Downshifting 101 (questions)

Sounds like you've got the math pretty well taken care of. To be honest, when I first learned all this, I had no tach (yeah, low-end Civic) and no interest in figuring out numbers anyways. I simply listened to the car and felt the response in my feet and in my chest. Numbers may be an interesting starting point, but don't rely on them too heavily. While the car may be a machine, it will often behave much more organically than you'd expect.

Well, that's the very basic way to do it! This is a good procedure to start with. Before you make it more complicated or try to perfect it, though, I would eliminate all of your uncertainty about driving stick "politely." Once you are doing normal, non-aggressive shifts with almost no "mental effort," then you probably have the state of mind (enough consciousness to throw around without freaking out) and the connection to the car to be able to really work on this technique well.

There are a few little things I would change, once you're ready to progress beyond what you've outlined here:

1) If the down shift you're making needs to be done FAST, I would not take my foot completely off the gas when you push in the clutch. Your procedure calls for coming completely off, then leaning in for the blip. This is fine if you want to baby your car or are stretching the time interval before your down shift needs to come. Once you're ready, try to leave the foot where it is. You'll feel the difference in both feet as the clutch slips off the drivetrain, spinning up real quick. To improve upon this, get the clutch in quicker, to reduce the wear on the clutch. With the revs going up sooner, you can shift and let the clutch back out sooner, meaning a quicker shift. 2) Same deal with going back on the gas to drive out of the shift. No need to come completely off. Come up a bit if you like, but don't waste time getting to the "top" of the pedal. 3) Learn the exact disengagement point of your clutch. It will change over time, but learn where it is now really well. Some BMW owners will even purchase these adjustable screws that don't let them push the pedal down farther than they absolutely have to. It is a waste of your shifting time to go to the floor with every shift. Be careful that you do actually completely disengage the clutch, but learn how far is just enough. Try sitting on a mild uphill and, using just the clutch and first gear, holding the car still. You may burn a little material, but you'll learn that magic point.

Again, all of this brings up the important point that any aggressive driving, especially when you get into the more advanced techniques, can and will exert wear and tear on your car. Your clutch, though strong, is not indestructible. Neither is your transmission. So master the basics first. Really.

Best of luck!

-r0ll

That's cool, 'cos I didn't get the car to crunch numbers. ;-)

Sound advice. I have to admit, the basics aren't second nature to me yet, but still take conscious effort. Guess I'll have to do some more driving (aw)..

This does sound more effective. I think I was trying to reconcile my downshifting procedure with the beginner's admonishment not to be on the gas with the clutch partially engaged.

Yeah. Left foot is getting a feel for exactly where it is. I have found it annoying to go through so much pedal travel every time.

Be careful

How far below this point would you say equals complete disengagement? If I'm picturing this right, it seems like there would be at least a little zone of slippage immediately below.

Good stuff.

I would assume the design of cars evolved to be more intuitive to people. As I guess we evolved to be more intuitive about cars.

Somewhat like the story of the man and the pet starting to look alike?

Leon :)

Knowing the mechanics, physics and math behind the (re)action is helpful. But then so to is the sound and feel. -- Kill the radio, drop the top and drive...

As you practice, things should become more intuitive. Though you shouldn't ignore your instruments, you should reach a point where you no longer need to rely on them to *smoothly* pilot your vehicle.

- L

'97 STO, "Chouki"

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This might come in handy. Someone sent it to me a while back. Hitting your shifts should become second nature, not that it is ever impossible to do, but this may be helpful, maybe not. It's free anyway. ;-)

Pat

Errr, make that, not that it is ever impossible to miss one. Need caffeine.

Pat

I know, it's like you bought a car worth driving or something!

You've got the idea basically right. There's a difference between engagement and contact. Engagement means contact with sprung pressure...just contact doesn't have this pressure. With pressure on the clutch plate, the force of friction increases dramatically. Without the increased pressure, if there is still contact, the force of friction is much lower, and slippage is much more likely. That's why you want to depress enough to actually separate the two pieces. In a perfect car, I'd imagine the difference would be very small. In our car, I'd push the pedal at least one inch deeper than the disengagement point. Maybe two inches...it's up to you. Eventually you'll be going down and up so quickly on this kind of shift you'll hardly have to disengage at all.

Thanks! :-D I try.

Cheers,

-r0ll

Thanks man, this is interesting. I wonder if the technique in diagram

3 has any danger of going from 2-5? I just did a bunch of 2-3 shifts in an ordinary way and they're getting pretty good, at least at a normal speed. The Diagram 4 technique would likely have prevented my 3-2 mis-shift earlier.

Please put my mind at ease about one thing, though:

THE CAR WON'T LET YOU SHIFT INTO REVERSE BY MISTAKE, RIGHT?

TIA & ZZ

Sure, but that won't be a problem unless you are entering a highway or need speed right then for any other reason. Then you will need to do a quick pull into 3rd or 4th because a stock miata has about nothing as far as power in 5th at that rpm.

It's up to you whether to try it or not. I probably would give it a shot if I was learning from scratch, but after this many years I doubt if it would help, and I don't miss shifts often. Since you care and are practicing, it doesn't sound like you will have any trouble either. I really don't know if that technique page is of any use or not.

No, but it will grind like crazy. I still haven't tried that one, but I have been in the car when someone did and it felt and sounded like the miata was about to fall apart. You really almost have to try to hit reverse. Your biggest danger is the shift from redline-area rpm's in third to fourth and hitting second instead. The rev limiter won't save you there.

Pat

We should specify: the car won't let you shift from fifth to reverse. Otherwise, there's no lockout. But think about it, when could you possibly miss something and hit reverse? 3-4? Nah, it's straight back. The likelihood of even coming close to shifting into reverse at the wrong time is very low, unless you hallucinate and think you have a 6-speed. :-D

One tip for getting into reverse when you should, though...while the clutch is in, shift to second then into reverse. If you can't get it in still, re-clutch and try again! This is also helpful for getting into first with a cold tranny.

Zoomie....

-r0ll

Then there was my fumble a couple-three years ago - On the freeway, but exiting via a nearly straight "ooze to the right" ramp. I'm at full freeway speed in a new (to me - just got it back on the road the afternoon before) Looking ahead, notice the light at the surface street ahead changing such that'd I'd be guaranteed a red light by the time I got there. Pulled out of 5th, going for 4th, and it feels a bit stiff. Pull back just a smidge harder, and it drops in - with a VERY out of place "thud" accompanied by a sort of whining noise, which turned into a rattling whir as the speed dropped, and I seem to have no clutch. WTF? Down from 4th to 3rd. That's when I realized I was pulling out of *2ND* to go to 3rd... Uh-oh... Blown shift. Still no clutch. By now, speed has dropped, and I've hit the light - make a left coasting, and get lucky - coast through the next 2 lights, and have just enough momentum to pull into the parking lot at work.

What have I killed? Step on the clutch, and all is good - no funny noises. Release the clutch, in any gear - NO motion. PERIOD. And LOTS of funny noises.

Tow it home. Drop the tranny. Out falls god's cat's own hairball. Clutch disk grenaded. Almost certainly due to over-rev and no flywheel/pressure-plate support as I went from 5th to 2nd while moving at 60+. Looked like somebody packed the bell-housing with hair and chunks of brake pad.

The *REAL* bitch? I'd just put that clutch in less than 24 hours previously as part of an engine transplant after buying the car and not liking how the engine it came with was behaving.

One new clutch disk (and a lot of cussing) later, all was well. In fact, that same car is still running fine on that clutch. Although I've swapped the transmission on it since then, due to the rear bearing on the countershaft dying. (That was an interesting one, too... Fortunately, I still had the good tranny from the wreck sitting in the garage)

Yikes! That couldn't have been any fun. I liked "god's cat's own hairball", that was funny. What is your miata transmission doing in the garage? Do you have a wife or something? My spare transmission is in the laundry room, right next to the spare hood. The hood is for sale on the local Craigslist, but the only response I have had is from someone in Pennsylvania who wants me to ship that large and fragile item across the country to them.

I suspect that Iva had a role in that e-mail. ;-)

I was thinking of selling the transmission, it is in excellent shape with 75K miles on it. The transmission on my '91 turbo is one of the few mechanical things that was not replaced and it is approaching 150,000 miles, though it still operates great, but your rear bearing countershaft comment has me thinking. I am at least positive about the mileage and condition of this one versus hitting a salvage yard later.

I keep hemming and hawing about keeping the car, but if I do keep it, I guess it would only make sense to put the tranny from the '96 in there. I also have some other donor parts that I will hold onto if I keep the car; starter, ignition switch, alternator, etc.

Pat

5-R was the main concern, so no worries there, but also, the chart Pat pointed me to recommends always backhanding the shifter into 4th, both from 5th and from 3rd. Pulling straight back from 3-4 in a normal way as I had been doing, a 3-R misshift is pretty unlikely, but like I said, I managed to do an unintentional 3-2 by angling back a little bit toward myself and getting caught up in the gate. With the backhand technique and the accompanying outward pressure, 3-2 is now unlikely, but I was wondering about an outside chance of 3-R. I guess it should be fine as long as I don't exert a huge amount of outward force - but now I have to be aware of that, I guess.

I tried a few shifts with the backhanding technique last night. I think it may end up being more reliable and direct than straightforward gripping and shifting, but at least for me, I will have to build up trust that it will always do the right thing from, say, 2-3, because I can't feel it snaking across as well now. It just does it.

(A 2-1 misshift is something I never want to see.)

Glad you mentioned this. The shifter has been recalcitrant at times starting up, and I've been wondering what the deal is..

Hey! I'm innocent - at least this time.

Besides, it's the wrong color.

And where in PA? If it's not within 100 miles of *this* side of the state, you Definitely Cannot Blame Me!

On the other hand if it is......... ;-)

Iva & Belle.) '90B Classic Red.) #3 winkin' Miata

I hope that it is helpful and that I didn't just end up helping you to "over-think" your shifting as you are learning. I have to agree with Lanny on this one, (imagine that!), relaxing and taking your time between shifts are the most important things, especially as you are learning, though research is good as well.

As Don's post shows, you definitely don't want to do a 5th to 2nd at highways speeds, something I have done myself in a non-miata with much less catastrophic results.

It will all be something that you barely think about before too long, at least as far as any question about if you are doing it correctly.

Pat

I have heard that one before.....

I think that Leon would disagree, though he would not like the blue stripes, but they can be peeled off. I thought about replacing my red hood with it. It would look horrible, but hey, it is a few extra free hp.

There was no address, hence my suspicions. I hold you accountable for the entire state anyway. ;-)

Pat

Or unless you have a white NA and a white NC. I am always mixing up the keys, but so far I have not done a shift into reverse with Bozo on the highway yet. Fortunately, I do not usually skip gears. :)

Leon

Don -

Sounds almost as much fun as snap shifting from 3rd to 4th and dropping the clutch just *before* I got it into 4th and trying to meld the accellerator with the floor. -- Wouldn't have been too bad in a car with a rev limiter, however the mid-70s Honda didn't take it so well. The tranny survived, however the headgasket did not...

- L

'97 STO, "Chouki"

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