sounds like clutch slip to me...

And clutch slip usually starts on the higher gears and work its way down. This is due to increased load in the upper gears.

This sounds like the perfect time to upgrade to an aftermarket clutch! I want this one.

soo wait if this is clutch slippage, why is this happening to my AT too.

yours is not clutch slip. Yours just sounds like your ecu adjusting to your driving style.

dmhenderson, do you ride your clutch or have some reason to suppose you are too hard on the clutch? If so you may not have a warranted item. If not perhaps it is another conundrum that is warranted. Good luck.

no to get off topic what is a drive by wire throttle body? newbie sorry

The throttle is controlled electronically, No Wire Cable is used like in older models

regardless of throttle setup, it doesn't explain why a mechanical manual clutch would not engage when it's........well, engaged. :D

Owe you guys a beer:

On the way to the airport on Tuesday I floored it in 6th to move into the fast-lane and the clutch utterly failed (car redlined, didn't re-engage until I let off the gas). Horrible burning clutch smell filled the car. Slippage in all gears even with steady pressure on the gas.

Dropped the car back at the dealership last night on the way home.

They're replacing the clutch and flywheel under warranty.
Booya.

To answer various questions
-I haven't been overly rough on the clutch but starting too fast in 1st has caused the clutch to slip since I bought the vehicle.

-I got into the habit of engine braking - especially in bad weather or if I had the need to stop really suddenly. Apparently this is hard on the clutch.

-Dealership can't explain what happened. They believe it has been faulty since day 1.

Anyway, tl;dr:
-My initial suspicion proved correct. If this happens to you, your clutch is about to go and you should take it to a shop immediately.

Heh, Altered Atmosphere was shut down last year/maybe 2 years ago after a rash of customer complaints and rumors of other shady activity (I forget what the deal was exactly). Now they own a R&D project shop mostly focusing on GT-Rs but if I remember right, they had a pretty sick 370z project car working too.

Anyway, at least the dealership was true to its word and is replacing everything under warranty. Really nice to see a dealership stand by their cars like that. Rare these days. One of the reasons I'll continue to buy Z cars.

Here's one of their project cars. Just look at this thing:

YouTube - AAM 370Z Twin Turbo: 500RWHP/372RWTQ

The first proves the 2nd. :D

This happened in both my cars. I think its just the ecu is slow at times so the clutches don't engage quick enough, then the ecu hits like a gear changing limp mode to protect the auto. It does feel like a slippping clutch. I've had my tranny checked and they tell me its normal in. Nissan cvvt sport transmissions to feel quirky at times.

You may need to have the hydraulic clutch bled. Maybe some air in the system (?)

IIRC, some owners ('07 Z on up) experienced premature clutch failure due to CSC and/or master cylinder failure.

I assume that I shouldn't have to ask the dealership to check the master cylinder - it would be caught when they're replacing the clutch & flywheel...?