I just bought a steel one piece driveshaft for my '90 ZX and i was just wondering if i will notice any difference in power or anything like that. It's about 20 lbs lighter than the stock two piece driveshaft on the Z, so I'm hoping it will free up a little bit of power. What do you guys think?

 

you will be freeing up some horsepower...probably not enough to really tell
the engine will also rev a little faster, but it will also ???de-rev??? faster

 

Depending on which driveshaft you bought..you'll have a few different gains. But they may be so insignificant you maight not notice immedialty.
1) the one piece driveshafts from Z1 are re buildable. Where as the factory units were not.
2) you will have these crap there to suck the energy you want when you launch. It will preload better givin you a more powerful launch.
3) I beleive the figure is..but dont quote me...I think for every pound u take of the crankshaft drivetrain you regain like 1 to 2 horsepower
4) additionallly, you will rev faster thus acceleratin faster

I wonder if it will help with engine longevity by reducing the weight it has to spin??

 

Well if i think it is about 1.7 hp for every pound you save. So if that's right, with a 15 lbs lighter driveshaft, that should free up about 25 hp? Do you guys think that's right?

 

No. You likely gained a max of 5HP at the wheels. By reducing the weight of the driveshaft you reduce the amount of power that is lost through the drivetrain. Most cars lose approximately 15-20% through the drivetrain. That's why the HP rating at the flywheel is so much higher than the HP at the wheels.

 

BINGO, 91zxtt het the nail again, and just so all understand I'll give the following example:
Engine flywheel=HP300
RWHP=250HP
Difference= 50HP
The engine is working with 300 HP were as the drivetrain is working with 250 HP.
If you had a 10% reduction in mass weight, you'd have 10% of 50=5, so you'd have 5 HP gain.

 

It's not really as linear as that. Since the drivetrain mass matters less and less the faster it's turning, you won't see any more top end power, but you'll get quicker response and a little improvement in acceleration. Most of the power lost through the drivetrain if from friction, not weight.

BTW what the hell is mass weight? That doesn't even make sense.

 

Same thing holds true for the engine. Less rotating weight, quicker reving and quicker deaccelerate.
Gee, I hate to confuse the collage boy with big words. Look up mass weight.

 

Besides that, just make it so you have less weight setting on the four contact patches. That equals better performance. I'll be going with an aluminum d/s if I ever need one.

 

But that doesnt answer my question...by doing a 1 piece drive shaft. Would this add in engine longevity by reducing the rotational masses that the engine has to turn??
ANother thing, which is better in terms of launch? a carbon fibre or steel driveshaft? I know carbon fibre are safer, but i ve heard carbo fibre will pre load better than steel or aluminum.

 

Only speculation here, buy maybe with it being lighter and not having the center carrier, any out of balance that will exist (in any rotating mass) would be less amplified, ie: vibration, which is transferred throughout the rest of the drivetrain. Hence, reducing wear on bearings and seals. How's that for a shot to left field...

More speculation, With the carbon fiber d/s. one of the benefits is that it will twist quite a bit more than steel and aluminum without permanantly deforming. It will act like a shock absorber (torsion bar?) between the clutch and the tires on the ground. On hard launches, the intial force of dropping the clutch would be distributed over a longer period of time (maybe miliseconds) to the rear wheels which helps maintain traction.

 

CC has hit the bullseye dead center. I've heard of aluminum DS breaking but never seen one do it, and it was only hear-say.

 

I though about this a little more last night............ I asked myself while would nissan go to a 2-pc. d/s with a center carrier? My guess would be that they did this for durability/longevity purposes. Based on the rotating mass, vibration, torque loads and input/output angles, etc. the high $ engineers figured this was the best design. They don't do these things for nothing. With that in mind, we're prolly all killing our tranny tailshaft and diff bearings by going to a 1-pc. d/s. The difference being that we might only get 150k miles out of our tranny/diff bearings instead of 170k miles........

And on d/s strength, I've seen a twisted d/s or two, but more often than not, once you get enough rubber on the ground (bigger tires) to improve traction, the next weakest link in the system is usually an axle shaft. I've seen those break more often than d/s

 

Uhh.. that's exactly what I said.

It's still not anywhere near as linear as you suggestted in your first post. And like I said won't bring any significant hp gains.

Please.. enlighten me. What is mass weight?

Also, what's a collage boy?

 

Well according to the National Physical Laboratory it's as follows:

Mass is a measure of the amount of material in an object, being directly related to the number and type of atoms present in the object. Mass does not change with a body's position, movement or alteration of its shape unless material is added or removed. The unit of mass in the SI system is the kilogram (abbreviation kg) which is defined to be equal to the mass of the international prototype of the kilogram held at the Bureau International des Poids et Mesures (BIPM) near Paris. Mass can also be defined as the inertial resistance to acceleration.

In the trading of goods, weight is taken to mean the same as mass, and is measured in kilograms. Scientifically, however, it is normal to state that the weight of a body is the gravitational force acting on it and hence it should be measured in newtons (abbreviation N), and that this force depends on the local acceleration due to gravity. To add to the confusion, a weight (or weightpiece) is a calibrated mass normally made from a dense metal.

 

Hence. the mass weight of 1 cu/ft of foam is a little less than the mass weight of 1 cu/ft of lead. The mass being the material, whatever it is, in a given shape.

 

I learned something today.

 

Thanks.. you described mass and weight. Elementy school physics....

Now what is "mass weight"?

 

...

Mass is dependent on volume and density, weight is dependent on mass and gravity.

Obviously since lead is far denser than foam, it will have higher mass, and higher weight.

And..... what is mass weight?

 

I dunno to be honest.

If, providing a description of 1 cu/ft of foam and 1 cu/ft of lead isn't describing two specific examples of a mass, I guess I can't do it.

How about if the statement was refraised from "mass weight" to "mass' weight". would that make more sense to you?

The original topic of this thread was about one piece driveshafts. It then headed into the weight. When the mass' weight topic came about, we were discussing steel, aluminum and carbon fiber. Assuming in general, that they all have the same mass. Zgringo the compared the weights of the various mass'.


holy $hit this is rediculous.........

 

Yeah.. ok... my point was that mass and weight are two different quantities. There's no such this *** 'mass weight'. So saying something has a mass weight of X doesn't make any sense.

All I asked was what mass weight was, so I could understand what the hell ZGringo was talking about. I didn't need three different responses about elementary physics.


Back on topic, as I said in my original post, you won't see power gain, but will see improved response and a small increase in acceleration.

 

You're definitely alot farther along in physics than some of us.......... seriously

 

According to "The American Heritage Book of Engilsh usage the term Mass Weight is as follows:

Although most hand-held calculators can translate pounds into kilograms, an absolute conversion factor between these two units is not technically sound. A pound is a unit of force, and a kilogram is a unit of mass. When the unit pound is used to indicate the force that a gravitational field exerts on a mass, the pound is a unit of weight. Mistaking weight for mass is tantamount to confusing the electric charges on two objects with the forces of attraction (or repulsion) between them. Like charge, the mass of an object is an intrinsic property of that object: electrons have a unique mass, protons have a unique mass, and some particles, such as photons, have no mass. Weight, on the other hand, is a force due to the gravitational attraction between two bodies. For example, one’s weight on the Moon is 1/6 of one’s weight on Earth. Nevertheless, one’s mass on the Moon is identical to one’s mass on Earth. The reason that hand-held calculators can translate between units of weight and units of mass is that the majority of us use calculators on the planet Earth at sea level, where the conversion factor is constant for all practical purposes. Thus the term mass weight is used.

It seems Turleboy is one of my followers from over on 300zxClub with [Banned Member]. Sorry guys for this having to go on here when all anyone wanted to know was about 1 piece driveshafts.
In contacting 2 different driveshaft mfg's they both stated about the same. You'll realize about 5-7 RWHP gain going to a 1 piece drive shaft.

 

zgringo - that's what I was trying to say, in laymans term, with the lead and foam comparo.

To further discuss (argue.. ) the driveshaft to h.p. issue. A lighter driveshaft, or anything else aft of the cranshaft, will not increase or decrease the output of a engine. It will change the characteristics of the application of the h.p. to the wheels. I do believe that a lighter driveshaft will increase the performance of a vehicle to the equivalent of 5 - 7 h.p. by reducing the overall vehicle weight. The old "pound per horsepower ratio".

The physicists here are more suited to calucate the lb/hp ratio and the improvement that is achieved by reducing the weight side of the ratio by a certain amount.

 

Zgringo.. google king. You haven't explained much.. but it's worthless trying to get any answers from you hah. People like you is what makes Zdriver such a joke. Ahh but whatever, enough off topic in this thread I'm done with it. If you feel giving me a real answer, PM me.