Is this normal for AT rpm behaviour?

[Pureness]

so the situation is i'm cruising at 80km/h without my foot on the accelerator when i decide that i need to pick up speed

 

when i step on the accelerator, the rpm will increase from 1.5k rpm to 2.4k rpm then drop back to 2.2k rpm. all this while the amount of pressure that i apply is constant.

noticed that this doesn't happen at lower speeds, only from 60km/h and up.

 

adding on, my car does not jerk while switching gears during low speeds or does it have problems entering into reverse or drive gears.

 

 

is this normal?

Edited November 15, 2012 by Pureness

[Jordanplus]

Is yrs AT, cvt or conventional AT?

[Happily1986]

  On 11/15/2012 at 12:54 PM, Pureness said:

so the situation is i'm cruising at 80km/h without my foot on the accelerator when i decide that i need to pick up speed

 

when i step on the accelerator, the rpm will increase from 1.5k rpm to 2.4k rpm then drop back to 2.2k rpm. all this while the amount of pressure that i apply is constant.

noticed that this doesn't happen at lower speeds, only from 60km/h and up.

 

adding on, my car does not jerk while switching gears during low speeds or does it have problems entering into reverse or drive gears.

 

 

is this normal?

 

the A/T gearbox simply dropped a gear the moment you stepped on the pedal (to overtake) causing the blip on the tachometer.. Then afterwards, it upshifts again which explains the drop in rpm.

[BoneStock]

  On 11/15/2012 at 12:54 PM, Pureness said:

so the situation is i'm cruising at 80km/h without my foot on the accelerator when i decide that i need to pick up speed

 

when i step on the accelerator, the rpm will increase from 1.5k rpm to 2.4k rpm then drop back to 2.2k rpm. all this while the amount of pressure that i apply is constant.

noticed that this doesn't happen at lower speeds, only from 60km/h and up.

 

adding on, my car does not jerk while switching gears during low speeds or does it have problems entering into reverse or drive gears.

 

 

is this normal?

 

 

If it doesnt happen at low speeds than it should be the torque convertor lockup. It only happens on the top gear when your car is cruising. The lockup is to improve the fuel efficiency of the car.

[Pureness]

  On 11/15/2012 at 1:28 PM, Happily1986 said:

the A/T gearbox simply dropped a gear the moment you stepped on the pedal (to overtake) causing the blip on the tachometer.. Then afterwards, it upshifts again which explains the drop in rpm.

 

i'm very certain that it didn't drop gear, i didn't step that hard, just a light tap to increase speed just a little

[Pureness]

  On 11/15/2012 at 1:34 PM, BoneStock said:

If it doesnt happen at low speeds than it should be the torque convertor lockup. It only happens on the top gear when your car is cruising. The lockup is to improve the fuel efficiency of the car.

 

so i shouldn't be worried? with this function wouldn't it wear out the internal AT clutch?

also then the appropriate driving behaviour would be to keep my foot slightly depressed rather than to constantly step and let go?

[Watwheels]

Whether it's a CVT or a gearbox mated to a torque converter this is only the hardware we are talking about. The gearbox does not have a mind of its own hence this is where artificial intelligence comes in or we would call it the software. Different car manufacturers will have a unique set of software of their own to govern their gearbox.

 

I believe what you had experienced is the final drive whose main purpose is to help improve fuel economy. In other words the manufacturers program the gearbox to behave this way. Not just the gearbox but also the engine & throttle.

 

Now that computer management in cars has greatly improved over the years, manufacturers use sophisticated throttle called "fly by wire" rather dan mechanically linked to a cable to control the throttle valve. Means that the throttle pedal is no different from a large switch connected to wires. The " large switch" detects how much you had depress the pedal to "react " accordingly. Your car becomes more responsive from the inputs from your right foot. The engine, throttle, gearbox are linked in such a way that you will not experience there's a lag or no response when you step hard to accelerate.

 

That's why I say not all AT are made equal. Other dan the hardware there's also the software, both are equally important. It's the software that makes a difference.

Edited November 15, 2012 by Watwheels

[Happily1986]

  On 11/15/2012 at 1:37 PM, Pureness said:

i'm very certain that it didn't drop gear, i didn't step that hard, just a light tap to increase speed just a little

 

Like Watwheels, mentioned, whether it dropped gear or not really depends on the programmed logic governing the A/T behaviour. I am very certain that barring extenuating circumstances, a blip on the tachometer is due to a downshift and a drop in revs in due to an upshift.