Paper Lawyer

perhaps it too early in the morning, but to my mind it is impossible to change down a gear and match revs without blipping the throttle. I think I know what you mean Rob, if you are slowing down gracefully and you don't hover in neutral then its a small rev change as you change the gear

JRM74

Heel and Toeing I do all the time as it's much smoother, but double declutching I always thought was for non-syncho gearboxes and it takes forever to change gear!

S2000 0E

theres an informative piece about double d here bless em

Xd

Nah about 50, his pride and joy is a Porche Roadster (1968) though. Took me for a ride in it last time when he was doing a commentary. I told him off for only driving it four miles and so not giving it a chance to warm up, he confessed that was a foolish.

He did point out at an early stage that my driving was good and therefore he was going to be picky with me. I'll check with him on the heel and toe bit but, for the mo though I need to work on my commentary skills

MarkB

Double de-clutch into 1st since there is not synchro between 2nd and 1st, however there is synchro between all other gears so it is completely unneccesary.
Matching revs between downchanges is kinder to the clutch and the rest of the transmission, whether you do this by heel and toe or simply by ensuring the revs match the road speed is up to the individual.
He's right about the flywheel, it's quite light - the flywheel gives the crankshaft inertia and keeps the engine running at idle, but that same inertia works against the engine when accellerating. A light flywheel means that less inertia is working against the engine, but that revs drop more readily when you lift off the accellerator. Hence, the need to match revs in this car is more important than most others.

AlexC

I can't believe how noticeable the difference in flywheel effect is between the TVR and my recently acquired Focus - come off the gas in the Focus, and the engine just feels like it will cruise on at some speed for quite a while, so you have to use the brakes. Come off the pedal in the TVR, and the revs drop so quickly it gives you serious engine braking.

Nick Graves

Double declutch is for people who can't H&T, which IS essential.

Either that, or it is one of those cars where the pedals are positioned for the ham-footed, making it impossible.

In traffic, clutchless gearchanging is smoothest of all.

sammyc

Did my IAM about two months ago.

All the observers have a different 'take' on what is required for the test, but only the examiner can tell what he wants. They are all pretty decent chaps though and you won't fail on something like that as it is a driving style rather than a fault.

You will be marked down badly for heal-toeing simply because with IAM you should have done you planning and not need to change down and brake at the same time. Different on the track sure but on the public roads not needed in the eyes of IAM.

Matching revs is important for IAM, so you get the smoothness they want, but as the flywheel is so light the synchromesh has a very easy job if you manage the match.

Ask Robs-Silver-S2K about this as he was thinking about becoming an observer.

san2000

So what's the difference between d DEclutch and d Clutch?

Or are they synonymous?

Nick Graves

San,

Think of a DDC as H&T without using the brake pedal as a pivot. I think the Septics call it rev-matching.

That comment about H&T the IAM is probably true in an idealised, happy world of 1950s motoring, which is why I've always shied away (or overtaken!) the IAM.