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Discussion Starter #1
Maybe a silly question but I am curious if there is an impact on having the clutch in or out while at idle; i.e. a stop light. Thanks.

Forza,

Dane
 

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Dane,

That is indeed a good question. I do not know, there is something to say for both of it.

I think car-wise it is best to do not touch it and thus put it into 'idle' (not sure what it is called officially in English!) This means no pressure will be on the clutch and therefor its livespan will be higher. Remember it is also better to stay of the clutch with your foot during driving (and not changing gear) Many drivers keep there left foot on the clutch and think no pressure is on the clutch that way. Well, I have been told that it always has some pressure on it this way and therefor it will lest shorter then when you don't.

For safety, the clutch down might be better! If someone bumps you from behind, your foot can slip from the clutch and your engine might stall so you cannot bump into the car in front of you. Of course this is all theory!

Again, just what I have heard. I have not found any proof of this theories yet but when I drive my car, I always think of the first option although it needs some concentration because I often forget about it.


Niels
 

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I've always been a fan of "clutch out" at idle. Reason being is that the throwout bearing is a non-serviceable item and I don't like to give it any more wear than neccesary. With the clutch out the throwout bearing is doing no work; it is true that you have the tranny shafts and gears spinning around with the clutch out in neutral, but they are also slinging oil around and keeping everything lubed.

So, Dane, I'll say to you as I say to my wife "Keep your foot off the freakin' clutch!" :D Of course I had to keep saying that to her to get her to stop driving the vehicles with her foot resting on the clutch pedal. :eek: She prefers automatics.
 

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Well, just as I thought.

It is better for you car to use it only when totally necessary. BTW, brings me to another question: what is the best number of revs to warm up a car probably in general and what is the normal warm-up distance.

Last weekend I was co-piloting a friend of mine to a Toyota MR2 club meeting and most of the guys there said they keep te car stationary for one or two minutes before even move!

My own procedure is to start, let it go stationary for maybe 10-30 seconds and driving it for at least 10 miles before I will revs it over 3000-3500 rpm. Okay, it is just a Nissan, but still I think this is quit alright, but I would like to hear the experts on this one!


Niels
 

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Discussion Starter #5
Fella's,

Good stuff and points well taken. Thank you. Clutch out for now until something Earth shattering comes along that says otherwise.

As far as warming any car, I would say this: Ferrari or not, cars are still metal machines lubricated by oil (I know, pretty deep, huh?). Now, I have heard two different views for warm-up. One says, fire the rig and go but gently. The other says, fire it and let it sit and idle before oil temperature begins to register. With the GTB, I did the first; fired and went gently. The Mondial receives a different treatment. I let her sit until I see that oil temp guage come alive. Why the difference? I'm not sure! Perhaps it was advice I received from Peter Sweeney and Bill Pollard. Since they're very reputable, I let the car idle until there's some heat brewing under the engine cowling. Plus, the Mondial warm's itself up in a sense; i.e. the high idle upon start-up and then the decompression a few moments afterwards. Still, I find second gear engagement as a decent indication of a complete warm-up. If she's stubborn, then let her be until that oil temp guage has risen further. Having said that, I still find myself going from first to third even with the engine warm (oil temp at least 170F). Just my two cents...Thanks again guys.

Forza,

Dane

P.S. Peter (GT4) any thoughts??
 

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Dane, I am of the "Warm-up AND drive gently" crowd for all of my vehicles. I have done this to my daily driver since Day 1 (seven years ago) and the thing is in perfect shape. It has 186K+ Km on it and consumes a litre of oil every 4K Km - excellent figures.

I'll warm up the car for a few minutes and drive gently the first couple of Km. With the GT4, I'll warm up for around 5 min. and rev no more than 3000 for the first 10 min.

Naturally, during the winter, it'll take forever to get to operating temp. so I just take it easy until the water/oil temps are warm enough (150* range).
 

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Same here, Dane. I do just as Peter does. This time of year it takes forever for the oil temperature to get to 150 degrees.

Barry
 

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Discussion Starter #8
Hi guys,

Thanks for the great feedback. I do appreciate it.

Forza,

Dane
 

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about the, clutch in while idle, question

I use to work at a speed shop where we dealt with a Japanese car that had a bad reputation for a case called "crank walk". I am not familiar with any other automobiles that suffer of this case. The best way to describe the problem is:

The crankshaft's "THRUST BEARING", not to be confused with the "THROW-OUT BEARING", wears out on the side facing the clutch. The purpose of the "THRUST BEARING" is to maintain proper tolerance on the endplay of the crank. When the "THRUST BEARING" wears out on the side facing the clutch, it makes the crank move back and forth about .0625"--which I think is the average thickness of the sides of a thrust bearing. What this causes is the crank to move those .0625 inches back and fourth. When the crank moves this much it puts an excessive side load on the pistons side facing the timing belt. The metal shavings from the aluminum of the pistons, the iron of the crank, the iron of the cylinder walls, and the bearing material, all flows through the entire motor carried by the oil system. The shavings get into your oil pump they scrape the main journals and the rod journals, all the camshafts journals ect. ect. Everything that receives oiling (basically your motor is no longer any good).

There are many rumors about why this problem happens to this Japanese car. Some say it’s the materials that the crankshaft is made of. Others blame it on poor "thrust bearing" lubrication designs.

But the most popular one, and the one I believe is the most solid reason, is that the motor does have a poor lubrication design and that there might have been a poor batch of alloys in the castings of these crankshafts. All of the owners of these cars have one habit in common when they post on the Internet. They always leave the clutch in at stop lights, idle, and ect. ect.

Why would this be the major cause for Crank Walk?

The answer is because when the clutch is disengaged, meaning over 2,600 psi (pounds per square inches) of side load on the crank shaft, you are multiplying the risks of getting crank walk because there isn’t enough oil pressure to maintain the "THRUST BEARING" against crank properly lubricated. With 2,600 psi pushing on the "THRUST BEARING" against the crank I don’t believe it would have any oil at all in between these two parts, at least not with the oil pressure available at 500-1,500 rpm which is about 90 psi. Another fact that would support my opinion is the design of this particular thrust bearing it is a flat surface on the side with only two slits on it, and the part of the crank that touches this side is also flat with no slits or perforations. The perforations within the design of other "THRUST BEARINGS" would help maintain proper lubrication under 2,600 psi of side loads, during the low oil pressure at idle.

In conclusion I just want to advise "don’t put the clutch in while you are idling the car”. And I would also advise to disconnect the plug for the clutch sensor, so that you don’t have to start the car with 2,600 psi of side load on a motor that has very little oil pressure.

( ( ( ( (((WARNING))) ) ) ) )

I DO NOT SUGGEST THAT YOU UNPLUG THE CLUTCH DISINGAGEMENT SENSOR FOR STARTING THE CAR IF YOU CANNOT UNDERSTAND THE FACT THAT YOUR CAR HAS TO BE IN NEUTRAL WHILE CRANKING.

<NOT RESPONSIBLE FOR ANY BLOWN OUT FERRARI STARTERS>

NOTHING WILL HAPPEN TO YOUR STARTER IF YOU START THE CAR IN NEUTRAL.
 
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