HellFire

Whenever I give my car some beans I change gear only to be too eager to change gear and press the clutch in very rapily and release it just as quickly, this creates a really annoying jerkiness which wasnt there on my Mondeo (which had a really heavy clutch). However if I try to gently change gear I loose too much momentum and find myself loosing probably a second on whatever the 0-62 time should be or any in gear time. Is there a good time to lift or change gear to get the optimum change?

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Metro Blue '06' 5 Door Astra 1.8 SRi

Furball

Its all in the wrist action, try to think of some way of exercising it regularly

Turbostream

you'll go blind!

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Ade, Brummie.
Corsa SRi 1.7 CDTi... dont laugh, its really very good.
previously 2001 Furbie Elegance TDi, Nature Green, no mods
To Tinker: May your pain be at an end ....we will miss you my furry friend.

stathap

Badminton ?

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"Classic" Black Magic

mcbunny

pool ???

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First step to recovery is admitting you have a problem

Hi, my name is Mike and I own a Skoda and to top it all off it’s a diesel.

Turbostream

another one who likes ball games!

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Ade, Brummie.
Corsa SRi 1.7 CDTi... dont laugh, its really very good.
previously 2001 Furbie Elegance TDi, Nature Green, no mods
To Tinker: May your pain be at an end ....we will miss you my furry friend.

Alex

Sack race anyone?????

dsemuk

Don't wear pants?

Neo_VR

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ColGod the UberMod


,___,
[O.o]
/)__)
-"--"- ORLY??

studbuckle

back on topic...

The smoothest and the quickest are two totally different skills.

The quickest change, for the quickest time can be achieved one of two ways.

1) the American, non mechanically sympathetic way means full throttle changes are achieved by dipping the clutch just long enough to swap cogs with the biting point being at the point the synchro starts to engage. WITHOUT lifting the throttle and letting rev limiter stop the motor from blowing. This is jerky as hell. Bad for gearbox and very bad for clutch as it has to take an engine on full power to full torque revs (normally) instantly

2) The english quick way is the dip the clutch for the same amount of time but during that period give a full or at least partial lift on the throttle (which relies on Flywheel ection of the engine and it's method of aspiration). This means that at the point that the clutch starts to bite then power can be re-applied. This is still jerky but less mechanically wounding.

The smoothest change, and the one you should be looking for on every change you make on the road is:

As you accelerate make a mental decision at what revs you want to change. As you approach that rev then you should start to lift the throttle so that you stop accel at that rev. At the same time start to apply pressure to the gear leaver in the direction of change and as the revs are reached dip the clutch. As the clutch dis-engages you should lift the throttle (fully or partially i'll come on to) and swap cogs making sure that the gear selector is fully in place before releasing the clutch. The clutch should reach biting point at the same time as the engine revs have died down to match the new gear. This takes practice and skill to know what revs you will need to be at. At the point the clutch starts to bite then power can be gradually re-applied. The full or partial lift depends on the engine. If the engine is a light flywheel normally aspirated 4-cylinder then a total lift might cause the engine revs to die off to quickly for you to make the gear change before they reach the new rev. So, a partial lift would solve this. the same goes for some Turbo Diesels. A nice slow relaxed gearchange in my TDi means I left to approx 10% throttle. This means the fuel is kept running and the turbo doesn't spin down much.

The art is matching your clutch action so that the engine revs match the gearbox revs (in the new gear).

HTH and I haven't waffled tooooo much

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Simon Houghton
Octavia II, Elegance with toys
Westfield SEiGHT in garage

spinndrift

Is that another phrase for maggot racing?

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Rev. Andy
The Rallying Reverend
www.miniroadrunnerrallying.co.uk
Engine data aquisition is fun

Skodacious

The Advanced Driving Manual (IAM 1998) says...

'When changing up, you should release the accelerator completely and only press it again when the clutch has re-engaged, timing these movements accurately so that you maintain smooth progress. When changing down, however, it is best to maintain a little pressure on the accelerator as you select a lower gear, so that the engine speed has become matched to road speed when you engage the clutch.'

Roadcraft also suggests you adopt the correct grip on the gearstick - thumb down for 1st and 2nd and then thumb up for 3rd, 4th, 5th (and 6th!). You use the action of the spring mechanism to aid correct gear selection.

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2004 Skoda Octavia vRS MK1 'The original and best'
2003 Peugeot 206 SW 1.1 LX 'It has a split tailgate!'

rikodars

Never mind all that . How do you make it GO like sh1. Thats the Q. Not maintaining smoooooth progress. If you want to go really fast get a BIKE with a gert big engine!!

skodaTDI

What's everyone's rush? You're polluting the environment more, adding extra wear and tear onto your engine, clutch, gears etc.. I generally change up gears at around 2250rpm, unless someones being a bit of a twonk on my inside or trying to get around my outside and then I may go up a little further.. harsh acceleration only means you'll need an oil change sooner! Rush.. Rush.. everyone's in a rush these days..

Regards,

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If only eveyone drove at 70mph on the motorway, we'd never have to brake then.

HellFire

But I figure that if I save 10 mins on every trip to work thats 20 mins a day which is 1 hour 40 mins a week I can spend at home instead of driving

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Metro Blue '06' 5 Door Astra 1.8 SRi

studbuckle

What twoddle....

If you're changing up at such low revs all the time you're not being efficient. Remember, an engine is its most efficient at peak torque and the more torque it's producing then the better. Especially with a TDi you should at the very least change up at the rpm that will bring you back down to peak torque or just slightly below in the next as the torque curve drops off very sharply below this, regardless of how 'harsh' you're accelerating. This is the best way to save the precious environment.

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Simon Houghton
Octavia II, Elegance with toys
Westfield SEiGHT in garage

ap0gee

I agree. In order to make sure that your revs are at 2000 or above each time you change up, my extensive research (ahem) has lead me to the following points for up-shifts for a Fabia vRS (and any other PD 130 vehicle?):

3500 rpm 1st-2nd, 3000 rpm 2nd-3rd, 2500 rpm 3rd-4th, 4th-5th and 5th-6th.

Of course, you can hold onto the gears for longer if you want, but if you change up earlier you'll end up sub-2000 rpm in the next gear, and hence the engine will bog down, and you'll make no progress.

Don't forget: High revs don't have to mean high speed!

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