mdloops

looking for a little manual shifting advice. Is there a way to downshift into a gear easier without so much of a jerk? I am talking about as situation like being in 4th gear at say 3500 RPMs and shifting into 2nd at 4-5000 rpms. Basically downshifting to smoke somebody's BS slow car or pass a car.\

Thanks,

Mark

spirilis

iTrader: (2)

Yeah, give it some gas. And to make it go into gear easier (which is easier on the synchros), double-clutch (clutch pedal down, shift to neutral, clutch pedal up, rev it up to the general target RPM, clutch pedal down, put it into gear, clutch pedal up while giving it some gas)

Max51

Yup......just match the engine speed(rpm) with the wheel speed for a given gear and should be smoother, nicer, better, easier

Mick Max

Yep like they said. You can do it even when braking, It is called heel and toe.
You brake with your right heel and use the tip of your foot to blip the throttle.

ALL downshifting should be done using the gas to match RPM to the lower gear.
Your clutch will thank you by lasting much longer

Progress

iTrader: (26)

A variation on this is just simple throttle blips. I do it all the time, it isn't high performance or anything. Just when you are slowing down (coasting or braking) before you put the car into gear or let it off the clutch, blip the throttle up close to where you think it will be if you were in that lower gear at that speed, and then release the clutch pedal, that way the engine is up to it's proper rpm to match the wheels.

Trance Artur

iTrader: (2)

Why clutch up when giving it gas?

spirilis

iTrader: (2)

Clutch up while giving it gas ensures that not only does the engine & flywheel get up to speed, but the transmission's input shaft gets up to speed with it.

By getting the input shaft up to speed, it allows the next gear selection to engage much quicker, since the input and output shaft gears are already moving at around the same speed. Most of the "notchyness" when shifting into a different gear (especially when there's a large RPM difference between them) is the resistance given while the synchros (in between the freewheeling gear and the gear that's splined to the shaft, which are dog teeth I think?) get the input shaft (along with the clutch disc, which is splined to the input shaft) spinning up to the right speed. Doing this relieves the synchro of much of its work and makes the shifter go into the intended position much quicker.

Mick Max

No need to double clutch, if you get pretty good at matching engine speeds to the gear you are going to, it is -0- strain on the syncros. I got a friend that is so good at this you cant even feel he has down shifted.

spirilis

iTrader: (2)

Well, it'd have to strain the synchros unless you pull the clutch up a little while you're pushing it into gear (which essentially does the same thing, but it gets the input shaft up to speed while you're putting it into gear rather than before...)
I think I've actually done that before "by accident", but never really practiced. Maybe I should look into that

2000 Maximus

iTrader: (4)

I think we have all done that more than a few times without even noticing it. Matching engine speed is a great way to downshift without feeling the kickback and your clutch will last longer as well.

Ammi

iTrader: (26)

rev match...

HNDA ETR

iTrader: (10)

so funny.... i was just explaining to my friend how this works... and i call it rev match too...

Stev02

I call it rev matching too...

silverkorn

iTrader: (3)

double clutching on a synchro gearbox is pointless, synchros are there for a reason so use them. double clutching is really only needed on a straight cut gear box where there is no transition between gears, either your in or out.

rev matching is what you can do to to make the downshifts smoother

heel toe shifting uses the throttle blip (rev matching) but you want your toes on the brake and either the side of your foot on the throttle or your heal, cause you usually have more control and traction on your toes then your heal and your brake pedal is the most important one.

it doesnt take much to rev match, just a quick hit on the throttle, after a while it becomes second nature

mdloops

so to rev match out it in neutral, rev it up to where I think it would be, then shift into gear?

mdloops

err. I will rephrase that. Push the clutch in, rev it up, shift into new gear, release clutch?

silverkorn

iTrader: (3)

the order in which you do it doesnt matter, just as long as your blipping the throttle with your foot still on the clutch.

when done right the engine will hit its high mark and just as its about to fall back down in RPM's you release the clutch and the car stays at that RPM, without the car making any sudden movement.

mdloops

ahh, thanks.

mdloops

tried it today. Great advice. Just push in the clutch and tap the throttle, and shift. Works great...

dbrooks

...your clutch wont really be whats goes, it's more the synchros in the transmission. Modern transmissions have synchro mesh for a reason -- we're not driving Model-T Fords anymore that require a double-clutch downshift to sync the layshaft to the driveshaft and engine speed.

Downshifting without double clutching is fine, and there's nothing wrong with it. (I double-clutch out of habit, though.)

GreenSeMax

silverkorn is correct, there's no reason to double-clutch, it merely wastes time, if your pressure plate is in good condition it should be fully releasing the clutch plate, therefore no wear occurs there, and the input shaft if the tranny will already be moving from the momentum stored in the previous gear's pull. And beyond that the synchros will not be harmed as long as you match it, if your doing a 5-3 at like 85, and only get the revs to like 4500, then of course the car will jerk when the energy of the 3200 lbs moving down the road tries to yank the engine up to 5500 or so where it should be, the jerk is the kinetic release of that momemtum, in this case expelled as braking force if you under-match, or it will lurch forward if you over-match and dump it. and i agree heel-toe needs to be done heel on the gas and toe on the brake for a couple reasons, first the gas is too far forward of the brake on maxima's to really get your toe on it while your heel's on the brake. It's best to toe the brake like normal, but blip the throttle with your heel on the lower portion of the pedal.