lag/hesitation in acceleration +80kmh

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g4qber
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lag/hesitation in acceleration +80kmh

Post by g4qber » Fri, 02 Aug 2013, 05:57

in all modes:
normal, sport and hold

initial pause when flooring accelerator if it has been travelling at a constant speed for a while
similar to turbo lag

but once this is done, volt is responsive, as long as a constant speed is not kept.

http://gm-volt.com/forum/archive/index.php/t-48714.html

http://gm-volt.com/forum/archive/index.php/t-30449.html


<modified title 071213>
Last edited by g4qber on Sat, 07 Dec 2013, 21:04, edited 1 time in total.

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lag/hesitation in acceleration +80kmh

Post by g4qber » Sun, 08 Dec 2013, 07:25

Just worked out that when cruising above 80 is when the volt goes into power save mode.
below 80 there is instant torque.
Need to do more research.
This is 80 according to the volt's speedo which is 5kmh slower than real speed.
Last edited by g4qber on Sat, 07 Dec 2013, 21:06, edited 1 time in total.

marty11
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lag/hesitation in acceleration +80kmh

Post by marty11 » Sun, 08 Dec 2013, 14:39

Yep.. seems normal from posts liek this one

Hesitation to "Unclutch" then "reclutch"

An excerpt of one post in that thread..

"SharkVolt
06-02-2013, 10:48 PM
That is "normal" behavior for what you did at the time.

You may have heard that the Volt "occasionally" uses the ICE to help drive the wheels. It does this only at speeds above 35 mph, and only when you are "cruising" at a steady speed. But the Volt also does the same thing with the generator motor at steady speeds over 35 mph, even if the ICE isn't running. They clutch both electric motors to the planetary gear and can then reduce the RPM of the motors, (sort of like an "economy overdrive gear") for about 15% better mileage.

However, when it has changed into the "overdrive" mode, and you step on the throttle, they have to "unclutch" the motors into a neutral, and raise the RPM of the drive motor, then reclutch the drive motor before allowing the car to accelerate harder (to eliminate slipping and wear on the clutches). This is all done by the computer, but takes a second or more, resulting in the "hesitation" you noticed. It's similar to what would happen with an automatic transmission if you had to downshift in order to accelerate hard.

The "cool" thing about this is that because of the computer controlled speed matching and clutch operation, you will get virtually no wear on the clutches, so you get far longer life of the "transaxle" than any ordinary car."

There are lots of other good posts in that thread.

My first long drive (1600 kms) the other day, also showed a slight amount of hesitation, and in Low, I also found that I had to press hard on the accelerator to overtake vehicles , so accelerating from 100 + kph.

Still getting used to highway driving a bit, but enjoyable!   Also had fun flicking between Hold, then as I started long downhills, changing to normal, and watching the Regen click up a few more kwhs of battery charge. (Or estimated battery charge to be more correct)

Getting back to the "Hesitation", will try and pay closer attention to this.
Holden Volt - June 2013
-----------------------------
Solar Charged from 10kw

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g4qber
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lag/hesitation in acceleration +80kmh

Post by g4qber » Sun, 08 Dec 2013, 15:14

Noice
marty11 you are a wealth of information.
I will always remember your tip about holding down the Power button for 6 secs to get into accessories mode.
do you have any more Volt tips?
Last edited by g4qber on Sun, 08 Dec 2013, 04:16, edited 1 time in total.

marty11
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lag/hesitation in acceleration +80kmh

Post by marty11 » Sun, 08 Dec 2013, 15:22

of course I do Image

Heres one.

Have you had any software updates done? like powertrain software?

"Reliability never let me down on the road, only had odd charging issue with my combination of L2 charger and this was fixed a couple of months back with the powertrain software update.: "

This quote from a fellow Aussie on this post just today..

http://gm-volt.com/forum/showthread.php ... nnaversary

You may wish to PM him. Or ask him directly on that forum, which brand Level 2 charger he was using..and what the "odd charging issue" was .

Image   Cheers. .Marty

EDIT . .I already asked the question on that forum thread for you just now
Last edited by marty11 on Sun, 08 Dec 2013, 04:28, edited 1 time in total.
Holden Volt - June 2013
-----------------------------
Solar Charged from 10kw

marty11
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lag/hesitation in acceleration +80kmh

Post by marty11 » Wed, 11 Dec 2013, 18:40

Just took the Volt out to try an replicate any lag, and accelerated on a flat stretch from 80 kmph to 140 kmph, and no noticable lag at all. Although this was in Low on EV mode.

So I will check in Hold mode (running in range extended mode)
Holden Volt - June 2013
-----------------------------
Solar Charged from 10kw

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g4qber
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lag/hesitation in acceleration +80kmh

Post by g4qber » Thu, 12 Dec 2013, 06:51

I tried this on a black loaner from Melville sometime ago. It was the same.
try this
a) set cruise control to 90kmh
b) leave for 1 min
c) floor accelerator.


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