KAF

Hmmm, I'm an ex-police driver, trained high speed pursuit driver, advanced trainer, teach driving for a living, with all the qualifications that entails here in the UK and I have a little experience of single seat racing.

No, I probably have no idea what I am talking about,

v_therussian

haha Krozi, you are busted

jm545i

Any time things aren't matched there'd be a chance for damage from excess shock, but as long as you're not abusive, logic would indicate that removing the CDV might reduce wear and tear on the wear surface of the clutch. Would depend on ones normal driving style obviously - in my case it would result in a lot of extra clutch slipping.

Krozi

That's right you don't. If you did, you would know the difference between heal-toe downshifting and double clutching.

porsche911targa

Nope, I mean the heel and toe technique is no longer necessary because today's advanced transmissions handle this task all by themselves.

Analogy: In today's computers, you can direct your mouse to open files with one left click. You like to double click anyway because that's what real computing is all about. The software allows you to do it, but it can also handle a single click. More fun to double-click/heel-and-toe, but not really necessary.....

Krozi

This thread is about cars with true manual transmissions. 3 pedals. Try popping the clutch at idle RPM when the RPM's are supposed to at 7000 and tell me how that works out for you.

KAF

That is dealt with by sustained rev gear changing. All that matters is that the revs are right when the clutch comes up, not how you achieve it. As long as you are off brake and on gas before bringing clutch up the transmission will be fine.

Nothing wrong with using heel/toe if you want, but as said in the OP, in the hands of the less talented it is highly dangerous as it can compromise braking effort.

Original reasons for heel toe were to be able to apply power before coming off the brakes. main reason for this was that cable and carburettor controlled fuel supply systems had a considerable lag between hitting the gas and the subsequent increase in revs. Modern engines with fuel injection and fly by wire gas pedals do not suffer anything like the lag previously experienced.

heel toe will still enable you to prevent the lag caused by the time it takes to move foot from brake to gas, but is far less beneficial now than it was many years ago.

Krozi

Modern engines with fly by wire actually do suffer from considerable throttle lag. While not having the lag from a old school carb, the fly by wire system is not faster than a throttle cable. Some cars are worse than other cars regarding lag. My car doesn't have much lag because it has eight individual throttle bodies. Either way, being in gear before exiting a corner makes for faster lap times. And that's proven.

KAF

No argument there, but braking before the corner getting the gear and being on gas as you traverse it brings better stability than braking as you go around it.

This is especially so with rear wheel drive as you can begin to transfer the 'weight' to the rear driving wheels so getting increased grip.

Braking and steering at the same time increases skid risk, so timing of the gear change and return to drive is, as, if not more, important than how you achieve it.

v_therussian

And to revive this magnificent subject, I announce my short shifter!


I bought a Z4 shift lever from Garry Romani and went to Motorcepts. Turned out the shifter was wrong, but Leo @ Motorcepts actually had one in stock (Awesome? I think so!!!), so he was nice enough to give it to me in exchange for the one I had. Installed the shifter pretty quickly, drove around with it unmodified for a few weeks, but went back and convinced Leo to bend it. Took some ingenuity on his part to figure out how to bend it just right without damaging it, but it is all done now and I'm loving it. Ideally, I'd bend it a little bit more, but for now, it is fine.

Let's get some real drivers talking here again (Krozi ) - I'm sick of all the Babkens out here!