I imagine it would destroy the engine and the transmission, but it’s just a guess.
You’d prolly destroy the transmission as it would take most of the strain.
That said it may not even be possible to get it into gear. Synchros certainly wouldn’t handle it well and I’m not sure how easy it works be to rev match it.
I believe that’s called a “money shift.”
Because when you do it, it ends up costing a lot of money because it can grenade engines, transmissions, or both
Each vehicle will differ some. It’s a matter of the weakest point. And largely what the driver does (start to let clutch out, and realize vs letting clutch completely out and mechanically over revving the engine). I’ve seen all manner of failure from misshift. Usually it’s 5 to 2 on the track. Sometimes it’s immediate catastrophic failure. Sometimes it’s like the video the other comment or posted.
Edit: fixed a word and finished my thought. Hit send too soon the first time.
Interesting! Would you care to share some of the more catastrophic failures?
Back in the early 2000s the celiac gt drivers loved to do the 5 to 2 shift. They claimed their was something wrong with the close ratio gearbox (spoiler it was really bad drivers) iirc Toyota even acquiesced and warrantied some of them. They were killing both the engine and trans. There was a pretty funny video floating around of some younger dude doing exactly that on YouTube. It didn’t sound good.
As for others, I’ve seen windowed blocks, steam/smoke everywhere, gears with zero teeth left and shrapnel everywhere, crankshafts cracked (this one was part of a development program we were doing, and the guy did it more than once, I still don’t understand how)Needless to say, it got expensive for them.
I can’t currently think of any of them that I witnessed. We just usually get the aftermath to deal with.
Edit: to add, a lot of the cars we deal with already have stronger than stock/upgraded parts, so they don’t always follow the same failure pattern as a street car.
People also don’t like to tell the whole story to the mechanic so we have to do some educated guessing how shit fails sometimes. We usually have seen it before and know exactly but sometimes people do some creative shit and we scratch our heads.
When I owned my workshop I once had to replace the engine in an old Ford Fiesta that had this happen.
From what I could tell they went from 4th to 1st.
The damage started when the middle two pistons broke and allowed the conrods to separate from them pulling out the wrist pins as they did. Then the free floating conrods hammered the pistons into the head destroying the valves, rockers and pushrods too. After that the rods had bent enough to allow them to fall out of the cylinder and punch a hole in the back of the block, then the sump then parts of the rods exited through the front of the block, One of them destroyed the radiator as it left.
That is my rundown of the series of events from what I could work out at the time.
That was an interesting read. Thanks for sharing mate
No problem, It was interesting to strip the car down and work out what had gone on. This was before the days when we all had cameras with us otherwise I would have lots of pics of the carnage.
It’s called a “money shift”, and, assuming there isn’t a gate or interlock in the transmission to stop you, you will massively over rev the engine, and destroy it.
There’s a few videos on YouTube of it happening.