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Race car - heal 'n toe

Started by RallyRed , Dec 09 2013 10:32 PM

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53 replies to this topic

#26 _JohnUC_

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Posted 11 December 2013 - 05:46 PM

Left foot braking is no substitute for Heel-Toe downshifting.

Hi, just wondering if you could explain this a bit further for me as you have clearly done quite a bit of racing and I have only ever done maybe 20 or 30 laps. When i did the laps I would left foot brake, rev match with my right foot and then change gears with no clutch, is this bad for the gearbox? There was no graunching or anything whenever i matched the revs correctly. Also i was lead to believe that left foot braking is slightly faster over a lap as you get straight on the brake as soon as you come off the gas rather than moving your foot over from the gas to the brake. Love to hear your comments on this and more than happy to be proved wrong,

Cheers

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#27 Litre8

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Posted 11 December 2013 - 06:28 PM

Not claiming expertise here but I always considered left foot braking for scenarios where the braking is done in cases where gear changes are not involved, you just need to slow/settle the car and then get back on the gas asap.

So in your case above you just pull neutral as soon as you back off, and then rev match to the about to be selected lower and then just pull the lower gear? If you could get that correct 100% of the time, even for cases where you are going from, say, 6th to 2nd then great but I can see it being tough on the gearbox (is it a dog or synchro gearbox?).

Get it wrong and I can see it being expensive. With dog boxes I have heard of drivers upshifting without using the clutch (pull the next gear when the rev limiter kicks in) but this is also hard on parts.

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#28 _Bomber Watson_

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Posted 11 December 2013 - 08:22 PM

You can clutchless shift up and down on late model jap sports bikes no worries, but a Torana?

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#29 Litre8

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Posted 11 December 2013 - 08:43 PM

I believe the MotoGP bikes run a slipper clutch to prevent compression lockup when downshifting? Was never an issue with the old 500cc 2 strokes.

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#30 _Bomber Watson_

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Posted 11 December 2013 - 08:53 PM

frOcks me about GP, i was talking about riding around town. I rarely used the clutch bar stopping and starting back when i was rolling 1990+ jap bikes.

Sadly now days im to silly on them to own one :(

Cheers.

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#31 _LS2 Hatch_

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Posted 11 December 2013 - 09:17 PM

My Harley has a slipper clutch. I don't use the clutch on the way up, but not confident enough to not use it down, so I use it.

I thought gearing down (in car and bikes) when on a track, was used as a brake as well. What I'm getting at is if your rev matching would the engine brake be as usefull? Or is gearing down more so about the correct gear selection to get out of the corner, and brakes for braking?

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#32 RallyRed

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Posted 11 December 2013 - 09:19 PM

yeah WhiteA9x - LJ. Might try your cable tie idea. Simple is good.

Jacob - its cable to 3 x Webbers, so some adjustment there.

Thanks guys

Will feedback once sorted.

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#33 rodomo

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Posted 11 December 2013 - 09:24 PM

http://www.gmh-toran...nd-toe-braking/<br /><br />If you look here http://www.gmh-toran...or-bust/page-25 , I modified the "hang down" type of pedal on the Grease Slapper. This is VB Commodore, hangs down like LJ Torana. I made a pedal hinged off the floor like LC Torana.

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#34 RallyRed

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Posted 11 December 2013 - 09:39 PM

thanks rodomo...I actually did a search for any old threads on this, before I posted, but didnt find any?...thanks again mate

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#35 rodomo

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Posted 11 December 2013 - 09:39 PM

2ELCS will have more info if you PM him..................he's a tap dancer............some call him "twinkle toes"

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#36 RallyRed

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Posted 11 December 2013 - 09:45 PM

ta mate....twinkle toes eh?

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#37 _Bomber Watson_

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Posted 11 December 2013 - 09:45 PM

My Harley has a slipper clutch. I don't use the clutch on the way up, but not confident enough to not use it down, so I use it.

I thought gearing down (in car and bikes) when on a track, was used as a brake as well. What I'm getting at is if your rev matching would the engine brake be as usefull? Or is gearing down more so about the correct gear selection to get out of the corner, and brakes for braking?

In my tiny mind both are reasonable points.

The brakes probably do more of the stopping, but alas you want to be in the right gear when its time to hit the go pedal, and im sure the engine braking doesnt hurt. Win win by cogging down as you go?

Cheers.

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#38 _JohnUC_

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Posted 11 December 2013 - 10:10 PM

Not claiming expertise here but I always considered left foot braking for scenarios where the braking is done in cases where gear changes are not involved, you just need to slow/settle the car and then get back on the gas asap.

So in your case above you just pull neutral as soon as you back off, and then rev match to the about to be selected lower and then just pull the lower gear? If you could get that correct 100% of the time, even for cases where you are going from, say, 6th to 2nd then great but I can see it being tough on the gearbox (is it a dog or synchro gearbox?).

Get it wrong and I can see it being expensive. With dog boxes I have heard of drivers upshifting without using the clutch (pull the next gear when the rev limiter kicks in) but this is also hard on parts.

Yeah i guess it would be quite hard on the gear, probably for more serious race teams who are rebuilding their gearbox every couple of races, and it was a dog box.

My Harley has a slipper clutch. I don't use the clutch on the way up, but not confident enough to not use it down, so I use it.

I thought gearing down (in car and bikes) when on a track, was used as a brake as well. What I'm getting at is if your rev matching would the engine brake be as usefull? Or is gearing down more so about the correct gear selection to get out of the corner, and brakes for braking?

I think that ideally you want to use as little engine braking as possible and rely mainly on your brakes, my thinking behind this is that it would be more consistent and therefore efficent as the tyres only have a certain grip limit and you want to brake as close to that grip limit as possible so if you add engine braking either your tyres would lock up or you would have to ease off the brakes to counter the added resistance of the engine. I guess it all depends on your setup though and also brake balence

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#39 Retyred

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Posted 12 December 2013 - 11:09 PM

Col, if you've got a standard brake system, you don't want to go lowering the brake pedal. If you're giving them a hard time on the track, you may need all the travel you can get.

As others have suggested, I added a block of wood to the throttle pedal in my XU1 and it worked fine. This way you can also experiment with different thicknesses until you get a relative height that works for you. Maybe do something more permanent then?

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#40 76lxhatch

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Posted 13 December 2013 - 06:19 AM

I know this sounds cheap and nasty, but an alternative to the block of wood is those pedal covers you get at Repco etc. Just use the one for the accelerator pedal, and position it wherever suits. This is also a good way to widen the pedal so its not such a big gap from the brake (where necessary).

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#41 RallyRed

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Posted 13 December 2013 - 07:18 AM

.

Col, if you've got a standard brake system, you don't want to go lowering the brake pedal. If you're giving them a hard time on the track, you may need all the travel you can get.
As others have suggested, I added a block of wood to the throttle pedal in my XU1 and it worked fine. This way you can also experiment with different thicknesses until you get a relative height that works for you. Maybe do something more permanent then?

I know this sounds cheap and nasty, but an alternative to the block of wood is those pedal covers you get at Repco etc. Just use the one for the accelerator pedal, and position it wherever suits. This is also a good way to widen the pedal so its not such a big gap from the brake (where necessary).

now I've figured out how to use that multiquote thingo...I will try one or both of those ideas

Edited by RallyRed, 13 December 2013 - 07:17 AM.

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#42 _Ned Loh_

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Posted 13 December 2013 - 07:25 AM

a dog box doesn't necessarily need heaps of maintenance when well driven.

generally engine braking has no real role in racing. you rev match so as to not upset the balance of the car...however...Depending on the type of racing you may let the clutch out without rev matching to help the car turn in.

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#43 Heath

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Posted 15 December 2013 - 03:15 PM

I shift gears with the aussie box in my hatch at least half the time with no clutch - throttle response and directness of the shifter mechanism is such that it ain't really a challenge - you can easily go through the gears at 7-8/10ths but at 9-10/10ths I find it tricky and there is other stuff I want to be concentrating on. When I have raced I double the clutch instead and heel & toe with a modified accellerator pedal in the Torana.

Photos in the car are difficult to get. This thing is twisted towards the driver and a lot closer to the brake pedal. Obviously I cleaned it up the welds and added some bracing on the side too.

Edited by Heath, 15 December 2013 - 03:20 PM.

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#44 RallyRed

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Posted 15 December 2013 - 06:03 PM

thanks Heath

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#45 _Inj gtr202_

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Posted 16 December 2013 - 07:02 AM

Is that because the brake fade meant you had to push it almost to the floor and it lined up better with the throttle ?

on the money Dato :spoton:

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#46 _Yella-5000_

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Posted 16 December 2013 - 07:05 PM

???? You can heal-toe standard Torrie pedals as they are. Is there any other way to drive?

V8 Stupid Car boxes are made for left foot braking, clutchless downshifting, but I think that is post-M21 technology. Do it in your Torry and you will probably be picking up bits of metal off the track.

Edited by Yella-5000, 16 December 2013 - 07:07 PM.

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#47 N/A-PWR

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Posted 16 December 2013 - 07:38 PM

I agree standard pedals still work, but I guess the easier the arranged pedals are on our feet the better. Dave I

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#48 _datpsi_

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Posted 16 December 2013 - 08:11 PM

Definitely a better and safer option to modify accelerator pedal. First race car We offset the pedal by bolting up an ally block to get the distance right... With grip tape to finish. And the brake fade is something we kept in mind until the Brake package was sorted.