# Double Clutching



## sarsourus (Apr 8, 2005)

is double clutching really effective? when i tried it today i felt an extra kick on each gear but i really don't know if i am doing it right.... little help explaining anyone ?


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## Acceler8ter (Feb 5, 2005)

You have a synchronized transmission. You don't need to double clutch, its useless. Stop watching Fast and the Furious.


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## jeff9nissan (Jan 9, 2004)

What exactly is double clutching?


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## no1see2me (Oct 1, 2004)

Pushing the clutch in and moving the transmission to neutrel then letting the clutch back up and pressing it in again to put it in gear then releasing.

This was a method that was used back in the old days when big truck two transmissions. One was the main and the other was the splitter.

Now; Big Rig transmissions are automatic or the stick version uses air for splitting and with the fuller transmissions you don't need the clutch expect to take off


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## Zac (Mar 10, 2004)

Acceler8ter said:


> You have a synchronized transmission. You don't need to double clutch, its useless.


Unless your B15 has a '77 Ford tranny in it with a half burnt clutch, then double clutching is a thing of the past. Upshifts in a synchronized transmission are significantly slower when double clutching.


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## mille-16i (Jun 16, 2004)

only time you should even think of double clutching is when down shifting and that is just to be nice to your gears and mainly in older trannys I would hope a B15s tranny would not grind like mine if I down shift to aggressively


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## matt123 (Dec 2, 2004)

_only time you should even think of double clutching is when down shifting _ 

Rev matching is the only thing required on the downshifts, and that's done by blipping the throttle before re-engaging the clutch. But this is mostly done to maintain proper weight balance during high speed cornering...in RWD cars, which the Sentra is not.


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## damonfong0 (Jul 13, 2005)

i heard double clutching helps when you shift up too...
if your RPM isnt high enough, just clutch, shift neutral, let go, rev, clutch, shift next gear, let go.. then u will feel a jerk from the high RPM the engine is in when it engages... but wont this wear your tranny a lot?


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## sarsourus (Apr 8, 2005)

another thing i do that helps is clutch, while shifting you rev and then relase clutch ressume speed and u will feel a little extra kick when u drive.


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## Acceler8ter (Feb 5, 2005)

sarsourus said:


> another thing i do that helps is clutch, while shifting you rev and then relase clutch ressume speed and u will feel a little extra kick when u drive.


And that would be the basics of REV-MATCHING. Learn to drive that way and you'll be on your way to tearing up the auto-X. :thumbup:


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## chimmike (Oct 17, 2002)

sarsourus said:


> another thing i do that helps is clutch, while shifting you rev and then relase clutch ressume speed and u will feel a little extra kick when u drive.



the "kick" you feel, when u do that during an upshift, is the car lurching back to normal speed, not a kick of acceleration.

rev matching on downshifting is good. Doing what you do on upshifting is pointless.


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## Acceler8ter (Feb 5, 2005)

chimmike said:


> the "kick" you feel, when u do that during an upshift, is the car lurching back to normal speed, not a kick of acceleration.
> 
> rev matching on downshifting is good. Doing what you do on upshifting is pointless.


I thought he was talking about downshifting. Which is why I made my auto-x comment... but upshifting... erm... okay? I think he's more interested in feeling fast then actually being fast. :loser:


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## Flying Vv (Apr 10, 2003)

double clutching is pointless. Also, like mike said the kick is the car returning to normal speed. Just because the RPMS are higher doesnt mean that the car will go faster, you have to factor in the speed of the wheels too. Plus the kick is extremely bad for your transmission and will slow you down more than speed you up.

The kick means abopsultely nothing when performance is concerned. Smooth and quick shifts are the way to go.


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## wildmanee (Nov 21, 2004)

Double clutching is not pointless if you're downshifting.


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## Flying Vv (Apr 10, 2003)

yes, granted. But with a syncrhonized tranny, you need not to double clutch. If you happen to be towing a boat with your sentra 1.8s, then I can see the use. But rev-match downshifts are 1ox more efficient.


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## chimmike (Oct 17, 2002)

wildmane said:


> Double clutching is not pointless if you're downshifting.


then it's not called double clutching. it's called rev matching.

double clutching is pointless on our trannies, period.


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## matt123 (Dec 2, 2004)

It's no wonder so many people add useless crap to thier cars, they don't know how their cars work to start with.

Look, people, feeling the car jump forward because you've taken it out of gear and then re-engaged is not some mystical power you've tapped into. The car's engine is still putting out the same power it always was. What you've done is allowed the car's speed to drop (and so the gears in the tranny have also slowed down) and then suddenly re-engaged the clutch while parts (namely the flywheel and drive shaft) are spinning at different speeds.

That's all. You've lost speed. You've gained nothing. Don't be a tool.


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## Spec A! (Sep 8, 2004)

matt123 said:


> It's no wonder so many people add useless crap to thier cars, they don't know how their cars work to start with.
> 
> Look, people, feeling the car jump forward because you've taken it out of gear and then re-engaged is not some mystical power you've tapped into. The car's engine is still putting out the same power it always was. What you've done is allowed the car's speed to drop (and so the gears in the tranny have also slowed down) and then suddenly re-engaged the clutch while parts (namely the flywheel and drive shaft) are spinning at different speeds.
> 
> That's all. You've lost speed. You've gained nothing. Don't be a tool.


That and you're putting more stress on the motor mounts, just as in hard shifts when you side step the clutch to chirp the tires. Imagine what it must look like in the engine bay when the engine's spinning at 4krpm and you introduce a gear that's spinning 2krpms below. This is also why harder motor mounts make for nicer feeling shifts.


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## jeff9nissan (Jan 9, 2004)

Uhm, I don't see the point of releasing the clutch in neutral to rev up. Why not just hold the clutch in and rev up inbetween gears?


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## Atif Farooqi (Jun 26, 2005)

Are the synchros that strong on a SE-R tranny not to worry about it? I was actually debating myself whether i should heel-toe with or w/o double clutching.


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## Acceler8ter (Feb 5, 2005)

Atif Farooqi said:


> Are the synchros that strong on a SE-R tranny not to worry about it? I was actually debating myself whether i should heel-toe with or w/o double clutching.


I'm gonna stick with Chimmike on this and say... Double clutching is pointless.

I heel/toe almost by habit now during normal driving. I do not double clutch while doing it. Its just an extra step that serves no purpose. Rev matching is faster and accomplishs the same task.


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## kaizer (Jun 7, 2005)

Just want to share with you guys. Rev matching is also called Heel and Toe downshifting.

I notice the fastest way to upshift is to side step the clutch pedel (during releasing pedal motion). But I got a feeling it hurts the tranny/clutch alot.

My previous car uses clutch cable, I manage to pierce through the firewall doing the above. Have to weld back the joint.


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## Atif Farooqi (Jun 26, 2005)

Does anyone find the pedal positioning on the 02 Spec-Vs difficult to heel-toe?


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## b18_crx (Aug 14, 2005)

chimmike said:


> the "kick" you feel, when u do that during an upshift, is the car lurching back to normal speed, not a kick of acceleration.
> 
> rev matching on downshifting is good. Doing what you do on upshifting is pointless.


agreed double clutching is a dowshifting technique


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