Down-Shifting
 

I am sure this has been discussed at length, but just could not locate those posts this evening, hence I am offering the following for comment: My manual transmission cars were a TR-4, MG-C, Karman Ghia, Mustang and a Cutlass. With these vehicles I down-shifted frequently when slowing down to a stop or when my speed dropped to a point where I did not want to lug the engine. I almost never down-shifted simply for acceleration performance. Now, with my 8, down-shifting feels very different. Is down-shifting a rotary as efficient as when doing such with a traditional engine?

what do you mean by 'efficient'?

i have only had 1 other manual transmission car a 83 VW Scirocco but this is something i noticed also. just thought i'd chime in because im interested to hear more about this
:hippie:

Downshifting feels a lot like my older piston car.

If by 'efficient' you mean 'good engine braking' - yes. The 8 is geared down so much to produce sufficient torque you get a lot of engine braking when you downshift at speed. If you mean "is it good for the car, brakes, transmission, etc." then I would say no. The 8 has such strong brakes that stopping is a minor event to the car in general vs. the stress on the gearbox by consistantly doing downshifting. As far as lugging the engine, if you are driving with a light foot, you'll find it difficult to 'lug' the engine at almost any speed (RPM) as it just goes round-n-round, but you'll need to ds if you want more significant power from lower speeds.

I always thought for manual cars, you should downshift to slow down rather than "ride the clutch."

I downshift near every single stoplight.

Cruising in 6th, downshift to third, slowly start tapping the brakes, and then clutch in all the way.

Sometimes, just for fun, downshift third... second... and then use my brakes. Downshifting to first is just ass, unless I'm intending to speed the fuck up when the light turns green, midstop.

Perhaps "efficient" was not the best word. It almost seems as if there is a slight delay when down-shifting with the rotary as compared to other engines... a delay between ds and the noticed slowing-down. Maybe I'm trying to make too much out of this guys, I don't know...

Replacing brake pads are a lot cheaper than clutch discs and synchros. Put it in neutral, leave the clutch in and drop it into the appropriate gear to accelerate, if needed.

My 2cents.

Mike

Engine is for accelerating, brakes are for slowing down, although I know a lot of people (including myself) like to use engine braking on the street because of the low speeds and low rates of change of speed. For instance, coasting down to a turn, as the car slows, you down shift, eventuallly getting on the brakes.

If you are going to use engine braking, I would also blip the throttle before engaging the next gear. That will help match engine speed to gear speed and will result in smoother down shifts, quicker down shifts, and less wear on your clutch.

I don't know off the top of my head but probably 1st and 2nd gears have more than 1 synchro. I believe this is what you might be feeling as a delay as you are engaging the gears. If they were only 1 synchro, the engagement would feel reasonably quick and precise.

I know u guys want new perspective on this but here is some old (pretty damn good one too):

https://www.rx8club.com/series-i-tech-garage-22/all-downshifting-gurus-65279/

https://www.rx8club.com/rx-8-discussion-3/long-downhill-engine-braking-73173/

Why the hell would you do that?

I don't ever downshift unless its for performance/passing.....I simply slap the car in neutral and coast my way to a stop light or sign...hollywood stopping at signs so as to slap it into 2nd instead of 1st and then of course if I come to a complete stop at a light then will slap in 1st

Because its fun, and works well? If you're intelligent, and know the mechanics of it all - and know how to treat 'er right, there's nothing wrong with it.

Exactly, I don't see why you should furthur stress the engine and waste gas. Or maybe I don't know what I'm talking about.

Note: I'm talking about daily street driving. Not pulling up next to a car on a track.

Me too. The gearbox is just so darn much fun to use. I love the "wummm!" sounds when going down through the gears (rev matching). I don't do it to engine brake or be "efficient," I do it to enjoy a terrific sports car.

One thing I have noticed in all the comments about down-shifting is that nobody is stating that a lot of the problems or no problems at all with the procedure depend on the speed and gear one is downshifting to. All of the down-shifting I was referring to when I started this post was basically for going to a lower gear as the car was slowing down for a red light, etc. It's not like such ds'ing ran the tach up much. I do not ds to dramatically slow the car down. If for example I am going 40 mph and see I will be stopping at a stop sign, obviously I will go ahead and let off on the gas...and as the engine winds down, I will shift into the next lower gear, etc. I really don't think I would want to put the car into neutral as at that point it would be like a rolling wagon with only brakes and not as much control.

If I'm rolling to a stop sign and know I'm going to be coming to a full stop I shift to neutral and coast to the stop. I shift into 1st when stopped and proceed. If I know I'm going to be doing a California stop, I shift to 2nd, roll up to the stop, (mabe push in the clutch if I've really slowed down), and proceed out of the stop in 2nd.
Every manual transmission I've ever driven seemed to have "issues" going from 1st to 2nd. Nothing bad, just seemed to be a little resistant at times. I just chalk it up to gears not fully alligning at times. Same thing trying to hit 1st while rolling up to a stop. If it resists I just double clutch and try again. Seems to always go in smoothly on the 2nd attempt.

I actually just brake in the gear I'm in until the rpm is down to like 1500. Then I stick it into neutral. True it may be not as fast to act out of neutral, but I just do it.
Downshifting to the next lower gear in the way you are doing it... as in letting the rpm fall down, isn't bad. The engine braking doesn't kick in hard at lower rpms.

Question:

What about when you are travelling @40mph in 5/6th gear, and shift it down to 3rd to push it to 70mph @8000rpm..is this bad for the engine? Any better techniques for achieving more speed?

icy, you rev-match or double clutch down shift to go from 6th to 3rd.

Done correctly, down shifting on the street should not have and detrimental effects to your clutch, unless you start abusing it and the transmission. In my previous manual vehicles, I would downshift a lot, my 97 Ranger had 70k on it with the original clutch and tranny, no problems, the 02 WRX had 32k on it and again no problems and I downshifted probably as much in it as I did the Ranger, even though it was half the mileage, I also cooked the brakes on the WRX in 22k too, so maybe I was just a little hard on it? The 8 seems to be able to handle downshifting well and it help keeps the motor in the power band. I also typically do not skip gears and rarely downshift to a gear that would result in more than 5k RPMs. As long as you rev match, which I found to be super easy on these cars, there should not be a problem. It is a sports car and downshifting is part of the experience, does it hurt gas mileage, yes, does it save brakes, yes, does it sound really cool in an 8, HELL YES!

Do you mean if I was travelling @40mph in 5/6th gear (2500rpm), before I shift to 3rd, rev it to 2500rpm, then let the clutch go before accelerating to 8000rpm?

I see no point in downshifting. When I'm coming to a stop I leave the car in whatever gear it's in (while on the brake) until about 2000rpm where I put the car in neutral and ride the brake until I stop. Downshift doesn't seem to slow me down any better, and if it's not down right you can do serious damage to the tranny, not to mention your back tires. Lastly, I have done many brake jobs before, but never once have I worked on a tranny. I'd rather add extra wear to something I know how to fix.

Ah, yes, another "your transmission is made of crystal, don't make it do an iota of work more than it has to!" thread. It's utter nonsense. Yes, if you really *abuse* the transmission, if you consistently downshift into really high revs, then I'm sure you can damage it. But a little normal engine breaking coming up to stop lights or whatever isn't going to hurt anything such that you'll ever notice the difference. I've driven this way on every manual car I've had, in some cases put over 100k miles on them, and never had the kind of transmission problems that people seem to fret about here without any documented evidence that it causes problems. Yeah, if you're intending to keep your car for half a million miles, then maybe you should utterly baby the thing, but otherwise, don't lose any sleep over it.

From what I've been able to gather reading this site, it appears that, back in the paleolithic era, transmissions really WERE much more fragile, and did require more babying, and so a body of wisdom built up about how to treat them, which got handed down to each succeeding generation, a body of wisdom that never kept up with the improvements in technology. So now a lot of it is, to some extent, old wives tales.