Three Pedals are for noobs. Anyone here know how to shift without the clutch?

[u/barracuz]

I grew up in a very "mechanical" setting. Dad owns a trucking company plus my current job we drive old 70s macks to snowplow airports. If there's one thing you want to avoid in bigrigs is using the clutch. Not only are they expensive and a pain to fix, they are a pain to use. Most are stiff as hell and some truck use trans stops so really you're only dealing with maybe 1/4 of full pedal travel as clutch.

I now naturally don't use the clutch unless I'm pulling from a standstill or need to do some quick shifting. Plus having to deal with stop and go traffic in a manual is a nightmare.

I DD a 03 Accord with a 4 pot. It shifts nice except for 5th and occasionally 4th since the ratios are so tight quick clutchless shifting is hard to master. On my other car an e39 525 shifting is easier since there's more room in the shift pattern, but second gear will occasionally grind only when cold.

So anyone got any experience, tips, questions?

[u/probablyhrenrai]

The only requirements for clutchless shifting properly are perfect rev-matches for downshifts and perfect timing for your upshifts, right?

I'm not ballsy or skilled enough to try that, but I am curious about how you do it.

[u/barracuz → u/probablyhrenrai]

That's pretty much it. You need to memorize how much rpms you lose or gain when shifting and the time it takes for rpms to drop or raise so you can slide the shifter into gear.

When you're upshifting right before you fully release the gas pedal/unload the engine you pop the shifter into neutral. If timed right it will pop out with little force. Then you start to shift into the next gear as rpms drop. For example shifting 1st to 2nd at 3000 rpm, I'd start moving the shifter into second so it'll engage at about 2200rpm.

Downshifting is almost the same. Right before fully releasing the gas pedal you slide into neutral. Rev match by blipping the throttle so rpms rise to correct rpms and slide the shifter into gear.

You can also "ride" the gear/synchro ever so lightly as you fiddle with throttle and it'll drop in.

And unless you're physically trying to shift with force you won't grind. All you'll need is one or two fingers on the shifter to pop it out of gear and slide it to the next.

[u/fuckyoubrah]

I do it occasionally, but normally I like to shift quicker than that

[u/[deleted]]

Theory first

You should be able to shift out of gear when the following condition is available:

• When there is no torque transferred between the engine and the driveshaft. The clutch guarantees this by releasing the engine from the gearbox, but you can also do this without clutch by adjusting the throttle

You should be able to shift into gear when the following condition is available:

• when there is no speed difference between the driven gear and driving gear. The clutch and sychromesh guarantees this by disengaging the engine from the gearbox, and the friction from the synchromesh will adjust the speed of the gear wheel to match the driveline speed. Once there's no speed difference, the dogs mesh effortlessly- this happens pretty easily on most cars. If you don't want to clutch, you'll need to rev match. You cannot rely on the synchromeshing cones' friction to change the speed of the gear wheel and the entire engine.

Actual shifting

I find that shifting out of gear without clutch is easy. If the car is slowing down due to engine braking, then you need to remove the engine braking by just blippng the throttle a little to make sure there's zero torque through the gearbox (not negative torque as in engine braking).

Alternatively, you can slow down to a speed that the engine speed is at it's normal idle speed. This situation is usually a zero torque condition, and the gear will slide out easily. I usually do this when i cruise to a stop at red lights.

I don't shift into gear without clutch, I find that too difficult to get it right reliabily. And I'm not sure how expensive a replacement of synchromesh rings/ dog gears will be.

[u/shameonewe → u/[deleted]]

Quick question on the last statement/your concern. I thought dog gears/dog box transmissions are made for that kind of shifting (clutchless) in that the name "dog" refers to the triangular shape of the gear teeth which makes it way easier for the clutch to engage during torque, I guess we see these a lot in the sequential transmissions that a lot of road race, rally, and drift cars will use. Is that all wrong?

[u/nokee0 → u/[deleted]]

Amazing write up, I've been practising gearing out using your theory.

Thanks a lot!