Engine Braking
#11
Re: Engine Braking
Last edited by nash; 08-03-2010 at 03:29 PM.
#12
Re: Engine Braking
The I4 Escape uses a conventional automatic transmission with discrete gear ratios, so engine braking could be set by the shifter (1-2-3-D).
Just my thoughts. Could be wrong.
#13
Re: Engine Braking
Because of the CVT it makes engine braking easier, and not the other way around.
You can have, and hold steady a maximum engine RPM, to get maximum engine braking effect as your vehicle speed changes. It's quite elegant actually. But different than what most people are used to.
The "L" position in a Ford Hybrid is NOT low of anything. There's no mechanical difference between D and L.
The pretend "shifter" is a joystick, and L is a computer signal... a signal that says "Hey... me the driver wants to slow down!".
So it turns the generator on the wheel end on, and this puts resistance to the wheels. Your pretend "engine brake". If the battery is low, then this generated power ( up to 94 Horsepower of brake ) goes into the battery.
If your battery is full, or close to full, this generated electricity is sent to the starter motor and this motor uses those kilowatts to spin the ICE as an air compressor basically without fuel to the engine. You slow down either way.
You can have, and hold steady a maximum engine RPM, to get maximum engine braking effect as your vehicle speed changes. It's quite elegant actually. But different than what most people are used to.
The "L" position in a Ford Hybrid is NOT low of anything. There's no mechanical difference between D and L.
The pretend "shifter" is a joystick, and L is a computer signal... a signal that says "Hey... me the driver wants to slow down!".
So it turns the generator on the wheel end on, and this puts resistance to the wheels. Your pretend "engine brake". If the battery is low, then this generated power ( up to 94 Horsepower of brake ) goes into the battery.
If your battery is full, or close to full, this generated electricity is sent to the starter motor and this motor uses those kilowatts to spin the ICE as an air compressor basically without fuel to the engine. You slow down either way.
#14
Re: Engine Braking
Because of the CVT it makes engine braking easier, and not the other way around.
You can have, and hold steady a maximum engine RPM, to get maximum engine braking effect as your vehicle speed changes. It's quite elegant actually. But different than what most people are used to.
The "L" position in a Ford Hybrid is NOT low of anything. There's no mechanical difference between D and L.
The pretend "shifter" is a joystick, and L is a computer signal... a signal that says "Hey... me the driver wants to slow down!".
So it turns the generator on the wheel end on, and this puts resistance to the wheels. Your pretend "engine brake". If the battery is low, then this generated power ( up to 94 Horsepower of brake ) goes into the battery.
If your battery is full, or close to full, this generated electricity is sent to the starter motor and this motor uses those kilowatts to spin the ICE as an air compressor basically without fuel to the engine. You slow down either way.
You can have, and hold steady a maximum engine RPM, to get maximum engine braking effect as your vehicle speed changes. It's quite elegant actually. But different than what most people are used to.
The "L" position in a Ford Hybrid is NOT low of anything. There's no mechanical difference between D and L.
The pretend "shifter" is a joystick, and L is a computer signal... a signal that says "Hey... me the driver wants to slow down!".
So it turns the generator on the wheel end on, and this puts resistance to the wheels. Your pretend "engine brake". If the battery is low, then this generated power ( up to 94 Horsepower of brake ) goes into the battery.
If your battery is full, or close to full, this generated electricity is sent to the starter motor and this motor uses those kilowatts to spin the ICE as an air compressor basically without fuel to the engine. You slow down either way.
I'm sure all of you've read in the manual that the FEH engine RPM has no relation to direct wheel spin. John is right, the only braking comes from two sources 1. The Generator (MG2) and 2. The Brake Pads. The engine spins by the Generator (MG1) which is powered by MG2 which John calls pretend "engine brake". This is why I told Mountainman to use his electric A/C compressor going down that mountain so those used kilowatts can help save the pads and rotor heat. Regen from MG2 is what slows the FEH down which you can feel more in the '05 thru '08 FEH in "L" gear until the battery gets full or hot. After this, there is only enough kilowatts coming from MG2 to just spin the engine by MG1.
In the '09 and newer FEH, Ford changed the strategy for "L" gear and you no longer get that heavy regen. All you get is engine spin with fuel cut which feels like the drag (regen) you get from MG2 while just coasting in "D". Not much engine braking there as Mountainman found out. The good news mountainman, is you can still use more regen to help slow you down without using the pads. Ford has still programmed the brake pedal to use 100% of regen before going to the pads. Most of the braking I do in my '05 and '09 FEH is from regen. I get it from "L" in the '05 and I get it with the brake pedal in my '09. The "L" is only good for fuel-cut in the '09 and '10 FEH and you can that in EV below 40mph and in "D" above 40mph. If it's too cold out for EV, you would be better off using "L" coasting down a mountain under 40mph and still using the brake pedal for extra regen.
GaryG
#15
Re: Engine Braking
This is the first post I remember seeing that someone reports they were able to overheat the brakes. Luckily as indicated here it's not really typical driving, even for the mountains.
I still wonder if someone has done it on the older model FEH which has disc brakes all around instead of disc/drums like the newer ones?
Another possible solution might be to change brake pads to a higher temp version, but I don't know for sure if you can use ones like Powerstop on a hybrid.
I still wonder if someone has done it on the older model FEH which has disc brakes all around instead of disc/drums like the newer ones?
Another possible solution might be to change brake pads to a higher temp version, but I don't know for sure if you can use ones like Powerstop on a hybrid.
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