Thank you, I'm not usually lazy about it. It really only happens for me downshifting during abrupt turns when I need to get to a lower gear quickly.

 

Rule #1: if you skip a (or) gear(s) the synchro you DO select also has to do the work of the skipped gear(s).
Note #1.1: this is true for up- and downshifts.
Note #1.2: as soon as you press the clutch pedal it does not matter what you do with the throttle as the car at speed is powering the transmission.
You can blip, rev match and do all kind of cool sounding things with the throttle, with the clutch in it does nothing for the trans.
Note #1.3: if you row through the gears with the clutch in, for example 3-4-5 or 5-4-3, you are not skipping gears.

Rule #2: energy wise it does not matter to accelerate mass m from rpm a to rpm b or to decellerate mass m from rpm b to rpm a in the same time frame, that is: in a friction less world.
Note #2.1: in reality the friction will help decellaration and you have to overcome it to accellerate.
Note #2.2: with note #2.1 in mind you can figure out it is worse to skip downshift fast when you end up in a high rpms.

Now..

Skip UP shifting usually happens at high engine rpm's, or better said: at high input shaft / primary shaft rpm's.
Therefore the energy you have to take out of aforementioned shaft is high, when you skip a gear the energy load on the synchro you select is a lot higher (rule #1) than it was designed to handle.
Skip UP shifting at low rpm's is.. silly and I think no one does this.

There are 2 scenario's for skip down shifting.
It can happen at mid range - relatively high rpm's.
Imagine driving in 6th at those rpm's and you want to accellerate fast, you also know 5th is not going to do this for you, so you go from 6th to 4th directly.
The synchro you select now has to transfer much more energy to accellerate the input shaft and overcome friction - note #2.1 - than it was designed to handle (rule #1)
So skip down shifting can be worse than skip upshifting.

Imagine driving in 6th and a known turn is ahead, a turn you know you have to take in 4th and at a slower speed.
You brake, keep the trans in gear (obviously), right before the turn in you downshift from 6th to 4th directly.
This is a low rpm skip down shift.
Yes, rule #1 applies.
But, the energy needed to accellerate the inputshaft to the rpm's needed for 4th, at the speed you're going right before turn-in and the downshift, is a lot less.
Therefore the synchro will not take a high load, most likely a lower load than it was designed to take at max allowable rpm downshift from 5th to 4th.

Skip up shifting = don't do it.
Skip down shifting at mid/high rpm's = don't do it.
Skip down shifting at low rpm's = depends on the amount of skipped gears, 1 gear skipped IMO is not a problem.

 

 

Thanks for saying this! I was wondering as I read this thread why everyone seemed to think that skip-downshifting is ok.


This probably isn't AS bad, because she probably isn't redlining 4th before she goes to 6th.


Another thing everyone should think about is that input shaft RPM = clutch disc RPM. A clutch disc may not be all that heavy, however I wouldn't want to grab onto one spinning at 8,000 RPM and slow it down in a split second to 4,000. Neither do your transmission synchros!

 

Thoughts?

https://youtu.be/tpGsNXUlX1c

 

You know, there seems to be two parts of this argument. 1.) Is it okay to skip gears? --- If done correctly you won't lug the engine or lock up the rear wheels. You won't lose control of the car. 2.) The wear issue on the gears, after many miles of skip shifting.

It would be interesting to break apart that guy's BMW, after a year or two of skip shifting. Then, compare to a transmission that was shifted through each gear, both up and downshifting. Finally, compared those results to a Honda S2000 tranz under similar conditions.

 

There shouldn't even be a debate anymore about this, it was settled years ago... There were some definitive threads by xviper and Woodwork (both rank above most of the armchair experts on s2ki nowadays).

For the people who don't remember, Woodwork worked for Honda out of Torrance and was active on the boards years ago -- unfortunately with how this board was maintained, it appears most of the pictures have vanished:

https://www.s2ki.com/forums/s2000-un...can-do-237209/
https://www.s2ki.com/forums/search.php?searchid=318127

 

First off, I'm a retired truck driver with over two million miles in trucks and most of that time I never touched the clutch pedal(upshifting or going down through the gears). I skip gears all the time in my S, have for 7 years and 100k+ miles. Just like anything, if you do it right all is good. If you don't, THEN you put excessive wear on multiple parts in the transmission. When around town or just being lazy(as some would say) I go 1st 3rd, 5th to 6th or most times getting on the freeway I just get to 3rd then skip to 6th. That is because I can get to a little over 80 in my S in 3rd, so I let it slow down to 70 and slide it into 6th around 3600 rpm's.

ROD

 

If Billman says it is harmful to skip-shift then I just avoid it and spend my time on other things in life that need attention, I don't give it a second thought or question it.

I used to skip shift in other vehicles I had as I never thought it was an issue, but not in the S2000 now. Skip shifting up is bad, skip shifting down is fine. That's all I need to know.

 

It seems there are several reactions to learning a behavior you thought was benign might actually be harmful. Some of these include:

1. Stop doing it just to be safe, but ask lots of questions and try to learn as much as you can about why its harmful. Then base your decisions on what you learned.

2. Stop doing it because the experts are those you've come to trust, and the behaviour is something you can live without.

3. Keep doing it until someone can prove to you its harmful.

4. Keep doing it and try to argue with the experts about why they are wrong (those arguments often sound a lot like the equivalent of 'my grandpa smoked a pack a day his whole life and never got cancer, thus I conclude cancer isn't bad for you')

Which reaction seems wisest to you?