Quote:
Originally Posted by BMRLVR
I am of the belief that since an over rev that is the result of a mis-shift, increases the engine speed so fast that it is possible that even the extremely smart MSS60 DME in the M3 might not keep up.
If, the engine was indeed mechanically over revved, the 8705 RPM is irrelevant. The violence of the sudden increase in speed during the clutch engagement (the mechanical over rev itself), then the sudden decrease in speed after the clutch disengagement (after the driver realizes he f---ed up). Is what does the damage. Bring load onto an object slowly is much different than a sudden jolt. This coupled with the entire mass of the vehicle spinning the engine.
Think about this analogy and you will realize how big a deal mass makes in the equation.
If a person runs into the back of your car at 20 MPH it gives a pretty good jolt, right!?
Is the jolt much bigger if a motorcycle hits you at the same velocity?
How about a car hits you at the same velocity?
How about a pick-up truck?
A Semi?
Hopefully this drives the point home how mass increases force delivered even if speed is constant.
Think about this, it takes the S65's full output (in stock form) to move our M3's over the distance of a quarter mile in 12.8 - 13.2. At the end of the quarter mile the car is doing between 108-115 MPH, it takes a lot of energy to do that! The speed at the end of the quarter mile is not to far off of the alleged mis-shift, imagine all of the energy that was expelled to get the car to that speed (obviously subtracting frictional, inertial and heat losses) and start delivering it back into the engine in a millisecond and expect it to deal with it without breaking.
Does this help to drive home the notion of how much damage a mis-shift can cause???!!!
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Think about drifting when they release the clutch,the rpm is increased so fast,The DME still keeps up.
I don't think the engine braking effect would stop the rpm from passing 8,700 rpm if a mis-shift took place.
Also,it's very hard to confuse 3rd for 5th coming from 4th on an upshift,I've heard of guys moving the shifter too far to.the left passing the gate for the desired gear. Like wanting to go from 5th into 4th and accidentally put it in 2nd by movin the lever too far to the left.
I mean you can't move the lever too far to the right from 4th to end up in a lower gear.