GFB 3-Piece lightweight aluminum pulley kit

[WolfsFang]

Is it possible to get 2 piece? I already have a lightweight pulley

[gmookher]

nice kit

[Darryljr11]

Interested but I wanna see how it performs for others. Won't be putting any parts on the FR-S till May anyways.

[OrbitalEllipses]

Originally Posted by Captain Insano

Awesome writeup!!

For those asking if this benefits AT - of course it does. Anything that drops rotational weight is beneficial for quicker revs and acceleration the more weight you drop... and less driveline weight the engine needs to directly move/spin. You wont notice from a shift "feel" perspective like a MT though since that is all "automated" on the AT cars.

The problem with the AT will be the torque converter. You can drop all the rotational mass you want, but that torque converter will always have the most drag (fluid).

[Captain Insano]

Originally Posted by OrbitalEllipses

The problem with the AT will be the torque converter. You can drop all the rotational mass you want, but that torque converter will always have the most drag (fluid).

Ummm... Even if you think the torque converter is a huge loss in power (in reality it's not) dropping rotational mass is still only going to help. If you have to fight the fluid in torque converter and 100 lbs of mass to spin, and you change the equation so you have to fight the fluid in the torque converter and only have to fight say 90 or 80 or 70 lbs of mass... Does it help to have dropped that mass? Rhetorical question.

[OrbitalEllipses]

Originally Posted by Captain Insano

Ummm... Even if you think the torque converter is a huge loss in power (in reality it's not) dropping rotational mass is still only going to help. If you have to fight the fluid in torque converter and 100 lbs of mass to spin, and you change the equation so you have to fight the fluid in the torque converter and only have to fight say 90 or 80 or 70 lbs of mass... Does it help to have dropped that mass? Rhetorical question.

The point was that incremental drops in rotating mass won't help as much as you're making it seem like they do. You can't defeat physics at the end of the day.

And I never said power.

[Captain Insano]

The same could be said on an MT or AT.
The point was that incremental drops in rotating mass won't help as much as you're making it seem like they do.

And the tiny fraction of a difference the torque converter makes compared to the MT, you could again say the same thing you said...
The point was that incremental drops in rotating mass won't help as much as you're making it seem like they do.

I guess my opinion is - if you are contending these pulleys make no difference or minimal difference on an AT or MT, maybe that is true, I haven't run them. But I would say I'm a very firm believer in dropping weight, especially rotational weight. If you are trying to say these pulleys make a bigger difference on an MT versus an AT, maybe, but I woudl think it would be so imperceptible that the diff would not be noticeable.

I'm done, I'm not going to fight about AT versus MT. It has been beaten to death.

The pulleys look great.

[OrbitalEllipses]

Heavy fluid filled torque converter vs. flywheel that you can replace for a lightweight piece; that's where the most difference in feel will be had from dropping rotating mass.

Enjoy your delusions. /out

[Captain Insano]

Originally Posted by OrbitalEllipses

Heavy fluid filled torque converter vs. flywheel that you can replace for a lightweight piece; that's where the most difference in feel will be had from dropping rotating mass.

Enjoy your delusions. /out

OK, I will enjoy my delusional state that a torque converter somehow renders dropping rotation weight as a pointless exercise. I guess lightweight wheels, lighter drive shafts, lighter pulleys are all pointless modifications on a car with a torque converter. Thanks for all your wisdom on this topic I do appreciate it. /out

[soros151]

Originally Posted by Touge Factory

Here is what Go Fast Bits wrote:

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.

That's a good theory. Nice. The CEL engine everyone is talking about is about the pulley being so light that the crank sensor would read twice and thus throw a check engine light.

[Touge Factory]

Good news guys,

GFB will allow customers to purchase the two accessory pulleys for anyone that already has the crank pulley.
MSRP: $190.00 for the two pulleys.

[Touge Factory]

The 3 piece pulley sets are BACK IN STOCK!

[Celica00]

Originally Posted by number1Tango

this won't throw CELs for being so light? don't quote me on this but, I remember reading on here someone talking about the wrx's and what not having CELs because the system was so light the car thought it was misfiring.. anyone have any incite? Perrin said something that that's why they kept theirs at a moderate weight and they HAD the option of going lower in weight but didn't. maybe that's just a thing of the past..

no it wont. its just like getting a lighter flywheel. just makes engines more responsive during acceleration

[bpracer]

Originally Posted by Touge Factory

Here is what Go Fast Bits wrote:

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.

...

It was a fine explanation until that point, but the last part is utter crap.

It is the outer mass that does the damping, it is that mass that is tuned.

I'm not saying there is anything wrong with the product, but that explanation is just wrong.