RadioActive Motorsports - Lightweight Pulleys

[Sentientbydesign]

Finally spoke to Greg!

So here are the details on this group buy.

We're selling lightweight crankshaft pulleys for the following vehicles:

G25
G35/350Z (VQ35DE and VQ35HR
G37/370Z (VQ37HR)
M35/Hybrid
M37
EX35
FX35

Weight is between .8 and 1 lb depending on application.

Pulleys are machined from 6061 T6 Aluminum and anodized Gunmetal Gray. Laser etched with the RAM logo.

Pricing: $160 presale
$175 NICO after production pricing

Here's one of the first pulleys off the machine (It's for another application, Just FYI).

[joe603]

Cool. Can you give the folds a quick description of the benefits to the pulley? Also, what tools would you need to replace the OEM one?

[Sentientbydesign]

Here's a quick and dirty benefits list, I'll go into my in depth list with more time.

Engine revs faster - Very few people realize that TQ and HP are not the be all end all determinations of an engine. It's ability to build power and deliver it QUICKLY is just as important.
More torque and power are delivered to the drivetrain instead of spinning a heavy pulley.
HP and TQ numbers will vary depending on application and supporting mods. A 5-10 hp increases are fairly common, however these pulleys are lighter than most others on the market.

Lightweight pulleys act in a similar way to installing lighter wheels or a lightweight flywheel. They allow the moment of intertia (a spinning objects resistance to acceleration) and/or the total mass to be lowered. In a case like our pulleys, both the moment of inertia as well as the mass were reduced.

Installation requires an impact gun or a torque bar and breaker bar.
Jack and jack stand to access pulley from wheel well
And in many cases a new belt (unless you have a relatively new one to begin with).

[kmckis1029]

ill most likely buy from you when I get my belts changed then... so I can save on labor costs.

Product looks great as usual.

[Sentientbydesign]

ill most likely buy from you when I get my belts changed then... so I can save on labor costs.

Product looks great as usual.

Can't wait for the anodizing and laser etching to be completed. These things are going to be gorgeous. There might be a small batch of special edition colors in the next month or two.

[Sentientbydesign]

lightweight-crank-pulleys-g25-g35-g37-3 ... 39570.html

Fab market thread!

[tollboothwilley]

Looks nice

I have a Unorthodox Racing lightweight pulley. They really do help you rev faster.

These look great. For those of you who are FI consider that the stock pulley has a harmonic balancer and you dont want to introduce harmonic vibrations for longevity. FI performance has also been questioned and has not always shown improvements.

For NA guys like myself, I think they are a great mod for the car.

[joe603]

So I'm confused...Does the OEM have a dampener or not?? Here is the FAQ from the FAB market:

What about the OEM Dampener? I don't want my engine to blow up.
The OEM unit is NOT dampened. It's a solid cast iron unit (or two piece unit for the dual belt setups). Our pulleys are balanced within 1/2 gram and can be balanced to 0 net bias for an additional fee.

[Sentientbydesign]

Looks nice

I have a Unorthodox Racing lightweight pulley. They really do help you rev faster.

These look great. For those of you who are FI consider that the stock pulley has a harmonic balancer and you dont want to introduce harmonic vibrations for longevity. FI performance has also been questioned and has not always shown improvements.

For NA guys like myself, I think they are a great mod for the car.

I knew someone would mention harmonic balancing...*sigh* You couldn't have let me have a day without explanations, could you TBW? lol

Joe, I'll answer your question right now.


These engines were designed around NA applications. When you introduce FI, those tolerances that were completely fine before are now a HUGE problem. As such, if you go FI, you should have your internals beefed up and precisely balanced. Knife edged and all that goodness. That combined with a lightweight pulley should be fine (assuming the tripled torque numbers don't break all of your accessories as well as the crank pulley...lol ask if you want details). The FI guys on stock internals rely on the mass of the OEM pulley to make up for balance issues inside the engine. It's a poor method, but it works (to a point).

So, NO, there isn't a harmonic balancer or the need for one if you keep the engine as intended. For FI, spend the money and do it right!

[Sentientbydesign]

After writing all of this and thinking about the physics behind it, all I can say is poor crankshaft (for the FI guys...)

[joe603]

OK, so when TollBooth said the OEM had a balancer, he was referring to the weight of the OEM pulley acting as a balancer...got it!

[Sentientbydesign]

OK, so when TollBooth said the OEM had a balancer, he was referring to the weight of the OEM pulley acting as a balancer...got it!

Here's a "cute" way to put it. A heavy crank pulley on an FI car makes the Crankshaft turn into the harmonic balancer. Who needs rubber when you can have torsional stress

[vq35XXde]

really interested in buying them is the price for the set ??and how can i buy them also got the vq35de

[Sentientbydesign]

really interested in buying them is the price for the set ??and how can i buy them also got the vq35de

No, the price is for the Crankshaft pulley. Most sets are significantly higher in price.