GFB 3-Piece lightweight aluminum pulley kit
 

GFB (Go Fast Bits) has just released their 3 piece lightweight aluminum pulley kit for the FR-S / BRZ FA20 motor.

The pulleys are made out of 6061 T6 billet aluminum. Design is slightly different then AGP and Perrin.
With GFB kit, you get crank pulley, alternator pulley, and water pump pulley.
One of the main reasons why you would install a lightweight pulley on your car is to reduce rotational inertia. Reduction in rotating inertia allows the engine to accelerate throughout the rev range much more efficiently. This allows you to get up into the power band much faster.

Install was a nothing out of the ordinary. The Alternator and water pump pulley came off easily. The crank pulley will require the use of a breaker bar.
Since the pulleys are not underdriven, the stock belts can be re-used.

With the pulleys installed we started the car and went for a test drive.
We immediately noticed the difference in acceleration in the 2nd and 3rd gear. Once it gets up to around 3500 rpm range revs really come on fast. Rev matching is much easier, and car feels more responsive to your throttle inputs as well.

Overall we are very pleased with the quality of the pulleys, and best of all we like the overall improvement on the drive-ability.

http://cdn2.bigcommerce.com/server28...48.600.400.jpg

Crank Pulley: 4.15 pounds difference!!!!
http://cdn2.bigcommerce.com/server28...42.600.400.jpg

A/C pulley: 50% less weight!
http://cdn2.bigcommerce.com/server28...45.600.400.jpg

Holding these two in your hands... pretty shocking to feel the difference.
http://cdn2.bigcommerce.com/server28...46.600.400.jpg

Installed...looking pretty
http://cdn2.bigcommerce.com/server28...47.600.400.jpg

For Pricing please CLICK HERE

Are they under driven as well?

They are not.

Perfect! Thank you for the quick reply :thumbup:

You might have some more of my $...

Is that not the water pump pulley not the A/C?????

does it cone in any other color?

GFB pulley kits are typically black.

Any long term effects to the engine?/ alternator

You are correct. A/C pulleys are "clutched" cannot replace that.
The lower pulley is the WATER pump pulley.

Sorry about that.

Please PM me price to 86351 thanks

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.

Would this be beneficial on an AT? I've been waiting to see what other options come out and considering swapping out most of the pulleys to reduce weight.

Just for that writeup send me an invoice and ill buy it..