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Discussion Starter #1
Ok everyone, I've been racking my brain and my computer trying to figure this one out...

I'm sure we've all seen the movie "The Fast and The Furious".  My question is when Vin Diesel say's the line "granny shiftin' instead of double clutchin' like you should, you're lucky that double-shot of NOS didn't blow the welds on your intake" what the heck is double-clutching and how is it done and what are the advantages.  I've looked and haven't been able to locate anything about it.

 

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Double clutching is a way of shifting gears (in manual, of cause).

The purpose is to synchronize the engine RPM speed with the transmission input shaft speed. This is needed (well, a good practice for your car) if your transmission does a poor job (or, not as good job) on synchronization.

Since there is small difference (in speed) when upshifting, people usually would not do it. Doing so, is mostly wasting your shifting time. Nevertheless, it is mostly used (almost 100%) when downshifting. It is because there is a big difference in speed (think of 5,000 RPM in 3rd gear and you try to downshift to 2nd gear).

P.S. The sentence was said after their 1st race. Just to let you know.
 

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advantage? A lot smoother transition on shifting in term of speed and to protect your investment (transmission).

Below paragraph is copied from a site (Sorry. I try to give you credit but, don't know who's it is).

Here is Double Clutching

1 Clutch in
2 Tranny to neutral
3 Clutch out
4 Rev the engine in neutral to spin up the transmission input shaft speed
to get the engine near the rpm that will occur in the lower gear.
(now both sides of that gear's synco are spinning at the same speed)
5 Clutch in
6 Slip into the gear
<minimizes syncro wear>
7 Tach up to engine RPM that will occur when the clutch is released
<minimizes clutch wear and engine braking>
8 Clutch out

Note that if you double clutch downshift in a corner you achieve the same
purpose with repect to minimizing engine braking as if you heel and toe
downshifted. Double clutching takes more time and is more difficult to
master, so if your syncros are in good shape, heel and toeing is easier.


P.S. Why it called double-clutching? Cause u need to clutch in 2 times!!
Hope this helps,
 

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If possible, please do not support "TF&F".

It gave bad images to all sports cars.  :angry:

Many places and laws keeps on going after any sport cars now.
 

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This is one of 54 mistakes listed on http://www.movie-mistakes.com for Fast & The Furious:

After Brian, Dom, Eddie and the Asian guy race down the street Dom starts making fun of Brian. Dom says "Granny-Clutching, not double-clutching like you should" (and everyone laughs). Double clutching hasn't been around for years, it was primarly used by truckers that didn't have good syncros on their transmissions. Granny clutching is actually faster than double-clutching, so it's a good thing that Brian was granny-clutching
 

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Discussion Starter #7
Thanks everyone for your input!  I was wondering why import tuner was making fun of that line, now I know.

 

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What't the difference between double-clutching and granny-clutching? Anyone knows?
 
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