Originally Posted by ZDan,Jan 21 2011, 09:15 AM

"OK"? Double-clutch upshifts on the S2k and any of the cars you learned on is totally needless. On upshifts, unless you're power-shifting, you're automatically matching revs as you get off the gas and allow revs to drop.

Going through the considerable effort of reengaging the clutch midway through the shift isn't buying you anything. The time required to do that is going to be greater than the time that the revs would come down to the appropriate rpm for the next gear doing a NORMAL single-clutch upshift.

In coming up with maintenance intervals for aircraft, it is important to not to overschedule maintenance, not only due to the increased cost and downtime, but because there is *risk* associated with doing work. If you do 3k oil changes, you're probably getting into the region where the risk of such things as stripped threads, filter or plug not properly tightened, faulty or wrong part or wrong oil, etc. etc. is outweighing the potential benefit vs. changing it at the manufacturer's recommended interval.

Regarding double-clutching upshifts, you're not getting any benefit vs. properly "single-clutch" upshifting, *and* you're increasing wear and tear on the clutch master, slave, fork, throwout bearing, pressure plate, disc, etc.

If the synchros were damaged, you should be able to detect that. In any case, you're using the synchros when you "double-clutch upshift" anyway. Whether or not the vtec was ever engaged or not wouldn't worry me. In fact I might be more concerned buying a used one where that system had never been used. Overrevs would of course be bad, but never-used-vtec doesn't to me imply


What I'm saying is that double-clutch upshifting *doesn't* help (shift times will be longer), and probably *does* hurt (increased clutch wear and increased likelihood to botch upshifts) to some degree.

Unfortunately for me, I *do* care when I see driving techniques that are wholly unnecessary *at best* being recommended as valid methods to people who don't know better.


When it's cold it takes longer to upshift. But I guarantee that your upshifts will be quicker and more consistent doing it the normal way, properly.

I don't have any issues upshifting smoothly in the cold. Yes it takes longer, but it'll still be quicker than the double-clutch upshifting.

"Double-clutch" upshifting an S2000 isn't buying you anything vs. properly upshifting. Totally pointless.

Originally Posted by -Jordan-,Jan 21 2011, 12:52 PM

I agree that it is not ideal to shift mid turn but if you're driving on the street and you know you want to exit a long corner in 2nd, you may not want to wind the motor through the whole corner to be in gear when you come out of the corner. A lot of the time if Im exiting the highway on a winding ramp I will come off in 3rd or 4th and downshift during the corner exit. Sure I could have slammed the car into 2nd at 50mph and rode through the corner at 7000rpm but its impractical. Its much easier to just learn rev matching and down shift during the turn.

Originally Posted by edspecR,Jan 21 2011, 12:35 PM

zdan ftw.

Originally Posted by ZDan,Jan 21 2011, 02:40 PM

I tried it after I tuned in to this thread. In my very limited experience, it doesn't work AT ALL. At best it achieves about the same or slightly slower cold 1-2 shift times for VASTLY greater effort. Yeah, by the time I've declutched TWICE it's ready to fall into 2nd, but my impression is that it woulda fallen into 2nd by that time *anyway*.

You mean there are others doing this?
To avoid the cold 1-2 "crunch" on the AP1, just be *patient* and you'll accomplish the same task in the same amount of time or less upshifting "normally".

I'm a decent driver for an amateur, but I suck at heel/toe downshifting. I get it done, but it ain't always pretty or smooove. For me, any additional work required is potential for screwing up. Double-clutch upshifting seems to me to offer NO upside but increases opportunities for screwing up.

Yup, IMO it's just giving you something else to do during the *brief* time you have to wait for the cold 1-2 upshift
The input shaft is going to slow down pretty damn quickly. The rotational inertia of the input shaft is tiny, and the also smal drag loads in the bearings will slow it down very quickly.
I think that if you had data acquisition you'd probably find that simply doing normal single-clutch upshifts you would do the same task of upshifting more quickly and more consistently.

I did. Now you try single-clutch upshifting!