over revved engine
#1
over revved engine
hey guys, so at an HPDE (at laguna) i mis-shifted from 3rd to 2nd. i was probably going at least 70 (2nd max is 64mph) when i wanted to get 4th. so the mis-shift happened, the rear wheels lock up, and i immediately put the clutch back in. this is for a split second so i have no idea what the revs were. afterwards the car drives fine. i know our vq is not an interference engine, but im wondering how did the rear wheels lock up and is there a chance anything was damaged? ive put on a lot of miles after this happened and the car drives fine and sounds fine.
#3
i might sound dumb, but by what mechanism does engine braking work by int his situation of overrevving? do all the valves close and prevent the chamber from expanding thereby causing wheel locking?
#4
Sam Rothstein
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Hehehe... Nah maing... Hmmm, how can i explain this.... What happens is the engine is at around 3000 rpms in 4th gear at 60 mph (for instance)... When you downshift to 2nd gear going the same speed (60mph), the engine jumps to 7000 rpm.... Doing this slows down the car drastically and makes the engine actually "brake" (slow) the car faster... This is why the tires "locked"... Because the engine had to jump rpms so quickly and couldn't due to the tires preventing it from jumping rpms as fast as it wanted to... Has nothing to do with valves closing irregularly or anything... Hope i didn't confuse you... Is this your first MT?
#7
Hehehe... Nah maing... Hmmm, how can i explain this.... What happens is the engine is at around 3000 rpms in 4th gear at 60 mph (for instance)... When you downshift to 2nd gear going the same speed (60mph), the engine jumps to 7000 rpm.... Doing this slows down the car drastically and makes the engine actually "brake" (slow) the car faster... This is why the tires "locked"... Because the engine had to jump rpms so quickly and couldn't due to the tires preventing it from jumping rpms as fast as it wanted to... Has nothing to do with valves closing irregularly or anything... Hope i didn't confuse you... Is this your first MT?
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#8
Sam Rothstein
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heh it is, though not what i learned on. i was paranoid because i thought that at my speeds, going to 2nd would be way over the redline because max speed in 2nd is 64. i was most likely doing faster than 70 at least. probably 80 because i wanted to grab 4th. so that would put 2nd gear speed way higher than 8k? but i think i understand now. thanks!
#10
Just a question...were you pistol gripping the shifter?
Also, it was probably an instant but, did you manage to see where the rpm needle went up to before you pushed the clutch in? It can't hurt to get a compression test just in case if it actually did overrev.
Also, it was probably an instant but, did you manage to see where the rpm needle went up to before you pushed the clutch in? It can't hurt to get a compression test just in case if it actually did overrev.
#12
well this happened back in february. back then i used pistol grip, but since then i have used backhand. since its been so long, 5months at least, i assume theres no damage =/
#14
Ah, so in that case you were pistol gripping? Just to clarify.
If you haven't really onticed anything then it's probably all good..
#15
Who got pistol whipped? Why wait 8 months to say something
If it hasn't exploded by now and you aren't leaving a smog trail driving around town you should get another 10,000 miles out of it
If it hasn't exploded by now and you aren't leaving a smog trail driving around town you should get another 10,000 miles out of it