[vmaxlvrs]

Has anyone attempted to replace the 08 crank pulley yet?
Apparantely the set up is defferent from previous years. I beleive there is a tentions bolt missing. Any light on this will be greatle appreciated.
I have been reading about this replacement and was wondering, and i know there is a lot of heat on this, if there are pople out there that has replaced it witha dampered pulley vs. a LW pulley alone that might give me some info.
Thanks in advance.

[tom@kartboy]

the guys at TIC have installed one of ours with good results. i havent had time to try the install on our shop STi yet. not sure if others will fit.

T

[1day]

The new setup does not have a tensioner at all, just a stretch belt. I saw a thread on 3gwrx about this. They cut the belt off and the new belt came with a tool to install a new stretch belt. I hope that there is a another way to do this.

[Turninconcepts.com]

I have replaced the crank pulley with one of kartboy's (Great pulley btw!!). It was pretty straight forward to work around the AC belt. I loosened the bolts that hold the AC compressor in place to get some slack on the belt. That allowed me to take a flat head screwdriver and work th ebelt off the pullet more easily. Same process only in reverse for getting the belt back on. I have had no issues with stretching of the belt and all is well some 5000 miles later.

Tony

[vmaxlvrs]

Originally Posted by 1day

The new setup does not have a tensioner at all, just a stretch belt. I saw a thread on 3gwrx about this. They cut the belt off and the new belt came with a tool to install a new stretch belt. I hope that there is a another way to do this.

I guess you buy this tool from subaru?

[vmaxlvrs]

Originally Posted by Turninconcepts.com

I have replaced the crank pulley with one of kartboy's (Great pulley btw!!). It was pretty straight forward to work around the AC belt. I loosened the bolts that hold the AC compressor in place to get some slack on the belt. That allowed me to take a flat head screwdriver and work th ebelt off the pullet more easily. Same process only in reverse for getting the belt back on. I have had no issues with stretching of the belt and all is well some 5000 miles later.

Tony

I already got a pulley and dont doubt Kartboy's is a great pully i got thier shirter, i also wanted to hear from people that has installed dampered pulley. Just wondering

[gOt_rally?]

To my understand light weight pulleys r very unhealthy for the motor. The reason why subaru's is heavy is becuase it is used to dampen the engines vibrations. OEM engines are balanced with this pulley. Putting on a leighter pulley may lead to faster wear and tear on ur bearings and other internal compenents. IMHO it is not worth it, but on the other hand their is no definitive evidence that proves pulleys cuz more wear and tear but it is a theory that many knowledgeable tuners and engine builders agree on.

[vmaxlvrs]

Originally Posted by gOt_rally?

To my understand light weight pulleys r very unhealthy for the motor. The reason why subaru's is heavy is becuase it is used to dampen the engines vibrations. OEM engines are balanced with this pulley. Putting on a leighter pulley may lead to faster wear and tear on ur bearings and other internal compenents. IMHO it is not worth it, but on the other hand their is no definitive evidence that proves pulleys cuz more wear and tear but it is a theory that many knowledgeable tuners and engine builders agree on.

Agreed, but there was a thread i beleive from last year about a dampered pulley wich was also lighter then the stock, i was just wanted to get some imput from the guys that actually did this swap.

[caveguru]

There was a company releasing lightweight damped pulleys this winter - not sure if they've released one for subaru's yet. I'll have to go look for the article where I saw it.

FWIW, I've had a lightweight pulley in my '02 since 20k miles. Its now over 70k running stage 2 with no problems. There's always tons of answers like this whenever these get brought up, but no one can ever point to engine X and say, "it just gave up for no reason, maybe it wore out because of the crank pulley," or, "my front crank bearing failed prematurely." I wish someone would though so we could assign a probability to it happening...

Frank

[DrPhyzx]

Originally Posted by vmaxlvrs

Has anyone attempted to replace the 08 crank pulley yet?
Apparantely the set up is defferent from previous years. I beleive there is a tentions bolt missing. Any light on this will be greatle appreciated.
I have been reading about this replacement and was wondering, and i know there is a lot of heat on this, if there are pople out there that has replaced it witha dampered pulley vs. a LW pulley alone that might give me some info.
Thanks in advance.

I've been wondering for a while what's up with this mod. If you assume the mass has been removed at a radius of about 2" from the axis, then in first gear each pound you remove from this thing is worth about three pounds of non-rotating mass from anywhere else. Now... that's in first gear... by the time you are in third or fourth, the advantage is negligible over general weight reduction. If you don't believe me, I'll post up the calculation.

Perrin claims that this is equal to removing 100 lbs. of non-rotating mass, to which I call a giant B.S. That would imply that this part is 30 pounds lighter than the stock piece... and the advantage shrinks pretty quickly in the higher gears.

Now... if the idea is quicker response when blipping the throttle... that can actually make sense.

...

OK... so looking at Perrin's page, they claim 4 pounds lighter than stock. That's equal to 12 pounds of mass from anywhere else when in first gear. FAIL.

[caveguru]

Originally Posted by DrPhyzx

If you don't believe me, I'll post up the calculation.

yes, do please...

[DrPhyzx]

Originally Posted by caveguru

yes, do please...

Not sure if you're serious or not, but here is the version of the calc I did while enjoying the drive to work

Again, assume mass is concentrated at about 2" radius, and that any material removed will be concentrated at that radius. (What we really want for this simple version of the calculation is the r^2-weighted mean, so mass near the outside dominates the calculation.)

Now... how fast does that material move due to crank rotation at 6000 RPM:

v = pi * d * 6000 = 3 * 1/3 ft * 6000 (1/min)
= 6000 feet/min * (60 min/hr) / (5280 feet/mile) = 68 miles/hr

So... at 6000 rpm, the effective mass of the pulley is moving at 68 miles per hour. In first gear, that is probably about twice as fast as the car is moving, so you've saved twice the mass reduction on any other part of the car just getting it spinning.

Now, of course, you also have the linear motion of the pulley, where you've saved just like you would for any non-rotating part and there is your factor of three.

So... saving 4 pounds off the pulley is like 12 from any non-rotating part of the car.

Gotta run...

[krzrider24]

yea the ac compressor is a full on bolt on you are going to have to cut your ac belt in order to get the other pulley on. and you are going t spend about 80 dollars for a new a ac belt. this years belt is a stretch belt that you have to rotate into the actual pulley.

[whatstidude]

Originally Posted by DrPhyzx

Not sure if you're serious or not, but here is the version of the calc I did while enjoying the drive to work

Again, assume mass is concentrated at about 2" radius, and that any material removed will be concentrated at that radius. (What we really want for this simple version of the calculation is the r^2-weighted mean, so mass near the outside dominates the calculation.)

Now... how fast does that material move due to crank rotation at 6000 RPM:

v = pi * d * 6000 = 3 * 1/3 ft * 6000 (1/min)
= 6000 feet/min * (60 min/hr) / (5280 feet/mile) = 68 miles/hr

So... at 6000 rpm, the effective mass of the pulley is moving at 68 miles per hour. In first gear, that is probably about twice as fast as the car is moving, so you've saved twice the mass reduction on any other part of the car just getting it spinning.

Now, of course, you also have the linear motion of the pulley, where you've saved just like you would for any non-rotating part and there is your factor of three.

So... saving 4 pounds off the pulley is like 12 from any non-rotating part of the car.

Gotta run...

dude one... ur ****ing smart as **** and two if this is bull**** or not id still believe it just because he put so much thought into it... i gotta give u a

even tho i have no idea ever to see if ur math it right or wrong let me call me asian friends and ask them what they think lolol

[Turninconcepts.com]

The big discussion of lightened pullies and removing the damping the stock one provides is the side loading of the front crank bearings. A very valid concern in inline engines for example. Thing is despite everyone screaming about this I have yet to see an example of a dead bearing due to side loads from removing the damper on a boxer motor.