Heel Toe

[bugger]

Hey mate,

i have a debate with my mate regarding down shifting gears, using heel toe.

i said is to prolong the life of the clutch and the transmission and gearbox.

he say no need. and give me an example of a Honda Jazz 5 speed manual.

say for example, a 50 year old lady driving a honda jazz, does she need to learn heel toe to maintain her clutch and transmission?

all i know is that the power of the car is link to the transmission..

please share your views...

one example:

this is what he said:

GEARBOXES AND CLUTCHES ARE DESIGNED TO DO WHAT THEY DO

IS TO SHIFT UP AND DOWN

WEAR N TEAR IS INEVITABLE

PROLONG FOR HOW LONG?

5 MORE YEARS?

does this mean every freaking stop sign, traffic light, corner must heel toe?

every man woman old child must heel toe?

rubbish

utter and fully rubbish

and why cannot ride the clutch to move off?

u mean at 800rpm, the clutch is destroying it self? when it rides against the plate?

800 rpm?

how much destruction can 800 rpm do?

i don't know.. but curious

why must car have clutch

_________________________

Response needed..

i find this topic interesting.

Cheers.

Edited August 19, 2007 by bugger

[Fujiwara]

I don't believe heel toe would prolong the gearbox.

Double clutching would prelong your synchros but thats about it i believe.

[GTRsean]

Matches revs of engine speed to gbox speed so less wear on clutch if you heal toe to match revs.

Can be up to 4000rpm difference in speed of eng to speed of gbox.

My osgikken tripple plate can't be wrong(3+years 70,000k of daily driving, drags etc and still good) was already in car when I bought it 3 years ago.

[dmr]

as long as you are doing it properly and matching revs i see it as a gearbox saver over time

i personally don't like hearing the wind back sound of gearing down

[dan.1337]

It also allows u to brake less and for the engine to help brake.

imo u'd do it more when doing spirited runs thru the twisties when u want to downshift and not lock the back wheels because u didn't rev match.

[mattymagoo22]

heel and toe is used first and foremost to stop compression lock-up. If you are doing 100 ks and drop it back to 3rd and let you foot off the clutch we all know whats going to happen. rally drivers of older days used this method to both maintain and overcome grip particularly on dirt/snow surfaces when down shifting and skipping gears ie: 5th down to 3rd is quicker than 5th 4th 3rd also helpful to keep smooth on a track.

Rev matching will work when your syncrhos are worn out to help stop the crunching.

Engine braking ,i believe, on the track is useless in slowing the car, really when you let the clutch out your using the brakes to slow the engine and not the opposite.

Maybe in the older days when drum brakes were used and were no longer working too well after getting extremly hot engine braking was used to assist but now in the age of 4 wheel discs multi piston calipers the only reason people do it is out of habit. And old habits die hard.

I reckon that double clutching heel toeing would probably wear out your clutch quicker as there are twice as many instances of friction as opposed to leaving the clutch in the whole time. And saving a gearbox and going to the drags should not be mentioned in the same passage imo.

as for the longevity of your drivetrain it comes down the how the car is both maintained and driven. Had a mate with a car from new (tp magna) with 230 000klms on original clutch disc gearbox and engine no crunching a little smoke from exhaust but driven properly it shows how long things can last.

as for saving synchros they are designed to be the friction point on the gears to help them engage but the pressure applyed to them when changing gears would have more of an affect then the difference in gearbox and engine speeds so again driving style is a big factor

cheers matt.

[GTRgeoff]

Hmmmm, heel toe

worth 3 seconds a lap at Phillip Island

Otherwise only good for reducing shockloads through the drivetrain.

See...mechanical sympathy.

[mattymagoo22]

where do you pick up your 3 seconds?

under brakes, good line/smooth line being in the right rev range or combination of these?

[r33_racer]

avoiding compression lock ups, keep car balanced whilst braking and changing down gears, and lets you actually change down gears if you run a non-synchro box. Usefull for lots of things, only on the track though.

[arep3]

normal driving on my way home from picking up my car from rebuild with a new clutch. changed down a gear like i would do if i wasnt using the brakes and car locked up under compression. heel toe is good if used in the right manner, little old grannys in honda jazzes wouldnt exactly be going fast enough to warrant heel toeing.

[Jdfnq]

normal driving on my way home from picking up my car from rebuild with a new clutch. changed down a gear like i would do if i wasnt using the brakes and car locked up under compression. heel toe is good if used in the right manner, little old grannys in honda jazzes wouldnt exactly be going fast enough to warrant heel toeing.

you should tell that to the clown in his little black jazz that tries to race me (and everyone else) on the way into town each morning...

And yep....

He does it everyday

:laughing-smiley-014:

i let him go.....

no way my skyline would keep up with his jazz

[Gav]

avoiding compression lock ups, keep car balanced whilst braking and changing down gears, and lets you actually change down gears if you run a non-synchro box. Usefull for lots of things, only on the track though.

Best response of the thread goes to r33_racer. The technique is about fast lap times more than mechanical sympathy and fast lap times are about smooth driving. The less often you upset the inertia of the car (either braking or down changing gears) the better. By combining both into a single movement (i.e. heel/toe downchange) you reduce the inertia change before the corner to a single event.

[33drifta]

when i got my r33 i decided to learn how to heel toe, so at every trafic light, stop sign and every other situation i forced myself to do it till i had it dialed, now i cant drive without doin it, i get confused if i dont lol.

[cosworth1971]

heel/toe is for dog boxes (straight cut gears) as they have no syncro`s and u need to match the rpm on down shifts then no clutch on upshifts..

I do it on my street car also but be carefull in traffic

as too it being less wear i dont think so .

Edited August 28, 2007 by cosworth1971

[cosworth1971]

oh yeah i drive with racing shoes only(full time even if going out and change my shoes)<makes a huge differance

[GTRgeoff]

heel/toe is for dog boxes (straight cut gears) as they have no syncro`s and u need to match the rpm on down shifts then no clutch on upshifts..

Ummm no. A dog box doesn't necessarily have straight gears. Double clutching gives better slow changes in a dog box. Heel toe is simply for what R33racer described above.

as too it being less wear i dont think so .

It also helps with less wear and impulse loading due to smoothing the gear transition.

Sif wear race shoes every time you drive.

[RBwhatever]

Sif wear race shoes every time you drive.

Yeah man, because it makes a huuuge difference when driving around town.

"Why are you changing your shoes man, we're just going down town?"

"Because I'm hardcore, you never know when I have to start drifting takumi style."

Hahahaha jokes

[cosworth1971]

Ummm no. A dog box doesn't necessarily have straight gears. Double clutching gives better slow changes in a dog box. Heel toe is simply for what R33racer described above.

It also helps with less wear and impulse loading due to smoothing the gear transition.

Sif wear race shoes every time you drive.

straight cut gears (usaully are called Dog boxes) because there hard to drive but there are diff cut gears out there(straight cut is full race)

and once u drive with race shoes u wont never go back!well i cant drive as good or wont with big shoes

and normal cut boxes and syncro`s u can do any gear anytime ,even if u drive like a tool.

[GTRgeoff]

Mate, I don't normally pull the pi55 but you are really asking for it. I'm sure others will do that for me......

Race shoes are for racing and for pulling yourself on chapple st in melbourne on friday nights. Plus I heel and toe in work boots and sandals. It is just practice.

I've only raced for 22 years in rally, formula ford, sports sedans and sprints. I'm a mechanic and a mechanical engineer that has worked for a couple of V8SC teams. I've also got over half a million kays driving heavy trucks with dog boxes.

So do you still think I won't know the difference between a dog engagement and synchromesh engagement of gears, or a straight cut or helical (what you cal normal) tooth mesh? I bet you don't even know how a gearset works.

Do yourself a big favour and spend some time on wikipedia and why things work and learn before you decide you are an expert.

Then come back, show some humble and redress every statement you just made. Just do it for yourself.

[Beer Baron]

straight cut gears (usaully are called Dog boxes) because there hard to drive but there are diff cut gears out there(straight cut is full race)

and once u drive with race shoes u wont never go back!well i cant drive as good or wont with big shoes

and normal cut boxes and syncro`s u can do any gear anytime ,even if u drive like a tool.

if you read your own writing you'd realise you have no idea. dog boxes are called dog boxes because they use large rings featuring 'dog teeth' as the type of engagement. straight cut gears are called straight cut gears because the tooth profile of the gears is straight... the two things are not related. you can have straight cut gears with syncrho engagement, of you could have straight cut gears with dog engagement. or you could even have both in the same box. so before you try and teach us all a valuable lesson on how gear boxes work make sure you know what you are talking about.