Effectiveness of a Lightweight pulley

[Celica00]

Originally Posted by OrbitalEllipses

As has been said numerous times: it's because the boxer is naturally balanced (moreso than inline and vee engines) and doesn't use the pulley as a harmonic damper.

unfortunately it needs repeating because...

[bpracer]

Originally Posted by OrbitalEllipses

As has been said numerous times: it's because the boxer is naturally balanced (moreso than inline and vee engines) and doesn't use the pulley as a harmonic damper.

Every time a cylinder fires, the crank throw on that cylinder is twisted as it is accelerated, every compression stroke the opposite occurs. Each time this happens, harmonic vibration are induced in the crank, this has nothing to do with the boxer engine being naturally balanced or not.

Harmonic dampers are tuned for a particular rpm range via mass of the outer ring and/or the stiffness of the rubber ring. You may be able to get by without a damper on an engine depending on the rpm range in which it operates. If you happen to operate the engine at the cranks natural frequency for a long period of time, bad things "could" happen.

On a standard V-8 engine the damper is a very tight press-fit and keyed to the crank. If they are not tight, bad things happen.

The Subaru engine pulley does not seem to be a press fit and only uses a dowel pin for locating the damper/pulley. That would cause me to believe there isn't nearly as much force acting on damper/pulley from these harmonics.

Drag racing, short(er) track road racing it may not matter at all. Buzzing down the LONG front straight at Road America near red-line for a good while might be another story.

You make your choices, you take your chances...

[mister.bond]

After 3 Years now

What is going on with using the Lightweight Pulleys ???

Any Long Term News ???

Any Engine Issues while using them ???



Hope i can start this discussion again

[why?]

please let's not. If you are running huge boost and modding the carp out of the car stay stock. If you are staying NA and aren't beating the ever living shit out of the car it doesn't really matter.

[Slade]

I kind of have a blue theme under my hood, if I bought a pulley that was black, can I spray paint it blue, to match my theme? Or would the paint add weight to the pulley? Maybe a dumb question, but I never considered myself a genius.

[Tcoat]

Originally Posted by Slade

I kind of have a blue theme under my hood, if I bought a pulley that was black, can I spray paint it blue, to match my theme? Or would the paint add weight to the pulley? Maybe a dumb question, but I never considered myself a genius.

Probably add about a 100th of an ounce. Make sure you clean it up really well before painting though.

[Slade]

Originally Posted by Tcoat

Probably add about a 100th of an ounce. Make sure you clean it up really well before painting though.

Thanks for the response, and you did it without giving me a wise guy answer

[Tcoat]

Originally Posted by Slade

Thanks for the response, and you did it without giving me a wise guy answer

Happens sometimes!
Depends on how the question was asked more than anything.

[Shark_Bait88]

Originally Posted by Tcoat

Happens sometimes!
Depends on how the question was asked more than anything.

Nice guy TCoat is nice.

[team3d]

guys, google crank pulley damage, you will find almost 0 complains on light weight pulley, and if you click on google photos, all the damage crank pulleys you will find are stock, damped pulley.

if you drive a 30-60 years old domestic v8 ? i will not suggest 1pc pulley. for a inline 4 or boxer engine, i have not witness any engine that's damaged due to the removal of stock crank pulley

as for the power gain, are you gonna run faster with heavy shoes or lighter shoes ? even for lebron james, he can still run very fast with heavy shoes, but with lighter shoes, he will benefit more & use less energy...

who can honestly tells me, running with 20lbs back pack or wearing a 2lbs combat boots will make you run faster ?

light weight wheels, brake rotors, pulley, flywheels, crankshaft, pistons & rod all can reduce engine's energy use...

[swarb]

Originally Posted by team3d

guys, google crank pulley damage, you will find almost 0 complains on light weight pulley, and if you click on google photos, all the damage crank pulleys you will find are stock, damped pulley.

if you drive a 30-60 years old domestic v8 ? i will not suggest 1pc pulley. for a inline 4 or boxer engine, i have not witness any engine that's damaged due to the removal of stock crank pulley

as for the power gain, are you gonna run faster with heavy shoes or lighter shoes ? even for lebron james, he can still run very fast with heavy shoes, but with lighter shoes, he will benefit more & use less energy...

who can honestly tells me, running with 20lbs back pack or wearing a 2lbs combat boots will make you run faster ?

light weight wheels, brake rotors, pulley, flywheels, crankshaft, pistons & rod all can reduce engine's energy use...

http://www.evoxforums.com/forums/showthread.php?t=50463

maybe because ALL cars come with stock pulleys?
maybe because less than 1% of cars get light weight pulleys?

Have you worn Lebron's shoes? or even picked up a pair? They're heavy! They are built for strength.

[norcalpb]

Originally Posted by swarb

http://www.evoxforums.com/forums/showthread.php?t=50463

maybe because ALL cars come with stock pulleys?
maybe because less than 1% of cars get light weight pulleys?

Have you worn Lebron's shoes? or even picked up a pair? They're heavy! They are built for strength.

Doesn't an evo have an inline 4? I'd never put a lightweight on an inline 4, inline 6, v6 or a v8.

Boxer motors are super balanced as it is...they've made airplane motors for decades now.

[wbradley]

Engine spins up faster when in neutral. Difference when shifting into gear zero or indiscernible.

Looks good in engine bay.

[Lantana frs]

I will never use one again. Thank God Toyota didnt refuse my warranty because of it. Made the car snappier in lower gears.