I have an unorthadox aluminum lightweight crank pulley. It came with the car. The pulley weighs maybe .5 lbs. I never liked the idea of running that pulley as it doesnt have a balancer on it so I ordered a harmonic balancer. It came in today and weighs about 15lbs!!! Thats all that extra weight on the rotating assembly.

Discuss

I'd rather have some extra weight on the rotating assembly than have a broken crank, but that's just me.

I'd rather have a Fluidampr . They apparently weigh 5.5lbs. (never weighed mine), but that is probably for the Aluminum version, which I think they are made out of steel now.

Damn, for $289, I'd rather buy a stock mitsu piece and spend the rest on something else.

I perosnally would rather run a new stock harmonic dampner than the UR part. The very minimal gain isn't worth the possible issues.

Lightweight crank pulley = FAIL.

When you take weight off the crank, you are changing the rotating balance of it.

Want more power? Turn the boost up. /ubbthreads/images/graemlins/dunno.gif

^^^ Can you explain that? I've never understood why you can't just static balance every crank component (flywheel, etc.) and put them together to create a balanced unit.

Is the stock unit dampened for the crank, or the accessories running off the crank? Either way, stock unit is proven to work, it cheap, and the crank pulley isn't really the last place to find extra power on this engine. Unless maybe, it is a track only car and you don't care about failure and you need every HP you can find.

It's to dampen the crank from unnecessary vibrations.

Quote:
I have an unorthadox aluminum lightweight crank pulley



And you call me a hack /ubbthreads/images/graemlins/grin.gif Any way toss that pulley in the trash. Just spend the money and buy a ATI or Fluidampr. Why spend the money on a factory one to take the chance of it coming apart and taking out you timing belt cover and or timing belt.

Quoting Kenny_Kline:
I have an unorthadox aluminum lightweight crank pulley. It came with the car. The pulley weighs maybe .5 lbs. I never liked the idea of running that pulley as it doesnt have a balancer on it so I ordered a harmonic balancer. It came in today and weighs about 15lbs!!! Thats all that extra weight on the rotating assembly.

Discuss



Are your engine internals stock?

Add a lightweight flywheel & v-cut crank, that would make up the weight difference.

I bought the car with the pulley on the car. I already bought an OEM balancer. I will probably be using it.

The stock damper is tuned to the harmonics of stock internals.

Spend the money and time and get a lighter flywheel. In my opinion that is.

What you are talking about is primary imbalance, which creates main bearing loads - as long as all of the components are equal weight, those won't be a problem.

The crank damper is to damp out "secondary" resonances, which are "twisting" vibrations in the crank. What happens is that every two revolutions, each cylinder fires. This creates a twist as it fights against the compressing cylinder and the flywheel mass. it springs back quickly, but when the crank RPM matches up with these vibrations, the crank starts wringing back and forth. The damper adds an extra wobbling mass that keeps the resonance from amplifying. Without the damper, you can eventually cause the crank, or clutch/driveline parts to fail.



Quoting jepherz:
^^^ Can you explain that? I've never understood why you can't just static balance every crank component (flywheel, etc.) and put them together to create a balanced unit.

Well I am on stock internals, ARP rod bolts, new bearing, new rings, balanced pistons/rods, BSEK. I hated the idea of having that aluminum pulley on there. I bought an OEM one which I hope will do the job and after reading the info in this thread, it looks like that I made the right choice.

FYI: I have heard horror stories about using the fluidamper

Quote:
FYI: I have heard horror stories about using the fluidamper



And what would they be. /ubbthreads/images/graemlins/dunno.gif

Never heard one problem with the fluidampr.

The horror stories you have probably heard involve running the fluidamprs up to very high RPM on high horsepower cars - It works by heating the silicone fluid up, causing it to stiffen (just like a VCU). What happened was they got so hot that the fluid expanded and burst the casing.

I believe they fixed the problem by switching from the original aluminum case to the steel one - slightly heavier, but safer.

A new OEM unit is suitable for most applications. A fluidamper or ATI is usually only called for on high RPM, seriously tuned engines.

Of all the places you can shave weight, the harmonic balancer is not the place to skimp

Quoting Kenny_Kline:
I have an unorthadox aluminum lightweight crank pulley. It came with the car. The pulley weighs maybe .5 lbs. I never liked the idea of running that pulley as it doesnt have a balancer on it so I ordered a harmonic balancer. It came in today and weighs about 15lbs!!! Thats all that extra weight on the rotating assembly.

Discuss


i have had mine for over 8 years on my car and i even had one my 4g63 rail car without any problems.