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Discussion Starter · #2 ·
People think their car is fast

People think their car is faster than it really is. When they realize that it is not that fast they seem to compensate.......they "drop" the clutch more often to get that extra fast start. this will wear out any clutch in no time.

I have noticed that more 308s burn up clutches than other Ferraris. Since the 308s are the slowest Ferraris, one can see why.

I have put 40,000 miles on my TR clutch, and it still has 1/3 left. It is plenty fast for me.

Of course, there are 360s with replaced clutches, after only a few miles........again, the driver wanted something faster.
 
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Discussion Starter · #3 ·
I drove my 275 GTB 65,000 mile

I drove my 275 GTB 65,000 miles.
I drove my 308 GTB 85,000 miles.
I drove my TR 115,000 miles.
I've never had to replace a clutch.
Clutches go because people don't know how to use them.
E Gear/F1 clutches go because computers don't know how to use them in stop and go, on hills, and in back and forth parking.
BTW if you know how to match rev's you really don't even need a clutch. The clutch cable on my 308 snapped on the West Side Highway. I was able to drive it 40 miles to WWOC with no problem.
If you have to come to a dead stop shut off the car in gear. Start it in gear and you're off. Once you're rolling back off throttle, put lever into N, blip throttle to match rev's, up shift. If you do it right, as with most things, it will go right in.
 
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Discussion Starter · #4 ·
I had a T-bearing break in ha

I had a T-bearing break in half on one of my cars and had to drive without a clutch for quite a ways. When coming to a stop I would let off of the gas pedal slightly to achieve a neutral load on the drive train and just knock it out of gear. No lurching to a stop and easier on the brakes. I then shut the engine off and put it back into gear before the light changed.

I always try to keep the RPM's as low as reasonable when taking off. With a 308 it isn't that hard to do. Like Jim I have gotten over 50k on every clutch I have installed.

I believe the key to longevity is the 'judicious application of power'.
 
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Discussion Starter · #5 ·
Jim put it very well. I too ha

Jim put it very well. I too have never replaced a clutch in one of my cars due to wear. It's the driver that causes short life. Compared to domestic cars, especially old muscle cars, Ferrari clutches are small in diameter. They're engineered for the correct amount of torque and Hp, but not overdesigned as were the domestics. I think GM, Ford, and Chrysler used larger then necessary clutches in some cases as they knew the skill level of the customer base.
 
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Discussion Starter · #6 ·
Is there any wear on the clutc

Is there any wear on the clutch if I hammer my F355 once it is fully engaged? I think the answer is no, but better I ask.
--tony
 
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Discussion Starter · #8 ·
Bill,

I like to learn new t


Bill,

I like to learn new things and was hoping you could teach me this. How does a larger vs smaller clutch size alleviate the problem of poor driving? It is stronger?
 
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Discussion Starter · #9 ·
Welcome Andrew,

This is a


Welcome Andrew,

This is a good place to come for straight forward answers to your questions. There are a number of automotive masters on this site with years of experience. Even so, maybe I can answer,

The larger diameter clutch has more friction surface which equates into a better grip requiring less slippage producing less heat. Inept drivers usually slip the clutch too much generating huge amounts of heat, burning the clutch disc and creating hot spots in the surface of the flywheel. I believe the larger clutch is also easier to modulate. Slippage and heat are the destructive factors.

The larger diameter clutch also has more mass which slows the rate at which an engine increases in RPM's when acclerating which explains why high performance/race cars use a low mass clutch and lightweight flywheels. Less weight, faster revs, more power, quicker.

Hopefully this will explain why it is so easy to FRY a lowmass, small diameter clutch.

Any additional information is welcome on this guys.................

DJ
 
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Discussion Starter · #10 ·
Spasso,
Thanks for the very i


Spasso,
Thanks for the very informative, and right on target response.
 
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Discussion Starter · #11 ·
Cool I didn't understand t

Cool I didn't understand the clutch part. Thanks for the education.

The part about the flywheel. Some physics 101. By reducing the flywheels mass you reduce the power needed to rotate the mass. This means that power is freed and goes strait to the friction on the pavement = more top speed and quicker accelerations, but more top speed.

Never really thought about the heat and size. Good info.
 
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Discussion Starter · #12 ·
My pleasure Bill.

Andrew,


My pleasure Bill.

Andrew,
To further demostrate, take a look at the clutch & flwheel on a semi truck some time, huge and heavy. A semi relies rotating mass to maintain the torque potential of the engine while starting out with a heavy load..

I have enjoyed watching vintage gasoline powered stationary engines that were used for running threshing machines in the 20's and 30's. They employed a huge weighted flywheel that once in rotation did most of the work through inertia with only a minimal amount of power to keep it spinning.

With the heavier clutch and flywheel in your car it may not excelerate as quickly as one with a light weight flywheel but will eventually reach the same top speed and want to stay there with less applied power.

Trade-offs based on purpose.

DJ
 
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Discussion Starter · #14 ·
Moment of Inertia (MOI&#41

Moment of Inertia (MOI) is the big advantage of smaller diameter clutch's, flywheels, even brake rotors, wheels. A low MOI will allow clutch, flywheel to accelerate and decellerate faster. It does matter where on the part the weight is. The farther from the center of rotation, the higher the MOI will be for that part. Watch a ice figure skater spin. As she spins and moves her arms into her body, the spin rate increases, but the total mass has not changed.She will still weigh the same, but moving her arms in closer to the rotation center has reduced her Moment of Inertia. On engine and drive train parts, Lower MOI will add Quickness, Engines will increase rev's faster per second with lightweight rotating parts. Engagement modulation harshness is a factor of the friction materials that are bonded on the clutch disc. As stated by others, slipping causes heat and that heat will cause more slippage, Just my 2 cents worth!
 
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