I always hear people saying do you know how to double clutch. What does this mean exactly? Is it bad for your car etc.?

 

When changing gears, push the clutch in once... then pop the car out of gear into neutral, then blip the gas so that your engine RPM's match the RPM's that the engine would be in once you put the car into the next gear that you are shifting to, then put the car into that gear and let the clutch up.

Here is an example and the scenario is as follows:

You are driving with car in 2nd gear and car at 3500 RPM and decide you want to shift up to 3rd gear

1) Push the clutch in and let off the gas at the same time
2) Once the clutch is fully disengaged(clutch pedal is to the floor), shift the car into neutral
3) Allow a few brief moments for the engines RPM's to fall close to about 2500 RPM's(2500 RPM's is specific only to this situation) since that's about where your car would be at if it was in 3rd gear at the current speed.
4) Once the RPM's have dropped to the appropriate level(2500 in this case), blip the throttle a bit so that the RPM's stay at that level and don't continue to drop
5) Push the clutch in and then shift the car into 3rd gear with your foot still on the gas just enough to keep it at the desired RPM's
6) Let the clutch out

The whole point is to try to reduce wear and tear on your synchros as you're shifting into gear by making sure that your RPM's are as close to the speed of the transmission as you're putting the vehicle into the next gear and it also prevents unnecessary wear on your clutches throwout bearing by you holding the clutch down for a few extra moments in between each shift to wait for the RPM's to drop to the desired level. It should also make your shifting a bit smoother if you are good at rev matching(car won't buck as much between shifts).

Hope that explanation wasn't too confusing.

 

It's my understanding that double clutching is completely unnecessary with the cars these days. I think that the synchros and clutches are strong enough to handle shifting without rev-matching.

 

YOur completely right Jellysick, its not needed with cars these days. Though with down shifting I rev match like 90% of the time, not with double clutching becuase that is unnecisary (sp?). The only time I had to double clutch was when driving trucks, even then I hardly did it because I power shifted everything. Sezki, dont even worry about double clutching, you dont need to do it.

 

i doubled clutched with this car the first week i had because the clutch was strange to me and i would get a lot of ruff shifts into second gear. Now that i figured this tranny out i dont bother with it anymore.

 

loved double clutching when I had the tilton lightweight clutch and flywheel.. i didnt even realize that what I was doing could be considered double clutching.

 

Synchromesh trannies have only been out for around 30 years. Prior to that you had to double clutch. You can easily rev match by the heel and toe method, and don't have to rely on double clutching. For those that want a technical description of why double clutching is a waste of time:

http://www.singster.co.uk/mascot%20m...003%20(4).html

 

I think the people who ask you this watched fast and the furious too much

 

lmao.. for real

 

Yeah, for Dump Trucks only.

 

Nooooooooooooooooooooo. Monicaaaaaaaaaaaaaaaaaaaaaaaaaa!

 

Its not how you stand by your car, its how you race your car.

 

downshifting however is awesome !

 

The whole point is to try to reduce wear and tear on your synchros as you're shifting into gear by making sure that your RPM's are as close to the speed of the transmission as you're putting the vehicle into the next gear and it also prevents unnecessary wear on your clutches throwout bearing by you holding the clutch down for a few extra moments in between each shift to wait for the RPM's to drop to the desired level

Actually the opposite is true. Here's an excerpt from the tool box that I referenced earlier:

If your car has a synchromesh gearbox it is recommended you do not double-de-clutch as this can cause undue wear on the synchro rings.

 

That is NOT double clutching!

Double clutching is exactly what the name implies: You depress and release the clutch pedal TWICE! Not once, as your description implied. What you described is commonly known as "Rev-matching" or "heel-and-toe" when done while braking.

Double clutching should not be performed on a G35 or any other modern car with a synchromesh gearbox. Rev-matching, on the other hand, helps to provide smooth shifts and works well with synchromesh gearboxes.