Ggpz06

383vett

The transmission is downshifting.

Ggpz06

Mikec7z

my car does something similar, try a ported TB and see if that solves it, i drove another car than mine and the ported tb did solve their issue. Not sure that you have the same issue i am describing.

The other possibility is the torque converter having some issues, but that was supposed to be resolved by 17 i thought?

Null Pointer

Try pulling and holding the left paddle shifter. That should cause the computer to immediately downshift the car into the lowest gear possible within rev limits. The only time I have experienced something similar to what the OP is describing is when I have been tenative about flooring it.

Mikec7z

i agree with the above, i guess an important thing we need to know is... is it in one gear as it does this? or is it downshifting twice at 2 separate moments to lower and lower gears?

Null Pointer

Not sure, Mike. Probably a question for Bill Dearborn. I have seen on my PDR it will drop from 4 to 2 without going through 3 just flooring it without operating the paddle.

Ggpz06

Mikec7z

i dont know that bills car is an automatic.

Mine is, and now that you describe it and my memory is working a bit better, i absoluetly know what you are talking about... it is a double pull on some WOT punches, its a quick blip and then another blip. The throttle and engine noise literally get quiet for a second between the blips and then it pulls hard. I'll see if i can get a video of my car doing it.

So anyway, it might be the traction control... i can get mine to kick in upwards of 80mph if i stomp on it... it could be the TB needing to be ported... and it could be the Torque converter... and it could be the trans doing weird things while it is shifting.

All I can tell you is, mine has done this as well, since day 1, and i drive the car as hard as anyone, and im at 18,000 miles, and no issues.... no drastic failures that will throw you into the ditch, so i think its okay to not worry about, or if you want to try to eliminate it, those are my 4 tips above. I'll try to find a video of it doing it. And it could be your v4 idea too, i wont argue against that, but i dont think that is what it is, as i believe ive gotten it to do it when im not in v4 mode.

Bill Dearborn

You might be getting two hits because when you floor it the engine switches to V8 mode and then the transmission downshifts. Try punching the throttle when there is a load on the car such as going up hill. The engine shouldn't be in V4 mode when there is a load on the engine. On my M7 in Eco Mode it only takes an almost imperceptible uprise to take the engine out of V4 mode. A long gentle up hill section of road might work for you. If you only get one hit then you know the switch to V8 mode at wide open throttle is causing a huge power hit. When you punch it in V4 mode the engine is going from producing minimum torque to maximum torque for that rpm. If the engine was turning 2K rpm you would suddenly go from just enough torque to maintain speed to about 550 lb ft of torque and from less than 40 HP to 225 HP almost instantly. That is going to cause some sort of a hit. The throttle dropping to wide open lets the transmission controller know you are serious and downshifts the car the proper amount for what you are asking it to do.

Bill

MCK_Z06

Does the second "kick" correlate with the car coming off the bypass and into boost?
My car literally feels like there is a little kick from behind when the bypass closes and it gets into boost. Maybe that's what it is.
Try and watch your gauge and see if that's it... I don't have an auto and my car has all of the DoD stuff removed (can't go into V4 mode.) so I'm not sure what that feels like but this is the first thing I thought of when you described the symptom.

Mikec7z

mine literally goes WAW WAWWWWW just as fast as you can read and speak those words. There is a pause of silence in there, and the kicks correspond with the engine noise obviously. I know what he is talking about. I don't think it is the bypass. Car would not lose power in between for a moment like it does.

user0405240328

I can report experiencing the same issue as OP in my 2016 Z06/Z07 A8. Unsure as to cause.

FastestBusaAround

That is the built-in throttle lag that people complain about, just that the description in the OP's post is not fully accurate.

It is normal...and if you load it up a bit before a WOT punch, you won't feel it.

It also doesn't happen from a launch...and a bit less in lower gears.

Some will swear that that the Vitesse throttle controller eliminates that, but they are simply wrong. I know from experience what they do and how they work. Others say the the polished TB eliminates that, which seems a bit off to me as well...and I doubt it eliminates the lag fully.

To fully eliminate it, you just have to dial it out in a tune, which also voids your powertrain warranty...and it's not worth it just for that.

The lag is by design and is likely there to protect less experienced drivers, IMO, but that's just my speculation.

FWIW, my Huracan Performante does it to a certain extent as well, but in that case more to protect the power train than the driver...

Mikec7z

i agree with your statement most, i dont believe it has to do with the v4, but that is just me.

jaden61

Put it in sport mode and give it 2 quick kicks. Learn something new every day/
Perf shift active.

GeorgeR_Zed06

Mine does the same thing but I think it's only because its coming out of AFM/DOD mode. That, and the exhaust is also opening up all the way. It's annoying but I've kind of gotten used to it...

Bill Dearborn

My M7 doesn't have a throttle lag. In any mode except Eco the car doesn't enter V4 operation so when the throttle is hit the car just accelerates very smoothly as the manifold pressure increases. There is a smooth progression from vacuum to pressurization. This is something I have duplicated many times coming off a corner at 50 mph in third going from maintenance throttle at the apex to wide open throttle and running to 123 mph when I shift to 4th. I have never experienced any hesitation even when PTM was active and modulating power to the rear wheels so the car wouldn't slip sideways under full power with the front wheels still turned.

I have my exhaust permanently set in Track Mode so it is open all the time except when the engine is operating in V4 mode when the drive mode is set to Eco. When driving in Eco Mode with the engine in V4 mode if I nail the throttle the engine switches to V8 mode while the exhaust reopens. There is a slight lag as the engine switches but it is barely perceptible.

Bill

MrBlackZ06

I believe It may has something to do with traction control

jstewart

I saw something like this on my A8 when transitioning from off-on & on-off throttle transitions but the Mamo ported TB solved that. Never saw it when under enough load as Bill described on a kick down.