This quote from the Owner's Manual made me laugh:

"SHIFT DENIED: This message displays when attempting to shift to a gear not appropriate for the vehicle speed and engine revolutions per minute (rpm)."

 

Seriously, there is a "Shift Denied" display? LOL

 

Makes sense. I was wondering about this and rev matching, since it can guess which gear you're going to let's say you were downshift from 6 to 4 to pass someone and accidentally went towards 2nd. Would it rev match to the rev limiter and stop there? I've never been in a 370Z so no experience with computer rev matching. Guess I assume the engine wouldn't grenade itself.

 

Wait... are we saying that the C7 will not allow a "money shift" in the 7MT? If that is true, that is fantastic!

 

It is probably for the manual mode of the automatic. It should not allow you to downshift to an over-rev condition. The Manual transmission does not have a way to do that the "gate" that is there is slides you from 1st to second. So it could conceivably block a downshift to 2nd only that would be an over-rev, but I don't see it for other gears.

 

Who wants to volunteer and try?

 

Cars are increasingly just peripheral hardware for computers. Remember when Windows accused us routine users of "Illegal" actions?

 

You'd think with current tech a manual could be designed to immediately "detect" an incoming money shift and lock it out...

 

Agreed. If the computer can lock out Reverse gear above a certain speed it should certainly lock out gears based on current speeds and throttle.

 

What will happen? Rev limiter kick in and cause rear wheels to start sliding? I am trying to recall my manual transmission days and what would happen in that (very rare) occurrence---- it seems I can remember pushing the clutch in VERY QUICKLY as soon as I heard revs starting to climb wildly.

 

LOL! I just read that too and posted it on Facebook.

 

Nothing new. They have this on the automatics. It also denies upshifting to the point of lugging.

As usual, if you want full control, get the manual.

Michael

 

It does already. its called "CAGS"

 

Good point - so why not use that tech to actually do something useful, like saving guys from trashing their engines through over-revving on a money shift?

 

So now we have A6 and AM7 as opposed to the old A6 and M6....

 

Downshifting a manual at too fast a road speed is called "zinging the engine". The rev limiter can't stop it from happening since the engine is still mechanically connected to the spinning clutch, which is connected to the torque tube, which is connected to the transmission, which is connected to the differential, which is connected to the rear wheels. The rev limiter can cease feeding the engine fuel, but the crank shaft will still be turning, and that's what does the damage to the engine.

 

Exactly right!

Another way engine damage can occur is when a lower gear is chosen to use engine braking on a steep grade and the grade is sufficient to push vehicle speed (and resulting engine RPM) beyond the safe limit. This is a case where at least some automatic transmissions will allow excessive RPM and engine damage. The Allison automatic in my GMC pickup allows manual shifting via the range select paddle and if you try to choose a gear that is too low or too high for current conditions it will flash a "shift inhibited" message on the DIC. If you are traveling at high speed and place the shift lever (not the manual range selector) in first it will downshift as quickly as it can without exceeding recommended engine RPM. HOWEVER if you select a range which is acceptable for the current speed but then allow the vehicle to continue to pick up speed on a steep down grade it will not automatically upshift and this is when damage can occur.

This last point does make sense from a manufacturer liability standpoint as it would be better to risk engine damage in the attempt to keep some careless driver from running off of a mountain road.

 

If you're spinning the torque tube when you over rev the engine(or any time), you have more problems than you can imagine.

 

I will fess up I have done it. Power shifting 2 to 3 and slipping it back into 1st, as you slip off the clutch...with that O crap this doesn't feel right. As the clutch grabs and spins the motor to 8000rpm or what ever, the rear wheels lock and skip, valves hit pistons bends pushrods and dings valves on the top of the pistons. That was in my Camaro LS1...The LT1 has higher compression so the valves may hit with more force on the pistons.

I think that this may be the reason for the LS7's valve dropping, some guys miss a shift ding; a valve and over time the valve wears and then drops, but they forget that they missed a shift 6 months ago or have to much pride to admit driver error. Which is fine, but it would be smart if GM could stop the readline power shift from 2 to 1 shift; or 3 to 2; or 4 to 3; or 6 to 5; or the 7 to 6 lots of gates to hit perfect every time.

I would like to see the 7 to 6 red line shift 230 mph and drop in down a gear. BOOOMMM

 

If your lucky enough, the rear wheels may break loose giving you time disengage the clutch before the engine got too deep into the red line.
If not, It's one of your more expensive brain fart moments.