Driving Advice

[Icemizer]

A terrible editing job on the car chase in Bullitt. The black car loses 5 hub caps, they pass the same green beetle 4 times over the same hill, the positioning of the actors in the black car is inconsistent, and there was an obvious crash of the black car into a parked white car.
That said its still one of the more exciting car chases in cinema history.

Sponsored

 

[BCeagle08]

Never double clutch on upshifts, double clutching is optional on down shifts if you are going to end up in a high rpm.

Think of double clutching like double rev matching. One rev match to get the gears in the transmission aligned, and a second rev match to get the engine and the transmission aligned. To do a double clutch downshift, do the following:

1) Clutch in, gear selector into neutral
2) Clutch out, rev engine to RPM the car will be at when you eventually engage everything together
3) Clutch in, gear selector into desired gear
4) With clutch still in, rev engine to RPM match again
5) Release clutch

Make you sure are doing all this heel toe while threshold braking

 

[10splaya22]

I'm very clear on what you think.

What I mean is that there are lots of circumstances where I double-clutch on downshifts and I disagree with your opinion that it slows anything down. There's no reason to down shift three times with fast clutch pedal movement if you are down shifting from 5th to 2nd, for instance.

Using heel and toe to get the revs up can also help synchronize the speed of the transmission parts if the shifter is in neutral and the clutch is out when you use the heel and toe technique. It's a way of putting less stress on the transmission that doesn't slow you down.

I see. So for instance from a 5-3 downshift under braking, you prefer to go from 5-3 and double clutch, therefore shifting once?

I guess I just prefer to go from 5-4, then 4-3 and rev match twice. It seems easier for me that way.

 

[MagneticA]

Never double clutch on upshifts, double clutching is optional on down shifts if you are going to end up in a high rpm.

Think of double clutching like double rev matching. One rev match to get the gears in the transmission aligned, and a second rev match to get the engine and the transmission aligned. To do a double clutch downshift, do the following:

1) Clutch in, gear selector into neutral
2) Clutch out, rev engine to RPM the car will be at when you eventually engage everything together
3) Clutch in, gear selector into desired gear
4) With clutch still in, rev engine to RPM match again
5) Release clutch

Make you sure are doing all this heel toe while threshold braking

Any harm in skipping the first part of #1? I often put the car into neutral (while downshifting) without using the clutch. There's a certain point where there isn't any resistance and it easily pops out. I've done this for years and haven't seen any negative consequences, but that doesn't mean there aren't negative things happening that I don't know about.

 

[Herr_Poopschitz]

Dad had a 1930 Chevrolet that req'd double clutching. Driven a few pre-war tractors that needed it too. Why you'd do it on a modern synchro'd car other than to say you do is beyond me.

 

[BCeagle08]

Any harm in skipping the first part of #1? I often put the car into neutral (while downshifting) without using the clutch. There's a certain point where there isn't any resistance and it easily pops out. I've done this for years and haven't seen any negative consequences, but that doesn't mean there aren't negative things happening that I don't know about.

I don't know enough to tell you if it's really something to worry about. Mechanically you are putting more pressure on the dog teeth than if you used the clutch, but I don't know if it's significant enough to matter.

Sponsored