car talk says double clutching is bad?

[Wh33lhop]

double-clutch when upshifting anyway, which is presumably what you do during a drag race.

I hope you're joking.

[nando]

my zf320 has 95k miles on it, and the clutch has about 15k miles on it w/ a lightweight flywheel.

so it's just broken in then. :p

[daniel]

^Unless you bought your car from a no driving track monkey who had the trans trashed at 123k miles.

my zf320 has 95k miles on it, and the clutch has about 15k miles on it w/ a lightweight flywheel.

[RangerGress]

that's the common name for it, but since I don't actually use my heel, rev matching is a better term. It's more like pinky toe/ball of foot. ;)

Rev matching isn't a better term because no one will understand that you mean HnT. Most folks don't use their heels with modern pedal systems, but they still understand what the phrase means. Most people HnT by braking with the ball of their big toe and (if necessary) rotating the foot a little such that the outside of the foot can hit the gas. If you pedals are set up well, you don't move your heel hardly at all, you just kind of roll your foot, instead of rotating it.

Which sounds pretty much what you were describing.

When I say rotate I mean around the axis of your shin, whereas by rolling the foot I mean around an axis that goes from toes to heel.

There's a lot of confusion about what HnT and double-clutching means. Most folks that use those terms are really just blipping the gas during downshifting.

Now don't leap on my ass shouting "I KNOW WHAT < > IS". If you know what HnT and double-clutching is, then obviously I wasn't talking about you.

[z31maniac]

^Unless you bought your car from a no driving track monkey who had the trans trashed at 123k miles.

[nando]

like I said, unless your Getrag 260 has 500,000 miles on it, synchro wear probably isn't even on the radar yet.

as long as you aren't just putting it in a lower gear and letting out the clutch, whatever method you choose is just fine. heel/toe is likely better if you are braking into a corner, DC may be better for slower driving where entry speeds and corner exit are perhaps not a big priority.

[daniel]

I really can't make this any easier for those of you who believe DC'ing will harm synchros.

people aren't saying that. they are saying that it wears out other parts of the drivetrain, instead, like the clutch, and that it is better to put wear on the synchros and just rev-match instead of DC.

[HiTheNameIsBJ]

Not double clutching like you should, not to mention the piston rings you fried now me and the mad scientist gotta rebuilt the block.

[Beach Bum]

Double clutching SAVES synchros; to all of you who thing DC'ing is going to burn them faster, you're simply wrong.

I'm going to make this easy for all of you. Read these.

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

http://www.mproved.com/dblcltch.htm

"Double-clutching is the proper way to downshift at speed without placing excessive wear on the transmission's synchronizers."

If you examine how a transmission works and understand it, and then take the time to understand how double-clutching manipulates the parts and forces in the drivetrain, you'll see that the above statement is true.

I really can't make this any easier for those of you who believe DC'ing will harm synchros.

[daniel]

Quoted for un-truth. Sure, some cars are more difficult than others to blip into first gear at a roll, but if you can't do it with your E30 via a simple rev-match, then you've probably already beat-up your transmission trying to learn the useless art of double-clutching a synchro'd tranny.

alright, well considering how much easier it is to shift into first gear when DCing, i see no reason why someone should just rev-match to get into first.

i don't see how DCing is useless with a synchro'd tranny when downshifts are much much smoother when executing a DC correctly. if one is going for smoothness, then DC, if you are going for convenience, then rev-match.

[WillisE30]

Quoted for un-truth. Sure, some cars are more difficult than others to blip into first gear at a roll, but if you can't do it with your E30 via a simple rev-match, then you've probably already beat-up your transmission trying to learn the useless art of double-clutching a synchro'd tranny.

This pretty well summarizes the entire three page thread.

[ieatpeople]

i wear boots while driving to/from work, and i sometimes have a problem heel/toeing my e28, but usually i just rev match and then use the brakes to get the correct angle on the offramps, followed by the slideways action.

[cagedbunny]

if you want to get into first gear while moving over like 5mph, double-clutching is what you need. its fun to do this.

Quoted for un-truth. Sure, some cars are more difficult than others to blip into first gear at a roll, but if you can't do it with your E30 via a simple rev-match, then you've probably already beat-up your transmission trying to learn the useless art of double-clutching a synchro'd tranny.

[daniel]

do you wear boots when you drive or something?

try a driving shoe like puma, piloti, etc. or even a skater shoe. I'm size 13 as well, you can definitely heel toe with feet that big.

i wear adidas sambas. i can ball-toe just fine, just not heel-toe, especially since my feet naturally point outward.

[nando]

ah, now i get the 2001 thing. no, i didn't really listen to Vin there when he said "not double-clutching like you should!". and i never double-clutch when upshifting anyway, which is presumably what you do during a drag race.

if you want to get into first gear while moving over like 5mph, double-clutching is what you need. its fun to do this.

and for the record, i have size 13 feet and there is no way i can heel-toe. i care barely even fit my whole foot down there with a shoe on.

do you wear boots when you drive or something?

try a driving shoe like puma, piloti, etc. or even a skater shoe. I'm size 13 as well, you can definitely heel toe with feet that big.