Double clutching, Heel Toe downshifts

[Land Yacht]

I know less about manual transmissions than anybody. Never owned one. I have driven them on a few occations though.

Before synchronizers double clutching was needed to keep from grinding gears on downshifts, but not on up-shifts? The idea being to match the turning speeds of the two gears so they mesh without grinding. Probably the only time anyone would still do it is on a tractor, or a vintage car. Is there another purpose for it?

Heel-toe downshifts, or working the brake and gas at the same time so that you can enter a corner braking, and at the same time blip the gas pedal with the clutch pushed in before downshifting to try and bring the engine speed up to match the speed the lower gear will want to turn at, so that when you make the down shift to leave the turn there is no lag from being connected to the engine turning too slow. Does anyone do this in real life driving or is it just a race track deal?

It's all Greek to me, but interesting as heck.

[enjenjo]

Big truck are very often double clutched. On both up and down shifts. A lot of drivers say they don't do it, but if you watch them drive, they are doing it without thinking about it. Big rigs do not have syncronizers.

On doing hell and toe, unless you are getting after it, not really necessary. I have done it, but it doesn't come up much in normal driving.

I had been driving 10 years before I owned a car with an automatic trans.

[Carnut]

I drove a stock Model A to college for 4 yrs.

Non syncro trans ain't a whole lotta fun in modern traffic.

But ya do get used to it after a bit.

Heh, heh, the sporty car types do talk of using that heel n toe thing when they are getting with the program.

Only time I've ever done the heel n toe thing was when I was just trying to keep a balky missing engine running. Strange how often I've had to do that.

[kb426]

I'll add something to this that is completely different. I ride sport bikes, alot. The newest models have "slipper clutches". Not to be confused with the clutch that I ran in the dragster. Their purpose is to keep the back tire from locking up on downshifting. I have older bikes and I double clutch to avoid that situation. I still double clutch some when driving my 32 when down shifting just because I have been doing it on the bikes for ever. I'm old enough to have driven non syncro trans in cars, pickups, and heavier farm trucks. It was just how you drove them to avoid looking like a beginner.

[taxpyer]

I have driven log trucks , trains and lowbeds for years in very mountainous terrain and for the most part never used the clutch at all except for starting or stopping.  The technique used most was the brake /throttle method to keep engine rpm up and to shift as smooth as possible and retain consistent torque. Got so you would shift hundreds of times a day and not really pay much mind to it other than listening to your rig.  
As for the straight cut transmissions, I drove old Euclids, 20-30 ton models with the exhaust straight up through the hood. They had a staight cut five speed in them and you double clutched up and down with them but you could slip in the odd brake/throttle shift the on occassion. If you blew a down shift you could have a runaway if you were not on the bit cause the brakes sucked. :oops:
That was in the so called good old days,,(glad they are over)

[Land Yacht]

I keep toying with the idea of buying a beater 4cyl manual to force me to learn to drive one. That plus having a second car so I can work on the primary when it needs service. I hate having other people work on my truck. Weekends aren't always long enough to get stuff done. Trying to stick to domestic, was thinking either Saturn or Ferd Escort.

[Crosley.In.AZ]

A fellow at my work  has  2 daughters ; both now  in their  early 20's.

they learned to drive with standard transmission in S-10 truck with 4 cyl...

The guys they dated could not drive a stick shift and the girls loved it.  They had fun teasing the guys that could not drive a stick shift