I have a low mileage 458 under 10,000 kilometres. The other day I was on an open highway and in 3rd gear - had to slow down as the car in front exited the highway. I slightly revved the engine meaning to shift into 4th but shifted into 2nd instead. The car sort of bounced a bit and I quickly rectified the situation shifting into 3rd 4th and higher. would that have done any damage? As I say it was not high revs.
You should be fine. Sounds like you abruptly hit the rev limiter and/or just mis-matched the revs and caused the car to jerk a bit. The rev limiter should protect the motor from over revving. Generally speaking, over revving a motor can damage the ring lands or sometimes spin a bearing. But again, since the Ferrari has a rev limiter, I would say you are probably fine. Ray
I think a rev limiter is no protection against over-revving when downshifting - because the speed of the car will translate into an engine speed, no matter how the engine management cuts the fuel injection or ignition (the gearbox mechanically transmits the speed from the wheels to the engine). With a manual gearbox it's therefore possible to over-rev when down-shifting (the engine will "resist" that, because it's not free-revving - so that's where one can experience "locking" the wheels, although they're not locked, just brutally braked). With the DCT (or even with the previous F1 systems) it's not possible because some ECU will reject the order to downshift (the paddle having no mechanical link to the gearbox). Besides over-revving, there is the issue of putting more stress on the gearbox and the engine if the revs of both are completely unmatched when the clutch is re-engaged (that's the reason for blipping the throttle when downshifting, so that the engine speed is increased and closer to what it has to be); but one single occurrence of such mismatch should not result in noticeable damage.
As LVP488 mentions, I believe the DCT will reject requests to shift into the wrong gear. I think that might even be stated in the manual. Probably what happened is you just down shifted right into the rev limiter. When it cuts fuel/spark, the car naturally bogs as it slows down slightly. It's sort of a popping sensation. If you keep at it, it happens over and over again. Have you ever hit the rev limiter before and know what it feels like? I had a car once (back when I was 19 or 20) which had a design flaw in the shift linkage; under high lateral loads, the frame could shift in relation to the shift linkage and allow you to accidentally select the wrong gear. They even sold a "linkage relocation kit" in the performance parts catalog for racing. I looked at the part a few times, but didn't really understand what it was for. I even called the tech department and they explained it to me, but mentioned that, unless I was racing the car, then I really didn't really need it. So I didn't purchase it and didn't think I really needed it... that is, until I was racing some kid around a corner. I was redlining the motor in 2nd gear and went to shift into 3rd gear, but it went into 1st gear instead. The engine over revved and immediately spun a bearing. Ray
Haha... yeah, that was me! And to this day you probably still think your stock BMW 320 is faster than a highly modified Auto-X car lol. Ray
