Does anyone have one or know the pros/cons besides the obvious?

lighter ones will help motor rev quicker

but you get harmonics

heavy ones give motor more torque

Do 6G--'s not have harmonic balancers? I've thought of lighter pulleys too but where could you get them and of course, the harmoics is a problem.

If your talking underdrive pulley, there are none for magna's yet.
Basic principle is they are lightweight, less mass for the motor to spin. They also drive your belts that run off them (power steer etc) at like a 60% rate, meaning they still work but put less load on the motor meaning more engine power to the tyres.

Thats the idea of it.

If you find one though let us know as the companies I have asked dont have them.

If your talking underdrive pulley, there are none for magna's yet.
Basic principle is they are lightweight, less mass for the motor to spin. They also drive your belts that run off them (power steer etc) at like a 60% rate, meaning they still work but put less load on the motor meaning more engine power to the tyres.

Thats the idea of it.

If you find one though let us know as the companies I have asked dont have them.
3sx lightweight pulleys are stock size just lighter weight. 3sx.com The hermonics is exactly what I was wondering about I have heard good and bad. Thanks for the input. Also I have a 6g72 DOHC there are underdrive pulleys for it but I would never do that. (I need all the battery juice I can get):D ./

Not really worth the trouble or effort IMHO.

Cheaper and probably easier to get a bit of material taken off your flywheel.

Harmonic inbalance shouldn't be a problem, if they are built properly then they are balanced before they are shipped.

Thanks for the info!!:D

I have one on the lancer. lightend and undersized. deffinately revs free'er and harder, and the accessories are not affected at all. alternator is still charging at the same rate. all i know is now i can light up the tyres even faster lol

Not really worth the trouble or effort IMHO.

Cheaper and probably easier to get a bit of material taken off your flywheel.

Harmonic inbalance shouldn't be a problem, if they are built properly then they are balanced before they are shipped.


agreed. the effect of weight removal is to the square of the increase in distance from the centreline of the crank (mind you this is way old lecture material so may be well wong) so weight from FW is far more effective than weight from pulley

Would a pulley off a dohc work on a sohc? i'm assuming there'd be no diff but i just thought i'd ask.

agreed. the effect of weight removal is to the square of the increase in distance from the centreline of the crank (mind you this is way old lecture material so may be well wong) so weight from FW is far more effective than weight from pulley

Weight from flywheel can also cost upwards of 4 times the cost of an underdrive pulley.

Weight from flywheel can also cost upwards of 4 times the cost of an underdrive pulley.

Cost me $60 to get FW lightened and balanced. How much is the pulley?

Ok;

With Lightweight pulleys, it's just weight reduction, less effort to spin the pulleys which makes little difference... The inertia is less than a lightened flywheel so the results won't be obvious.

As a general rule of the thumb, the reduction in rolling resistance is multiplied by 7. So if you get a pulley 600 grams lighter for example, the reduction in rolling resistance will be 4.2kg lighter in rolling resistance... As opposed to running lightweight wheels which gives more reduction in rolling resistance... Running 1/2 tank of fuel is better than lightweight pulleys...

As for Underdrive pulleys, the gains I've read are comparable to a lightened flywheel BUT one thing you guys have to know is that the battery will charge less, power steering pump etc will spin slower because the Under drive pulley is smaller.. Think of a mountain bike, normally the front gears are larger than the rear ones, if you switch the front ones to a smaller one, the rear will spin less and slower.

With Under drive pulleys, it's recommended that the belt be changed because the OEM ones might be too long. Also as stated earlier, your battery won't charge as much and at first, you won't notice it but later, it will wear out because the battery is running less than it's full charge, you will find that the battery will not hold a charge at all. But you can overcome this by paying $$$ to get a deep discharge battery like Optima....


Hope this helps... :)