Perrin Crank pulley - Page 2 - Subaru WRX Forum
LinkBack Thread Tools Display Modes
post #16 of 20 Old 03-22-2011, 11:12 PM
Vew's Avatar
Join Date: Feb 2004
Location: West Virginia
Posts: 3,485
Images: 10
Send a message via AIM to Vew
Exactly my point. Sure, no one's reported problems or have experienced them. But it's an obvious risk like any mod we do. The question you need to ask yourself is if that little gain with the given the little risk worth the hundred or so dollars you spend on this mod.

Personally, I'd put it toward a part I KNOW will gain me performance I'll see or feel.

Subaru Ambassador
Vew is offline  
Sponsored Links
post #17 of 20 Old 03-23-2011, 09:23 AM
WRXtuners Member
man show's Avatar
Join Date: Apr 2007
Location: Maryland
Posts: 3,235
Images: 2
So we know that the stock crank pulley was well-engineered for a specific purpose: to absorb any extra vibrations that might escape from a naturally balanced engine, which is certainly a good thing. A small benefit can be had there.

We also know that the stock crank pulley weighs several pounds more than a lightweight aftermarket pulley, so the reduction in rotating mass by switching to an aftermarket pulley is a small benefit too. At the same time, the lightweight crank pulley does not have the ability to absorb vibrations like the stock crank pulley does, so that's a bit of a hinderance.

You're spending money for something that both helps and hurts your car, so in the end, it really does nothing.

But... with the amount of movement in every direction that entire car experiences while in motion under normal driving circimstances, is the ability of the stock crank pulley to absorb small vibrations from the naturally balanced engine completely necessary? Are the tight tolerances of the bearings and other parts inside the engine enough to keep the crank spinning true without the aid of the dual rotating masses of the stock crank pulley? Was the stock crank pulley over-engineered? Is the addition of the lightweight crank pulley MORE of a benefit than a risk!? :eek:

07 WRX
man show is offline  
post #18 of 20 Old 03-23-2011, 06:51 PM
WRXtuners Member
turmic's Avatar
Join Date: Jul 2007
Location: Pennsylvania
Posts: 4,371
Images: 6
Send a message via AIM to turmic
I'm seriously at a loss as to what the big deal about doing it is? Its a bling mod IMHO, It doesn't do much but make you feel good that you "changed" your rev ups. If you do clutch work and get light weight flywheels or drive shafts. That'll be where you really see rev ups being really different. I don't know, to each his own. But, it seems like a worthless mod to me.

378awhp/373wtq Custom Dom 3 & CBRD tuned 2006 STI.
"When in doubt...flat out" - Colin McRae
turmic is offline  
Sponsored Links
post #19 of 20 Old 03-23-2011, 10:37 PM
WRXtuners Member
Join Date: Feb 2011
Location: Iowa
Posts: 2
There can be no gain of "horsepower" from adding a light weight crank pulley. By adding less rotational mass you can see a small increase torque however. i wouldnt expect alot though
WRX04RPM is offline  
post #20 of 20 Old 03-24-2011, 06:00 AM
WRXtuners Member
Join Date: Jun 2007
Location: Texas
Posts: 4,996
It's rotational weight....Any little bit helps <--My ˘2

2002 WRX Sold
2007 WRX Sold
2007 STi totaled
2007 Foz XT sold
2007 MS3
pzr2874 is offline  

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome