Heel-Toe Shifting
03-23-2009, 11:17 PM
#31
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"Hammer the throttle" came from the point that someone had about the engine getting fuel faster and responding to throttle input. I was basically asking if that was a desire in a turn, as I dont think it would be either. Certainly we are talking on no shift turns, but Im still trying to wrap my head of how its different than just lift, or is it a way to cheat brake bias and really do a late brake, trail brake turn in because the LFB negates the bias to a point.
Ill re-read your post as to why again.
I also see a lot of folks testing out of habit the brake with the left foot to make sure there is a pedal there. I dont do this either. I guess Ive never had the brakes not be there, becuase i guess its good to know a little earlier rather than at the 100ft marker!
EDIT: I read what you said again and still dont get how its going to be any different unless you mix what you said with what Kurt said, and then you are allowing the fronts to be used without using much rear (Kind of addressing a dynamic brake bias function). one thing that comes to mind is when you are off the brakes (either way) if you are LFB, you are obviously on the gas much quicker. (like the time you would have by not having to shift) , if through the corner, you would be applying gas at that point. there are some parts in the early corner that im kind of neutral and not on the gas anyway, so this might not help, but in thinking about it maybe with a longer LFB, im on the gas earlier and ............hmmm. Ill have to look at some video and see how this would work. anyone have some left foot braking video of laguna or Sears?
Ill re-read your post as to why again.
I also see a lot of folks testing out of habit the brake with the left foot to make sure there is a pedal there. I dont do this either. I guess Ive never had the brakes not be there, becuase i guess its good to know a little earlier rather than at the 100ft marker!
EDIT: I read what you said again and still dont get how its going to be any different unless you mix what you said with what Kurt said, and then you are allowing the fronts to be used without using much rear (Kind of addressing a dynamic brake bias function). one thing that comes to mind is when you are off the brakes (either way) if you are LFB, you are obviously on the gas much quicker. (like the time you would have by not having to shift) , if through the corner, you would be applying gas at that point. there are some parts in the early corner that im kind of neutral and not on the gas anyway, so this might not help, but in thinking about it maybe with a longer LFB, im on the gas earlier and ............hmmm. Ill have to look at some video and see how this would work. anyone have some left foot braking video of laguna or Sears?
But the weight transfer is not the same. See my earlier post for why. And you don't need/want to hammer the throttle. But LFB in places like this (assuming no gear change) allows more throttle thru midcorner, and thus more speed carried to the point where you actually can go to WOT. If you can carry even 10% more gas thru the entirety of the corner, that is an advantage.
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Last edited by mark kibort; 03-23-2009 at 11:35 PM.
03-24-2009, 08:13 AM
#32
Mr. Excitement
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I can certainly see tricking the bias setting, but doesnt any deceleraton create weight transfer? (whether rear or front brake initiated)
I guess there are two kinds of thoughts here. at laguna, as VR has mentinoed. I love to see brake lights out of turn9. it means the guy in front is not confident in the grip, as it is a little bit of a daunting sweeper. however, his point is that i wouldnt have to lift as much which does lift the rear end up, ill admit, and it might stay more planted if i do the same LFB that creates the same amount of decel as Im used to by lifting? If that is the case, am i not counter acting the rear brake bias by doing so and just applying more braking force in front as little as it is, on the slight decel around turn 9 at laguna ?( exit of the corkscrew down hill left for those not familar with this turn.)
Also, there are turns like turn 8 at Thunderhill that could be a nice candidate for testing this out. currently, its a lift and quick stab of the brakes from 120mph to 100mph. left foot braking could allow less rear braking force on the approach.
VR also mentioned turn 3 at laguna. Its a pretty dramatic stab, threshold brake. pretty traditional, as I dont think that would be a likely candidate for LHB, but turn 4 might be as it is much faster and a much quicker stab of the brakes.
I know what you mean about knee jerk reaction of the left foot. I do a lot of left foot braking when bedding my brake pads and the foot feels pretty nimble. Ill do some left foot braking turns on the way to the track this weekend to practice. I think turn 10 at sears might be a nice candidate, but dangerous!!
mk
I guess there are two kinds of thoughts here. at laguna, as VR has mentinoed. I love to see brake lights out of turn9. it means the guy in front is not confident in the grip, as it is a little bit of a daunting sweeper. however, his point is that i wouldnt have to lift as much which does lift the rear end up, ill admit, and it might stay more planted if i do the same LFB that creates the same amount of decel as Im used to by lifting? If that is the case, am i not counter acting the rear brake bias by doing so and just applying more braking force in front as little as it is, on the slight decel around turn 9 at laguna ?( exit of the corkscrew down hill left for those not familar with this turn.)
Also, there are turns like turn 8 at Thunderhill that could be a nice candidate for testing this out. currently, its a lift and quick stab of the brakes from 120mph to 100mph. left foot braking could allow less rear braking force on the approach.
VR also mentioned turn 3 at laguna. Its a pretty dramatic stab, threshold brake. pretty traditional, as I dont think that would be a likely candidate for LHB, but turn 4 might be as it is much faster and a much quicker stab of the brakes.
I know what you mean about knee jerk reaction of the left foot. I do a lot of left foot braking when bedding my brake pads and the foot feels pretty nimble. Ill do some left foot braking turns on the way to the track this weekend to practice. I think turn 10 at sears might be a nice candidate, but dangerous!!
mk
03-24-2009, 08:51 AM
#33
Burning Brakes
Thread Starter
Bob,
You wrote "Don, I think he is getting the brakes pumped up to get rid of pad knock. " I once rode with a club racer from TroySport in a great little 914/6 at Roebling. There was a cone on the side of the track halfway down the main straight . Every time we passed the cone, he'd apply light brake with his left foot. After the run I asked him about it. He said he was making sure he had brake pressure (had not boiled his brake fluid) before the next brake zone. Of course at RR at the end of the main straight there is a short run-off then a large berm. Hitting that berm would leave a mark.
You wrote "Don, I think he is getting the brakes pumped up to get rid of pad knock. " I once rode with a club racer from TroySport in a great little 914/6 at Roebling. There was a cone on the side of the track halfway down the main straight . Every time we passed the cone, he'd apply light brake with his left foot. After the run I asked him about it. He said he was making sure he had brake pressure (had not boiled his brake fluid) before the next brake zone. Of course at RR at the end of the main straight there is a short run-off then a large berm. Hitting that berm would leave a mark.
03-24-2009, 12:38 PM
#34
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I've only done this in karts. explain to me what happens with left foot braking that cant be done with lifting. are you really concerned with keeping the gas on so that that there is no lag with when you do get on the gas, if you were left foot braking? or is it a balance of power thing, where the gas and the brake applied at the same time, basically creates less rear brake force bias.
I do like to do do it with karts, but the centrifugal clutchs work better when the engine is spinning faster, so you keep the thing floored and use the brakes which just over power the rear forces. I would think the shifter Karts do something similar, just to keep the power applied.
I dont left foot brake, but ive seen it done on Tv.
mk
I do like to do do it with karts, but the centrifugal clutchs work better when the engine is spinning faster, so you keep the thing floored and use the brakes which just over power the rear forces. I would think the shifter Karts do something similar, just to keep the power applied.
I dont left foot brake, but ive seen it done on Tv.
mk
One other comment for an earlier question:
Yes, in heel and toe, you can apply constant pressure while braking and blipping - it just takes a lot of practice. You have to forget about turning fast laps and just practice the heel and toe until you have it, then it's second nature and you can go back to being fast. There's a video on here somewhere of Leh Keen (kingleh) at Sebring, he goes 6-5-4-3-2 with a clutch release in between every gear, so fast and so smooth I almost gave up driving the first time I saw it.
03-24-2009, 01:14 PM
#35
Three Wheelin'
"Hammer the throttle" came from the point that someone had about the engine getting fuel faster and responding to throttle input. I was basically asking if that was a desire in a turn, as I dont think it would be either. Certainly we are talking on no shift turns, but Im still trying to wrap my head of how its different than just lift, or is it a way to cheat brake bias and really do a late brake, trail brake turn in because the LFB negates the bias to a point.
03-24-2009, 04:47 PM
#37
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This has been stated by several others in this thread in several different ways, but I'll state it like this. With LFB, there is no "coasting" time transitioning from brake to throttle. And as a result, it keeps the car more balanced since there is no distinct transition from brake to throttle. As others stated, it will only work in braking zones and corners where no gear change is required.
Having said all of this, I still suck at LFB and am still working on the technique.
Having said all of this, I still suck at LFB and am still working on the technique.
03-24-2009, 07:20 PM
#38
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We used LFBing all the time at Daytona in the draft. If you're sucking up on the back end of the car in front of you and are either boxed-in or don't have the time to make the pass before you have to enter the infield or chicane than we'd use a little LF to keep from running into the guy. It also allowed us to bump draft the car in front of us w/o hitting him so hard he lost control. Never really did it anywhere else like Sebring or Moroso though. Have to give it a shot and see if it helps. Maybe in the esses at Sebring?
03-24-2009, 07:56 PM
#39
Rennlist Member
That makes sense. I think turn8 at thunderhill fits the bill easily!
I bet the great qualifier are those turns where there is some debate that some can take them flat out , when maybe they dont.
mk
I bet the great qualifier are those turns where there is some debate that some can take them flat out , when maybe they dont.
mk
There are two big advantages. In a situation where you would normally use a slight lift you can replace it with a slight brake apply with your left foot. Any engine braking is negated so the motor doesn't have to spin down and then back up. Its useful on quick transitions where you need to slow the vehicle slightly. The other advantage will be in the time you save having to transfer you right foot from the gas to the brake and back again. With LFB the transition can be almost instantaneous
03-24-2009, 07:58 PM
#40
Rennlist Member
got it and will try this season.
Kingleh "lee".......amazing! Like to see him try that in a 928 with stock pedals
mk
Kingleh "lee".......amazing! Like to see him try that in a 928 with stock pedals
mk
Hi Mark, this one falls into the "try it - you'll like it" category. You have to play around quite a bit to get used to it, but you can really keep the car balanced along a continuum using the throttle and the brake, and then the transition from braking to accelerating is incredibly smooth. Think about the perfect trail brake - with RFB the transition from brake to throttle always has a lag in it as you move from brake to throttle, with LFB there is a seamless transition and the car really does feel better. In the sports racers with the sequential tranny, or the Camaro with the dog box, I only use the clutch to get going, from then on it's left foot only on the brakes and it is more fun than words can describe.
One other comment for an earlier question:
Yes, in heel and toe, you can apply constant pressure while braking and blipping - it just takes a lot of practice. You have to forget about turning fast laps and just practice the heel and toe until you have it, then it's second nature and you can go back to being fast. There's a video on here somewhere of Leh Keen (kingleh) at Sebring, he goes 6-5-4-3-2 with a clutch release in between every gear, so fast and so smooth I almost gave up driving the first time I saw it.
One other comment for an earlier question:
Yes, in heel and toe, you can apply constant pressure while braking and blipping - it just takes a lot of practice. You have to forget about turning fast laps and just practice the heel and toe until you have it, then it's second nature and you can go back to being fast. There's a video on here somewhere of Leh Keen (kingleh) at Sebring, he goes 6-5-4-3-2 with a clutch release in between every gear, so fast and so smooth I almost gave up driving the first time I saw it.
Last edited by mark kibort; 03-24-2009 at 09:12 PM.
03-24-2009, 08:56 PM
#41
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03-25-2009, 01:26 PM
#42
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Besides all the LFB and HT techniques, this clip hits me strange. It looks like a 944, but my tranny doesn't shift that fast. If I tried to shift that fast my synchros would be screaming in pain. Is this guy running some kind of special box? Also, why does the instructor start out in one language (sounds like German) and finish in English? And why does the driver hover over the clutch with his foot? I think I put mine back on the dead pedal. But now the next time I go out, I'm going to be thinking what I do with my feet. I definitely don't do the contorted HT. Mine's more of a toe - toe maneuver. It would be fun to video what I'm doing in there. It may scare me.
