[CJG]

Hello - today while driving about 82-89mph, I meant to go from 6th gear to 4th, but accidentally grabbed 2nd. When I started letting the clutch out, the car decelerated quite a bit. I *think* I depressed the clutch before letting it all the way out, but I don’t remember. I do know that the RPM gauge was at or over redline. The car ran perfectly normal afterwards. I parked it at home for about an hour, and took it for another spin. Nothing out of the ordinary. Am I in the clear or can I expect stuff to start going wrong?

[Richard0nee]

Damn you did a money shift. Hopefully everything is okay cuz if something were to go wrong the dealer can see that it over revved and use it against you.

No codes, no limp mode, etc.. you should be fine tho

[JFM-jr]

Mechanical over rev In most cases you would bend a pushrod but the car would certainly not run smoothly if so.

[soloknight6]

lol, you are fine. if an over-rev did damage, you would know right away... trust me.

Heres a tip so it never happens to you again: Drive with REV MATCH ON haha. Its saved my ass a couple of times, as the car will auto rev to the point of fuel cutoff before you even release the clutch, keeping you from mechanically over-revving the engine.

Seriously dont sweat it. These engines are engineered with this sort of thing in mind, as these are passenger vehicle engines, and not super tuned race engines.

[HDRDTD]

Originally Posted by soloknight6

lol, you are fine. if an over-rev did damage, you would know right away... trust me.

Heres a tip so it never happens to you again: Drive with REV MATCH ON haha. Its saved my ass a couple of times, as the car will auto rev to the point of fuel cutoff before you even release the clutch, keeping you from mechanically over-revving the engine.

Seriously dont sweat it. These engines are engineered with this sort of thing in mind, as these are passenger vehicle engines, and not super tuned race engines.

Cutting off the fuel feed will have NO effect on a mechanical over-rev.

A mechanical over-rev will happen with or without fuel as well as with or without a spark.

[SSummit]

Avoid skipping gears when downshifting, rather go 6-5-4, you will be far less likely to make this mistake, skipping gears is not only risky, its more work for the synchros and can wear them faster (though I doubt it will have much of an effect).

That being said you will be fine. The Camaro SS does 80 mph at 6500 rpm in 2nd gear, if you were slightly over 80 mph you would have been around 6700 rpm, which is only slightly over red line (6600rpm fuel cut off) and won't be a problem for that very short period of time.

[SSummit]

Originally Posted by soloknight6

lol, you are fine. if an over-rev did damage, you would know right away... trust me.

Heres a tip so it never happens to you again: Drive with REV MATCH ON haha. Its saved my ass a couple of times, as the car will auto rev to the point of fuel cutoff before you even release the clutch, keeping you from mechanically over-revving the engine.

Active rev match won't stop you from mechanical over rev, if you are at 100mph and downshift to second the engine is going to rev to around 8000rpm, no matter if the active rev match revs up to 6500rpm. The shock of the engine revving to red line violently when might warn you in time before you make the mistake of choosing the wrong gear, which may be what you meant.

The OPs mistake was skipping gears, he should have gone 6-5-4, 6-4 is not only risky, its more work for the synchros and can wear them faster.

[soloknight6]

Originally Posted by SSummit

Active rev match won't stop you from mechanical over rev, if you are at 100mph and downshift to second the engine is going to rev to around 8000rpm, no matter if the active rev match revs up to 6500rpm. The shock of the engine revving to red line violently when might warn you in time before you make the mistake of choosing the wrong gear, which may be what you meant.

The OPs mistake was skipping gears, he should have gone 6-5-4, 6-4 is not only risky, its more work for the synchros and can wear them faster.

SSummit and HDRDTD, you guys both misread my post. With rev match on, the car will cut fuel as soon as you DEPRESS THE CLUTCH AND SHIFT INTO THE WRONG GEAR, if the driver has any sense, he WILL NOT RELEASE the clutch until the mis-shift is corrected, PREVENTING A MECHANICAL OVER REV.

You can not over rev the engine with the clutch pedal depressed. Rev match will let you know you ****ed up before you even release the clutch.

[Rock-It Man]

Nannies do not prevent mechanical over-rev.

Automatic transmission is under-appreciated.

[My87z28]

You should be fine, you did mechanically over rev the engine, but luckily not by too much. I wouldn’t think you hit 7k rpm. I know I’ve hit the fuel cut off in 2nd at least 4-5 times. It’s not the same thing but it’s still 6500-6600rpm.

[ChevyRules]

Originally Posted by Rock-It Man

Nannies do not prevent mechanical over-rev.

Automatic transmission is under-appreciated.

His point is with active rev match, it would send the engine to redline and hopefully the driver would go, " WTH why is the engine hitting the limiter" and then realize they shifted into the wrong gear before letting out the clutch. Of course if one doesn't catch it and lets out the clutch, then you're doomed to the mechanical overrev.

[srcstc]

Originally Posted by HDRDTD

Cutting off the fuel feed will have NO effect on a mechanical over-rev.



A mechanical over-rev will happen with or without fuel as well as with or without a spark.

What he's saying is the rev match happens instantly giving you a little extra warning that you F'd up. And he's right.


Sent from my iPhone using Tapatalk

[garfin]

Originally Posted by soloknight6

SSummit and HDRDTD, you guys both misread my post. With rev match on, the car will cut fuel as soon as you DEPRESS THE CLUTCH AND SHIFT INTO THE WRONG GEAR, if the driver has any sense, he WILL NOT RELEASE the clutch until the mis-shift is corrected, PREVENTING A MECHANICAL OVER REV.

You can not over rev the engine with the clutch still engaged. Rev match will let you know you ****ed up before you even release the clutch.

For the record, and to clear up any confusion about a clutch being "engaged" or "disengaged" (I believe you may be confusing the terms)... a clutch is "engaged" when your foot is not depressing the clutch pedal. When "engaged" the disc is "squeezed" between the flywheel and pressure plate, and power from the engine is transmitted by the disc's hub to the input shaft of the transmission.
Therefore, when the clutch is "disengaged", your foot is holding down the clutch pedal. Think of the clutch as something that connects the engine to the transmission, and when this mechanism is "engaged", permits the engine and transmission to work together to move the car.
When the clutch is "disengaged", the engine basically is separated from the transmission (by pressing the clutch pedal down).
The bottom line is that the engine most certainly can be over-revved mechanically when the clutch is "engaged".
The common mistake here, is thinking that one "engages" the clutch when you press down on it - when it is exactly the opposite that is true.

With all that being said, the chances are that no damage was done to the engine - especially if it seems to be running normally. The only caveat here that I can think of would be a scenario where the over-revving incident could have possibly weakened the valve springs to the extent that if the same incident were to be repeated, a bent pushrod might be the consequence, due to the weakened condition of the valve springs (ask me how I know), but that's doubtful based on the description of the incident which was not extreme at all.

Best regards,

Elie

[soloknight6]

Originally Posted by garfin

For the record, and to clear up any confusion about a clutch being "engaged" or "disengaged" (I believe you may be confusing the terms)... a clutch is "engaged" when your foot is not depressing the clutch pedal. When "engaged" the disc is "squeezed" between the flywheel and pressure plate, and power from the engine is transmitted by the disc's hub to the input shaft of the transmission.
Therefore, when the clutch is "disengaged", your foot is holding down the clutch pedal. Think of the clutch as something that connects the engine to the transmission, and when this mechanism is "engaged", permits the engine and transmission to work together to move the car.
When the clutch is "disengaged", the engine basically is separated from the transmission (by pressing the clutch pedal down).
The bottom line is that the engine most certainly can be over-revved mechanically when the clutch is "engaged".
The common mistake here, is thinking that one "engages" the clutch when you press down on it - when it is exactly the opposite that is true.

With all that being said, the chances are that no damage was done to the engine - especially if it seems to be running normally. The only caveat here that I can think of would be a scenario where the over-revving incident could have possibly weakened the valve springs to the extent that if the same incident were to be repeated, a bent pushrod might be the consequence, due to the weakened condition of the valve springs (ask me how I know), but that's doubtful based on the description of the incident which was not extreme at all.

Best regards,

Elie

Hey thanks for the correction, learn something new everyday. Thanks man!