Clutchless shifting

[SkullWorks]

yeah, coming from a childhood of sliding dirtbikes around in the hills of idaho, then old farm trucks, you learn that a clutch is simply there to allow the speed differential to be taken up by something with cushion rather than gears, but again that is a problem for humans, if there is no speed differential there is no need for a clutch.

And yes this car shifts exceptionally well clutchless, but I am lazy and it's a better safe than sorry sort of deal, I use the clutch 98.657% of the time.

[ElectronSpeed]

If the “Seriously?” was aimed my way, yes. There were enough issues with shifting during the race that a decision needed to be made late in the race: take the time to sort out the damage or put in a driver who can drive clutchless. The choice was pretty simple. We put in the driver that could bring the car home as it was.

If you have never shifted clutchless, I would start with an upshift:

Pick a gear that is a straight pull across the transmission gate in the middle of the gear range (3rd to 4th in most cars) and a speed that is in the middle of the RPM range (say 3000).

Shift to neutral (and learn a bit about feel):

While lightly accelerating, apply a light pressure (a couple of pounds) on the shift lever and then lift the throttle. There is an instant in time when the gear will transition from loaded in the acceleration direction and head toward loaded in the deceleration direction. At that point, the lever will start moving toward neutral (aka fall out of gear). It will not take much effort but the lever should be moved fairly swiftly out of gear.

Use that feel again to complete an upshift:

Ease the car out of gear and swiftly apply a light pressure (a couple of pounds) on the next gear. The pressure should be the minimum necessary to feel when the gear synchro starts to allow the gear to engage. When the pressure eases, swiftly move the lever completely into the new gear.

Since the second step is about waiting for the RPM to match the speed for the next gear, it is helpful to know how fast you need to be. High RPMs and low gears require the largest RPM drop and will be the longest wait between the first and second motions. Low RPMs and high gears (typically closer spaced) will require the swiftest movements so that it almost becomes one motion.

When making the shift with the clutch, the disengaged clutch allows the synchros to easily match the speeds on the transmission input and output shafts so you do not grind the gear (smooth on your hand). However, it is still the clutch (or driver’s) job to match the engine speed to the new gear and vehicle speed (smooth on your neck). This is the part of the story that was leading to problems at Daytona. The clutch was being asked to take up too much of the match.

There are exceptions to every rule . . . modern tractor trailer drivetrain controllers can automatically match the RPM of the engine to the next gear and speed to make clutchless shifting nearly effortless.

Have fun,

Eric Schieb
Electron Speed

[mangostick]

Good clean description. Well said.

[Laika]

Originally Posted by 2point0

Now I'm tempted to try...did this all the time in my first car (Karmann Ghia). Old VWs were so easy.

Hoooold on! Wasn't there something unique about this car and it's clutch? I'm really struggling to remember but I thought it was something along the lines of only needing to use the clutch to get going. Some sort of manumatic?


Interesting to hear everyone's accounts on the topic. I never even tried clutchless upshifting in the BRZ. I guess I felt more confidence in downshifting from all the rev matched down shifts I had been doing with the clutch for these past months. Thanks for sharing everyone, glad this didn't turn into some argument about why not to do it. But you shouldn't do it

[mangostick]

some of the old VW's had a "autostick" trans. My Father restored one for a friend of his. They're quite a bit of a pain to work on and still shifted very rough. Akin to a dogbox trans imho.

Most Ghia's were a normal manual transaxle.

Shifting on the rpm correctly will NOT hurt your transmission. So why not do it? .. Granted, if you've never done it and dont know what to feel for to do it right.. yeah maybe using the clutch is a better Idea. Otherwise there's no harm if its done right.

[Mister_Sir]

my understanding is... there is a reason they put that extra pedal there. Maybe you should've gotten an auto.

[Laika]

Originally Posted by Mister_Sir

my understanding is... there is a reason they put that extra pedal there. Maybe you should've gotten an auto.

With all due respect...if your clutch master goes (or any other related part) and you realize you can't drive your car without the clutch in an emergency situation, maybe you should've gotten an auto

[mangostick]

Originally Posted by Mister_Sir

my understanding is... there is a reason they put that extra pedal there. Maybe you should've gotten an auto.

Then your understanding is limited.