Need Help getting power without Forced Induction

[Shiv@Openflash]

Originally Posted by 2016 Camaro SS

Here we go again with the lightweight crank pulley nonsense.

I've been running one for two years with 0 issues. The engine is already balanced. If anything, it revs slightly more freely with it. Not a major change, but looks nicer than the heavy stock pulley.

No one said that eliminating the factory harmonic damper will cause any noticeable sign of wear and tear in a matter of X years. But it will put more stress on the crankshaft and its bearings than running with a damper in place. And in high boosted applications where you are already putting the bottom end through much more stress, it can indeed lead to a premature failure. This is fact. If it wasn't, there would be no reason for OEMs to invest hundreds of thousands of dollars to design a unique harmonic damper for each of their engines.

A lightweight pulley won't cause the engine to rev up noticeably faster because, unlike a lightweight flywheel, a lightweight pulley only takes a few pounds off near the center of rotation. If you feel it rev faster, it's a placebo. However, if you went with an under-drive pulley (smaller diameter) will you notice the engine to rev more freely because you are spinning all the accessories (alternator, AC, etc,.) slower. This means less parasitic drag and power power to the wheels.

It's perfectly OK to be willing to accept the downsides of running a lightweight (damperless pulley). Many people do and they don't experience spontaneous engine failure. But it's not OK to pretend they don't exist and tell people it's "nonsense". It's only nonsense to people who don't understand the science behind it.

And no, no engine is "balanced" to the point where it is free of 1st, 2nd and 3rd order harmonics. This is a myth spread by those who sell lightweight pulleys. Any engineer or race car developer will laugh at that notion.

[stugray]

Originally Posted by mad_sb

No but they do reduce rotational mass resulting in more power at the contact patch and better acceleration. Dynodynamics can actually measure the power gain from lighter wheels and tires, saw it many times when i used to tune on one.

Some of us still contend that you cannot have horsepower gains by reducing any part of the rotating mass.

Why lightened engine (rotating mass) components will not make a difference in horsepower:

Consider a Manual Transmission car in a fixed gear climbing a hill.
The engine is coupled to the transmission (via clutch), and the transmission is coupled to the rear wheels all with a fixed drive ratio.

So the engine is coupled to the wheels, and the wheels are coupled to the ground.
So the engine is coupled to the ground.

So now imagine that the driver mashes the pedal to the floor.
Does the engine rev up uncontrollably? – Like sitting out of gear?
No, the wheels are “connected” to the ground.
So the engine will rev as fast as the car can accelerate.


The “momentum” keeping the engine from spinning up is not ONLY due to the rotational mass of the engine & drivetrain components it is ALSO due to the mass of the vehicle and therefore it’s resistance to acceleration (inertia).

The resistance that is keeping the engine from revving out of control is NOT limited only by the rotating mass, it is limited by the rotating mass PLUS the mass of the vehicle.

The rotational mass of the drivetrain is definitely a “component” of the inertia, but it is a very small component of the total system inertia.


So if you remove the mass from the car chassis, you will see no difference in 0-60 times than if you had removed it from rotating mass.


Now reducing rotating mass is DEFINITELY helpful in reducing forces inside the engine so it is still a good idea.

[midnight23]

NOS, two of the big ones.

[Shiv@Openflash]

The performance benefits of lightweight wheels (and to a lesser extent, LW flywheel) very real and measurable on a Dyno or on the road. The power to the wheels gains are very significant in 1st gear, a bit less in 2nd, less in 3rd and so on. The lower the gear, the faster the rate of acceleration and the larger the inertial component in driveline loss. 15 or so years ago, SCC mag tested the effects of lightwheel wheels on a Honda Civic. In a first gear pull, it picked up something like 20whp on the Dynojet. In second gear, maybe 10whp. By 4th gear, there where no measurable gains. I wish I had the article in front of me to provide details but that's the gist of it. So in a 0-60 sprint shaving weight of wheels will make a substantial difference. In top gear 50-70mph passing times, not so much

Keep in mind that brake dynos that hold engine speed at steady state conditions will not show these gains because acceleration is zero. But on a ramp up pull (or on the road) they are very real.

[cdrazic93]

Weight reductionnnnn. Boom. Youre welcome.


Gawd, its like physics class in here all over again

[wootwoot]

Nos?

[cslntuee]

What's your comment for this description?




"Why no Harmonic Balancer?

A better name for a harmonic balancer would be "torsional dampener" since its main task is to absorb the rotational pulses inflicted on the crankshaft by the pistons. Most often it is incorporated into the crank pulley by attaching the outer belt drive ring to the inner by means of vulcanized rubber. At the right RPM, it is possible for a resonant frequency to be set up torsionally on the crankshaft. Resonant frequency occurs when the pulses of the engine correspond with the natural frequency of the crankshaft and it ancillary components. However, since factory pulleys are often comparatively heavy (reasons for this are described later) it is actually the large mass (and therefore inertia) of the factory harmonic balancer and flywheel that will help to excite this natural frequency. So by dramatically reducing the weight and inertia of the crank pulley, the natural frequency of the crankshaft is shifted and its ability to self-excite is greatly reduced. So in fact it is the harmonic balancer's own weight that necessitates the dampening, and since the weight of a GFB crank pulley is typically about 20% of the factory component it cannot supply an exciting force significant enough to damage the crankshaft.

An opinion often expressed is "if the manufacturer put it there, it must be there for a reason". However, if you look at it from the car manufacturer's point of view, casting pulleys from steel is very cheap and easy, because they can be produced in large numbers and there is no waste (as opposed to machining them from billet). But because the resulting pulley weighs significantly more than one made from aluminium alloy, it requires dampening.

Manufacturers will always build cars (even high performance cars) to suit the widest possible selection of driving scenarios and drivers, which means there are always compromises. The weight of the flywheel and pulley also affect how fast the revs drop between gear shifts, and a production car is designed to only allow the revs to drop fast enough for average shifts. If you hurry the shift the revs will be too high for the next gear, resulting in a sharp jerk as the momentum of the engine transmits through the drivetrain. Reducing the engines' inertia with a lightweight pulley kit allows faster and smoother shifting.

When looking at high performance engines such as those found in Honda VTEC equipped cars and the S2000, it is obvious that manufacturers do understand the benefits of reducing engine inertia, and have utilized lightweight pulleys to help the power output and responsiveness without the use of a harmonic balancer.

However, this is not the case for all engines, many of them do require the use of the harmonic balancer to prevent failure. Skylines with the RB20, 25 and 26 are a good example of this, which is why we don't make a pulley kit for them. The pulley kits we do make are for engines that do not rely on the balancer to any significant degree."

http://www.ft86speedfactory.com/go-f...y-kit-602.html

Thanks.

Originally Posted by Shiv@Openflash

No one said that eliminating the factory harmonic damper will cause any noticeable sign of wear and tear in a matter of X years. But it will put more stress on the crankshaft and its bearings than running with a damper in place. And in high boosted applications where you are already putting the bottom end through much more stress, it can indeed lead to a premature failure. This is fact. If it wasn't, there would be no reason for OEMs to invest hundreds of thousands of dollars to design a unique harmonic damper for each of their engines.

A lightweight pulley won't cause the engine to rev up noticeably faster because, unlike a lightweight flywheel, a lightweight pulley only takes a few pounds off near the center of rotation. If you feel it rev faster, it's a placebo. However, if you went with an under-drive pulley (smaller diameter) will you notice the engine to rev more freely because you are spinning all the accessories (alternator, AC, etc,.) slower. This means less parasitic drag and power power to the wheels.

It's perfectly OK to be willing to accept the downsides of running a lightweight (damperless pulley). Many people do and they don't experience spontaneous engine failure. But it's not OK to pretend they don't exist and tell people it's "nonsense". It's only nonsense to people who don't understand the science behind it.

And no, no engine is "balanced" to the point where it is free of 1st, 2nd and 3rd order harmonics. This is a myth spread by those who sell lightweight pulleys. Any engineer or race car developer will laugh at that notion.

[Shiv@Openflash]

You are quoting GoFastBits, manufacturer of lightweight pulleys (damper-less). And they are incorrect about the S2000. It does have a rubber inertial ring coupling a HEAVY steel pulley to the crankshaft. This rubber ring does the job of damping destructive harmonics. For every one advertising spouting pseudo-science and misinformation, there are dozens of engineering papers discussion the effects of harmonics and dampers used to minimize them.

Originally Posted by cslntuee

What's your comment for this description?




"Why no Harmonic Balancer?

A better name for a harmonic balancer would be "torsional dampener" since its main task is to absorb the rotational pulses inflicted on the crankshaft by the pistons. Most often it is incorporated into the crank pulley by attaching the outer belt drive ring to the inner by means of vulcanized rubber. At the right RPM, it is possible for a resonant frequency to be set up torsionally on the crankshaft. Resonant frequency occurs when the pulses of the engine correspond with the natural frequency of the crankshaft and it ancillary components. However, since factory pulleys are often comparatively heavy (reasons for this are described later) it is actually the large mass (and therefore inertia) of the factory harmonic balancer and flywheel that will help to excite this natural frequency. So by dramatically reducing the weight and inertia of the crank pulley, the natural frequency of the crankshaft is shifted and its ability to self-excite is greatly reduced. So in fact it is the harmonic balancer's own weight that necessitates the dampening, and since the weight of a GFB crank pulley is typically about 20% of the factory component it cannot supply an exciting force significant enough to damage the crankshaft.

An opinion often expressed is "if the manufacturer put it there, it must be there for a reason". However, if you look at it from the car manufacturer's point of view, casting pulleys from steel is very cheap and easy, because they can be produced in large numbers and there is no waste (as opposed to machining them from billet). But because the resulting pulley weighs significantly more than one made from aluminium alloy, it requires dampening.

Manufacturers will always build cars (even high performance cars) to suit the widest possible selection of driving scenarios and drivers, which means there are always compromises. The weight of the flywheel and pulley also affect how fast the revs drop between gear shifts, and a production car is designed to only allow the revs to drop fast enough for average shifts. If you hurry the shift the revs will be too high for the next gear, resulting in a sharp jerk as the momentum of the engine transmits through the drivetrain. Reducing the engines' inertia with a lightweight pulley kit allows faster and smoother shifting.

When looking at high performance engines such as those found in Honda VTEC equipped cars and the S2000, it is obvious that manufacturers do understand the benefits of reducing engine inertia, and have utilized lightweight pulleys to help the power output and responsiveness without the use of a harmonic balancer.

However, this is not the case for all engines, many of them do require the use of the harmonic balancer to prevent failure. Skylines with the RB20, 25 and 26 are a good example of this, which is why we don't make a pulley kit for them. The pulley kits we do make are for engines that do not rely on the balancer to any significant degree."

http://www.ft86speedfactory.com/go-f...y-kit-602.html

Thanks.

[Captain Snooze]

Where have I read this discussion before?

[swarb]

Last paragraph.

Originally Posted by cslntuee

**snipped**
However, this is not the case for all engines, many of them do require the use of the harmonic balancer to prevent failure. Skylines with the RB20, 25 and 26 are a good example of this, which is why we don't make a pulley kit for them. The pulley kits we do make are for engines that do not rely on the balancer to any significant degree."

[URL]http://www.ft86speedfactory.com/go-fast-bits-pulley-kit-602.html

here is a manufacturer of dampers opinion- ATI racing
Crankshaft Vibration Dampers 101
The Danger of Power Pulleys & Understanding the Harmonic Damper

they make a 10% underdrive damper here
http://www.atiracing.com/products/da...dam-subaru.htm

[swarb]

ELECTRICSUPERCHARGER

[2016 Camaro SS]

Originally Posted by Captain Snooze

Where have I read this discussion before?

http://www.ft86club.com/forums/showthread.php?t=79308 Questions about LWCP and LWFW
http://www.ft86club.com/forums/showthread.php?t=21676 Caused by flywheel

Still no engine failures due to a LWCP, N/A or boosted. Like I said, the charts and evidence of a LWCP is so minor, that its mostly for looks than performance, and getting rid of a brick for a pulley.

I probably would not run a LWCP boosted just because of the added stress and power, but that's a personal choice. I think there are still plenty of people both turbo and SC'd that have no issues running them.

You can even look at Grimmspeed's in depth research of why they made the pulley and straight up said, it's not THAT much of a performance increase or anything you will feel, but some of the data suggested there is still a benefit to using it. Granted the tests ran can always be improved further, but the cost of doing those also rises.

Lightweight Crank Pulleys are fine. The stock pulley is fine. Pick your Coke or Dr. Pepper.



Back on topic: A pulley isn't going to do much on power.

Header, OP/FP, Tune, E85 is the strongest combo for N/A hands down. Drop in filter on your intake if you want to save money, or go with a good cold air intake that has good MAF placement and air straighteners. (i.e. Grimmspeed, Skunk2)

Some light weight wheels also help.

[stugray]

Originally Posted by 2016 Camaro SS

You can even look at Grimmspeed's in depth research of why they made the pulley and straight up said, it's not THAT much of a performance increase or anything you will feel, but some of the data suggested there is still a benefit to using it. .

Yes exactly the same as removing the weight from anywhere else on the car.
I will bet $1000 that someone would feel a bigger difference in 0-60 times by removing the spare tire from the trunk than installing a LWCP.

[cslntuee]

Originally Posted by Shiv@Openflash

You are quoting GoFastBits, manufacturer of lightweight pulleys (damper-less). And they are incorrect about the S2000. It does have a rubber inertial ring coupling a HEAVY steel pulley to the crankshaft. This rubber ring does the job of damping destructive harmonics. For every one advertising spouting pseudo-science and misinformation, there are dozens of engineering papers discussion the effects of harmonics and dampers used to minimize them.

How do you think about GrimmSpeed's post as below?


http://www.ft86club.com/forums/showp...5&postcount=69


Thanks again.