Walt White Coupe

For those with the new 8 speed automatic please report on the lag time between executing a paddle shift and the actual shift taking place under as many driving conditions as possible.

AFVETTE

I believe there are two distinct issues/measurements. One is the actually amount of time it takes the transmission to execute a shift. That has been improved and the second is the time from when the driver initiates a manual shift via the paddle and when the transmission responds. I haven't heard if that "lag" has been reduced.

Now the question I have is how are those time's actually measured and what are the goal's/standards to beat? I mean empirical data.

That's how I understand it.

Tom

Formula52

Walt White Coupe

Let's keep this simple: You hit the paddle, how long does it take for the transmission to respond with a shift.

DerStig

Also, how does this compare to the DCT in BMWs for example? My car is extremely quick with instantaneous responsiveness. When I touch the paddles, there is no lag at all.

I'm never getting the A8, but I'm just curious.

CaryBob

Tom asked a good question though. Once the shift is initiated, either by the driver via paddle or by the computer, the activity of the transmission itself should be exactly the same. The difference is whether there is a lag introduced by pressing the paddle and the extent to which that is influenced by the driver' decision to shift at a different point than the computer would have chosen.

There would clearly be a significant delay in multiple gear shifts. The computer could downshift 8 to 4 in one step, where a human would have to hit the paddle four times.

BRCC

You make a good point on the computer making the down shifts. On up shifts I assume GM is using the computer shift times when stating they are 8/100th faster than a DCT. As far as up shifts with the paddles we have to wait for results to be posted by forum members. However, members on the fast list have stated they let the computer shift in the 1/4 so the open question would be on a road course.

mjw930

According to Tadge and many others there are multiple computer maps for this transmission so when doing these tests it's likely the responsiveness will be relative. For example, if you are cruising it's quite likely the shift will be somewhat slower and softer, by design. In sport / competition mode the shifts should be quicker and more positive. Just take this into account.

Woodson

And this is what's relevant. Super fast shifts are useless if it takes forever from the time you request the shift until it is actually executed. Unless you're drag raining in which case you should have a Hellcat anyway.

Inquiring minds want to know.

Walt White Coupe

Anymore input?

Dif

and also there is a BIG difference in the quickness and sharpness of the shift relative to the amount of throttle.
The more throttle, the faster it shifts.
With my 09 Coupe with the A6, anything close to 1/2 throttle it shifts without any perceptible delay or lag.
Anything close to full throttle and it shifts instantly,... with or without using paddles.
The A8 should be noticeably better once it breaks in

OC Sadler

What kind of empirical evidence is obtained by data consisting of individuals’ perception of speed of an automatic mechanism timed (How?) by each person’s judgment of when the mechanism executed its mechanical function. What measuring device is used other than the subjective feeling of the person providing his/her data. What then the use of the data as compared to the manufacturer’s already existing data - assumedly, I admit - obtained by an objective, scientific and accurate timing device.

BIC

I've always had manual transmissions in sports cars and expected to order the same in the C7. I test drove the M7, which was great with the rev matching.

Then drove the A8 in Sport Mode in various scenarios. My perception was it shifted up & down instantaneously with the paddles and faster than a manual. I have a 2010 CTS with the A6. That transmission sucks as far as manual mode shift responsiveness but I ordered the A8 in my C7 as it is pretty awesome either paddle shifting or letting it run itself.

vettesmith02

Supermassive

Oh jeez. The A8 paddle shift is nothing like a DCT, anyone hoping for that will be disappointed. If you have had seat time in any car with the ZF 8 speed thats in the Jaguar F-Type then you already have a feel for it. Basically you hit the paddle and it takes about 1 full second for the shift to occur. So if paddle shifting is your thing stay away from the Autos in the C7 because you arent gonna paddle shift this thing around a race track.

As for computer managed auto shifting the A8 is phenomenal. You wont find another auto quite like this. The upshifts and down shifts when performance shift mode is active are downright hilarious and are as fast or faster than the almighty PDK. The shift logic is also amazing, I havent tracked mine yet but just doing some aggressive road driving has yielded some impressive experiences where I was left giggling like a school girl at a Justin Bieber concert.

So if you want to paffle shift, buy a Porsche. If you want the best performance auto, buy the C7.

Paddle shifting the auto is for when you want to cruise around at 5000 rpm with the NPP wide open to annoy the general public.

hawkgfr

In 1500 miles I'm in manual mode 99 percent of the time....the more throttle the quicker it shifts. Now that is has miles there is no delay unless you let of the throttle then there is a slight delay.


I don't see using "D" very often at all....I've been in a manual car since 2001 except for three months back in 2011...well now four months.

The 8 speed is very impressive so far. I've held my breath thinking I was gonna hate it.. Not so as of yet. With 5 gears before 1 to 1 final drive ratio it is always in a "good" gear to snap your neck. I'm liking it so much I can't stay out of the car lol...

Steve Garrett

I drove an A8 and found the shifting to be instantaneous. Very smooth, very quick.

and12e

Some people say shifts are smooth and instantaneous others say there is lag. I think people are talking about two different things, which were cleared up in one of the above posts.

When paddle shifting the a8, there is significant lag between what your finger does and when the transmission shifts. Not a very enjoyable experience in the sense it leaves you unsatisfied.

In regular auto mode the shifts are great, they're nice and brisk.

hawkgfr

No, there isn't any lag...It has shifted before the number changes on the display...It changes before you release the paddle...It does NOT shift before you engage it though If you are in the throttle is shifts exactly like no lift shifting only faster...


The "sense" it leaves you with is... dammit man this thing hauls ***...

OLD_GOAT

I don't know how the beamer shifts, nor do I have any desire to drive one.


When I finally get the car to the track, I will let the computer do the shifting.

When people try to paddle shift and are 'on the edge', they may hit the paddle a couple of hundred rpms before hitting red line, and if they're too late, the car will hit the rev limiter.