Double Cluch

[amanthapar]

hey guys...
please temm me what double cluching is??? how do u do it??? isnt it bad for ur car and does it make it faster???
do people normally double cluch when they drag or race???

[snacky]

there's no use for 2x clutching unless maybe you're driving a big rig

reasons
1. good heel/toe execution will match revs between tranny and engine.
2. syncromesh transmissions
3. rotors and pads are cheap and most "sporty car's" brakes won't fade unless it's a seriously long track day. tranny parts costs alot more. I rather wear out pads than syncros anyday.
4. some of the newer cars are equiped with paddle/button shift transmissions


reasons 2x clutching was used in the past.

1. assisted braking with engine compression to avoid or reduce brake fade especially with cars equipped with drum brakes only
2. transmission did not have syncros and the releasing of the clutch( double clutch) matches rpm between tranny input shafts/flywheel thus making a smoother downshift and reducing possible wear on the tranny.

[stradale]

In some (even contemporary) cars first gear is not synchronized. You still need to double clutch.

Some professional driving instructors teach to always double clutch. I remember John Lyon teaching that in evo anyway. Probably to make shifts more smooth not to upset the balance of the car.

[scubywrxr]

Double declutching is unnecessary in modern cars, contrary what some of the guys said above. I recently attended an advanced drivers course and the instructor said that besides being a waste of time, u can actually get urself into trouble because the drivetrain is in neutral during a short period. If disaster happens around the next corner, u have no power to accelerate out of trouble. so not recommended. Even big rigs these days are mostly semi-auto and the manuals have synchros, so that rules them out as well!

Heel and toeing is fun when u get it right and can help u balance the car during braking for a corner. However using the transmission by downchanging to slow the car down is not recommended at all. Lift of the accelerator - the car should slow down to the appropritate speed if u have looked ahead and judged the corner appropriately before arriving at it.

use the brakes, as far as possible, in a straight line and gently to balance the car for the corner. accelerate once u see the edge of the road on ur exit point for the smoothest transition and cornering (plus u can get the tail out in a more controlled fashion coz u know what u gonna possibly hit! :mrgreen: )

By the way, the skill that is the most difficult to learn, is taken for granted and the one we have the least ability in is BRAKING - strange but true. We take it for granted that ABS is going to get us out of trouble and hope for the best as we barrel into a corner. On the skid pan, ABS equipped cars got into less trouble but were just as much a handful as non-ABS cars in collision avoidance. In fact every guy hit the "truck" without the training!

The fact is that in an emergency avoidance situation we panic brake (i.e. step on the brake pedal and scream for the best) even with ABS, steering became almost impossible with guys winding on full lock, the attitude of the cars veering only slightly in the intended direction.

Secret is - GET OFF THE BRAKE PEDAL THEN STEER!
If u dont go to a skidpan, abandoned parking lot, etc. u will never learn how to brake in an emergency.
and let me not start talking on braking on uneven surface, gravel, wet, half tarmac half gravel, oil surface, ice, stones or with a blowout tyre!

[coombsie66]

Not downshifting during braking makes your brakedistance a lot and a lot longer!
Like those idiots who press their clutch first and then start braking, no wonder they start spinning!

That appears to be the case when driving, but it is not actually the case. If you are braking optimally, then you are at the limit of the tyres adhesion to the road surface, by adding a retarding force by the engine, the wheels will lock, if you maintain the same braking force.
In the 0-100-0 tests that autocar do, they found that the the caterham r500 was quickest in braking due to the h-pattern box, so u could hit 100, shift to neutral and left foot brake to a stop.
Down shifting whilst braking can be usefull in balancing the car, but it does not reduce the braking distance if the brakes themselfs r being used to their full potential.

[SFDMALEX]

Secret is - GET OFF THE BRAKE PEDAL THEN STEER!

Depends on the situation I guess, because when you are trail braking you dont get of the brake pedal.

A lot of people people say brake before steering but I would say thats for amatures in a way. You will not be fast on a track if you brake before the corner then go back on the throttle before even hitting the apex.

[stradale]

If you do that and can get to the apex, you went in too slow in the first place. Otherwise the braking would upset the balance too much. Braking all the way to the apex is certainly not the best way for cornering.

[SFDMALEX]

If you do that and can get to the apex, you went in too slow in the first place. Otherwise the braking would upset the balance too much. Braking all the way to the apex is certainly not the best way for cornering.

Not braking all the way to the apex, you would get heavy understeer. When you trail brake you Enter the corner while still on the brake, then you smoothly start accelerating and then trying harder when your at the apex. You have to try left foot braking in this situation.

I see what you are saying about unbalancing the car when you brake all the way to the apex. Thats what the Best Motoring drivers do A LOT. They brake until the apex then their car ends up wigling the ass.

What I am trying to say that you do not do all of your braking in straight line before the corner. That wont get you anywere.

Anway a lot of braking technics depend on the corner. Obvoiously if you are about to hit an hairpin you wont be able to trail brake....