[Jaggu]

ok i guess that link is locked.. so posting it here..

some more info, the gear wheels for competition gear box, the cut on the teeth will be quite diff as in straighter cuts instead of angled ones, this is to help in high speed shifts and can be a pain during slow speed changes..

[GTO]

Originally Posted by [b

Quote[/b] ]what do u mean by over revv?

Taking the engine to an rpm limit it is not designed to run on. You cannot over-rev modern engines while accelerating as the revv limiter will cut in. But you can cause damage in one primary way....say you are high revving near the red-line in 3rd gear. Instead of upshifting to 4th, you mis-shift and put the gear lever in 2nd. The drivetrain will make the engine over-rev i.e. take it way beyond the redline.

GTO

[cheatingdeath]

Hello people, I am not the expert out here, but according to me, I think gear shifting that is the upshift should be done before you cross 2000 rpm. This is for cruising because when you shift from 2nd to 3rd and let the engine rpm just reach 2000 rpm and then shift to 3rd, the speed is automatically set to compensate with the 3rd gear min speed. That is when the car wont knock, and then just throttle steadily and cruise. This is what I think personally. If I am wrong, please correct me.

[Jaggu]

up shift when midway of the torque band..

[karthik247]

why do u have to rev before u shift down?? does it make any difference?? and is there anything worng if u take the rpm to the red line?

[Rehaan]

Originally Posted by karthik247

why do u have to rev before u shift down?? does it make any difference??

http://www.team-bhp.com/forum/showthread.php?t=3139

and is there anything worng if u take the rpm to the red line?

Well the faster the engine is running, the more stress on the components in the system, and the faster the wear and tear happens in the engine.
Its ok to take it UPTIL redline (but not past), and preferably do not stay in that area of the revvrange for too long, and dont do this too often, atleast on consumer cars.

cya
R

[khanak]

I have just about learnt how to drive. Can someone give me tips on how to start the car while on a slope. Also while braking by shifting down does one keep the clutch pressed while changing gears? The guy from the driving school told me i should start the car in gear and start using the clutch while my mum says start in neutral and then put it into first. Some help Please

[manaa45]

Dear khanak

the best that i know is use ur handbrake on the slope. keep it in neutral, start the car the press the clutch and go to first gear. all this while u have to have ur hand brake up. keep the clutch half released, press a bit on the accelerator and then release the hand brake. due to half released clutch and half pressed accelerator the car wont go back on the slope.

this is what i have learnt.

buit if there is a slope where u are driving the car and u have to halt then i think this is the best way to do it.

shubbhi

[manticore]

Originally Posted by khanak

Also while braking by shifting down does one keep the clutch pressed while changing gears?

By this, I guess you mean 'engine braking', right? It's better to depress the clutch while changing gears. It's possible to do so without pressing the clutch, but leads to gradual damage of the associated parts. And never ride the clutch....use it only while changing gears.

It's always safer to start the car in neutral. Otherwise, the car could inadvertantly jump forward if the clutch is not depressed. Guess your mom is right.

Starting on a slope, as Manaa explained, using the handbrake is one option. The other is ok (without using handbrake), but requires practice. If you start the car, put it in 1st gear and slowly release the clutch, you'll see that the car moves forward, albeit at a slow pace, but without the aid of the accelerator. For starting a stationary car on a slope -

depress the brake with right foot

start the car and engage 1st gear

slowly release clutch, while at the same time releasing the brake and depressing the accelerator. It's a kind of heel and toe thingy, where your right foot operates both brake and accelerator.

Hope this helps.

Manti.

[Deeps]

Originally Posted by manaa45

Dear khanak
keep the clutch half released, press a bit on the accelerator and then release the hand brake. due to half released clutch and half pressed accelerator the car wont go back on the slope.

Actually this may not always be the best way to take off from a slope considering the sorry state of clutch on some cars. Easier way is to take off like you normally would do (keeping in mind that the handbrake is still activated), then as the car tries to move forward you'll feel it. At this point disengage the handbrake and you are off. Another thing, do use the handbrake to remain stationery on a slope rather than balancing the clutch and throttle.

Personally, i start the car in neutral with the clutch pedal pressed. Someone here told me that its easier for the battery, starting motor etc. to crank the engine that way. I'd suggest that you get into the habit of starting the car with the clutch pressed regardless of which gear its in. Thats because it'll never jerk forward even though it may not be in neutral.

[khanak]

I just tried the handbrake method today and it worked. Thanks a lot.
I still havent understood the engine braking part though
Suppose I need to brake suddenly............
Do I despress the brake and the clutch and start shifting down keeping the clutch depressed until the car slows down ? ?

[karthik247]

hey do u have to blip b4 or after pressing the clutch??? bliping without pressing the clutch would be a bit dangerous in traffic won't it???

[abhi182]

nice thread....I usually corner without the clutch using engine+brakes to slow down, but this is something I learnt (not pressing the clutch while breaking for slow downs) less tan a year ago, and the age old habit of pressing the clutch more often than required keeps kicking in once in a while....

This brings me to another question though....I know that I shouldn't let the tacho fall below ~1200-1400 rpm and should downshift before that happens...
What should be the ideal rev ranhe while shifting up for good FE....
While enthu driving, I upshift at approx 3500 on my 1.4 Corsa, but when should I shift during sedate driving?

[rahuldeodhar]

Hi replying to Praveen -

Originally Posted by praveen_v

I understand you simplified it. Consider a scenario.. I am travelling at say 60-80kmph and see a singal a few hundred meters ahead turning red. Here's what i'll do

1.press the clutch, shift a gear down and slowly release the clutch.. The braking will be provided by the engine. Once the speed comes down a bit, once again shift down and release the clutch slowly. repeat till I get to first gear, put the gear in neutral, apply brake and stop.

2.Remove the foot off the accelerator, start applying the brake with the vehicle in gear till the engine shows signs of struggling to pull at the gear, depress the clutch,put the gear in neutral. Brakes being applied continuosuly but gently easing off to a stop

3. Remove the foot off the accelerator. Then before applying the brake, depress the clutch and shift the gear to neutral. Release the clutch and then start applying the brake and come to a stop.

I hope you can get the picture of what i'm trying to say. Now what I wanted to know is which of these 3 is the better/best way to bring the vehicle to stop. Leave out any inclines, i am just talking about a level road.

Here how I would do it

#) take foot off accelerator
#) start braking
#) as speed eases- engage clutch
#) keep downshifting - to match gear and speed- but dont engage
#) Come to stop

This is different from 1 as I dont use engine force to stop the car - trying to reduce stress on engine

But this is also different from 3 as I always keep the option of using engine stop available - as a safety precaution - keeping car in neutral will remove this option

In case of urgent stop I can simply engage and reduce (similar to what you mentioned in option 1)

RD

[rahuldeodhar]

Originally Posted by alto99

From what I understand about a clutch, you should - as far as possible - lift your foot from the clutch pedal (I remember some ads on doordarshan mentioning this long back - probably 10-15 yrs back).
At signals keep your vehicle in neutral and fully release the clutch instead of keeping the vehicle in a gear (or neutral) and pressing the clutch. Simple reason being whenever you are pressing the clutch, the two simplified discs mentioned in this thread start rotating at different speeds thus causing wear. Whereas when you release the clutch, you are making the discs rotate at same speed (at least thats what is desired) thus causing less wear or no wear.

Hi Alto,

You are correct about DD ads - however they mention not using clutch while regular cruising. Now you might laugh at this, but there are dudes who keep their clutch partly engaged while cruising. This is sometimes because the left foot has nowhere to rest but the clutch pedal and because of its weight it partly disengages the clutch.

About the clutch mechanism. Right again - keeping in neutral is better (in most cases)
But pressing the clutch pedal fully AND keeping car in neutral = both are equivalent in terms of wear of clutch plate.


Howstuffworks "How Clutches Work"
Howstuffworks Videos "How Clutches Work: Definition"

Also - it is better to be hand braked at signals - prevents the car from rolling
(Also safer in case some dashes you from behind you dont roll on to the car in the front. You get severe dents at the back rather than relatively lighter dents at both back and front)

RD