Downshifting 101, Part Deux (a quick report + couple qs)

Hey y'all, just got back from my first time really practicing. A fun hour over and over a woodsy loop, speed about 25-40, lots of 2-3 & 3-2 shifts.

2-3 is getting better all around - the feet are getting more automatic with their simple jobs, and I'm negotiating the kink in the shift more smoothly and naturally.

3-2 (with the single-clutch rev-matching) was not pretty at all in the beginning, a lot of fumbling around. But it was making some progress by the second half-hour. The small handful of times I got the basic synchronization of steps along with the right amount of blip were pretty satisfying. My blips are pretty rough and will take practice to tune them. But it looks like a little too much is better than too little, if you're going to be off.

Wondering a couple things:

I don't think I've found it necessary to do the 2-1 downshift at speed on the street. In what kind of situation would it come up? Maybe before a slow, tight turn in auto-cross? Unlike the other downshifts, this one takes a huge blip to match revs, doesn't it - if I figured it right you're basically doubling what you had in 2nd.

Is rev-matching upshifts ever an issue? I guess the natural drop in revs during the shift is often good enough, but there would be some discrepancy in a 1-2 shift near redline.

Reply to
earache
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Almost never. Once in awhile, I'll be rolling up to a stoplight, and it will turn green just before I've come to a complete stop. But 2nd will usually get the job done anyway.

N.B.: my first three cars did not have synchromesh in first gear, so I learned quickly to make do with 2nd, and perhaps a bit of clutch slip.

FWIW, your Miata will be happier longer if you just take your time and concentrate on getting the right gear. If you constantly stress the synchros making snappy shifts, you'll be rebuilding the transmission

100k miles too soon. Relax, and let the gears engage at their own pace.
Reply to
Lanny Chambers

Yeah. It dawned on me today why the 1-2 shift seemed to be getting rougher even as I improve overall. I'm starting to wind out the engine more, and even at 4500rpm, a rev-matched upshift wants only about 2500rpm in 2nd. (Near redline the drop would be about

3000rpm.) And of course at the same time, the slack is coming out of my shifting motions and I'm naturally doing everything a little quicker, so the mismatch has only grown worse.

It was nice to relax a little last night and actually do it more smoothly, if slower.

Reply to
earache

I didn't read the first volume in this set but got the idea it was about downshifting and associated techniques, I believe. When you start talking about 'rev-matched upshifts', you're just plain over thinking this whole thing. When you're accelerating, just get after it, if you're doing it right you'll know it :-)

Chris

99BBB
Reply to
Chris D'Agnolo

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