Fluidampr pulley DSS Carbon Driveshaft

[humfrz]

Originally Posted by twag4

This is incorrect. The crank pulley being smaller means the other components spin at lesser RPM compared to engine rpm.

You're both correct/incorrect ……. depending on whether or not, you are talking about the size of the crank-or pully or the size of the crank-ee pully ….. …… relative to each other.




humfrz

[gtengr]

For everything that spins in the drivetrain, the amount of horsepower released from inertia changes is a result of the difference in power that it takes to accelerate that part from rpm 1 to rpm 2 in time t. The time it takes for the car to accelerate itself usually makes the amount of freed power from rotating part inertia changes a negligible amount. For the driveshaft it is essentially 0. It could be weightless and the biggest benefit to acceleration would still be the static weight loss.

[twag4]

Originally Posted by nikitopo

This is not how you do it. You keep the crank pulley same size and change the size of the other pulleys. You want different underdrive ratios per component. You might also need to not underdrive certain components. For example, I underdrive the alternator and not the water/coolant pump. You also need larger pulleys and not smaller. Let's not misinform people.

I get that. The ATI unit, does in fact, reduce the size of the crank pulley. This underdrives all other systems.

[Spuds]

Originally Posted by humfrz

Smart move ……. since you tend to get all tangled up in your underwear late at night …..


humfrz

Yeah, got no idea what you are referring to... Is this too many meds, or too few?

[Spuds]

Originally Posted by weederr33

It's kind of like when you are stirring a pot of freshly made stew. The fluid is all rotational and physics-y, but all you care about is the soft chopped up potatoes, carrots, and beef. They add variables to the rotational mass right? I mean, they add mass regardless because the beef and veggies are converted to energy which is then either expended or stored in the body. But then it's sooooo tasty. But if you don't use a wooden spoon it's just not the same. Oh and fluid dampers help, right?

Damn I could go for some beef stew right now...

[humfrz]

Originally Posted by Spuds

Yeah, got no idea what you are referring to... Is this too many meds, or too few?

Hint...….


humfrz

[86TOYO2k17]

I found an in depth article explaining the physics and doing the math on everything. It was specifically for mustangs but principals still stands.

A 30lb shaft dropping to 15lbs with same diameter on a 13sec car would avg an extra 1/4hp for the run.

However a flywheel going from 25 to 12.5 bcs of the larger diameter would net about 3.5hp over a 13second run.

I guess I need to find something else to throw money at.

[Spuds]

Originally Posted by 86TOYO2k17

I found an in depth article explaining the physics and doing the math on everything. It was specifically for mustangs but principals still stands.

A 30lb shaft dropping to 15lbs with same diameter on a 13sec car would avg an extra 1/4hp for the run.

However a flywheel going from 25 to 12.5 bcs of the larger diameter would net about 3.5hp over a 13second run.

I guess I need to find something else to throw money at.

Interestingly enough, you would actually recover some of the flywheel energy on a shift if you do it right.

Also, those estimates sound about right.

[nikitopo]

Originally Posted by 86TOYO2k17

I found an in depth article explaining the physics and doing the math on everything. It was specifically for mustangs but principals still stands.

A 30lb shaft dropping to 15lbs with same diameter on a 13sec car would avg an extra 1/4hp for the run.

However a flywheel going from 25 to 12.5 bcs of the larger diameter would net about 3.5hp over a 13second run.

I guess I need to find something else to throw money at.

It is not only about how the mass is distributed like the diameter. It is also about where this mass is located. Gains from rotational weight are best if they located before the transmission. You can imagine that the car is much lighter because of the gearing, so even reducing a few kg makes sense. People arguing that this doesn't work, they don't understand the basic principle of gearing. The driveshaft on other hand is located after the transmission, so the gearing doesn't help at all.


And by the way, the gains of a flywheel weight reduction are more. You remove most of this weight from the outside part of the flywheel , so it has a much less inertia.

[churchx]

There are three bits important to rotational kinetic energy.Mass, it's distance from rotating center, and rpms. For engine flywheel it's all three. For driveshaft, only first to some extent with little left of later two. For wheels mostly first two.
It's not location pre or post transmission that increase or decrease need of energy spent to spin up some part. In this case it's difference of rpms that by chance are different for engine or post gearbox tranny parts, that affects that. Though drifeshaft also lacks diameter in addition to lower rpms it's spun at, for lightening to be very effective. If driveshaft had been spun at 10x faster rpms due different gearing from gearbox / final drive, results would be different. Rpms (and diameter), not location.
Think all of them as flywheels of different shapes/masses/spinning speeds and think what impacts energy needed to spin up flywheels in general and which each of them have of those properties.

[nikitopo]

@churchx Yes, you expressed this better. The pre or post transmission location affects the rpms.

[churchx]

It's not as lighter drive shafts don't make sense at all though, as due their sheer size/length there they still weight noticeably .. just that lightening them serve more like lightening car/it's sprung/unrotational weights in general, not so much vs lightening rotational weight of other parts that spin much faster and/or that have weights located further from rotation center, and for general car lightening there are better ways of better returns per buck or lightening by much larger weight if within limited budget, then buying expensive shaft. Interior ripping, removal of misc comfort items like AC/audio/noise insulation, lighter battery, lighter seats, rear seat removal, lighter exhaust, removal of crap in trunk, lighter wheels & brakes, lighter flywheel, removal of washing liquid tank and so on ..
If budget is unlimited and there are no class limits on that, shaft can also be one of many things to be installed for lighter weight too. But otherwise main purpose why someone should look at aftermarket driveshafts is their ability to transfer more torque of more powerful forced induction engines without breaking, lesser weight being just slight bonus of little importance, insufficient to justify the price if lightening being sole reason. Due a shape/small diameter that lightening being for rotational mass also doesn't make much difference in this particular case.

[chaoskaze]

Originally Posted by humfrz

Hint...….





humfrz

I wonder if Tcoat takes any? You folks should have a competition on who is taking the most pre day.


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[humfrz]

Originally Posted by chaoskaze

I wonder if Tcoat takes any? You folks should have a competition on who is taking the most pre day.


Sent from my iPhone using Tapatalk

Oh, that reminds me ……...be right back ……… OK, I'm good …… the Wed AM cell in my pill container is empty …..

I'm afraid that I would "win" the pill consumption per day contest ……

Besides, ol @Tcoat wouldn't fess up to taking ANY medications; @Ultramaroon has no idea of how many pills mrs Ultramaroon slips into his morning coffee, just to keep him level and ol @Sapphireho wouldn't fess up …. cause that would confirm our suspicions about his "condition(s)" …….





humfrz