Southernboy, with regards to your post on downshifting in this thread:

https://acurazine.com/forums/showthr...t=downshifting

you stated:

Junkyard asked a question about the concept of “passing through the neutral gate”. You don’t stop or stay in neutral. You are just passing through, so to speak. In your second question, you said I had mentioned to put the car in neutral when downshifting. Not exactly. Try this with the engine off.

Can you please explain why you dont want to leave it neutral for a second? Why does it have to be one fluid motion? I have been trying to learn this, and for me.... it's hard to do it in one fluid motion.... i have to pop it in neutral first, then perform the blipping of the rpms, and then put it into gear and let the clutch out. I guess I will practice it until it becomes one fluid motion....

But I just wanted to know why you can't leave it in neutral for a second or so where it's not the one fluid motion that you speak about.

Thanks!

 

I don't think there's anything wrong w/ leaving it in neutral for a second. It's just it'll look smoother and the transition would be quicker if you do it while going through the neutral gate.

 

I agree with Laxplaya11385 in that there is a moment when you are stopped in the neutral gate. Perhaps I should have written that one should pause in the neutral gate because that is really what's happening when you downshift in this fashion.

Junkyard (a member of a previous site on which I wrote these things) was talking about lingering in neutral while he was rev-matching as I recall. When done properly (once you have mastered this technique, it would look to a passenger that you were doing this in one fluid motion as you downshifted, say, from 4th to 3rd. But in reality, there is a moment's pause in the neutral gate as you release the clutch while blipping the throttle at the same time as you rev-match for your downshift.

As for getting this technique down, I would suggest that you concentrate on the correct procedures as you work through this until you have it down.. never mind the speed at which you can do it for now, just get the basics down pat. And then start increasing the speed at which you can perform this method. You are not in a race, so doing this really quickly is not the goal or the desired manner. Where you want to be able to get with this is to do it quickly enough that you are not without engine power and control passing through the drive train any longer than necessary. It's really not a speed thing as much as a smooth thing.

Good luck.. you'll get there, don't worry.

 

To sammieboy;

Perhaps I should offer an explanation as to the "why" of all of this downshifting effort I have described. I think there are some things left out of my text about this.

A clutch assembly only does one thing. Through friction generated by the pressure plate, it locks up the engine to the transmission. That's really all it does. There are three major components to a clutch assembly: the pressure plate, the flywheel, and the clutch disk. There are other parts for sure, but these are the most significant ones.

The pressure plate and the flywheel are bolted together and therefore "spin" together and as such, are attached to the engine's crankshaft. The clutch disk is sandwiched between the pressure plate and flywheel and is attached on a splined shaft to the transmission and as such, is the transmission's input shaft.

In the transmission when you shift gears, you are really not shifting gears, but rather you are moving a hub (or collar) inside of a gear with "dog" teeth that mesh with another gear to receive those dog teeth. The synchronizers act as little clutches to match the speeds of drive and driven gears so that these dog teeth can mesh smoothly with no damage.

Now the reason you want to rev-match is to get the engine up beyond the speed that it would be running in the next lower gear so that when its RPMs are falling off and your clutch engages, the drive and driven gears will be turning close to, or at, the speed they need to be for the lower gear.

The reason you let the clutch out a bit as you blip the throttle going through the neutral gate is to spin the gears, and synchonizers, up in the transmission so that the friction between the synchronizers and their mating surfaces on the lower gears is minimized or eliminated.

It's no easy to explain this because I don't know how much you know about the subject, but I hope this helps some.

 

This helps... and in addition Ive already read up on how a manual work on the website Howstuffworks.com. Thanks for the in depth explaination Southernboy!

 

I haven't been doing this- letting the clutch out as I go through neutral. I blip on the gas as I go through neutral to rev match to the lower gear but all while the clutch is depressed. How critical is letting the clutch out?

 

Correct me if i'm wrong, southerboy, but when you're releasing the clutch during the blip, you're creating less friction b/w the syncros and the gears (due to the fact that you're spinning the syncros to match the speed.) This in turn causes less wear/tear. On the other hand, by leaving the clutch depressed, the syncros aren't spinning up to match the speed, so it's causing a little bit of tear on the syncros themselves.

 

Yep, you hit it.

Basically the driven gears are being turned by the car' wheels and the drive gears are turned by the engine via the clutch assembly. By releasing the clutch some (or all, it really makes no difference) as you blip the throttle while going through the neutral gate, you are trying to match the speeds of the these sets of gears just before you make the shift.. which engages the synchronizers first to do the matching.. that's the slight resistence you feel when making the shift.

But, yeah, you got it right.

 

Let me jump in here with a question.

I have a 5AT so I don't know about the 6MT but I was led to believe by several posts here that the engine computer blips the throttle for you, and/or cuts it if you leave your foot in the same place on upshifts. Is that not true? Or half true?

For referrence, I just had an Infiniti G35 rental for a week. It was pretty neat, except for a step down in luxury and quietness (dig), but the G35 DOES do a throttle blip when you're in SS mode and you downshift with the automatic. It is very cool and a simple program for the chip.

You can downshift at high RPM, and there is no lurching in the lower gear. You can hear and feel the blip to match the RPMs in the lower gear. That's especially nice with a RWD when you are going around a wet corner when downshifting. The ABS doesn't help you in that circumstance. The VSC is of minimal help also.

 

The synchros perfrom the same function as the clutch only on a smaller scale. The engaging gear has a synchro that touches the engaged gear first, causing it to start spinning at the same speed so that when the two mesh, they are going at the same speed. Before the gears actually touch and mesh, the synchros are sliding against each other (no gears). Some are like one cone pressing inside another smooth cone. They are on the same shaft as the gears but in front of it. They slide out of the way when the gears mesh.

A historical note: Synchros are relatively new. Early cars did not have them. Big trucks didn't get them until the last 20 years or so. Even when cars and trucks got them at first, they were only for 2nd and 3rd gear (later, 4th) but not on first or reverse. Farm tractors were the last to incorporate them and some still don't have them. So, with an older car like a 60's or 70's muscle car, you either had to come to a stop or double-clutch to get into 1st gear.

In that light, double-clutching (or throttle-blipping) is optional today. If you do it, it is EASIER on the synchros because they really don't have anything to do. That also translates into less friction and less heat in the tranny- albeit slight. Less friction is also less wear and the synchros would last longer theoretically. Of course, they last a LOOONG time anyway. I've got 161,000 on my 5MT Jeep Wrangler and the synchros are still like new.

Southern Boy and I are, um, mature enough to remember when double-clutching wasn't optional- especially if you were on a farm.

 

I'm sorry but I have to make a correction here.
The supercars of the 60's (and the lesser ones of the 70's) had fully synchronized manual transmissions.. as in all forward gears. Not one of those cars was missing a synchronized first gear. Fully synchronized manual transmissions became common in the 50's and by the 60's you never saw a non-synchronized first gear in a manual transmission.

The last one I recall was in the earlier 50's and was the Buick LaSalle 3-speed. Oh, and there were other three speed trannies with un-synchronized manuals in the 50's, too. Much more common in the three speeds of the day back then.
But even the three speeds that made it into the 60's had managed to receive synchronized forward gears.

 

No, the 6MT TL ECU does not blip the throttle for you between downshifts. What it does do is briefly hold engine speed at a lower RPM when upshifting as an aid to a smooth shift and to reduce drive train shock.

 

Don't be sorry! Your corrections are always welcome here. I usually defer to your better memory and broader muscle car experience. I specifically remember a 1958 Chevy Del Ray (6 cyl) with 3 Speed and no synchro and I thought that my 1966 Biscayne 283 V8 3 Speed also lacked a synchro in first. Maybe not. Maybe I just destroyed it! (A distinct possibility)

I suspect they lingered longer in the 3 speed 6 cyls than in the V8s as they were not concerned as much with performance.

 

Thanks, I really hate to step on people's toes if I can help it.

I remember driving a friend's '54 Ford with a 3-speed column shift tranny (very common back then. No synchros in 1st gear with that one.

I'm not sure when the Big Three finally phased out 3-speed trannies without first gear synchronizers, but I suspect it may have been in at the end of the 50's. I do know that by the time of the beginning of the supercar era (fall of 1963 with the 1964 models), the standard 3-speed transmissions (floor shifted) were fully synchronized in the GM models.. for the supercars. By 1966, I don't think any of the Big Three supercar entries even had 3-speed transmissions available, but I am not certain about that. I know I paid extra for my 4-speed close Muncie in my 1966 396 Chevelle (I think it was $109.00.. I still have the original order form in my basement).

You may be right about some of the car companies and their 6-cylinder engines. Since I didn't follow those cars, I canno attest to that. I do have a detailed breakdown of every car offered to the general public in 1966 as to engines, transmissions, and states of tune (that means HP and torque.. as the information was made available in 1965). It's in my November 1965 issue of Car and Driver which also has the famous "Battle of the 427's" article.. road tests of the 427/425 Corvette and the 427 AC Shelby Cobra.

 

When you stop and think about it, the manual transmission is pretty simple but also pretty darned amazing. When treated properly (as in not abusing it such as in racing), the thing will last one heck of a long time. There is really nothing much that can go wrong with them. Relatively small and compact, and very reliable. In terms of reliability an automatic is no match for a manual.

And as for clutch assemblies, the same holds true. VERY simple and VERY basic. But also very reliable and capable of lasting well into the 300,000 mile range. When you think of what's going on in there, that is amazing when you hear of one with that kind of mileage.

This all assumes, of course, a good design, a correct installation, and proper operation. Very basic stuff and capable of outlasting most peoples' ownership of the car.

 

Southernboy - I just have to tell you (sorry to break up the posts here on this thread) that you're information is priceless and I really appreciate and I'm sure as do all members here, everything you have to offer on the MT realm.

As a new MT driver, this is my first MT car, going strong since APril 15, 2006 you've really helped me become much smoother, to the point that I have people sitting in my car last night (Who currently drive MT's on a TT and an 06-350Z) telling me in the back seat, "Dude I love this fucking car, I can't even feel the car shifting"

thanks man, just wanted to let you know I appreciate all your info!

 

Southernboy knows his stuff.... Just wanted to say thanks for the info, even for a MT Veteran like myself, it is nice to get a little more knowledge about what is happening within the car when I do the things that I do...

Thanks

 

Well that is a VERY nice compliment and I sincerely thank you. But more importantly, I am very pleased that you have found this information useful and helpful as well as all of the other postings on this website.

I have also learned quite a bit from other people's offerings. Just yesterday morning, I learned that our sunvisors extend! I had totally missed this in the owner's manual. No surprise because there's nothing in the owner's manual about sunvisors that I can find with a cursory examination.

I learned a valuable little tidbit from Road Rage when changing oil. He recommended to loosen the old filter enough so that you can finish removing it by hand. Then wrap a 1-gallon ZipLock bag completely around the filter and up and over the pickup arm and then remove the old filter. This traps the residual oil in the ZipLock bag instead of letting it spill all over parts of you suspension, driveway, and yourself.

Thanks again for the kind words.

 

Yep, we never stop learning. When someone tells you he knows it all, be aware.

Now if I could just master heel-and-toeing....

 

lol... find a NICE OPEN area with no other cars around.....

 

Really. Out where I live, that's not too difficult (Western Prince William County).

Since my preferences in autosports are more in tune with drag racing, I never really learned, nor felt the need to learn, heel-and-toe. I know how to do it. It's just that I am FAR from proficient with it.

Oh well, maybe in my next life, eh?

 

I also don't think big rig 18-wheelers use synchro's. I remember watching or reading somewhere that they would get torn up.

 

Yeah. Sychros are for poo-c's some would say.

In fact, many new tractors today are automatic trannies. Like big busses and fire-trucks.

 

Yes this is VERY difficult to do. I too have to pause in neutral for a split second. It feels weird doing that, but I do understand SouthernBoy's explanation on why it should be done like this. His explanation on how to downshift properly makes it sound so simple, but then when I actually try it, I can't get it in one simple motion to save my life..

Maybe one day I'll get it.

Southernboy does know his stuff, his knowledge has already caused me to unlearn some bad habits that were taught to me by people I know in person, now if I can only get this downshifting down.....

 

"..has already caused me to unlearn some bad habits that were taught to me by people I know.."

This is what I was hoping would be the case. To relearn and correct habits which are injurious to your car and to help you become a better manual tranny operator.

Most always, people teach us things with all good intentions and are flattered when we ask for their help and input. But when it comes to operating a manual transmission, it's funny how this works.

You know, we're seventeen, first car, and mom tells us, "call your Uncle Jim.. he's been driving sticks for years". So we do this.. we call Uncle Jim who sets about teaching us all of his bad habits, like holding the clutch in at lights (or worse, holding the car on a hill with the clutch). We just naturally think this is the way it's done and before you know it.. we're off and running, propogating Uncle Jim's errors.

I didn't have any of this when I was a kid.. I taught myself to operate a manual transmission. I'm not really sure when I learned the techniques I have imparted on this website, but I know it was during the time I owned my first car, because by the time I had my second car, my '66 SS 396/360 Chevelle, I was downshifting in the manner I describe. I think I learned this with my first car from an article in Car and Driver but for the life of me, I cannot be certain.

I once taught these techniques to a lady with whom I worked back in the early 90's. She had just bought a 1992 Honda Accord LX with a 5-speed and was worried about wearing out the cluch prematurely since she commuted in heavy traffic from Laural, Maryland to Reston, Virginia (about maybe 50 miles each way). I taught her these techniques and when I last spoke with her (in the 90's - we've lost touch), she had over 140,000 miles on the clutch and it was still fine.