The Lurch

[TepuruMan]

I have a new I2 ExNav. Love it.

Only one complaint. There is a lurch that occurs when the car is decelerating. Depending on the scenario, the force of the pull on the lurch ranges from almost unnoticeable to irritating.

Here's what I think is happening and if anyone can pipe up and second this or contribute other ideas please do so. When the I2 is coasting to a stop, the electric motor is in regenerative mode. Essentially, the electric motor is helping slow the car down, like a break. At somewhere between 6 and 11 mph I feel the regenerative electric motor release and simply coast freely. Thus, there is now less friction against the forward movement of the car and the car therefore lurches forward briefly. This can happen when I'm simply coasting and when I'm coasting while breaking.

Does anyone else notice this? Are there ways to mitigate it? How about a computer fix from Honda to address this?

Thanks,

[bish79]

Yup, it does that. I have either gotten used to it or it has mellowed out over time.

If you ask me, the real solution to this would be for Honda to offer the car in a manual. I've never had that problem on a car that I can just push the clutch in.

[carniver]

Originally Posted by TepuruMan

I have a new I2 ExNav. Love it.

Only one complaint. There is a lurch that occurs when the car is decelerating. Depending on the scenario, the force of the pull on the lurch ranges from almost unnoticeable to irritating.

Here's what I think is happening and if anyone can pipe up and second this or contribute other ideas please do so. When the I2 is coasting to a stop, the electric motor is in regenerative mode. Essentially, the electric motor is helping slow the car down, like a break. At somewhere between 6 and 11 mph I feel the regenerative electric motor release and simply coast freely. Thus, there is now less friction against the forward movement of the car and the car therefore lurches forward briefly. This can happen when I'm simply coasting and when I'm coasting while breaking.

Does anyone else notice this? Are there ways to mitigate it? How about a computer fix from Honda to address this?

Thanks,

Unfortunately it appears that for a regenerator to work, a certain speed is needed. i.e., the regenerative brake needs speed. As speeds drop off the amount of regenerative braking also drops off as you can see from the ASST/CHRG gauge. And when the speed drops below 10km/h the regenerative braking will be deactivated altogether adruptly, leaving you with a sudden lurch and you'll have to press the brake further down to activate frictional braking.

To me, however, this is of little concern. I apply hypermiling principles and anticipate any need to stop, leaving a lot of braking distance so I can press on the brake lightly and use all regenerative braking. By the time regenerative braking cannot be sustained any longer, the car will be so slow that it's well within my control regardless

[carniver]

Originally Posted by bish79

If you ask me, the real solution to this would be for Honda to offer the car in a manual. I've never had that problem on a car that I can just push the clutch in.

It's not so simple. If you disengage the clutch, the engine will not be able to slow the car down through IMA. Earlier models of IMA had the manual option, but the driver will have to leave the car in gear while slowing down, up to the point just before the engine stalls, then disengage, for the maximum regen braking. Which is even more complicated than computer controlled everything.

[Willie Williford]

A manual works the same way as an automatic. The only difference is when the clutch is pushed in. Most manual drivers use the transmission to slow down along with the IMA, not by pushing in the clutch and coasting to a stop till the engine dies.
The IMA also disengages at about the same speed as the autos. (Regen uses speed and rpm to operate)
(This relates to the Gen1 Insight.......Gen 2 doesn't have a stick.)
Willie

[joecvt]

Besides the "lurch" feeling being the IMA regen down to a certain speed, what you are also feeling is the start clutch of the CVT disengaging at approximately 5MPH. Under very light foot pedal braking, this allows the CVT Insight to roll along much further once disengaged because there is no more engine braking and CVT resistance at that time. (kind of like pressing in the clutch on a manual transmission car)

JoeCVT = Just your average CVT owner

[bish79]

Originally Posted by carniver

It's not so simple. If you disengage the clutch, the engine will not be able to slow the car down through IMA. Earlier models of IMA had the manual option, but the driver will have to leave the car in gear while slowing down, up to the point just before the engine stalls, then disengage, for the maximum regen braking. Which is even more complicated than computer controlled everything.

I am aware of this. I still want a manual. I'd rather control the car than the car trying (poorly) to control itself.

[Cobb]

I found bleeding my brakes helped to reduce that. I tend to ride the brakes so I get max regen and the people behind me see the red lights lite up. For shorter stops I hit the paddle and ride the engine to a stop.

Interesting the new crz keeps the engine rolling til after you stop vs have it cut out at 7mph.

[carniver]

Originally Posted by Cobb

Interesting the new crz keeps the engine rolling til after you stop vs have it cut out at 7mph.

Yeah, come to think of it, why does stalling the engine matter? Just auto-restart it?

[equin]

From what I understand, regen braking stops at 7 MPH, the clutch for the CVT disengages, and the motor (auto-stop) may shut down. Taking the car out of econ mode will mitigate this effect quite a bit.

I'd say its just one of the oddities of regenerative braking, nothing to worry about

-Eq