tajabaho1

Hey guys, I know this has been discussed before in another thread (which I can't find with the search function)

but I have a quick question, I am not trying to do it, but today driving back from getting nitrous refill, I was getting ready to go into 2nd gear (didn't press clutch yet) suddenly, I heard the whining of the synchro die down, and at about 3k rpm, I was in gear...........then suddenly the car stalled.............even though my car was moving at about 20mph..............

should I be worried? what the hell is going on?

Jedi54

iTrader: (7)

yes, it's possible.
No, you shouldn't be worried about stalling.

Use the clutch, your car will thank you

tajabaho1

No, I mean I didn't mean to do it, it just happened because I was leaning the stick on 2nd gear, suddenly it winded down and slipped in to gear, and then died.........

TeamRX8

iTrader: (25)

It won't restart or you don't understand why it died?

Either way, it should have nothing to do with it going into gear.

bd32322

Posting in this thread - since the topic title seems to match although I dont have a problem as described by the parent poster.

Do you guys shift without the clutch or preload the shifter? It actually seems to shift faster but I am not sure if its going to damage the transmission. Apparently its a common practice on street motorcycles, but of course, they could have a different transmission.

The process I am describing is this:
Method 1)
Get to a high rpm, say in 1st. Apply pressure on the shifter to go to 2 (It will stick in 1 at this point). Let out the gas and the shifter will slide through to 2 as soon as it matches the rpm for 2nd gear at that speed and hit the gas immediately.

A slightly smoother way seems to be to use the clutch to help move the shifter easier. So get the rpms up, preload the shifter to switch to 2nd gear, let up on the gas. As the shifter starts sliding from 1 to neutral, press the clutch lightly and shift into 2 quickly - hit the gas.

I have no idea about the mechanics of transmissions - I could read up on sites - but until I see one in action I wont understand So hoping some of you guys know whether this is damaging.

Thx,
Bodi

daisuke

putting pressure on the stick while waiting for the sound of the synchros to die down means that you're stressing the synchros a bit. The way to shift it without the clutch (so to speak) is to pull the gear out of where it was (prefferably with the clutch) and then blip the throttle, wait for the revs to match and slip it into gear with no grinding at the sweet spot, the catch is that you have to know from experience at what speeds and revs the cogs are going to mesh.

double clutching to shift is actually faster than a normal shift if you know how to do it and older race cars tended to have un-synched clutches for this exact reason, of course it takes an expert to shift them right and make them last.

I'm no expert, but motorcycles are different because they have a wet clutch and I believe most bike transmissions aren't synchronized because they don't have to be.

bd32322

I agree with you on double clutching and rev matching in neutral for downshifts - I do that myself. But I was talking about shifting up from a lower gear to a higher gear. Maybe you were talking about double clutching on upshifts also?

Also I think double clutching on an upshift will be slower than even normal upshifts - in my opinion - I never tried it since a normal shift with clutch is smooth enough - except that normal shifting just doesnt seem fast.

staticlag

I wouldn't recommend this.

If you want to shift without the clutch, then buy an automatic transmission

TrochoidMagic

to all of the process' above, here's a refined version or maybe the correct version of doing it. and in fact, once the car is moving you don't really need the clutch anymore.

1) any gear accel. let off gas and simultaneously pull gear out and (with slight pressure) put the shifter into the next gear.
2)then accel as usual.

testing step. example.
to know what gear/speed/rpm are the synchro's match it, try
1) about 20mph, let ur car be in neuutral
2)rev the engine a bit...maybe around 3k,then let it settle (blip the throttle)
3)with shifter going into 2nd, let it drop into gear.

its harder to explain this then to show in person. but all it is is matching the synchronizer's speed. and if you can remember exactly what mph in what gear at what rpm's...you'lll have better chance at getting right after the first few tries.

this is not a recommended technique to use on daily driving. and this technique is a must for a situation when you're stranded and your clutch line blew...which in our case, its really bad since clutch and brake share the same reservoir.

bd32322

Yes - but if you try double clutching - you will find that its much much smoother than simply rev matching and shifting and it doesn't work your synchros. Try it sometime - it will need quite a bit of practice but the downshifts will be teh smoothest ever.

Anyway I digress from the topic - which is to find out whether up-shifting quicker without the clutch is causing my transmission harm.

TrochoidMagic's reply seems to indicate that it could be okay - although not completely sure.

New2u

+1 Agreed

ken-x8

Double clutching on downshifts saves wear on the synchros. Instead of the synchros spinning the input shaft up to speed, the engine does most of the work. Also easier on the shift linkage because if you get the matching close you don't have to push as hard or as long.

Double clutching upshifts is a different deal. As near as I can tell, it lets you granny shift in a way that gives the illusion of knowing something rather than looking like a granny shifting wus.

Ken

staticlag

Yes, double clutching on downshifts does save wear on the syncros.

No, the technique described in this thread about not pushing in the clutch "the thing that takes the load off the transmission aka, the thing that takes the load off the syncros" is not double clutching, and it is directly putting too much pressure on the syncros.

If you ever put any pressure at all on the shifter while the clutch is still connected, then you are wearing out your syncros!!!

Pretend like the shifter and the clutch pedal are red hot, only touch them for the minimum amount of time to sucessfully complete a shift, then hands off

prozach007

The process being described, floating or speed shifting, is not using the clutch to shift. That is how big trucks (18 wheelers) are shifted. By matching the rpm of the trans with the engine rpm, and applying slight pressure to the stick it will fall into the next higher or lower gear. However those transmissions are designed to be either double clutched, or floated. They also require the clutch to be engaged to start the truck from a stop, or stop with the trans in gear. I don't shift my 8 that way!!! Use the clutch!

kersh4w

iTrader: (3)

so whats an appropriate non-granny upshift?

i assume heel-toeing counts as a non-granny downshift.

ken-x8

That's entirely between you, your transmission, and your mood.

Heel-toe is separate from granny. One can also argue that a true granny shifter never downshifts, except to put it back in first after coming to a stop.

Ken