|
|
|
10-05-2009, 08:59 PM | #23 | |
Car Geek
4132
Rep 3,829
Posts |
Quote:
Heel moves a bit backwards and forwards on the carpet over the full range, but not if you don't take the clutch all the way to the floor (usually I go about 2/3 down under normal fast shifting, only using the full range in 1st to move away), but ankle flexes quickly from about -20 degrees to +40 degrees - easy when you are sitting close to the pedals with the knee somewhat bent with the clutch fully depressed. Thighs always stay in contact with the seat, never lifted. When you are tightly strapped in with a very deep racing seat (not on the 135i), it is hard to lift the thighs off the seat anyway. |
|
Appreciate
0
|
10-05-2009, 09:04 PM | #24 | |
Car Geek
4132
Rep 3,829
Posts |
Quote:
Although this is a "heel/toe" technique taught in HPDE, it may more properly be called "side-of-foot/toe" |
|
Appreciate
0
|
10-05-2009, 11:09 PM | #25 | |
Major General
894
Rep 7,047
Posts |
Quote:
Also, I don't lift my thigh the way you make it sound. It's a simply slight lift, using the knee as something like a "pivot" point. That movement on the carpet is where jerky clutch use is happening. It's just not smooth due to the friction caused by your heel trying to slide on something not designed to let it slide. Maybe if you adapted something slick like those furniture moving sliders to your heel, that would allow the heel to slide more smoothly. I've tried the heel planted way and it's just inaccurate, odd, slow, and feels like all manner of incorrect. I've tried to make it work just to see if I can, but in the end it was pointless in my experience. I've had much better success in certain cars, namely the RSX and Civic Si due to how light the clutch action is, and how short the pedal travel is. In the 1 there is about 50% wasted travel that makes for a long pedal throw and a very awkward position at that. Overall, if it works for you then it works for you. But, I wouldn't recommend to new manual drivers that that is the correct technique. I can speed shift as well using the standard method of heel off the floor. If you know where the engagement point is it makes for very fast shifts. This could be because of how close one sits relative to the pedals. Maybe your short overall and thus you have to sit close and can't use your leg to be the muscle behind the clutch? I sit in a good position that makes heel off floor clutching very intuitive, controlled, and fast. My leg doesn't sit above the pedal as is typical in a truck setup where you are lifting your leg to operate the clutch. The position in my 1 is more parallel than that, so clutching is more of a knee and hip flex/pivot. I do recall that heel planted worked better in my 325i after I set up a nice clutch stop that reduced travel a good bit. I made a clutch stop for my 1 as well, but the position is different than the 3 series. I understand and accept that it 'can' be done, but I just don't find it more effective, so there is no appreciable reason to do it. It could also be how we differ in how we use our clutch. I like to be able to modulate it where needed, instead of treating it like an on/off switch. Coming hard into a turn with a good rev match and heel/toe, the clutch requires some finess too, at least for me it does, as I can keep the chassis from tweaking like it would if I just pushed in and let it off quickly for turns. IN a flat our straight 1/4 mile it's more in/out as fast as possible, except for the launch. |
|
Appreciate
0
|
10-05-2009, 11:16 PM | #26 | |
Brigadier General
166
Rep 3,496
Posts |
Quote:
and for the record, i have only had these problems with this car, not the other plethora of exotic MT vehicles i have driven in the past
__________________
some italian, german, and japanese ones; and on order more of the same
|
|
Appreciate
0
|
10-06-2009, 12:33 AM | #27 | |
Car Geek
4132
Rep 3,829
Posts |
Quote:
In terms of strength, ankle muscles have less movement than leg muscles, but mine can certainly flex over the full range with 100kg of mass on each leg - about the strength of my leg muscles (try standing on your tip-toes and moving up and down on one foot). I find in my project car seat that it is tight enough that I can stand up with the seat still attached to my (rather narrow) backside if it isn't bolted in the car, so moving the upper leg in this case is not easy. My clutch ankle flex technique is more like that used in a formula car, where you also have limited leg movement. I only modulate the clutch when moving off, but apply no power between shifts when shifting quickly, as I would smoke the clutch quickly in the Z4M if I did this at 8000RPM. If the revs are matched, there is no jerking without clutch modulation (although the revs do change much quicker in the ///M than most other cars). Can't say if the shifts can be as fast in the 135i as they are in the ///M, as it'll still be a month or so before it arrives. The down-shift technique in the ///M that works well for me is both feet flexing from the ankle with the minimum of movement heel-toeing under heavy braking and a quick shift with a rapid ankle flex on the clutch. Efficiency of movement while on the track when I'm straining against the seat belt under maximum braking from 220km/h to 110km/h into the first corner after the straight while making 2 gear changes, works well. |
|
Appreciate
0
|
10-06-2009, 12:44 AM | #28 | |
Major General
894
Rep 7,047
Posts |
Quote:
He wears big shoes. I'm just busting yer balls. I kid. |
|
Appreciate
0
|
10-06-2009, 01:18 AM | #29 | |
Major General
894
Rep 7,047
Posts |
Quote:
But, that doesn't translate to how much leverage you can exert when flexing your foot to move weight. From working out I know that I can move much greater weight with my quads than with my calf muscles. It's the calfs that you are using when you pivot at the ankle and push with the front of your foot. In your case, I'm sure your calves are stronger than most other daily drivers as you exercising them with your technique. But, in body building there are exercises for the calves and I can push a lot more weight with my quads and gluts than with the calves. When you stand on one leg on your tiptoes, the majority of your weight is still being supported by your quads and gluts. The rising up and down of your weight with the flexing of your foot serves to generate force to make that motion, but again, your weight is still being supported by the larger muscles. If your calves are as strong as your quads and gluts, then either you have skinny weak quads and gluts, or your calves are MASSIVE and look like overstuffed double footballs when you flex. What lb clutch are you using? It sounds like it's just 20lbs. Are you trying to make me believe that our clutch is as good as what would be in a real race car? F1, I assume that's what you mean with "formula car"?, don't use a clutch, at least not the modern setups. And back in the days of clutches, those were setup to have VERY short travel, nothing like what we have in our cars, at least what we have in our 1 series. |
|
Appreciate
0
|
10-06-2009, 07:07 AM | #30 | |
Major
199
Rep 1,457
Posts |
Quote:
My foot is on the ground while using the accelerator, while braking I lift my foot, brake very similarly with an angle as you said however my heel is on the accelerator for more control on gas, and I pulsate by putting my heel down and up. Similar to this video. Ignore the title of the video. http://www.youtube.com/watch?v=0j-3x...aynext_from=PL
__________________
|
|
Appreciate
0
|
10-07-2009, 12:36 AM | #31 | |
Car Geek
4132
Rep 3,829
Posts |
Quote:
In a leg press I can push the same weight (4x body weight) in a repetitive motion either with an ankle flex (flexing toes forward / lifting heel without any other leg movement) or full leg movement, I usually combine both movements into a single motion on the leg press. My quads have more strength over a large range, but my calf muscles are strong enough to pivot my ankles quickly and smoothly on a clutch pedal, works well for quick gear changes for me. I have no issues with rapid clutch actuation with just an ankle flex on most cars I have driven, the only limitation is the distance the clutch can be moved (2/3 range without moving the heel in most BMWs or most European cars, full range in a Formula Renault). Manual transmission pickup trucks and agricultural equipment don't seem to be conducive to keeping the heel on the floor, due to the huge clutch throw, though, probably covers most American manual transmission cars too. Last edited by aerobod; 10-07-2009 at 12:52 AM.. |
|
Appreciate
0
|
10-07-2009, 02:16 AM | #32 |
Private
18
Rep 94
Posts |
+1
__________________
2009 135i coupe | 6MT | Space Gray | Nav | ZSP (retired due to NYC)
2017 Toyota Highlander XLE AWD | Family beater |
Appreciate
0
|
Post Reply |
Bookmarks |
Thread Tools | Search this Thread |
|
|