Pulley Kit. Yes or no?

[M35byTC]

Hey Guys!! I need advice on a Pulley Kit. I am interested in purchasing the 3 Piece kit by Unorthadox Racing. Does Anyone have any info to share with me before I make the purchase. Does anyone have this type of setup or simalar?

[Ilya]

I don't think anyone here has one...but in the Maxima world many guys had them.

Just make sure you get the lightened stock diameter pulley's and you should be fine.

[M35byTC]

Nice, Thanks! Is that your car above in the picture?

[Ilya]

No problem. And yes, it is.

[EniGmA1987]

SentientByDesign sells a quality lightweight pulley for both M35 and M45. He is a member here on these forums and does good work.

[The Bodyguard]

Just wondering... What good is a new set of pulleys?? How can you describe what improvements you will feel to everyday driving??

[autoengr]

If you reduce the mass of the pulley it is easier to speed it up. If you change the diameters you can reduce the parasitic losses of the front end accessory drive. The pulley set can make the car feel more peppy.

This comes at a cost:
Reducing the parasitic loss from the accessory components will also reduce their efficiency. The compressor, alternator and PS pump compromise efficiency to run across a broad range of speeds. Modifying the pulley diameter modifies their speed and reduces their output for a given RPM.
The crank pulley is heavy because it has a damper to reduce the harmonic vibrations in the crankshaft. Removing this damper to reduce the mass of the pulley can result in crankshaft fatigue and failure (and that is bad).

[Mdeniz]

The crank pulley is heavy because it has a damper to reduce the harmonic vibrations in the crankshaft. Removing this damper to reduce the mass of the pulley can result in crankshaft fatigue and failure (and that is bad).

That right there is why i would say stay away from it, additional vibration and stress to the crank will cause extra stress on your rod bearings and its why the Supra, Evo, Honda crowd all have gone to the ATI dampers that provide all benefits without eliminating the pulley's ability to damper vibration. I wouldn't install an unorthodox crank pulley in my car if it was free.

[Ilya]

If you reduce the mass of the pulley it is easier to speed it up. If you change the diameters you can reduce the parasitic losses of the front end accessory drive. The pulley set can make the car feel more peppy.

This comes at a cost:
Reducing the parasitic loss from the accessory components will also reduce their efficiency. The compressor, alternator and PS pump compromise efficiency to run across a broad range of speeds. Modifying the pulley diameter modifies their speed and reduces their output for a given RPM.
The crank pulley is heavy because it has a damper to reduce the harmonic vibrations in the crankshaft. Removing this damper to reduce the mass of the pulley can result in crankshaft fatigue and failure (and that is bad).

Nissan motors are internally balanced.

This was a misconception on the VQ30 on the Maxima forums too. It's simply not true. An unorthodox pulley will do no harm to your car...but you are absolutely right about losing efficiency if you don't get a stock-diameter pulley.

[06M4.5]

going with a lighter pulley with the same size is no problem.

if you go with a lighter pulley and under-size I recommed you also get a smaller pulley for the alternator this will eliminate charging problems when at idle. everything else should be fine.

I had this done to a mustang (5.0) years ago and never had a problem.

[Mdeniz]

If you reduce the mass of the pulley it is easier to speed it up. If you change the diameters you can reduce the parasitic losses of the front end accessory drive. The pulley set can make the car feel more peppy.

This comes at a cost:
Reducing the parasitic loss from the accessory components will also reduce their efficiency. The compressor, alternator and PS pump compromise efficiency to run across a broad range of speeds. Modifying the pulley diameter modifies their speed and reduces their output for a given RPM.
The crank pulley is heavy because it has a damper to reduce the harmonic vibrations in the crankshaft. Removing this damper to reduce the mass of the pulley can result in crankshaft fatigue and failure (and that is bad).

Nissan motors are internally balanced.

This was a misconception on the VQ30 on the Maxima forums too. It's simply not true. An unorthodox pulley will do no harm to your car...but you are absolutely right about losing efficiency if you don't get a stock-diameter pulley.

Internally balanced does not protect against the harmonics (vibrations) created by eliminating the damper, it is fact not fiction.

[The Bodyguard]

Great lesson guys!! Good info... Thanks!

[walperstyle]

If you reduce the mass of the pulley it is easier to speed it up. If you change the diameters you can reduce the parasitic losses of the front end accessory drive. The pulley set can make the car feel more peppy.

This comes at a cost:
Reducing the parasitic loss from the accessory components will also reduce their efficiency. The compressor, alternator and PS pump compromise efficiency to run across a broad range of speeds. Modifying the pulley diameter modifies their speed and reduces their output for a given RPM.
The crank pulley is heavy because it has a damper to reduce the harmonic vibrations in the crankshaft. Removing this damper to reduce the mass of the pulley can result in crankshaft fatigue and failure (and that is bad).

Nissan motors are internally balanced.

This was a misconception on the VQ30 on the Maxima forums too. It's simply not true. An unorthodox pulley will do no harm to your car...but you are absolutely right about losing efficiency if you don't get a stock-diameter pulley.

The KA24 DE rotating assembly is not fully balanced.

[cruzad3r]

There are so many things you can spend your money on beside the pulley kit. If you want to be different, the this will deffy fit the bill :-)

[M35byTC]

great info fellas, I appreciate it!

[EniGmA1987]

Internally balanced does not protect against the harmonics (vibrations) created by eliminating the damper, it is fact not fiction.

true, but my understanding was that the lightweight pulley's are very well balanced like the OEM and you arent removing the damper, just getting a lighter weight pulley.

[myother45isalesbaer]

I am an old school guy. We didn't worry about pulley weights. What we used to do was install an electronic clutch that you could turn on or off for street racing. It cut out the AC, water pump, alternator and any thing else run by the belts. Used to add quite a few HP and then we would add nitrious to give it the extra kick. Of course you would have to turn the shut down appliances soon and turn off the nitrious, but it worked well for us street racing guys. Just my old man OP.