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      10-26-2019, 08:20 AM   #23
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Originally Posted by chris719 View Post
There is no such thing as protection from mechanical over-rev.
Some cars have lock-out's that won't allow a shift from 2 to 1 or 3 to 2 etc, at certain rpm's.

Most cars have this for 1st gear at least. Too bad Honda didn't have it for the original S2000.
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      10-28-2019, 01:38 AM   #24
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      10-28-2019, 01:01 PM   #25
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Quote:
Originally Posted by VisualEcho View Post
Some cars have lock-out's that won't allow a shift from 2 to 1 or 3 to 2 etc, at certain rpm's.

Most cars have this for 1st gear at least. Too bad Honda didn't have it for the original S2000.
I'm not aware of any car that actually has this, do you have examples? What people think is a lock-out is just resistance. A lot of cars are very hard to put into 1st when the engine is above idle.

The intentional braking thing is a myth, too. It would just cause accidents.
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      10-28-2019, 01:24 PM   #26
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Quote:
Originally Posted by chris719 View Post
I'm not aware of any car that actually has this, do you have examples? What people think is a lock-out is just resistance. A lot of cars are very hard to put into 1st when the engine is above idle.

The intentional braking thing is a myth, too. It would just cause accidents.
My 2005 STi had a lock-out for first for sure.
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      10-28-2019, 01:40 PM   #27
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And if there was nothing preventing it I would have needed at least 3 new V8s for my Mustang. Also you never see money shift threads on Mustang forums these days. I’m not saying spark and fuel cutoff guarantee no money Shifts. But it works in a Mustang on a 4 to 3 mis-shift. I was quick to get back on the clutch, but still. The V8 has more inertia and revs slower (therefore dragging the rear wheels some causing the squeal I heard every time) thus allowing more time to get back on the clutch.

I’ve never done a 2 to 1 but in that situation a lockout would be the only thing that could help.
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      10-28-2019, 08:20 PM   #28
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I've definitely had a lock out in at least one of my cars. You could hover the shifter near first and it just wouldn't go in until the RPM's dropped to a certain point. Not sure of the exact logic, but it was there.
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      10-28-2019, 08:24 PM   #29
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Quote:
Originally Posted by mattssi View Post
I've definitely had a lock out in at least one of my cars. You could hover the shifter near first and it just wouldn't go in until the RPM's dropped to a certain point. Not sure of the exact logic, but it was there.
I can find no evidence of an intentional one in any of the cars mentioned on the thread. It's not logic, it's just hard for synchros to work. I can't get my Z4M into 1st most of the time except from a dead stop at idle, but that's not an intentional lock-out. Almost every MT is hard to get into first while moving.

Quote:
Originally Posted by 5.M0NSTER View Post
And if there was nothing preventing it I would have needed at least 3 new V8s for my Mustang. Also you never see money shift threads on Mustang forums these days. I’m not saying spark and fuel cutoff guarantee no money Shifts. But it works in a Mustang on a 4 to 3 mis-shift. I was quick to get back on the clutch, but still. The V8 has more inertia and revs slower (therefore dragging the rear wheels some causing the squeal I heard every time) thus allowing more time to get back on the clutch.

I’ve never done a 2 to 1 but in that situation a lockout would be the only thing that could help.

Forgive me if I don't believe your explanation with no evidence. The hard truth is that you got lucky and/or that engine happens to be able to take spinning faster than redline better than some others. There is no way to stop a money shift if the transmission lets you into the gate.

I found 3 reports of it on Mustang GT Coyote V8s in a really quick google search.

Last edited by chris719; 10-28-2019 at 08:30 PM..
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      10-28-2019, 08:29 PM   #30
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Quote:
Originally Posted by chris719 View Post
I can find no evidence of an intentional one in any of the cars mentioned on the thread. It's not logic, it's just hard for synchros to work. I can't get my Z4M into 1st most of the time except from a dead stop at idle, but that's not an intentional lock-out. Almost every MT is hard to get into first while moving.




Forgive me if I don't believe your explanation with no evidence. The hard truth is that you got lucky and/or that engine happens to be able to take spinning faster than redline better than some others. There is no way to stop a money shift if the transmission lets you into the gate.
Touche!
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      10-28-2019, 09:29 PM   #31
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Quote:
Originally Posted by 5.M0NSTER View Post
And if there was nothing preventing it I would have needed at least 3 new V8s for my Mustang. Also you never see money shift threads on Mustang forums these days. I’m not saying spark and fuel cutoff guarantee no money Shifts. But it works in a Mustang on a 4 to 3 mis-shift. I was quick to get back on the clutch, but still. The V8 has more inertia and revs slower (therefore dragging the rear wheels some causing the squeal I heard every time) thus allowing more time to get back on the clutch.

I’ve never done a 2 to 1 but in that situation a lockout would be the only thing that could help.
Just to add a bit of additional context to your post, the reality is that spark and fuel cutoff really don’t do that much here since the damage is often mechanical in nature. Most commonly damage occurs when the piston slaps one of the valves causing damage. This can occur when the motor is spinning so fast the springs in the valve don’t have enough time to react and the piston high 5s one of the valves. If you are truly unfortunate the connecting rod can also go when it hits a valve or simply from the stress of the motor spinning that fast.

Where fuel and spark cutoff can help is if the cylinder is still combusting but the piston is traveling back up. Eliminating the combustion at least takes one stress factor off the table. The reality is even then, if the overrev is severe enough, damage is still going to occur. Now there is definitely credence to different motors being more susceptible. Some motors have more clearance between valves and pistons, others have forged connecting rods. These won’t always eliminate the chance of a catastrophic failure, but can help mitigate some of the ill effects.
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      10-28-2019, 11:31 PM   #32
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Quote:
Originally Posted by chris719 View Post
+1

I use a less extreme version of this. I use a handshake grip for 1st and 2nd gear shifts, overhand grip for 3rd/4th, backhand for 5th/6th.
+1
Me too, I also add a bit of pressure when using hand shake and back hand grips so it will always slot in to the left or right gates respectively, and has zero chance of staying in the middle gate.
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      10-29-2019, 12:42 AM   #33
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Quote:
Originally Posted by chris719 View Post
Quote:
Originally Posted by VisualEcho View Post
Some cars have lock-out's that won't allow a shift from 2 to 1 or 3 to 2 etc, at certain rpm's.

Most cars have this for 1st gear at least. Too bad Honda didn't have it for the original S2000.
I'm not aware of any car that actually has this, do you have examples? What people think is a lock-out is just resistance. A lot of cars are very hard to put into 1st when the engine is above idle.

The intentional braking thing is a myth, too. It would just cause accidents.
my 2002 WRX did this for first gear.
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      10-29-2019, 01:23 AM   #34
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Quote:
Originally Posted by msdss View Post
my 2002 WRX did this for first gear.
Got a link to an informed source? All I can find is that they are hard to put into first because of the gearbox being that way, not some intentional over-rev lockout. Bet $20 there is no lockout and it's just the speed / ratio difference and crappy synchro.

https://www.clubwrx.net/threads/1st-gear-lockout.82102/
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      10-29-2019, 01:32 AM   #35
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Quote:
Originally Posted by chris719 View Post
Got a link to an informed source? All I can find is that they are hard to put into first because of the gearbox being that way, not some intentional over-rev lockout. Bet $20 there is no lockout and it's just the speed / ratio difference and crappy synchro.

https://www.clubwrx.net/threads/1st-gear-lockout.82102/
I still have the classic original WRX (MY00 GC8) the last of the good ones. Since new going into first or reverse was always challenging. Even at a standstill.

Doesn't mean I don't love it though. It's still awesome today.

Talking of money shifts I remember a guy doing one on his brand new e46 M3 at a track day many years ago. What a mess! Some subterfuge involving a tow truck involved him getting the engine replaced under warranty!
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      10-29-2019, 02:16 AM   #36
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Quote:
Originally Posted by chris719 View Post
The hard truth is that you got lucky and/or that engine happens to be able to take spinning faster than redline better than some others. There is no way to stop a money shift if the transmission lets you into the gate.

I found 3 reports of it on Mustang GT Coyote V8s in a really quick google search.
This we can agree on. Once you're in the wrong gear the only thing which can help is tolerances of the motor, including rod and piston strength, and how fast and hard you get back on the clutch. I know there is no such thing as a flywheel brake. Spark and fuel cut may not be enough here.

But I don't agree that I got "lucky". With this kind of luck I should be playing the tables in Vegas.

The conclusion I draw here is that my previous V8 is more robust on a 4-3 mis-shift and it could just be because it has more rotating mass and therefore revs up slower. And the S55 is more fragile in particular situation.
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      10-29-2019, 02:39 AM   #37
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Quote:
Originally Posted by 5.M0NSTER View Post
This we can agree on. Once you're in the wrong gear the only thing which can help is tolerances of the motor, including rod and piston strength, and how fast and hard you get back on the clutch. I know there is no such thing as a flywheel brake. Spark and fuel cut may not be enough here.

But I don't agree that I got "lucky". With this kind of luck I should be playing the tables in Vegas.

The conclusion I draw here is that my previous V8 is more robust on a 4-3 mis-shift and it could just be because it has more rotating mass and therefore revs up slower. And the S55 is more fragile in particular situation.
Well, a lot of engines have survived over-rev. I believe some guys with E92 M3s have seen 9k+ RPM and lived to tell. A 4-3 is one of the safer mis-shifts, too. Every design has some safety margin, or they would be blowing up in regular use. Not too many failed Coyote engines, but the Voodoo in the GT350 seems to like to self destruct with alarming regularity.

The problem is, we have a sample size of 1 for an S55 here. What piqued my interest was that the crank hub spun. It's not really the usual failure mode for other engines. I was hoping it might shed some light on why the crank hub spins on S55 in the first place.
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      10-29-2019, 04:55 AM   #38
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Needs more of this...LOL

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      10-29-2019, 02:48 PM   #39
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Ouchhhh...
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      10-29-2019, 03:12 PM   #40
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Quote:
Originally Posted by chris719 View Post
+1

I use a less extreme version of this. I use a handshake grip for 1st and 2nd gear shifts, overhand grip for 3rd/4th, backhand for 5th/6th.
Same but opposite for RHD... i.e. start back hand 1st to 2nd.

I often just use finger tips for 3rd to 4th.

If you dont slam gears the box won't let you moneyshift as the syncros will never get the input shaft up to enough speed for an normal shift force to work.

Take it easy, let the box do its job and enjoy the shifting...
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      10-29-2019, 09:59 PM   #41
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Originally Posted by VisualEcho View Post
My 2005 STi had a lock-out for first for sure.
Yup, mine did too. Man I miss my my ‘05.
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      10-29-2019, 10:10 PM   #42
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Lock outs as other members mention, definitely exist. Typically they are solenoids that prevent access to first gear until certain conditions are met. Same technology in a more nefarious application is the dreaded GM Skip Shift feature. It wouldn’t allow you to access 2nd and 3rd gears unless you got on the throttle pretty hard and are above a certain speed. I know this is STILL a feature on Corvettes. Guess the DCT in the C8 solves that problem though...
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      10-29-2019, 10:18 PM   #43
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Quote:
Originally Posted by pz619 View Post
Lock outs as other members mention, definitely exist. Typically they are solenoids that prevent access to first gear until certain conditions are met. Same technology in a more nefarious application is the dreaded GM Skip Shift feature. It wouldn’t allow you to access 2nd and 3rd gears unless you got on the throttle pretty hard and are above a certain speed. I know this is STILL a feature on Corvettes. Guess the DCT in the C8 solves that problem though...
Again, I would love to see an example. The only one I am aware of is the Corvette skip shift, which is not a first gear lockout and also does not stop money shifts. I can find ZERO other examples produced in the past 10+ years. I know I have never driven a 6MT with a lockout.
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      10-29-2019, 11:17 PM   #44
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Quote:
Originally Posted by chris719 View Post
Quote:
Originally Posted by pz619 View Post
Lock outs as other members mention, definitely exist. Typically they are solenoids that prevent access to first gear until certain conditions are met. Same technology in a more nefarious application is the dreaded GM Skip Shift feature. It wouldn't allow you to access 2nd and 3rd gears unless you got on the throttle pretty hard and are above a certain speed. I know this is STILL a feature on Corvettes. Guess the DCT in the C8 solves that problem though...
Again, I would love to see an example. The only one I am aware of is the Corvette skip shift, which is not a first gear lockout and also does not stop money shifts. I can find ZERO other examples produced in the past 10+ years. I know I have never driven a 6MT with a lockout.
https://drivetribe.com/p/5-features-...T2uFKl-uc6xXiQ

They aren't hard lockouts, they just give you so much resistance that, short of having mom lifting a car off baby strength, they are basically impossible to shift through.

The only real "hard" lock outs I know of are the reverse gears, especially in a 5 speed configuration.
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