Downshifting Habits?
#61
Rennlist Member
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.
Michael, he is "dipping" the clutch, i.e. only depressing partially, then releasing fully to spin the intermediate shaft up and to "reconnect" the drivetrain to the wheels.
He prepares for every brake zone requiring a downshift (or multiple downshifts) by lifting his left knee up as he pulls his left foot off the dead pedal (where it is braced in between using it for this purpose and for upshifts), in preparation for "dipping" the clutch for each and every downshift gear selection.
Fair number of pro drivers do this.
He prepares for every brake zone requiring a downshift (or multiple downshifts) by lifting his left knee up as he pulls his left foot off the dead pedal (where it is braced in between using it for this purpose and for upshifts), in preparation for "dipping" the clutch for each and every downshift gear selection.
Fair number of pro drivers do this.
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!
Last edited by mark kibort; 01-18-2015 at 11:12 PM.
#62
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Here's another good example. 2-liter SWB car at Daytona, 205/225 R6's, 2:07's all day long... REALLY nice footwork.
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#63
Race Car
Yes, Leh is moving his feet and his hands about two to two and a half times quicker than most good club racers. He is dipping the clutch, selecting the lower gear (in order), stabbing the accelerator, releasing the clutch, ALL while maintaining steady and HIGH pressure on the brake pedal. This synchronicity can be practiced and learned, but you need a VERY clear vision of what you're doing before you begin to attempt to do it. It's not magic, but it is magical when done well. Leh, Seth, Brady Refenning and a bunch of people do it automatically.
To the OP, you are not "doing it wrong." Do not question whether you are developing bad habits. Just relax...
To the OP, you are not "doing it wrong." Do not question whether you are developing bad habits. Just relax...
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.
#64
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901 box...
#67
Rennlist Member
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.
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.
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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.
The throw on the clutch is much shorter than a street clutch. There is a pedal stop around 1/4" after the disengagement point.
#70
Rennlist Member
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
#71
Rennlist Member
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.
The throw on the clutch is much shorter than a street clutch. There is a pedal stop around 1/4" after the disengagement point.
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.
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.
#72
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
#73
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.
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.
#74
Race Car
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.
#75
Rennlist Member
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.
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.
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