Underpullies on a 6.1??

Discussion in 'General Discussion' started by srt8_hmi, May 6, 2008.

  1. CentralTexHemi

    CentralTexHemi PUNISHER

    Messages:
    5,844
    Likes Received:
    0
    Joined:
    Dec 19, 2007
    Location:
    Tejas
    This was a big topic when I had my modded 5.7 Hemi truck, if you want to know more about toner rings check with Stu at Inertia Motorsports at one time he was making some stronger ones but that was a long time ago
     
  2. mjc1241

    mjc1241 Full Access Member

    Messages:
    94
    Likes Received:
    0
    Joined:
    Dec 7, 2007
    Location:
    Atlanta, GA
    Thanks for the info. I learned my lesson from the March pulley setup so no SFI approved harmonic balancer, no dice for me.
     
  3. srt4evah

    srt4evah Raw Meat

    Messages:
    159
    Likes Received:
    0
    Joined:
    Jan 1, 2008
    Location:
    Austin, TX
    Underpullies, sounds like some sort of hazing you do to freshman... =]

    I don't think underdrive pullies will help that much on a large engine like the 6.1L, it makes much more of a difference on smaller lighter engines, where that underdriven and lighter pulley makes up a bigger percentage of the parasitic losses.
     
  4. Cheatek

    Cheatek SRT once, SRT always

    Messages:
    5,628
    Likes Received:
    0
    Joined:
    Nov 27, 2007
    Location:
    Nor Cal
    Underpullies ... hazing ... lol, now that's funny!! I agree, on smaller engines it makes more of a dif. On my 5.0 mustang it really was noticable, the motor spun up much faster, it felt almost "unburdened" in a way and made a definite difference.
     
  5. 1FST4DR

    1FST4DR Supporting Vendor

    Messages:
    2,051
    Likes Received:
    0
    Joined:
    Oct 14, 2007
    Location:
    Ft Laud

    You got that right!!!:worthy:
     
  6. LegMaker

    LegMaker LMI - LegMakerIntakes

    Messages:
    10,483
    Likes Received:
    0
    Joined:
    Oct 25, 2007
    Location:
    orlando
    get the hi -flows.....
     
  7. srt8_hmi

    srt8_hmi My dream is over.

    Messages:
    802
    Likes Received:
    0
    Joined:
    Apr 30, 2008
    Location:
    ohio
    hi-flows are on there way! i'm pretty excited about getting them on, hopefully this weekend. now if i can find a borla muffler with a little more rumble..
     
  8. mjc1241

    mjc1241 Full Access Member

    Messages:
    94
    Likes Received:
    0
    Joined:
    Dec 7, 2007
    Location:
    Atlanta, GA
    Borla XR1 Race mufflers. I got mine from Summit Racing. Gives the car a nice rumble and at WOT they sound AMGish. I love em!!!
     
  9. srt8_hmi

    srt8_hmi My dream is over.

    Messages:
    802
    Likes Received:
    0
    Joined:
    Apr 30, 2008
    Location:
    ohio
    Priceless info.. thanks. direct fit? no cutting or welding?
     
  10. PPPAndy

    PPPAndy New Member

    Messages:
    902
    Likes Received:
    0
    Joined:
    Nov 16, 2007
    In addition to what Matt has said, we have a 25% underdrive pulley that when installed gave us a documented 14rwhp with no loss of functionality to alternators or power steering and such. The guy that got 22rwhp by removing his belt may have seen more power, but I am sure his motor was getting very hot by the end of the run due to the water pump not running.

    The motoblue pulley that caused all of the issues was not a harmonic balancer. There is a huge difference between an underdrive pulley and a harmonic balancer.



    All of our underdrive pullies are also Harmonic Balancers and they are SFI approved, meaning no harsh/unwanted vibrations in the crankshaft. The 14rwhp gain we got was from removing an ATI balancer and putting our pulley in its place.

    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    You can see the SFI certification in the second picture.
     
  11. SRT8U

    SRT8U Supporting Vendor

    Messages:
    1,726
    Likes Received:
    0
    Joined:
    Nov 7, 2007
    Location:
    S Florida
    If you do an U/D definitely get one that is also a SFI Harmonic Balancer.
    We will be carrying one very soon that has this setup and comes from a reputable manufacturer. Initial dyno results show about 10hp/tq increases on a stock car.
     
  12. mjc1241

    mjc1241 Full Access Member

    Messages:
    94
    Likes Received:
    0
    Joined:
    Dec 7, 2007
    Location:
    Atlanta, GA
    I had my mufflers welded in. NEVER changing my exhaust.
     
  13. srt8_hmi

    srt8_hmi My dream is over.

    Messages:
    802
    Likes Received:
    0
    Joined:
    Apr 30, 2008
    Location:
    ohio
    watch out for the blasting borla brothers!!
     
  14. mjc1241

    mjc1241 Full Access Member

    Messages:
    94
    Likes Received:
    0
    Joined:
    Dec 7, 2007
    Location:
    Atlanta, GA
    I'v had two Vette owners compliment me on my exhaust; one with a modded C5 and another with a modded C6 and both stated that my exhaust is WICKED at WOT. The guy with the modded C5 has a cam in his car and was shocked at how loud my car was. (a good loud) Another Vette owner I recently enocuntered literally stopped in his tracks when he heard my car start up. The sound definitely signals bad intentions....and I love it!! SRT8 HMI told me in a PM that the Borla guys tried to talk him into not getting them because they throught they are too loud....HA!!!!!!
     
  15. CentralTexHemi

    CentralTexHemi PUNISHER

    Messages:
    5,844
    Likes Received:
    0
    Joined:
    Dec 19, 2007
    Location:
    Tejas




    UHHH yeah I know so not sure what you meant there???
     
  16. CentralTexHemi

    CentralTexHemi PUNISHER

    Messages:
    5,844
    Likes Received:
    0
    Joined:
    Dec 19, 2007
    Location:
    Tejas
    I guess what I am getting at more than anything else is that for the cost and what you have to do to install this is really not worth the money IMO Andy I know you guys have a great pulley/balancer and if you add this mod while doing other work like head and cam while the crank bolt is already out it might be worth it then
     
  17. mjc1241

    mjc1241 Full Access Member

    Messages:
    94
    Likes Received:
    0
    Joined:
    Dec 7, 2007
    Location:
    Atlanta, GA
    Subscribing for additional info. So this is not just a straight forward pulley swap ala one done on a Mustang?
     
  18. CentralTexHemi

    CentralTexHemi PUNISHER

    Messages:
    5,844
    Likes Received:
    0
    Joined:
    Dec 19, 2007
    Location:
    Tejas
    I think what Andy at PPP is pointing out that with a good harmonic balancer with the addition of a smaller UD pulley you should be okay and If I am not mistaken they actually carry such a setup so I would trust the judgement of what Andy says on this matter over mine
     
  19. mjc1241

    mjc1241 Full Access Member

    Messages:
    94
    Likes Received:
    0
    Joined:
    Dec 7, 2007
    Location:
    Atlanta, GA
    Oh I am good and trust PPP products as I have a few on my car now. I was just looking at difficulty of install. I am having the shop that does all of my work install the pulley when I receive it and just wanted to get an idea.
     
  20. PPPAndy

    PPPAndy New Member

    Messages:
    902
    Likes Received:
    0
    Joined:
    Nov 16, 2007

    Install is 2.5 hours here. Making install cost around $212.50. Thats $249.99 for the pulley and $212.50 for a total cost of $531.25. Thats $44 per hp which is better than any catback or header system. I will agree that the best time to put this on is during a cam swap of some sort so that there is no increase in labor cost.


    Sounds good. We are shipping yours out today.