill in heavy traffic with the driver behind you intent on getting as close as possible this situation is really unnerving. The old simple manual handbrake is in my opinion a much better system.

[lsb]

Vetteran said:

Having acquired my car in France (manuals in French), I have learnt the hard way (sort of) to get the hang of using an electric handbrake with a manual shift. In order to avoid the dreaded roll back when stopped on a hill: put car into neutral, apply electric handbrake and IMPORTANT take foot off footbrake and trust handbrake to hold car. When ready to go select first gear and press accelerator. If, as I was doing you apply the handbrake but keep your foot on the footbrake, when you move your foot off the brake and onto the accelerator the car momentarily rolls back causing you to quickly put your foot back on the brake. In the meantime the car's hill assist system, sensing your desire to move forward, has released the handbrake so that when you try to move off again you roll back (handbrake disengaged). On a steep hill in heavy traffic with the driver behind you intent on getting as close as possible this situation is really unnerving. The old simple manual handbrake is in my opinion a much better system.

Thanks, that is handy information. I agree re: the old fashioned type being simpler and easier.

[RBT0]

Are you kidding? :P

The hill holder should do everything for you, detect the hill condition and hold the car steady when you release the brake pedal to move forward.

Even my previous Abarth was doing that.

Am I missing something?

[lsb]

RBT0 said:

Are you kidding? :P

The hill holder should do everything for you, detect the hill condition and hold the car steady when you release the brake pedal to move forward.

Even my previous Abarth was doing that.

Am I missing something?

I'm old school - happy to do the "detecting" myself and use the lever

[RBT0]

But you can't turn off the hill holder, so no worth trying, you'll mess things up.

[sofaking]

RBT0 said:

Are you kidding? :P

The hill holder should do everything for you, detect the hill condition and hold the car steady when you release the brake pedal to move forward.

Even my previous Abarth was doing that.

Am I missing something?

My e92 M3 did the same thing.

[Pat Cash]

RBT0 said:

Are you kidding? :P

The hill holder should do everything for you, detect the hill condition and hold the car steady when you release the brake pedal to move forward.

Even my previous Abarth was doing that.

Am I missing something?

It does - I think the OP is missing the fact that the Drive Off Assistant will keep the brake pressure so you can take your foot off the pedal without having to engage the handbrake. It will then release the brake pressure as it detects torque.
Just having the confidence to take your foot off the brake pedal is the psychological hurdle...

Edit: Just found this as reference for OP -

The HOLD function, as an assistance function,
assists the driver when stopping and driving off on
upward slopes.
The vehicle is automatically prevented from rolling
back away from the desired direction of travel.
When the HOLD function is active, the indicator
light HOLD on the instrument panel comes on.
Driving off with the Drive-Off Assistant on
vehicles with manual transmission
1. Hold the vehicle securely on the slope with the
footbrake.
The engine must be running.
2. Press the clutch pedal fully.
3. Engage a gear corresponding to the direction
of travel up the slope (1st gear or reverse
gear).
4. Release the footbrake while keeping the clutch
pedal pressed.
The vehicle is held on the slope to facilitate
driving off and prevent it from rolling back.
5. Drive off as usual.

If the vehicle is held on the slope by the electric
parking brake, drive off in the usual way.
The electric parking brake detects the driver’s
intention to drive off and is released automatically.

The Drive-Off Assistant will not function:
– If the clutch is not pressed.
– If the vehicle is not stationary.
– If the engine is not running.
– On gradients of less than 5 %.
– If the pressure on the brake pedal is too low.

If the driver’s seat belt is unfastened and the
driver’s door is opened while the HOLD function is
active, the electric parking brake is activated
automatically.

If the vehicle comes to a standstill on a steep uphill
gradient without operation of the footbrake by the
driver, this may result in a certain roll-back before
the vehicle is held by the HOLD function. In this
situation, the roll-back can be reduced by pressing
the footbrake. Assist holding of the vehicle by increasing the
braking force with the footbrake.

Edited by Pat Cash on Monday 29th June 04:40

[Vetteran]

Pat Cash said:

RBT0 said:

Are you kidding? :P

The hill holder should do everything for you, detect the hill condition and hold the car steady when you release the brake pedal to move forward.

Even my previous Abarth was doing that.

Am I missing something?

It does - I think the OP is missing the fact that the Drive Off Assistant will keep the brake pressure so you can take your foot off the pedal without having to engage the handbrake. It will then release the brake pressure as it detects torque.
Just having the confidence to take your foot off the brake pedal is the psychological hurdle...

Edit: Just found this as reference for OP -

The HOLD function, as an assistance function,
assists the driver when stopping and driving off on
upward slopes.
The vehicle is automatically prevented from rolling
back away from the desired direction of travel.
When the HOLD function is active, the indicator
light HOLD on the instrument panel comes on.
Driving off with the Drive-Off Assistant on
vehicles with manual transmission
1. Hold the vehicle securely on the slope with the
footbrake.
The engine must be running.
2. Press the clutch pedal fully.
3. Engage a gear corresponding to the direction
of travel up the slope (1st gear or reverse
gear).
4. Release the footbrake while keeping the clutch
pedal pressed.
The vehicle is held on the slope to facilitate
driving off and prevent it from rolling back.
5. Drive off as usual.

If the vehicle is held on the slope by the electric
parking brake, drive off in the usual way.
The electric parking brake detects the driver’s
intention to drive off and is released automatically.

The Drive-Off Assistant will not function:
– If the clutch is not pressed.
– If the vehicle is not stationary.
– If the engine is not running.
– On gradients of less than 5 %.
– If the pressure on the brake pedal is too low.

If the driver’s seat belt is unfastened and the
driver’s door is opened while the HOLD function is
active, the electric parking brake is activated
automatically.

If the vehicle comes to a standstill on a steep uphill
gradient without operation of the footbrake by the
driver, this may result in a certain roll-back before
the vehicle is held by the HOLD function. In this
situation, the roll-back can be reduced by pressing
the footbrake. Assist holding of the vehicle by increasing the
braking force with the footbrake.

Edited by Pat Cash on Monday 29th June 04:40

[/q



The GT4 has motor sport heavy clutch so on any gradient where you are stationary for sometime it is more comfortable to put car in neutral and select the electric handbrake. All you need to remember is not to touch the footbrake. This from my experience all you need to do to have stress free move off when on an incline.

[bcr5784]

Vetteran said:

It does - I think the OP is missing the fact that the Drive Off Assistant will keep the brake pressure so you can take your foot off the pedal without having to engage the handbrake. It will then release the brake pressure as it detects torque.
Just having the confidence to take your foot off the brake pedal is the psychological hurdle...

Edit: Just found this as reference for OP -

The HOLD function, as an assistance function,
assists the driver when stopping and driving off on
upward slopes.
The vehicle is automatically prevented from rolling
back away from the desired direction of travel.
When the HOLD function is active, the indicator
light HOLD on the instrument panel comes on.
Driving off with the Drive-Off Assistant on
vehicles with manual transmission
1. Hold the vehicle securely on the slope with the
footbrake.
The engine must be running.
2. Press the clutch pedal fully.
3. Engage a gear corresponding to the direction
of travel up the slope (1st gear or reverse
gear).
4. Release the footbrake while keeping the clutch
pedal pressed.
The vehicle is held on the slope to facilitate
driving off and prevent it from rolling back.
5. Drive off as usual.

If the vehicle is held on the slope by the electric
parking brake, drive off in the usual way.
The electric parking brake detects the driver’s
intention to drive off and is released automatically.

The Drive-Off Assistant will not function:
– If the clutch is not pressed.
– If the vehicle is not stationary.
– If the engine is not running.
– On gradients of less than 5 %.
– If the pressure on the brake pedal is too low.

If the driver’s seat belt is unfastened and the
driver’s door is opened while the HOLD function is
active, the electric parking brake is activated
automatically.

If the vehicle comes to a standstill on a steep uphill
gradient without operation of the footbrake by the
driver, this may result in a certain roll-back before
the vehicle is held by the HOLD function. In this
situation, the roll-back can be reduced by pressing
the footbrake. Assist holding of the vehicle by increasing the
braking force with the footbrake.

Edited by Pat Cash on Monday 29th June 04:40

[/q



The GT4 has motor sport heavy clutch so on any gradient where you are stationary for sometime it is more comfortable to put car in neutral and select the electric handbrake. All you need to remember is not to touch the footbrake. This from my experience all you need to do to have stress free move off when on an incline.

My experience is on pdk and it doesnt inspire great confidence, One car I drove held the brake on too long which came off with a jerk, mine sometimes drifts back a bit Ok ish I suppose, but I can do better job.

[Jmachado]

Never used the automatic handbrake to hold the car on an incline hill... Just the regular brake and footwork when it's time to move, but I do agree the clutch is quite heavy and can be quite uncomfortable if used a lot

[RacerMike]

Generally, the calibration of Hill Hold should allow for most normal conceivable situations. Although I haven't driven a current generation Cayman/Boxter, the usual functionality from Bosch/Conti/TRW who make the ABS modulator (which contains the logic for Hill Hold) would be to activate in any situation when the car detects a drive away on a hill is likely.

The logic should therefore follow:

- Car stationary. Gradient >3-5%. Neutral selected - No Pressure Hold
- Car stationary. Gradient >3-5%. 1st gear selected. Clutch disengaged - Pressure Hold for 2-5s when brake released
- Car stationary. Gradient >3-5%. 1st gear selected. Clutch engaged - Pressure Hold until engine torque >= pullaway torque to enable forward motion

Basically. If you are in traffic, on a hill and you get tired of holding the clutch down, slip it into Neutral but keep your foot on the brake to stop it rolling back. When it's time to move off, dip the clutch, engage first gear whilst still on the brake and the system will hold brake pressure for pullaway.