dabbdc Posted March 8, 2010 Share Posted March 8, 2010 Some aftermarket crank pulleys remove a built-in harmonic dampener to save weight. This can cause engine wear problems. Is there a non-under drive crank pulley that saves 3.5 lbs +/- without doing this? Is there a formula that translates rotating weight savings to increased HP? Is there a non-underdrive 3 pulley set for LGT? Link to comment Share on other sites More sharing options...
m sprank Posted March 9, 2010 Share Posted March 9, 2010 There is no harmonic balancer in a Legacy crank pulley. This was verified by a Subaru engineer on nasioc a while ago. Just get a light weight crank or lightweight pulley set. Avoid underdrive pulleys. Link to comment Share on other sites More sharing options...
schwinn Posted March 10, 2010 Share Posted March 10, 2010 Is there a formula that translates rotating weight savings to increased HP? Is there a non-underdrive 3 pulley set for LGT?http://www.teamscr.com/motorsports/tech-articles/45-underdrive-pulleys-our-testing.html The motor will rev quicker, from what people say, but it's not going to get you much in the sense of power. Link to comment Share on other sites More sharing options...
joeblow Posted March 10, 2010 Share Posted March 10, 2010 I haven't seen any 3 pulley sets, but if you go to the vendor tab at the top a couple of them have 3 or 4 different lightweight crank pulleys. I know perrin and cobb make them, but the cobbs are expensive. http://www.fredbeansparts.com/servlet/the-Legacy-GT-05-dsh-09-cln-Engine-Parts-cln-Miscellaneous/Categories It's cool; I'm with the band Link to comment Share on other sites More sharing options...
m sprank Posted March 10, 2010 Share Posted March 10, 2010 There are 3 pulley sets. But they will be listed for a WRX. I believe they fit. I have seen them listed from Aussie manufacturers. I use Perrins because they are cheaper. Link to comment Share on other sites More sharing options...
grim Posted March 10, 2010 Share Posted March 10, 2010 Why not buck the trend and put on a Fluidampr? Link to comment Share on other sites More sharing options...
Darkness of Death Posted March 10, 2010 Share Posted March 10, 2010 group A makes a 3 piece pulley kit Link to comment Share on other sites More sharing options...
Underdog Posted March 10, 2010 Share Posted March 10, 2010 There is no harmonic balancer in a Legacy crank pulley. This was verified by a Subaru engineer on nasioc a while ago. Just get a light weight crank or lightweight pulley set. Avoid underdrive pulleys. While the crank pulley is not a harmonic balancer, it is a harmonic damper. The rubber section in between the mating hub and the pulley grooves prevents the full shock of the power pulses from hitting the accessories. I have spoken with a couple shops that recommend against lightweight pulleys and won't even sell them for a quick buck. However there have been people running aftermarket non-damped pulleys for years without a problem... so make your own decision. The Crimson Dynamo Link to comment Share on other sites More sharing options...
captainhook Posted March 11, 2010 Share Posted March 11, 2010 while the crank pulley is not a harmonic balancer, it is a harmonic damper. +1 Link to comment Share on other sites More sharing options...
rao Posted March 11, 2010 Share Posted March 11, 2010 So how much extra HP can I pick up with one of these? Rob IF YOU CARE ABOUT YOUR CAR YOU SHOULD NEVER DRIVE IT Link to comment Share on other sites More sharing options...
PhilT Posted March 12, 2010 Share Posted March 12, 2010 So how much extra HP can I pick up with one of these? More than you can handle Double Award Winning Legacy GT Wagon Link to comment Share on other sites More sharing options...
joeblow Posted March 12, 2010 Share Posted March 12, 2010 If you had a spec.B the lightweight pulleys would add 200 whp each. Since yours is just a regular GT, probably somewhere in the 2-5 hp range per pulley. One of the vendors lists a 5-7 hp gain with just the lightened crank pulley, but then again that could just be marketing exaggeration. It's cool; I'm with the band Link to comment Share on other sites More sharing options...
dabbdc Posted March 12, 2010 Author Share Posted March 12, 2010 Any known instances of warranty issues arrising from pulley's? One seller of a used pulley here said the dealer objected.... Link to comment Share on other sites More sharing options...
m sprank Posted March 12, 2010 Share Posted March 12, 2010 So how much extra HP can I pick up with one of these? Less than if you drain the oil. Link to comment Share on other sites More sharing options...
rao Posted March 12, 2010 Share Posted March 12, 2010 So I should expect like 50 more hp Rob IF YOU CARE ABOUT YOUR CAR YOU SHOULD NEVER DRIVE IT Link to comment Share on other sites More sharing options...
m sprank Posted March 12, 2010 Share Posted March 12, 2010 No. Like 500 more HP. It is unreal! Its so much power you could break the block. Just like if you ran with no oil. Link to comment Share on other sites More sharing options...
scoobydoobie Posted March 12, 2010 Share Posted March 12, 2010 While the crank pulley is not a harmonic balancer, it is a harmonic damper. The rubber section in between the mating hub and the pulley grooves prevents the full shock of the power pulses from hitting the accessories. I have spoken with a couple shops that recommend against lightweight pulleys and won't even sell them for a quick buck. However there have been people running aftermarket non-damped pulleys for years without a problem... so make your own decision. hmmm interesting. I've had a lightweight pulley sitting on a shelf in my garage for 4+ years, still trying to decide if its worth it for me to put on. I have a 5EAT so the effects should be noticable, but I don't want to do it at the expense of motor/crank problems. Then again I've read more than one post on here about the stock crank pulley failing... Link to comment Share on other sites More sharing options...
joeblow Posted March 12, 2010 Share Posted March 12, 2010 I think this debate is about the same as the intake silencer delete debate. No one has reported any real issues in connection with it, but people still say its bad news. Until there is hard evidence for or against lightweight pulleys, people will continue to make and use them. It's cool; I'm with the band Link to comment Share on other sites More sharing options...
LosAngelesLGT Posted March 12, 2010 Share Posted March 12, 2010 I think this debate is about the same as the intake silencer delete debate. No one has reported any real issues in connection with it, but people still say its bad news. Until there is hard evidence for or against lightweight pulleys, people will continue to make and use them. x2 I pondered a LWPul pull but after getting a LWFW I dont want to lose any more launching grunt. Link to comment Share on other sites More sharing options...
franklin Posted March 12, 2010 Share Posted March 12, 2010 What if you add the grounding kit too ? Another 10 HP ? Link to comment Share on other sites More sharing options...
Mark34 Posted March 17, 2010 Share Posted March 17, 2010 I have the Group A pulley kit. The power steering pulley is slightly larger than my stocker and I can not use a stock belt if I install the pulley. Has anyone else run into this and what belt did you go with? A last generation WRX belt? Thanks. Link to comment Share on other sites More sharing options...
Darkness of Death Posted March 17, 2010 Share Posted March 17, 2010 i noticed the power steering pulley was slightly larger as well. you'll have to muscle the belt back on. after you get it over the teeth, you'll be good to go Link to comment Share on other sites More sharing options...
FPerron Posted March 17, 2010 Share Posted March 17, 2010 Every time this topic comes up, either nobody mentions underdrive pulleys or someone says to keep away from them. This makes no sense unless your running a getto sound system. Underdrive pulley sets are the only way you're going to get a horsepower gain by messing with the pulleys. I've been racing and winning with underdrive pulleys for years. Link to comment Share on other sites More sharing options...
m sprank Posted March 18, 2010 Share Posted March 18, 2010 Underdrive pulleys are fine for the track. The lower parasitic drag makes more power. But, it also messes with the charging system. This is BAD for a street car. Still running that wing? Link to comment Share on other sites More sharing options...
FPerron Posted March 18, 2010 Share Posted March 18, 2010 Teh Wing FTW! Link to comment Share on other sites More sharing options...
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