mark kibort

the value is to be able to spin up the layshaft in the transmission and torque tube or short shaft and clutch disc (s), so that the force required to spin them up is reduced as much as possible. by going from a tall to short gear, there is greater force imparted on the synchros.
you do this by partially pushing the clutch in as it slides out of gear and you blip, (there is enough friction to spin up the clutch discs, short shaft, etc) then a full depression as it goes into gear , then a full release
this creates a double clutch like effect without having to actually push and release the clutch twice per gear change.

You basically describe a "double clutch" but that's not exactly what he is doing. (see what I wrote above for my take on it)
if he didn't want to go through the gears, he could just do once double clutch and make a shift ,skipping multiple gears. However, its easier to just get proficient in going through the gears as fast and precisely as you can.
It's a situation of a fast track and very close gear ratios and a peaky hp curve...... thinking of the only times we come down from , even up to 150mph, its only a two gear change situation to get to 2nd. ...... he is probably in that range, maybe up to 160. not sure, but that would only be for us , 3 changes... Leh has to go almost 5 changes. that 6th to 1st was almost funny!

ProCoach

Here's another good example. 2-liter SWB car at Daytona, 205/225 R6's, 2:07's all day long... REALLY nice footwork.

winders

Not that I am saying I could shift that fast even if I wanted to do so, but, in my car, with a 915 transaxle, I can't shift that fast. The balk ring design of the 915 precludes it. You have to be much more deliberate.

You should always question if you are developing bad habits when you are in the habit development phase of learning. Evaluation of what you are doing, self or from a qualified outside source, is a good thing.

ProCoach

901 box...

Rattle

Ah, there is less opportunity for me to screw up...

winders

And?

333pg333

I think Scott was talking about Leh Keen and Peter assumed it was about the guy in the early 911.

I don't think there is any real mystery to these good examples of heel / toeing. Having the responsiveness of the higher c/r n/a motors certainly helps during the clutch in/blip phase. Seat time is also pretty important.

Adam@Autometrics

Leh is definitely re-engaging the clutch in between shifts. All of the top drivers will, as it is necessary to lock the differential for braking stability.

The throw on the clutch is much shorter than a street clutch. There is a pedal stop around 1/4" after the disengagement point.

Fracture

^^^^^^^^
that's funny stuff !!

Geneman

adam thats what i thought... without locking the diff, during braking it would appear you would negate all the help of the LSD. it just did not seem his leg was giving far enough to allow engagement. i can see the blip for jacking the rpms on the layshaft as noted by others also... its all combined... while also smooth braking ..just incredible muscle memory to complete about every other turn. thats why i should stick to DE for the first ten years or so... ..but i would rather provide passing practice for the real racers.. its just my contribution!! thanks again to all who responded to this query. see you at sebring pca 48 for some heeltoe practice

mark kibort

Yep! you absolutely want the rear end planted as you approach the turns with that amount of speed and dece rates. plus, add in the trail braking and you don't want to be disconnected.

yep, big difference in some cars. including the 928 which is really sloppy compared to the newer 911s (post 85 era) and cars like the BMWs. Its an art form to do the quick shifts in the street set ups, no so much with the race cars.

Dr911

I have the 915 trans as well. Slow going, long throw.
However, since I'm allergic to money shifting, I'm open to working on sequential now.
The good news: heeltoe downshifting is fun.
Now I get to practice 4 downshifts at each traffic light.
Hope I don't get caught grinning like an idiot

Dr911

One thing brought up by Kibort's post preceding:

I was cautioned by a classroom instructor about going from 5th to 3rd as being far more risky than going from 4th to 2nd.

Her rationale was that there is a greater likelihood going into first by mistake.
She drives a corvette, which I have never driven but I think it might make sense in some cars that have a very light shift.

When I drive my son's E36, I have once or twice almost ended up in 1st...It's a very light touch compared with my 85 911.

For my car with the 915 trans getting into first gear is an act of faith, so I don't worry that I will end up going 5th to 1st.

winders

With an active 1st gear 5 speed 915 and the Rennshift shifter I have in my race car, it is harder to mess up a shift. At the tracks I race on, I don't use 5th gear, but I do use 1st. The Rennshift has strong springs trying to center the shifter in the 3rd/4th plane. Shifting from 4th to 2nd is easy. But, as I said, I only do that in one turn and on one track. Otherwise, I am sequential.

Veloce Raptor

Many cars including the E36 have shift mechanisms with springs that auto-locate the shifter when in neutral to the dead center of the gate. IE if the trans has 6 speeds it would be auto located to midway between 3rd and 4th vertically. As such, if folks just slightly slow down their shiftinhg, take their time a tiny bit, and allow themselves to feel when the shifter gets into those spring loaded center zones, it is a lot easier to (a) locate the next gear and (b) avoid a mis-shift