Anti-rollover = Hesitation....?

[wwest]

Volvo is advertising an anti-rollover feature in their latest cars & SUVs.

Does anyone know how this is being done?

Meanwhile I'm seeing these many complaints about engine acceleration lag, delay, or hesitation and a few of them seem to have to do with trying to accelerate while turning right or left.

The only instance wherein I have been able to replicate any sort of engine acceleration lag or delay in my 2001 AWD RX300 was in a tight turn with the gas pedal to the floor, literally. At about what I would consider the apex of my turn the engine died, or certainly appeared too. My educated foot was so quick to release the gas pedal and then reapply that I don't know what would have happened had I just stayed on the gas.

In any case if I were writing firmware/software specifications to prevent rollover one of the things I would look seriously at is limiting the engine HP in a tight turn.

Anybody have any factual input as too how the Volvo system works to prevent rollovers??

[SW03ES]

No Willard, the acceleration delay is simply the result of poor implementation of the drive by wire system its found on all Lexus vehicles, including cars, and a number of other manufacturers vehicles. You don't feel it because your older RX still has a tethered throttle.

[annec]

No Willard, the acceleration delay is simply the result of poor implementation of the drive by wire system its found on all Lexus vehicles, including cars, and a number of other manufacturers vehicles. You don't feel it because your older RX still has a tethered throttle.

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Is this drive by wire system problem in the new hybrid? What year did it start? So it's in all newer lexus cars and SUV's. Are owners just living with it? Do they have plans to fix it?

annec

[SW03ES]

Hybrids don't have the problem actually because the DBW systems compatibility with emission controls is what causes the hesitation. Plus hybrids have CVTs, constantly variable transmissions (they have no gears) so its a different driving experience.

Search around, LOTS of discussion of the issue here.

[wwest]

Toyota hybrids have a "virtual" engine compression braking system in that they simulate engine compression braking via regenerative battery recharge during coastdown. In the Prius you have the choice of regenerative braking/recharge or you can select the use of REAL/ACTUAL engine compression braking.

CAUTION note says that if you chose ACTUAL engine compression braking fuel economy will decline dramatically.

[SW03ES]

The RX400h has the "b" setting on the transmission also.

[ColinBarber]

No Willard, the acceleration delay is simply the result of poor implementation of the drive by wire system its found on all Lexus vehicles, including cars, and a number of other manufacturers vehicles. You don't feel it because your older RX still has a tethered throttle.

I think the problem is more to do with the auto transmissions not being in the correct gear and the throttle waiting for it to shift rather than the electronic throttle itself.

My wife had a manual IS200 for over two years and she nor myself never had any hesitation with it. I imagine the manual IS300 is the same.

I do get some hesitation in my GS430 but also in the RX300 which has a conversional throttle system.

[SW03ES]

But you have to make sure the emission regs in the UK are the same as here. Like I said canadian cars dont have the problem.

A member in the ES forum posted a big long explanation given to him by an engineer.