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Old 12th March 2006, 21:38   #31
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My funda of engine re- vitalisation.....
Yeah,right. Ur avatar pic says u do it more often.
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Old 30th March 2011, 11:09   #32
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Default Re: All you enthusiastic drivers - DONT OVER-REVV

Just came across this thread after GTO posted a link of same on driving typos thread. It was an interesting read and added to my knowledge.

Many of us do high revv our car's engines without knowing the consequences of the same. So, I'd like to revive this thread so that more people can learn from it.
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Old 30th March 2011, 11:52   #33
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Default Re: All you enthusiastic drivers - DONT OVER-REVV

Doesn't the breakdown also dependent on factors such as-
1. The mileage of vehicle.
2. The alloy used for manufacturing the engine block/piston.
3. The quality of engine oil (just guessing).
4. The fuel used.

I have been revving my 1.2 ELX for past 30k kms(read 80 kmph in 2nd gear), engine checked, no issues other than normal wear tear. The previous owner was no soft-footed either.

But honestly, the claims given by GTO is giving me jerks, since I tend to continue the same habit on my T-jet as well. But thanks to the shorter ratios of gear, the car hates revving in low gears though it can pick up well in high gear-low rpm.
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Old 30th March 2011, 12:34   #34
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Default Re: All you enthusiastic drivers - DONT OVER-REVV

I dont think redlining a engine is over revving. If you are at redline in higher gear and then drop to a lower gear then it can be called as over revving, and i don't think anyone of team bhp is stupid enough to do that lol ....
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Old 30th March 2011, 12:42   #35
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Default Re: All you enthusiastic drivers - DONT OVER-REVV

For all Diesel heads there who shift at 3k RPM or higher - you might end up doing more damage than you think - most modern turbocharged CRDI mills peak their torque under 3k. Ideal upshifting RPM for them would be anywhere between 1800 to 2750 RPM, depending on what you are driving.

EDIT: @Rahulkool - Siesel may Duck, but Setrols Puck the life out of your pockets if you drive it as hard as I drive my Siesel

Last edited by ph03n!x : 30th March 2011 at 12:43.
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Old 30th March 2011, 12:59   #36
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Originally Posted by ph03n!x View Post
For all Diesel heads there who shift at 3k RPM or higher - you might end up doing more damage than you think - most modern turbocharged CRDI mills peak their torque under 3k. Ideal upshifting RPM for them would be anywhere between 1800 to 2750 RPM, depending on what you are driving.

EDIT: @Rahulkool - Siesel may Duck, but Setrols Puck the life out of your pockets if you drive it as hard as I drive my Siesel
OT: thats just a joke mate .... even i am no light footed driver either , thing is i don't take out the car much so petrol bills doesn't hurt me much hehe.
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Old 31st March 2011, 00:36   #37
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Default Re: All you enthusiastic drivers - DONT OVER-REVV

Is there any technical way or some solid info to find out how optimistic are our revv limiters?. ie, how(relatively) safe is each car on its revv limit?

ie, a TATA nano rev limiter cutting in at ~3.5k needn't be more safer than a V-tec cutting in at ~7.2k

So, considering engine spec's, is the Nano revv limiter more safely positioned or the v-tec's, or vice versa?. And what about the rest of the lot?
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Old 31st March 2011, 00:46   #38
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Default Re: All you enthusiastic drivers - DONT OVER-REVV

Just read this thread,

As a memeber of various s2000 forums, my 2c.

All those damage was done when S2000 guys redline and misshift the gear. And keep in mind that the S2000 has a 9000rpm redline. So the damage is much higher on the S2000. That os one of the most highet revving production engines ever.

No damages were done to stock S2000 engines when we press the accelarator too hard and drive close to redline, The fuel cutout takes care of it.
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Old 31st March 2011, 01:09   #39
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Default Re: All you enthusiastic drivers - DONT OVER-REVV

Quote:
Originally Posted by Rahulkool View Post
OT: thats just a joke mate .... even i am no light footed driver either , thing is i don't take out the car much so petrol bills doesn't hurt me much hehe.
lol.. I was kidding too
Quote:
Originally Posted by dhanushs View Post
Is there any technical way or some solid info to find out how optimistic are our revv limiters?. ie, how(relatively) safe is each car on its revv limit?

ie, a TATA nano rev limiter cutting in at ~3.5k needn't be more safer than a V-tec cutting in at ~7.2k

So, considering engine spec's, is the Nano revv limiter more safely positioned or the v-tec's, or vice versa?. And what about the rest of the lot?
My rule of the thumb (not necessarily correct) is to keep a car close to its peak torque in the lower gears, and let it roll as needed in the overdrive gears. I rarely rev to the max BHP range, which will be closer to the redline.
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Old 31st March 2011, 09:40   #40
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Default Re: All you enthusiastic drivers - DONT OVER-REVV

As a general habit, whenever a vehicle doesn't start and it has been jump started, everyone tends to revv it as much as they can. Imagine the damage to the engine then!

To GTO and other who have narrated instances of people accidently going to 2nd/1st instead of 4th/3rd, if the speed is out of the range for that particular gear, doesn't the stalk generally not refuse to go that gear? As in, if I'm at 100km/hr on the 4th, wouldn't/shouldn't the gear NOT be able to be slotted on 2nd?
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Old 31st March 2011, 10:08   #41
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Default Re: All you enthusiastic drivers - DONT OVER-REVV

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Originally Posted by libranof1987 View Post
To GTO and other who have narrated instances of people accidently going to 2nd/1st instead of 4th/3rd, if the speed is out of the range for that particular gear, doesn't the stalk generally not refuse to go that gear? As in, if I'm at 100km/hr on the 4th, wouldn't/shouldn't the gear NOT be able to be slotted on 2nd?
Go ahead and try it - you'll learn something.

You will be able to slot the gear lever to 2nd at any speed just fine - BUT - for heavens sake DO NOT RELEASE THE CLUTCH if you are at a speed that is beyond what your engine is capable of in second gear.
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Old 31st March 2011, 10:14   #42
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Originally Posted by murlidar View Post
What is the safe limit in Turbo Indica ?
I think there is a rev limiter somewhere, but have been told that anything above 2.5k to 3k for too long can't be good
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Old 31st March 2011, 10:19   #43
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Default Re: All you enthusiastic drivers - DONT OVER-REVV

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Originally Posted by CrackedHead View Post
Go ahead and try it - you'll learn something.

You will be able to slot the gear lever to 2nd at any speed just fine - BUT - for heavens sake DO NOT RELEASE THE CLUTCH if you are at a speed that is beyond what your engine is capable of in second gear.
I think I know the results and love my car enough to not screw it up like this

I first drove a M800 and on that, I could NOT downshift to a gear when the speed was above its limit.
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Old 31st March 2011, 10:36   #44
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Default Re: All you enthusiastic drivers - DONT OVER-REVV

Quote:
Originally Posted by libranof1987 View Post
...
To GTO and other who have narrated instances of people accidently going to 2nd/1st instead of 4th/3rd, if the speed is out of the range for that particular gear, doesn't the stalk generally not refuse to go that gear? As in, if I'm at 100km/hr on the 4th, wouldn't/shouldn't the gear NOT be able to be slotted on 2nd?
There is nothing that prevents you from moving to a lower gear from a higher gear even if the speed is higher than what could be achieved by the lower gear you are moving into. What damages this can cause, I have no idea. But for sure, your engine will whine and make a loud complaint.
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Old 31st March 2011, 11:57   #45
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Default Re: All you enthusiastic drivers - DONT OVER-REVV

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Originally Posted by murlidar View Post
What is the safe limit in Turbo Indica ?
This is just a guesstimate after years of driving.
For street tuned turbo charged diesels of any make or configuration rev the engine to an rpm that is 50% above the peak torque value such that if peak torque for the Cruze is at 2000rpm then up shift at 3000 rpm through the gears for maximum acceleration without damaging the engine including the turbo. Down shift at peak torque which is 2000 rpm when slowing down. Mind you that this is not the fuel efficiency mode but the safe power mode with margin.

For fuel efficiency for all cars with street tune engines up shift at 20% below the peak torque such that for the above example of the Cruze which peaks at 2000 rpm up shift at 1600rpm. But driving like this robs all the fun of owning a Cruze. More over continuous low rev driving will initiate the automatic dpf cleaning cycle which will rob you of all the fuel that you saved; since during this cycle a lot of diesel is dumped into exhaust manifold which is not all that good for fuel efficiency. If you are forced to drive sedately do rev in the power mode without flooring the accelerator at least once every 500km to unclog the DPF to prevent the auto DPF cleaning cycle.

For good and safe power in normally aspirated Diesels, Petrols and turbo charged petrols reduce the percentage values by half by which I mean instead of 50% use the 25% values. Remember that peak torque in all Petrols and normally aspirated diesels happen at a higher rpm.
For example: The GTX has peak torque at 4200 rpm so up shift at 25% above that rpm which works out to 5250 rpm. Though the GTX sings to 7000 rpm it is bound to damage the engine if revved to this level, though I have not heard of any GTX with a seized engine as yet. Down shift at peak torque values.

For fuel efficiency in all cars including the GTX up shift at 20% below peak torque rpm which for the GTX works out to 3360 rpm. Driving the GTX below 2000 rpm is counter productive since auto fuel cutoff in the GTX while decelerating only happens above 2000 rpm. Below 2000 rpm in the GTX fuel is continuously flowing even with your foot off the accelerator.

Read the workshop service manual not the owners manual if you have doubts.
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