Why engine driveline components break with mis-matched RPM downshifts
09-02-2014, 07:57 PM
#61
uninformed gas bag
(contemplating on whether gas bag is one or two words)
Rennlist Member
(contemplating on whether gas bag is one or two words)
Rennlist Member
Yes, that's me. I've even played a couple of driving games, lol. Some of them aren't all that bad for what they are. Most of my xbox time was from a number of years ago when I had more free time; some friends and I would play driving games before or after watching F1 on one of our DVRs on Sundays. I haven't bought the latest version of the xbox and probably won't. The current one spends most of its time as Netflix conduit or DVD player for the kiddo TV.
Not sure what that has to do with real-life track experiences, though.
Not sure what that has to do with real-life track experiences, though.
09-26-2014, 01:10 PM
#63
Rennlist Member
Thread Starter
Not sure I agree with you here. Yes, the inertia of the vehicle is an input, but if the static friction of the tire doesn't change then you're threshold doesn't change. What I'm saying is that inertia of the driveline is a big factor. If your driveline inertia is high relative to high static friction at the tire then the resultant torque must be reacted thru the driveline components. The weakest one fails first.
trust me, the forces are much greater on the driveline, during a downshift at speed, then any possible speed shift going up a gear. the reason is that the KE source is the car vs the spinning mass of the engine. Big difference.
Quote:
Originally Posted by mark kibort View Post
The force is greater on the downshift due to the gearing reflects the entire inertia (mass of car) to the engine, which its force will go up with speed......
the force of breakaway force of the tire is constant.
Not sure I agree with you here. Yes, the inertia of the vehicle is an input, but if the static friction of the tire doesn't change then you're threshold doesn't change. What I'm saying is that inertia of the driveline is a big factor. If your driveline inertia is high relative to high static friction at the tire then the resultant torque must be reacted thru the driveline components. The weakest one fails first.