[turnsignalslol]

Originally Posted by Bumpinjeep

Literally a non-issue. The car is not damaged in any way shape or form. The transmission wont shift if it thinks that the car will be damaged. Calm down, there's literally zero chances that anything is broken or damaged. This isn't a manual where you are the computer, you're sort of removed from all of that. Enjoy your car.

Cool thanks!

[sacowich]

It’s just a strange thing to do.
25 years driving manuals and I can’t recall ever needing to shift down to high rpm 1st gear. For me, 1st is a one direction gear. Maybe drifters do this?
I have done it sim racing rally cars into a hairpin.

I will admit to having money shifted into 2nd or 3rd (can’t recall) and spinning my crank hub on the F80. Unintentionally.
Autos are electronically protected from money shifts, as discussed above.
I highly doubt any damage was done.

[kyrix1st]

You have a zf8. It cannot do aggressive downshifts

[turnsignalslol]

Originally Posted by sacowich

It’s just a strange thing to do.
25 years driving manuals and I can’t recall ever needing to shift down to high rpm 1st gear. For me, 1st is a one direction gear. Maybe drifters do this?
I have done it sim racing rally cars into a hairpin.

I will admit to having money shifted into 2nd or 3rd (can’t recall) and spinning my crank hub on the F80. Unintentionally.
Autos are electronically protected from money shifts, as discussed above.
I highly doubt any damage was done.

I honestly couldn’t tell you why he was doing it. He does the same shit in his own car so idk

[sacowich]

Originally Posted by turnsignalslol

I honestly couldn’t tell you why he was doing it. He does the same shit in his own car so idk

Must be his hooning style.

[turnsignalslol]

Originally Posted by sacowich

Must be his hooning style.

Yeah, and I’ve learned that I don’t appreciate it in my car so no one but me is driving it from now on 😤

[sacowich]

Originally Posted by turnsignalslol

Yeah, and I’ve learned that I don’t appreciate it in my car so no one but me is driving it from now on 😤

Yaa man. No valet parking.

[turnsignalslol]

Originally Posted by sacowich

Yaa man. No valet parking.

Luckily I don’t go places that require valet parking or I just carpool

[M2siast]

Originally Posted by sacowich

It’s just a strange thing to do.
25 years driving manuals and I can’t recall ever needing to shift down to high rpm 1st gear. For me, 1st is a one direction gear. Maybe drifters do this?
I have done it sim racing rally cars into a hairpin.

I will admit to having money shifted into 2nd or 3rd (can’t recall) and spinning my crank hub on the F80. Unintentionally.
Autos are electronically protected from money shifts, as discussed above.
I highly doubt any damage was done.

The M2 is the first car I have had that requires a shift into 1st when autocrossing, because of the gearing/low end torque. It used to be fine to ride second gear at low speeds in other cars, but it's not in the M2.

But this is for the manual, since the gears in the AT are shorter I'm not sure, I think the person in question here just liked to hear the noises.

[turnsignalslol]

Originally Posted by M2siast

The M2 is the first car I have had that requires a shift into 1st when autocrossing, because of the gearing/low end torque. It used to be fine to ride second gear at low speeds in other cars, but it's not in the M2.

But this is for the manual, since the gears in the AT are shorter I'm not sure, I think the person in question here just liked to hear the noises.

Yeah that’s what I’m thinking too. As long as it didn’t cause damage (which most of us here have come to the consensus that it hasn’t) then I’m fine. I just won’t do it because it sounds like my car is crying

[GYRKIN GT]

Hopefully you have learned a lesson from this and not just from a car perspective. I can count on one hand the people I would trust to drive my M2 and believe me not all fingers are needed. However, my attitude is not reserved to the car. It’s probably an age thing or maybe it’s from lessons learned years ago. The thing is, many people just don’t give a shit how they treat someone else’s property despite the relationship they have with that other person. So, take this away from your experience, “it’s okay to say, no”. That may not be easy for you at first but you will get better at it. I will only lend stuff to people whom I absolutely know will respect my property and return it in the condition they received it. And the rest, well, they can find some other sucker to borrow stuff from.

[turnsignalslol]

Originally Posted by GYRKIN GT

Hopefully you have learned a lesson from this and not just from a car perspective. I can count on one hand the people I would trust to drive my M2 and believe me not all fingers are needed. However, my attitude is not reserved to the car. It’s probably an age thing or maybe it’s from lessons learned years ago. The thing is, many people just don’t give a shit how they treat someone else’s property despite the relationship they have with that other person. So, take this away from your experience, “it’s okay to say, no”. That may not be easy for you at first but you will get better at it. I will only lend stuff to people whom I absolutely know will respect my property and return it in the condition they received it. And the rest, well, they can find some other sucker to borrow stuff from.

Yeah, I’m usually extremely selective about what I choose to let people borrow, regardless of what other people think, especially with my car, which is something I cherish very much. I honestly don’t know what was going through my mind when I just said “ok” but if anything, this made me just reinforce my previous values. Once again, I’m not saying I hate my friend and that our friendship is now over because of this, I just wished this didnt happen so I wouldn’t have to stress over it. Now I’m going the route of no one but me can drive my car, doesn’t matter if they disagree they can always find someone else’s M2 to treat like a rental car

[Fastfwd]

I'm glad somebody brought up the topic.... I'm ZF8 too.

[aerobod]

After the initial break-in period, some high-rev downshifts and engine braking with closed throttle may actually be beneficial for any residual ring seating that can be done. During the break-in period doing the same at lower revs (up to the 5000RPM break-in limit) is definitely beneficial, putting some reverse forces on the rings with vacuum in the cylinders.

[RockCrusher]

Originally Posted by aerobod

After the initial break-in period, some high-rev downshifts and engine braking with closed throttle may actually be beneficial for any residual ring seating that can be done. During the break-in period doing the same at lower revs (up to the 5000RPM break-in limit) is definitely beneficial, putting some reverse forces on the rings with vacuum in the cylinders.

Vacuum (low pressure) won't affect ring contact with the cylinder walls. While the throttle is closed and the intake is under low pressure so too is the crankcase.

Absent the increase in pressure during the compression, combustion and to a lesser extent exhaust stroke the normal ring tension will keep rings in contact with the cylinder walls but it will be fairly light contact.

[RockCrusher]

Originally Posted by turnsignalslol

Yeah, once again, lesson learned. Everyone else who I let drive my cars would treat it with respect and like they were going to be the next owner, while this guy literally gave 0 fucks. I love my friend but bro has to relax in other people’s cars. He drives even crazier in his own car so yeah 💀 Safe to say he isn’t driving my cars in the future again and I probably won’t let anyone else drive it ever.

Would you say there’s a very good chance that nothing was excessively damaged? Just worried about any driveline shock or damage to the engine or transmission.

Nothing was damaged.

The engine controller revs match on downshifts. If it didn't you'd get thrown against the seat belt/shoulder strap as the shift was completed.

The engine controller also prevents a downshift if the shift would result in an engine over speed condition.

My M2 is a manual. But my 230i is fitted with an 8-speed automatic.

So I had the 230i out the other day in sport plus mode and in 4th gear accelerated up to >60mph then applied the brakes rather hard. As the vehicle shed speed the transmission downshifted from 4th to 3rd and RPMs peaked to about 4K. Then with more slowing there was a downshift from 3rd to 2nd and this time RPMs peaked to about 5K. I didn't continue to see what the 2nd to 1st downshift RPMs would be.

The downshifts were quite smooth -- thanks to rev matching.

While I wouldn't make a habit of this type of driving the engine (and transmission) was fine.

[aerobod]

Originally Posted by RockCrusher

Vacuum (low pressure) won't affect ring contact with the cylinder walls. While the throttle is closed and the intake is under low pressure so too is the crankcase.

Absent the increase in pressure during the compression, combustion and to a lesser extent exhaust stroke the normal ring tension will keep rings in contact with the cylinder walls but it will be fairly light contact.

Lack of combustion and vacuum in the cylinders will change the forces on the rings, due to most ring force on a modern piston ring being generated by the combustion pressure through either the increased piston clearance above the top ring of the piston that allows combustion gases to reach the back of the ring or in some cases tiny bleed holes to the back of the ring, as opposed to the spring tension of the ring. Looking at the pistons and rings for my Caterham engine rebuild, the ring tension is about 50N from the spring effect, but a compression of 10 bar would exert about 250N to the back of the ring. Although there is vacuum in the crankcase, the rings should separate that from the cylinder vacuum. It is beneficial overall to change the forces on the rings to give the best mating with the cylinder wall.

Lots of rev variation under power combined with engine braking gives the best variation of the forces on the rings overall.

[haynstyleM2]

Originally Posted by turnsignalslol

Yeah, once again, lesson learned. Everyone else who I let drive my cars would treat it with respect and like they were going to be the next owner, while this guy literally gave 0 fucks. I love my friend but bro has to relax in other people’s cars. He drives even crazier in his own car so yeah �� Safe to say he isn’t driving my cars in the future again and I probably won’t let anyone else drive it ever.

Would you say there’s a very good chance that nothing was excessively damaged? Just worried about any driveline shock or damage to the engine or transmission.

Like everyone said, AT is definitely a non issue. I would tell your friend that you had to bring it to the dealer and they charged you $1k for a full diagnostic test. Just tell him you'll half it with him and you'll have money for the weekend.