Downshift vs neutral roll

[Celica00]

Originally Posted by rice_classic

So the moral of the story and 16 pages is:

You can it wrong, or you can do it right and there's more than one way to do either.


edit: who cares.. our Throw out bearings will fail every 50k anyway. Just replace your clutch then.

Is there any feasible or logistical way to make a more durable throw out bearing? Why or why not?


I've learned based on the age/profession thread that a hell of a lot of the members here are engineers, so it's a good resource to learn for someone like myself.

[rice_classic]

Originally Posted by Celica00

Is there any feasible or logistical way to make a more durable throw out bearing? Why or why not?


I've learned based on the age/profession thread that a hell of a lot of the members here are engineers, so it's a good resource to learn for someone like myself.

A: it's only after someone quotes me do I realize I can't type worth sh**.

B: Perhaps. I avoided the factory option and bought a more robust SKF bearing with a self centering function.

[Tcoat]

Originally Posted by rice_classic

So the moral of the story and 16 pages is:

You can it wrong, or you can do it right and there's more than one way to do either.


edit: who cares.. our Throw out bearings will fail every 50k anyway. Just replace your clutch then.

62K Original tranny oil. No throw out bearing issues, no grinds, no 2nd/5th gear lockouts, no problems of any sort.


You are 100% correct though. There are many ways to do things and none are "right" or "wrong" really. This same debate rages across the internet with even the experts taking sides.

[Tcoat]

Originally Posted by Celica00

Is there any feasible or logistical way to make a more durable throw out bearing? Why or why not?


I've learned based on the age/profession thread that a hell of a lot of the members here are engineers, so it's a good resource to learn for someone like myself.

OEM parts are a compromise between cost, durability and functionality. It is great for us to sit and say "why can't they make XXXX better?" but they have to meet all the requirements not just one or two. Like Rice says there are "better" aftermarket options available.

[Tcoat]

Originally Posted by rice_classic

A: it's only after someone quotes me do I realize I can't type worth sh**.
.

I have had that same realization about 22,000 times!

[Ultramaroon]

Originally Posted by Celica00

Is there any feasible or logistical way to make a more durable throw out bearing? Why or why not?


I've learned based on the age/profession thread that a hell of a lot of the members here are engineers, so it's a good resource to learn for someone like myself.

The Golden Rule of product design: Light, strong, or cheap, pick two.

There is something hinky about this TOB. They may have sacrificed some of the strong for the cheap.

[Tcoat]

Originally Posted by rice_classic

I think the difference isn't in the function, but in the application and in the application of the average driver.

Most folks aren't rev matching or double clutching, therefore on a downshift the clutch is speeding up an engine, whereas on an upshift it's slowing it down. The friction disk is being applied to retard or accelerate what is essentially a compressor. The requirement in force to slow down an off-throttle engine is much less than to accelerate one.

To compound this, on a down shift, the clutch re-engagement is generally slower for your typical driver so the delta between where the revs are when the clutch is disengaged to where the revs are when the clutch is re-engaged is greater, aka: even more work.

TRUTH!
I will amend my comment:
"There is no more strain put on a clutch by downshifting properly for the conditions then there is up shifting properly for the conditions.


And my usual disclaimer of:
"My statements are for regular driving only. Track and 'cuz racecar methods will vary"

[Ultramaroon]

Originally Posted by Ashikabi

Do you have a source on this? I skip gears on the highway all the time when I hammer on it then shift to 6th when I hit 60

At 60 from 5th to 6th there's maybe 500 RPM split? I'm totally spitballing.
But from 3rd at, what, 4500 to 6th at 2500? That's a lot time to squeeze all the lube from between the cones and get 'em cookin' real good.

Originally Posted by Capt Spaulding

Edit: It seems to me that the strain on the synchros is/should be directly proportional to the difference in speeds of the input and output shafts. If you're slowing down and reach a road speed that's compatible with gear ratio/engine speed for the gear you're downshifting into I don't see what excessive stress that puts on the box.

It's not bad at low speeds because the relative speeds all converge to zero RPM.

It's that 6th-to-3rd shift at highway speed that'll cook the 3rd gear synchro in no time. Those I ALWAYS double-clutch.

[soulreapersteve]

Originally Posted by Tcoat

Auto owners ideas of a "clutch".

[ame="https://www.youtube.com/watch?v=8OTDK9ZVQaA"]1v6 Clutch 29 Secs AMAZING Killcam! WOW! - YouTube[/ame]

[Ashikabi]

Originally Posted by soulreapersteve

MLG no scopes

[Capt Spaulding]

Originally Posted by Ultramaroon

At 60 from 5th to 6th there's maybe 500 RPM split? I'm totally spitballing.
But from 3rd at, what, 4500 to 6th at 2500? That's a lot time to squeeze all the lube from between the cones and get 'em cookin' real good.


It's not bad at low speeds because the relative speeds all converge to zero RPM.

It's that 6th-to-3rd shift at highway speed that'll cook the 3rd gear synchro in no time. Those I ALWAYS double-clutch.

Yep. Yep. And, I don't really do that. I'm generally a sequential shift guy. Seldom to never skip gears on the way up and, generally run down the gears coming to a stop. Occasionally, coming to a stop at a light or stop sign, I'll let the car coast in gear down to about 1500 then clutch in and slip into what ever gear would give me 2500 if I needed it. Once stopped, it's into first again. With the way I drive, going from 6th to 3rd at speed, isn't something I've considered doing. I can easily see double clutching that one. On the same page now.

[Ultramaroon]

Originally Posted by Capt Spaulding

Yep. Yep. And, I don't really do that. I'm generally a sequential shift guy. Seldom to never skip gears on the way up and, generally run down the gears coming to a stop. Occasionally, coming to a stop at a light or stop sign, I'll let the car coast in gear down to about 1500 then clutch in and slip into what ever gear would give me 2500 if I needed it. Once stopped, it's into first again. With the way I drive, going from 6th to 3rd at speed, isn't something I've considered doing. I can easily see double clutching that one. On the same page now.

Try it sometime. It's one of my favorite completely unnecessary things to do. #becauseracecar

Oh, and given a choice between buying your car, or mine at 100 Kmi, I'd buy yours in a heartbeat.

[Tcoat]

Originally Posted by Capt Spaulding

Yep. Yep. And, I don't really do that. I'm generally a sequential shift guy. Seldom to never skip gears on the way up and, generally run down the gears coming to a stop. Occasionally, coming to a stop at a light or stop sign, I'll let the car coast in gear down to about 1500 then clutch in and slip into what ever gear would give me 2500 if I needed it. Once stopped, it's into first again. With the way I drive, going from 6th to 3rd at speed, isn't something I've considered doing. I can easily see double clutching that one. On the same page now.

ALL THIS^
This is exactly what I do and just could not put into words.