Lightweight pulley wow

[Celica00]

Originally Posted by mike2100

Oh and how do you think a lighter weight pulley is causing your engine to consume more fuel?

I have no idea and nothing else to go on.. I've driven the same way and even when I drove 'spirited' w/ the stock pulley it was never below 28mpg and this is my only mod. doesnt make sense to me either.

[MmmHamSandwich]

I am kind of surprised to hear the pulley benefits AT. Where are you guys noticing improvements? Rev matching faster? Any other benefits? Any negative changes? I guess it is encouraging to see the ecu for the engine and transmission can take advantage of faster throttle response and aren't tied down to some default agressiveness. Wonder if other throttle response improving mods will also be as well received by the auto rev matches.

[Apollo_1092]

Sorry if this is a dumb question but isn't the engine designed to have some resistance and "weight" that the stock pulley creates? I would think changing the pulley to something that is lighter would freak out your engine. From what I saw that the perrin pulley is supposed to make your engine think the car is 100lbs lighter (if I read things correctly). This is something I've thought of doing further down the road, I just want to make sure it won't hurt the car. If non of this makes any sense I apologize, I'm still learning a lot about this car. Thanks

[gmookher]

http://www.ft86club.com/forums/showt...ghlight=pulley

beaten to death

its a choice you make, we all big boys and we all know all the weight of the factory pulley was put there for a reason, long with the rubber

it may be a few HP/throttle response to YOU

[FullBlown]

Originally Posted by gmookher

http://www.ft86club.com/forums/showt...ghlight=pulley

beaten to death

its a choice you make, we all big boys and we all know all the weight of the factory pulley was put there for a reason, long with the rubber

it may be a few HP/throttle response to YOU

He is absolutely right. Every engine produces harmonics and harmonics will wear down and break parts.

The oil pump and engine bearings will take a beating if you do not have a damper on it.

[gmookher]

Originally Posted by neutron256

$1000+ (moderate to advanced install)

Swapping a drive shaft is not that hard to do.

[Celica00]

Originally Posted by gmookher

Swapping a drive shaft is not that hard to do.

Rick @ rallysportdirect mentioned it took him 30 minutes to do it solo. so it shouldnt be that bad

[jarviz]

I've been reading this thread and still trying to find a consensus on this. Is it worth it?

What are the pros and cons of a light weight pulley? It looks like there are mixed feelings on here.

[gmookher]

research forum, beaten to death

[wlfpck]

Along with the link that gmookher posted...

http://www.yoursciontc.com/forums/12...lley-info.html


Pretty much detailed in Engineering terms, high school terms, middle school terms, and elementary school terms.



My own personal opinion is that the potential risk outweighs the benefits.

[Ranatsu]

Originally Posted by wlfpck

Along with the link that gmookher posted...

http://www.yoursciontc.com/forums/12...lley-info.html


Pretty much detailed in Engineering terms, high school terms, middle school terms, and elementary school terms.



My own personal opinion is that the potential risk outweighs the benefits.

Changing anything on the car always has some potential to cause failure. I'm not saying the pulley will not cause problems on THIS engine, but I do know that I have personally run Perrin's light weight crank pulley on 3 different turbo Subaru's well over 150k miles total and I've personally never experienced any problem.

I have personally seen the factory subaru crank pulley seperate into 2 seperate pieces and do more damage than a quality lightened crank pulley has caused.

This is just my experience.

I think many people are taking this way out of proportion. If you personally don't want to risk it, then don't. No one on this forum can 100% for sure say that this pulley is going to never cause a problem with this motor because the car hasn't been in existance long enough to have the mileage for those kind of tests. Anything you read is going to be speculation or theory. Honestly I don't think anyone can look up a LWCP problem on a Subaru motor. I know that I haven't read about any.

[wlfpck]

Originally Posted by Ranatsu

Changing anything on the car always has some potential to cause failure. I'm not saying the pulley will not cause problems on THIS engine, but I do know that I have personally run Perrin's light weight crank pulley on 3 different turbo Subaru's well over 150k miles total and I've personally never experienced any problem.

I have personally seen the factory subaru crank pulley seperate into 2 seperate pieces and do more damage than a quality lightened crank pulley has caused.

This is just my experience.

I think many people are taking this way out of proportion. If you personally don't want to risk it, then don't. No one on this forum can 100% for sure say that this pulley is going to never cause a problem with this motor because the car hasn't been in existance long enough to have the mileage for those kind of tests. Anything you read is going to be speculation or theory. Honestly I don't think anyone can look up a LWCP problem on a Subaru motor. I know that I haven't read about any.

But here's the thing...

If you use F/I on a car that was N/A from the factory, there is a risk. However countless hours have been placed into the research of turbo kits.

I never said that this pulley will not cause problems or they will. What I DO know is that on various platforms there have been problems with the lightened crank pulleys.

Think about it this way... would ATI racing and other companies sell a pulley that weighs more than the lightened pulleys from other companies for almost 3 times as much? What research has been put into a pulley that comes from these companies?

Note the laws of physics that applies to replacing a puelly that comes FROM the factory dampened with a non-dampened pulley. These were the basis of the arguements that were presented not just in the link I posted but also by the links that gmookher has posted.

If the pulley from the factory is NOT dampened... then going to a lighter pulley will not have an adverse effect.



On that note... yes, you are correct. There has not been enough information gathered on these engines to know how they will react to the lightened crank pulley. Is there a chance that they will be perfectly fine? Sure. Is there a chance something bad can happen, yes, it could as well.


----------------------------

The problem lies within the amount of research a company puts into a product before they release it. Look at Air Raid and other intake companies. Their threads show the amount of lab bench work and such for a "Tube with a filter on it". That part doesn't even move... It sits in the engine bay.

With a pulley that makes revolutions at an extremely high rate, I should hope that the research is there. Instead, there has been very little information behind any possible lab bench work. As far as we know, the company could simply take the stock pulley, and sketch up a pulley in CAD. Then CNC it in aluminum.



This again is just my own opinion. It was an opinion formed off of the multitude of forums and resources that I have read.

[Ranatsu]

Originally Posted by wlfpck

lots of text

Sorry I didn't want to just quote all of that.

I understand completely what you are saying. I will tell you I know for sure that Subaru, uses the exact same crank pulley for almost all of their cars for the last 10-15 years? I know my girlfriends 93 SVX has the same crank pulley as every turbo impreza I have. Thats one of the reasons I think it isn't as big of a deal as people are thinking.

We agree that it could create a problem or it couldn't. I'm just putting out my knowledge just so people have it as information

[wlfpck]

Definitely, I agree with you.

The other thing to note to... and this gets into some of the physics stuff that I was talking aobut...

At least for the Scion tC, the reason that a decent number of people have not seen a problem for 50k miles is that the engine was never revved high enough. For the supras and such that reported a problem, they are dealing with revving much higher. Could this be a problem? The physics behind it indicate that this is one cause. Could there be more reasons? Maybe. Maybe not.

But yeah. I definitely agree. It would be nice if a company that makes these lightweight crank pulleys actually showed video/photo of their testing phase and R&D like companies like AIR RAID and others have done.