hockeybronx
Hey a couple of my friends were talking about the benefits of double shifting. Does anybody here do it regularily?

I barely understand the concept and I also don't understand how it is both better for the clutch and better for acceleration:nut:

rage2
Do you mean double declutch? If so, I don't do it regularly because I'm not driving an 18 wheeler. My tranny (as does probably everyone on here) has synchros to take care of speed synchronization.

GTS Jeff
i double clutch my downshifts when im daily driving, but it is slower and wastes the clutch more. i only do it cuz it feels nice to have the shifter slide into gear like butter and cuz i see hardcore racers on tv doing it.

but as for dbl clutching upshifts? well, i guess thats only for when u want to drive super slow cuz u just washed your car.

gwkwan

hmm... i know how to double clutch to down shift
but how do u double clutch up shift???:confused:

t3rry
i prefer to use my brake to slow down... saves my tranny :D

rice_eater

dont worry about it man...the main purpose of a car is to slow down traffic in order to make a point...hell just learn to double clutch it in neutral and you're set

Mahk Uno
Double clutch, shit i dont even clutch coming out of a gear only going in.

DUBBED

:eek:

Mckenzie
As my tranny is aging a bit, I do double clutch to try and preserve whatever is left of my synchromesh. Shifts are smoother for sure.

I could really care less about the clutch...


"....Granny shifting...not double clutching like you should..."

-Vin Diesel (Master of going fast) :thumbsup:

rice_eater

new clutch will probably cost you as much if not more than a used tranny would it not :dunno:

mutsuraboshi

hahha... so for the record...
dubbo clutching is when you...:dunno:

Zero102
I always double clutch when I downshift or if I have been coasting in neutral for a while. My syncro's are all toast, the transmission is on it's last legs, so it needs all the babying it can get.

JAYMEZ_STi
I always do when im down shifting

Ben

new clutch installed into my car: 500 bucks (generous)

new tranny from VW, 3400USD

used tranny from VW wreckers, 1600CAD

Unfortunatly some of us wont ever see the car we drive at the wreckers, as they seem to go to some magial car heaven instead and we never see them. All the basemodel cars are at the wreckers, but I have NEVER seen the 16v's anywhere, and the trannys for them are big bucks.

Just an example.

ZorroAMG
Fuck.... I don't even need a clutch to downshift...





I do, on occasion, like to enjoy my double upshift non fat mocha with a twist of throttle.

three.eighteen.
my downshifts are sometimes heel-toe, some are double clutched

ron_cook
wat is double clutchin and how do u do it

hjr

you bairly understand it indeed. As mentioned, you probably mean double clutch (where you push the clutch twice when shifting). here is a basic explination:

Your tranny needs to be going the same speed as the engine in order to engage. When you double clutch you are taking disengaging the tranny from a low rpm and you need it to be spinning faster because you are going to a lower gear (shorter gearing). so when the tranny is disengaged you blip the throttle to speed up the tranny. then you push in the clutch to ...


do you what, fuck it. Do a search for double clutch or double clutching. im far to lazy right now to type it all out.

GTS Jeff

the same way u dbl clutch a downshift. its kinda pointless tho, cuz if u are shifting at the right speed, u need neither dbl clutching nor syncros to get into gear.

:confused: :dunno:

///M3
what exactly do syncros do??

hockeybronx

Ah you'll never let it go!

I gave her another wash today, didn't drive too slow though, the roads were pretty dry.

I'll get em next time:devil:

hjr

Manual transmissions in modern passenger cars use synchronizers to eliminate the need for double-clutching. A synchro's purpose is to allow the collar and the gear to make frictional contact before the dog teeth make contact. This lets the collar and the gear synchronize their speeds before the teeth need to engage.

cone on the blue gear fits into the cone-shaped area in the collar, and friction between the cone and the collar synchronize the collar and the gear. The outer portion of the collar then slides so that the dog teeth can engage the gear.

http://auto.howstuffworks.com/transmission4.htm


for future reference, a person should ALWAYS try checking this < http://auto.howstuffworks.com/ > site to see if it can explain things first. They put a lot of time into it and it is very useful. I use it myself when unsure about something.

air_mikey
i usually double clutch when im down shifting. its much smoother.

Ferio_vti
I like to blip the gas when I'm downshift, like going around corners. Smoother and more control when the revs are up.

jjjheimer
I double-clutch and rev match every downshift. Its the only way to drive a WRX smoothly (ie- when the wife is a passenger)

black94gt

same here 100% of the time i double clutch down, so much smoother i love it:)

hockeybronx
Hey guys I have to apologize, I just realize what I put as the title.

I meant double clutching not double shifting:nut:

Oh well at least I got some of your guys views on it.

Mckenzie

I would never find a used 6 speed tranny for sale in North America. They dont even stock the parts in North Amereica to rebuild it new. They have to come from Japan.

Rebuild = $3500 +waiting time and fucking around for parts
Clutch = $1200
Clutch with new flywheel = $2700 (I should have replaced my flywheel last time but at $1500 a pop, it is pretty expensive).

Mahk Uno

GOOD CALL:D

CycloneAWD

Gotta love those Slush Boxes huh Zorro??...But if I were you and I had your car, I would be triple clutching just to save money in the long run man...

SAiamNE
So let me get this straight...

Your comming to a red light and your in 3rd...
You push in the clutch, move shifter from 3rd to 2nd. With clutch still in rev the engine a bit and then pull out the clutch?
Is this correct?

///M3

i think its you push in the clutch, put it in to neutral, take your foot off the clutch, put it back in, and shift into 2.:dunno: am i right

Matthew
An example of double clutching for a 3-2 downshift:

- Step on the clutch
- Shift from 3 to neutral
- Engage the clutch
- Blip the throttle
- Step on the clutch
- Shift from neutral into second
- Engage the clutch

This procedure causes the input shaft on the transmission to speed up so that the relative speeds of the gears are closer when you actually engage the lower gear. It saves wear on the synchros in your transmission and results in smoother shifts. It's a much more important procedure when operating a heavy vehicle such as a 3 or 5 ton truck, and also allows shifting of transmissions with straight cut non-synchro gears, like the 1st gear in earlier heavy duty pickups (1981 F-350 for example).

The additional clutch engagement used in this procedure is not typically under much duress, so claims of wearing out the clutch through double clutching are greatly overstated.

-Matthew

INeedBoost

Think the point is to rev and match engine/transmission speed while your shifter is in neutral. Missed that part ;)

///M3

oh ya of course:D

Alpine Autowerks

Porsche fires race drivers who do this. It accelerates clutch and syncro wear and is slower .... it is not hardcore ...but out of place with modern machinery....

GTS Jeff

i guess im fired then :D

i know dbl-clutching is completely unnecessary and slower as ive said earlier, but u have to admit it is kind of fun. what im wondering is how it accelerates syncro wear . :confused:

hjr
it doesnt effect syncro wear. not by the standard method of how syncros work. they only come into affect when you go into a gear as it matches the output shaft to the speed of the gear.

Alpine Autowerks
it is a special case that applies more to porsche type syncros used in older 911's and some other euro cars. it reverses the synco parts against their "downshift" stops them moves them back against the "upshift" stop