Cobb Leightweight Main Pulley
Page 1 of 2 12 LastLast
Results 1 to 15 of 18

This is a discussion on Cobb Leightweight Main Pulley within the Engine Modifications forums, part of the Tech & Modifying & General Repairs category; I am looking to install the Cobb Leightweight Main Pulley on my 2011 WRX. I am looking for some insight...hopefully ...

  1. #1
    Registered User zaubuchon182's Avatar
    Join Date
    Sep 2010
    Location
    Grand Rapids, MI
    Posts
    85

    Cobb Leightweight Main Pulley

    I am looking to install the Cobb Leightweight Main Pulley on my 2011 WRX. I am looking for some insight...hopefully someone else has done this recently.

    I am looking specifically for a couple tools that will take the main pulley off and that will put the timing belt back into place after installation. I watched a video on the installation of the Grimmspeed pulley and they use the tools below...

    To take the pulley of the engine block


    To put the timing belt back on


    Does anyone know if these tools work for the Cobb pulley too? If so, where can I get them?

    Any information or insight would be greatly appreciated!

  2. Remove Advertisements
    ClubWRX.net
    Advertisements
     

  3. #2
    Gold Member lokey's Avatar
    Join Date
    Jan 2011
    Location
    Crofton, MD
    Posts
    2,169
    I Support ClubWRX
    * * COMPLETE PART-OUT STARTS FRIDAY, AUG 1, 2014. EMAIL REASONABLE OFFERS TO GREG.LOKEY@GMAIL * *

    Greg

    Build Thread
    ProTuned Stage 3ish '11 WRX Ltd HB (SWP) ~ 354 awhp 404 ft-lb tq on E85
    Friends don't let friends drive Mitsubishis.

  4. #3
    He simply abides. SD_GR's Avatar
    Join Date
    Jul 2002
    Location
    CA, US
    Posts
    22,279
    I Support ClubWRX
    Wait, what pulley are we talking about that requires re-installation of the timing belt? I find this confusing. Why is the timing belt removed?
    WRX Info Links, Courtesy TheJ
    The world breaks everyone and afterward many are strong in the broken places. Ernest Hemingway
    I lied. I cheated. I bribed men to cover the crimes of other men. I am an accessory to murder. But the most damning thing of all... I think I can live with it. And if I had to do it all over again - I would. Benjamin Sisko
    DISCLAIMER: Opinions expressed are the author's alone and are inherently worthless.

  5. #4
    Gold Member lokey's Avatar
    Join Date
    Jan 2011
    Location
    Crofton, MD
    Posts
    2,169
    I Support ClubWRX
    It's not the timing belt; it's the "accessory belt"?....you know, the front one. lol

    OP - Can you send a link or something that shows why that first "tool" is needed. I think I remember it going like this - REMOVAL: Put the car in gear, get out the longest breaker bar you're got, good luck breaking the bolt loose, and fish out of there. REPLACEMENT: Find the hole, line it up with key/notch, torque new one down. As for the belt, instead of buying and using the tool from your second pic, we just cut and replaced the belt with a better "stretch" belt.
    Last edited by lokey; 10-03-2011 at 09:52 AM.
    * * COMPLETE PART-OUT STARTS FRIDAY, AUG 1, 2014. EMAIL REASONABLE OFFERS TO GREG.LOKEY@GMAIL * *

    Greg

    Build Thread
    ProTuned Stage 3ish '11 WRX Ltd HB (SWP) ~ 354 awhp 404 ft-lb tq on E85
    Friends don't let friends drive Mitsubishis.

  6. #5
    Registered User zaubuchon182's Avatar
    Join Date
    Sep 2010
    Location
    Grand Rapids, MI
    Posts
    85
    Quote Originally Posted by lokey View Post
    It's not the timing belt; it's the "accessory belt"?....you know, the front one. lol

    OP - Can you send a link or something that shows why that first "tool" is needed. I think I remember it going like this - REMOVAL: Put the car in gear, get out the longest breaker bar you're got, good luck breaking the bolt loose, and fish out of there. REPLACEMENT: Find the hole, line it up with key/notch, torque new one down. As for the belt, instead of buying and using the tool from your second pic, we just cut and replaced the belt with a better "stretch" belt.
    This video below is what I was watching for removal and installation
    GrimmSpeed Subaru Lightweight Crank Pulley Install Video - YouTube

    Now that you mention it, putting the car in gear is probably 100x easier. As for the belt...even if you cut the belt you would still need a way to put the new one on. Since a tensioner pulley doesn't exist on this car I have no other choice but to use the tool or chance breaking the belt putting it back on.

  7. #6
    Registered User teflon_jones's Avatar
    Join Date
    Apr 2007
    Location
    8000' up in Colorado
    Posts
    6,753
    Lightweight pulleys are a total waste of time and money.

    Return it and buy something useful with the money.
    Scott
    Past Subies - '11 STI Limited stage 1+ and '04 STi stage 2+
    '13 Wrangler Rubicon - custom front bumper w/12k lb winch & off-road lights, skid plates, diff guards, etc.
    '04 Porsche 911 Turbo GT2 clone 600 HP/TQ
    '77 F-150 heavily modded for off-roading

  8. #7
    UnBanned Sinister's Avatar
    Join Date
    Nov 2006
    Location
    Denver Metro Area
    Posts
    17,617
    I Support ClubWRX
    so bitter scott Why do you say they're not worth the money?
    Kevin
    Moderator
    Sinister's Blowoff Valve FAQ
    WRX Gas Mileage FAQ
    Sinister's Progress Thread - 430whp 429wtq - Sold
    Firearms Enthusiasts Thread

    The Sheriff's Star at the bottom left corner rates a user's reputation.
    If you found a user's post to be helpful or quite the opposite, please make it known to them by clicking the Star!

  9. #8
    Gold Member lokey's Avatar
    Join Date
    Jan 2011
    Location
    Crofton, MD
    Posts
    2,169
    I Support ClubWRX
    Quote Originally Posted by zaubuchon182 View Post
    This video below is what I was watching for removal and installation
    GrimmSpeed Subaru Lightweight Crank Pulley Install Video - YouTube

    Now that you mention it, putting the car in gear is probably 100x easier. As for the belt...even if you cut the belt you would still need a way to put the new one on. Since a tensioner pulley doesn't exist on this car I have no other choice but to use the tool or chance breaking the belt putting it back on.
    Exactly. That's why you may want that second tool I provided a link to. But I'm still not sure if it works for any pulley other than Grimmspeed, after reading the description. They are stretch belts, so 1) no tensioner and 2) they shouldn't break if stretched a bit.
    * * COMPLETE PART-OUT STARTS FRIDAY, AUG 1, 2014. EMAIL REASONABLE OFFERS TO GREG.LOKEY@GMAIL * *

    Greg

    Build Thread
    ProTuned Stage 3ish '11 WRX Ltd HB (SWP) ~ 354 awhp 404 ft-lb tq on E85
    Friends don't let friends drive Mitsubishis.

  10. #9
    Registered User shadowpr's Avatar
    Join Date
    Jan 2011
    Location
    TX, NY
    Posts
    1,579
    i went with the grimmspeed pulley, and their tools. made it an easy install.

  11. #10
    The Fruit mangostick's Avatar
    Join Date
    Oct 2009
    Location
    VB VA .. the ghetto on the sea
    Posts
    4,735
    I'm curious too as to why reducing rotational mass is a bad Idea?

    The factory pulley weighs what 8lbs? Halving that should make a nice improvement pre-boost and for off throttle rpm drop.

    Unless I'm missing some quirk of the car that causes a reduction in mass to be a bad thing? ..
    OBP 2010 5dr *traded*
    SWP 2013 FRS
    My name is Shawn, I'm a Devout Practicalist and I'm addicted to flat4's
    This page has had 1,666 visits
    SUCH IS MANGO!

  12. #11
    Registered User Heide264's Avatar
    Join Date
    May 2010
    Location
    Pittsburgh, PA
    Posts
    4,168
    I Support ClubWRX
    Quote Originally Posted by mangostick View Post
    I'm curious too as to why reducing rotational mass is a bad Idea?

    The factory pulley weighs what 8lbs? Halving that should make a nice improvement pre-boost and for off throttle rpm drop.

    Unless I'm missing some quirk of the car that causes a reduction in mass to be a bad thing? ..
    Warning: No first hand experience. Just forum trolling education and a bit of intuition on my part.
    -Side Note: Too much rotational mass reduction may throw issues. This can be achieved with a lighter flywheel in itself.
    -Second hand observation: The pulley doesn't make a huge difference apparently... But yet the flywheel does.
    -Intuition: With such a small diameter the rotational mass/inertial is fairly low due to the shorter lever arm. The flat out 4lb reduction causes nominal rotational inertia changes without the larger lever arm for the majority of the weight... as opposed to a lighter flywheel where there is a large portion of the weight at a longer lever arm.

    That being said, its the same idea with a carbon fiber driveshaft from what I've read. Actually slows your revs down (adds rotational inertia), but is a lighter part (removes overall weight). I would infer that more of the weight is spread towards the surface of the driveshaft, than a traditional one that is uniformly weighted (in a radial sense from the center point outwards).

    Physics nerds, comment as well. Chances are, my logic is pretty far off from the truth. I don't deal with mechanical stuff much - on the electrical side personally.
    Quote Originally Posted by Trainrex
    He was throwing balloons filled with sulfuric acid and shrapnel at the swat team. They finally had to take him down with rubber bullets.
    2011 STi Build Log
    -Part 1 - Reading, Data Logging, and Analyzing Data
    -Part 2 - Turbocharger 101 & Basic Boost Control
    -Part 3 - EcuFlash, Experimental Defintions, and a Drive By Wire Intro

  13. #12
    The Fruit mangostick's Avatar
    Join Date
    Oct 2009
    Location
    VB VA .. the ghetto on the sea
    Posts
    4,735
    well no that makes sense that the flywheel reduction makes a bigger difference.. not only is it heavier to begin with its of a much larger diameter. I can def see why the shorter lever reference would make weight reduction less effective. But I'd think there should be some benefit. How much related to cost though.. that might be the question at hand. They're not hard to change (vs a flywheel) so if there is benefit to be had.. this would be an easy way to go about it.

    How many are running them and what are the opinions?
    OBP 2010 5dr *traded*
    SWP 2013 FRS
    My name is Shawn, I'm a Devout Practicalist and I'm addicted to flat4's
    This page has had 1,666 visits
    SUCH IS MANGO!

  14. #13
    Registered User shadowpr's Avatar
    Join Date
    Jan 2011
    Location
    TX, NY
    Posts
    1,579
    I think i noticed a positive change. it might all be in my head though.

  15. #14
    Registered User Heide264's Avatar
    Join Date
    May 2010
    Location
    Pittsburgh, PA
    Posts
    4,168
    I Support ClubWRX
    Quote Originally Posted by mangostick View Post
    well no that makes sense that the flywheel reduction makes a bigger difference.. not only is it heavier to begin with its of a much larger diameter. I can def see why the shorter lever reference would make weight reduction less effective. But I'd think there should be some benefit. How much related to cost though.. that might be the question at hand. They're not hard to change (vs a flywheel) so if there is benefit to be had.. this would be an easy way to go about it.

    How many are running them and what are the opinions?
    Quote Originally Posted by shadowpr View Post
    I think i noticed a positive change. it might all be in my head though.
    Most people report noticing a difference that I've read. I think it's just the idea that you can skim the weight off using a lighter flywheel much easier.
    Quote Originally Posted by Trainrex
    He was throwing balloons filled with sulfuric acid and shrapnel at the swat team. They finally had to take him down with rubber bullets.
    2011 STi Build Log
    -Part 1 - Reading, Data Logging, and Analyzing Data
    -Part 2 - Turbocharger 101 & Basic Boost Control
    -Part 3 - EcuFlash, Experimental Defintions, and a Drive By Wire Intro

  16. #15
    The Fruit mangostick's Avatar
    Join Date
    Oct 2009
    Location
    VB VA .. the ghetto on the sea
    Posts
    4,735
    effective maybe.. but definitely not easier. Installing a flywheel is quite a bit more involved lol
    OBP 2010 5dr *traded*
    SWP 2013 FRS
    My name is Shawn, I'm a Devout Practicalist and I'm addicted to flat4's
    This page has had 1,666 visits
    SUCH IS MANGO!

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •