[buildbright]

Does the Sports AT Blip the Throttle on Downshifts?

[KellerKiller]

Originally Posted by buildbright

Does the Sports AT Blip the Throttle on Downshifts?

I only notice it at higher rpms, like when I took it to the track. Under normal driving, I can't quite tell if it does, or if it's just the change in rpm.

[drob23]

Originally Posted by buildbright

Does the Sports AT Blip the Throttle on Downshifts?

One thing I don't understand is what a throttle blip means for an AT. Doesn't the torque converter just decouple the flywheel and transmission when you shift? Wouldn't the engine then "catch up" to the rest of the drivetrain after? I guess I don't understand the point of rev matching in an AT.

[Elk]

The torque converter remains locked at all times once the car is moving. It locks at low speed, I believe between five and ten MPH.

The transmission does not go into neutral between shifts, it simply switches gear sets.

There is no "blip" in the throttle per se other than the firmware adding precisely the amount of gas required to sustain the RPMs needed for the new gear. This has nothing to do with the shift itself. It merely makes the shifting process smoother.

[drob23]

Originally Posted by Elk

The torque converter remains locked at all times once the car is moving. It locks at low speed, I believe between five and ten MPH.

The transmission does not go into neutral between shifts, it simply switches gear sets.

There is no "blip" in the throttle per se other than the firmware adding precisely the amount of gas required to sustain the RPMs needed for the new gear. This has nothing to do with the shift itself. It merely makes the shifting process smoother.

I thought it remains locked only while you're in gear, not while you shift. Isn't this is what gives the "smooth" experience of an AT when shifting? Figured locking is for efficiency purposes. Just to be clear, my understanding of "locked" is when there is zero relative rotational speed between the flywheel and input shaft to transmission, caused by a clutch "locking mechanism."

So you are saying the only time the torque convertor is unlocked is when you're sitting there at a stop light?

[Elk]

Originally Posted by drob23

So you are saying the only time the torque convertor is unlocked is when you're sitting there at a stop light?

This is my understanding, the converter is used almost exclusively for vehicle launch and, according to ZF, can be omitted if there is a separate starting clutch.

[Bimmerfestool]

Originally Posted by pkim1079

Why sportsAT when you cam get manual?

Well, some of us don't know how to shift a stick and... Haha just kidding. AT is the future and I switched from manual to AT because I get better performance out of an AT on a really fast car like this. You just can't shift your manual as fast as the AT does, therefore you're not getting the advertised performance of your car.

[drob23]

Originally Posted by Elk

This is my understanding, the converter is used almost exclusively for vehicle launch and, according to ZF, can be omitted if there is a separate starting clutch.

Found an interesting document - http://www.zf.com/media/media/en/doc...wbis1000nm.pdf

Looks like the newer ZF torque converters have significant advances in damping technology to allow for more comfort and lower shift points. It appears also that the locking clutch is up to the user to control.

Unless you have factual evidence otherwise, I'd speculate that the lock up clutch does in fact disengage when you shift, however this period could be very small. I would further speculate that the rumored additional cooling of the Sport AT transmission allows the TCU to engage the clutch sooner after a shift - so the perception is very quick shifts in sport mode.

The time I spent recently in the 640ix, A7 and 328ix led me to believe that there was torque converter slip - the "bite" of my DCT is considerably harsher than the Zf8 (A7 has same engine). This all could change with the 2014 F30, which as you hinted towards, will allow for launch control and possibly more aggressive shifts with the hydraulic clutch. I don't see why they'd add this if the current lockup clutch could remain engaged at all times with no consequence (aside from being stopped).

[Elk]

Originally Posted by drob23

Looks like the newer ZF torque converters have significant advances in damping technology to allow for more comfort and lower shift points.

Yes, to help minimize NVH at low RPM. This allows earlier lock-up at lower RPM, resulting in better fuel efficiency.

Unless you have factual evidence otherwise, I'd speculate that the lock up clutch does in fact disengage when you shift, however this period could be very small.

There are three clutches in the transmission in addition to the torque converter.

[skeeny]

Speaking of low RPM, on my 2013 F30 335 with sport AT, at low RPM (for instance when I am leaving my neighborhood), I feel that the transmission is "juddery"...harsher downshifts than I would expect. Is this typical sport AT behavior? My previous car was a 2002 E46 330 with steptronic. Is this just something I need to get accustomed to, or should it not be this "unsmooth"?

Thanks.
skeeny

Originally Posted by Elk

Yes, to help minimize NVH at low RPM. This allows earlier lock-up at lower RPM, resulting in better fuel efficiency.


There are three clutches in the transmission in addition to the torque converter.

[pkimM3r]

Originally Posted by Bimmerfestool

Well, some of us don't know how to shift a stick and... Haha just kidding. AT is the future and I switched from manual to AT because I get better performance out of an AT on a really fast car like this. You just can't shift your manual as fast as the AT does, therefore you're not getting the advertised performance of your car.

actually, you're not getting the performance (advertised or not) if you are not going to the circuit and purely using the car as a grocery getter.

plus its about the emotion, and the experience, not about the fastest shift (these paddles do not equate to the emotion a 458, huayra, or any other exotic with paddles evoke!)

[Bimmerfestool]

Originally Posted by pkim1079

actually, you're not getting the performance (advertised or not) if you are not going to the circuit and purely using the car as a grocery getter.

plus its about the emotion, and the experience, not about the fastest shift (these paddles do not equate to the emotion a 458, huayra, or any other exotic with paddles evoke!)

Who says I don't go get groceries like I'm on a circuit

[buildbright]

Originally Posted by drob23

One thing I don't understand is what a throttle blip means for an AT. Doesn't the torque converter just decouple the flywheel and transmission when you shift? Wouldn't the engine then "catch up" to the rest of the drivetrain after? I guess I don't understand the point of rev matching in an AT.

It makes a smooth transaction for downshifting even with an auto and it sounds awesome.

[rconti]

Because the vast majority of people buying an automatic barely know what a transmission does, wouldn't want to bother with the paddles, wouldn't notice the extra delay on the non-sport auto, don't want to pay extra, and perhaps might even be annoyed with more crap hanging from the steering wheel?

[gomichaelkgo]

I love resting my thumbs where the shift paddles would have gone.

I learned how to drive on a stick, but they are awful for stop and go commuting traffic.

Not all of us just drive our cars on empty canyon roads.

[gnosis8]

Originally Posted by tojo_m

Function for changing gears:

changeGear( )
{
If(sportsAT NOT true)
{
InduceArtificialDelay(50); // in milliseconds - worth $500 to get rid of this line
}
doTheGearChangeNow( );
}

LOL that's awesome

[shivaswrath]

I wonder if the PPK over rides the Sport AT programming?
The PPK makes for wicked faster shifts for sure, more aggressive, so I'm glad I didn't spend the $500 on the sport AT. Just a thought...

[rallybull]

Originally Posted by shivaswrath

I wonder if the PPK over rides the Sport AT programming?
The PPK makes for wicked faster shifts for sure, more aggressive, so I'm glad I didn't spend the $500 on the sport AT. Just a thought...

I was thinking of the same thing .. Lol...
The shifts happen pretty fast and I was wondering if the MPPK had something to do with it.

[JK479]

Originally Posted by Elk

The torque converter remains locked at all times once the car is moving. It locks at low speed, I believe between five and ten MPH.

The transmission does not go into neutral between shifts, it simply switches gear sets.

There is no "blip" in the throttle per se other than the firmware adding precisely the amount of gas required to sustain the RPMs needed for the new gear. This has nothing to do with the shift itself. It merely makes the shifting process smoother.

Does anyone find the sound of the shift in sport setting and sport auto to be annoying? These light slams do not ake me think the car is faster, just not working as well.

Someone said on here the sound is more of a built in sound than any real advancement?

Does sport auto change 0-60 or the quarter mile. Or more marketing?

[citrixscu]

Originally Posted by tojo_m

Function for changing gears:

changeGear( )
{
If(sportsAT NOT true)
{
InduceArtificialDelay(50); // in milliseconds - worth $500 to get rid of this line
}
doTheGearChangeNow( );
}

This is good.

[nicknaz]

Originally Posted by Rossifumi

It is the exact same gearbox, just a different software.

The software makes a huge difference though. I have a loaner without the sport AT right now and the delay in shifts annoys the heck out of me.

InduceArtificialDelay(50); // in milliseconds - worth $500 to get rid of this line

so true!

[pkimM3r]

Originally Posted by Bimmerfestool

Who says I don't go get groceries like I'm on a circuit

HA - true that.

But I'm sure you're not entering the supermarket at 150mph!