• The development of any software program, including, but not limited to, training a machine learning or artificial intelligence (AI) system, is prohibited using the contents and materials on this website.

Clutchless shifting (my experience)

MXM

MXM

I paid for this title
Joined
Jun 9, 2004
Messages
5,631
Location
Finland
I drive about 10h a day now on small merc truck. Problem is that it has an incredibly heavy clutch, and since all that time is spent in the center of the city, left leg gets quite a workout. My knee and foot was hurting after 3 days.

So today I tried shifting without clutch :)
Tried disengaging gears at first. Peace of cake. Press throttle a bit, so car isn't accelerating nor stopping (no load on transmission) and any gear pops out easily.

Then I tried upshifting. So basicly I disengage gear like I just described, then let revs slowly drop while pushing the lever in direction of next gear. At certain point it goes in. Veery smoothly, much easier then with clutch, since synchro has nothing to do here, everything is matched. After 3 hours of practicing I can succesfully upshift through all gears (of course I still need clutch to get moving).
Downshifting proved to be harder. I can do 5-> 4 -> 3 in maybe 50% of times, but usually rev matching takes way too long. Couldn't catch 2nd gear once, the rev "window" is too narrow. I'll continue practicing of course :)

It's pretty easy with this truck because of big engine and big flywheel revs drop and rise slowly, plenty of time to "catch" the moment. Probably it's harder with smaller car. And of course the fact that it's not my car helps a lot :)

I see only one disadvantage - it takes more time. With clutch synchro helps to spin/slow the engine to match revs, and without synchro revs drop much slower. It takes 1~2seconds for it to drop from 1.8krpm to 1.2krmp (shifting points for 3 -> 4), so it gets much more difficult on uphill. Car starts slowing down too rapidly, so "window" starts moving lower and lower... After a moment I'm way behind the traffic and there's a queue behind me.

Now the important part. In my opinion it does no damage at all, if done properly. Right foot is used instead of synchro, theres no weird sounds coming and gears go in like knife in a butter. I actually think it saves the transmission because of smaller loads during shifting. Am I wrong?

If you know more about this, please tell :)
 
Don't really know what it does or is it bad or good. But I used to pratise this as well when I delivered packages for a living :D wouldn't do on my own car, because the sound is awful when not succesfull, but delivery vans are fine for this.
 
I've tried some clutchless shifting lately on my Escort. I think it's easier with the down-shift, as I just brake and wait for the gear to slide into place. The upshift is much worse, maybe because because I don't have a rev-counter, but in general there are some unhealthy sounds from the gearbox since I need very high revs for the up-shift to work.
 
Yeah I tried it too with a Merc van, but my clutch wasn't that heavy, mine had torque so I could stay in almost one gear in the city.
 
tloekke said:
I've tried some clutchless shifting lately on my Escort. I think it's easier with the down-shift, as I just brake and wait for the gear to slide into place. The upshift is much worse, maybe because because I don't have a rev-counter, but in general there are some unhealthy sounds from the gearbox since I need very high revs for the up-shift to work.
Click to expand...

I think you're confusing something. When you're upshifting, you need revs to drop. When downshifting - to rise. So why do you need high revs for upshift? It's the other way around.
 
^Hmmm... I find it a bit difficult to explain this in english, but I'll try. For instance, slowing down, I want first gear. It's in neutral and I press the stick up against the 1st gear slot while braking. When the speed is slow enough, it just slides in perfectly. Then I want to raise the speed, and go for second. The revs build, and since I have no rev-counter, I'll shift when it's at a certain pitch/speed. I release the throttle or else the stick won't budge. Then I let the revs drop until it slides into second. Same procedure for third. Haven't tried at 4th or 5th gear yet.
 
yep, I've been trying this for ages on my company car, I've realised that you need to be commited, no pussy gentle sliding here.

if your going quick down shift, let it bounce on to the over run, throttle up hard and yank it up and plant it in the next gear in one movement, if it grates on the change just hammer it in (glad it's not my car) with practise it's one quick change (noisey though ;) )
 
My friend has tried clutchless shifting on both a BMW M coupe and an Audi S4, and it worked most of the time. I'm not too sure how he does it exactly, but it only works for slow speeds (say under 60km/h). And the noises really scares the hell out of you when the shift isn't successful......something you really don't want to hear!! :cry:
 
Done it a lot on my previous A4 tdi and on my current A6 TDI... But as stated, when it goes wrong (and it goes wrong a lot of times) the sound isn't pleasing at all...
 
They only complain if you screw up. If you can actually heel-toe competently, you will never get a grind when clutchless shifting.

When you get it right, you can just left foot brake. It's handy for going quick as it requires less dancing (although that is fun too). :)

I find cars with big flywheels and inertia harder to shift quickly, because everything takes so long to respond. It's probably more to do with frustration (and this is why i hate sports diesels!), i'm not a paitent man when it comes to cars and empty b-roads. :D
 
^ For a purpose of comfort. And it's almost impossible to get moving without clutch :)
Tranny is paying a price only if you will not match revs. Think about how it works. One set of gears are always turning simultaneusly with wheels. Others are turning with the engine through clutch and synchro.

Press the clutch - and synchro will take care of rev-matching second clutch plate + short axle + one set of gears to the wheel-gears. When releasing clutch, it (clutch) will take the punishment of 2 clutch plates turning with different speed, so it forces engine to turn faster/slower (downshift/upshift).

Don't press a clutch and YOU will do the matching by revving engine itself. Clutch does nothing, synchro does virtually nothing and everything works at least as smooth as with clutch.

One thing that bothers me... If NOT getting it right too many times, gears could start jumping out by themselves :( Well, this car I'm driving did it before anyway, but I don't think clutchless shifting is helping.
 
like you said if you don't shift correctly the gears will pop out.
I think if wrongly shifted the gears knock and have an enormous wear.
 
I'm moving into my new house, today/tomorrow, so i've rented a renault kangoo 1.9dci, which, btw, does have a rather heavy clutch

Gonna try this clutchless shifting business on it.

Let's hope i don't end up with a knackered gearbox.

I love rented cars, they're so much fun.

What i do do is to shift gears with the pedal to the metal, only when my g/f is not in the car cause she hates it.
 
You must log in or register to reply here.
Top