Page 2 of 3 FirstFirst 1 2 3 LastLast
Results 16 to 30 of 34

Thread: Something about Pully sizes I don't understand

  1. #16
    Registered User
    Name:


    Join Date
    Feb 2005
    Location
    s. e. Michigan
    Posts
    114
    Like
    0
    Liked 0 Times in 0 Posts

    duh? II

    Well that was simple enough but now I have to ask is the only difference the upper pulleys and is it that simple? Putting an L upper on a HD and changing"stock tune" gives the HD 40 more h.p.? Seems like there has to be a catch here somewhere......... "Stock tune" needs what to be changed? Yeah, I AM this ignorant!
    Last edited by Danko; 05-12-2005 at 02:26 PM.

  2. #17
    ResFirma Mitescere Nescit
    Name: stew

    bgstew6's Avatar
    Join Date
    Jun 2004
    Location
    Charleston, SC
    Posts
    18,059
    Like
    0
    Liked 0 Times in 0 Posts
    Well you can take two identical motors with the same amount of boost. One has a tune with say 14 degrees of timing and fatter A/F ratios and the other has 16 degrees of timing and leaner A/F ratios. The latter of the two will produce more HP. (Hope I got that Right).

    Then you can factor in the parasitc loss that keeps the Harley from efficiently putting the HP down to the ground. Two peice steel drive shaft, heavier wheels/tire combo each, different rear end gears and overall weight of the vehicle.

    I think that the lightnings wheel/tire combo weighs as much as our 20 inch wheel alone. The lightning also has a one peice aluminum drive shaft, and over all is lighter than the harley.

    One of the experts will chime in here I am sure and give you some mathmatical computation to determine the parasitic loss in relation to rotational mass. LOl

    THat is about as good as I can break it down for you.
    Last edited by bgstew6; 10-05-2005 at 01:48 PM.

  3. #18
    Registered User
    Name:


    Join Date
    Feb 2005
    Location
    s. e. Michigan
    Posts
    114
    Like
    0
    Liked 0 Times in 0 Posts
    Damn! That is good! So what should an old fart consider doing to his nice two HD's, if anything, other than just drive them and trade them in on SuperDuties? If I could kick up the performance a bit with low effort and expense, maybe it would make sense? I have a 2005 regular cab F250 being built this week with the newly improved 362 h.p. V-10 with 457 ft.lbs. of torque, a 4.30 posi, steps, best radio, 6 speed, etc. and going out the door for $23K including 6% sales tax and $3K rebate on employee discount (thnx to a bro-in-law who had been with Ford but was not when I got the two HD's but is again).

  4. #19
    ResFirma Mitescere Nescit
    Name: stew

    bgstew6's Avatar
    Join Date
    Jun 2004
    Location
    Charleston, SC
    Posts
    18,059
    Like
    0
    Liked 0 Times in 0 Posts
    6lb lower pulley with app belt runs bout 180.00
    K@N Flat panel high flow filter bout 48.00
    A LIVE (not mail order) Custom Dyno Tune from a reliable tuner = bout 350.00

    SHould get ya up to the 365-375 RWHP range

  5. #20
    Registered User
    Name:

    Lightningforce's Avatar
    Join Date
    Feb 2003
    Location
    The Great State of TEXAS
    Posts
    310
    Like
    0
    Liked 0 Times in 0 Posts
    Here is what LFP offers.
    LFP Quick Change upper pulley with choice of a 2.80" upper or a 2.93 upper. Hardened steel hub, CNC machined billet aluminum pulley ring and stainless steel Allen bolt hardware........$89.00

    LFP Quick Change lower crank pulley in just about any size you can imagine........................................... ..........................$188.00
    Kit includes LFP mounting Hub, LFP pulley ring ( in 5 sizes, based on a 2.93" Lightning upper the sizes add 2#,4#,6#,8#,10# of boost ), Proper sized Goodyear Gatorback belt, Allen bolt hardware, converter lockup tool, forged 14mm hex tool.

    LFP also has a power package that includes our lower crank pulley kit, Predator tuner, NGK TR6 plugs, 160 stat.......$459.00
    Custom tuned ExCal2 also available for this package.

    Add an LFP 12" power stack CAI for as little as.............$119.00
    with new pre-installed air charge sensor.

    Mark/LFP
    1-281-385-5339
    www.lightningforceperformance.com
    " Check IT Out "

  6. #21
    Registered User
    Name:

    BlairTruck's Avatar
    Join Date
    Dec 2004
    Location
    Edmonton, AB
    Posts
    3,933
    Like
    7
    Liked 111 Times in 76 Posts
    way to dig this one up mark

  7. #22
    Registered User
    Name:

    fordfan1's Avatar
    Join Date
    Jul 2007
    Posts
    1,508
    Like
    0
    Liked 0 Times in 0 Posts
    great thread here i had no idea about the pulleys putting out less boost in hd's

  8. #23
    Registered User
    Name:

    fordfan1's Avatar
    Join Date
    Jul 2007
    Posts
    1,508
    Like
    0
    Liked 0 Times in 0 Posts
    hey guys 1 more question id 6 is really 4, and 4 is really 2, then there is no point in putting on a 2lb'r is there since it wil put out 0?

  9. #24
    Fast with Class
    Name: Tony


    Join Date
    Mar 2003
    Location
    Yorktown VA
    Posts
    1,643
    Like
    1
    Liked 7 Times in 6 Posts
    Have you replaced the upper pulley?

    I recommend using an L pulley. A used one is about ?? I can't recall ask around.

    Do a search for the pulley boost formula. Then research pulley size because a 4lb pulley might be a different size from company to company.

    best of luck,
    T

  10. #25
    World's Fastest Street HD
    Name: Josh

    Harley#356's Avatar
    Join Date
    Jan 2003
    Location
    NJ
    Posts
    31,073
    Like
    0
    Liked 6 Times in 6 Posts
    Quote Originally Posted by fordfan1 View Post
    hey guys 1 more question id 6 is really 4, and 4 is really 2, then there is no point in putting on a 2lb'r is there since it wil put out 0?

    not exactly, there is a ratio so its not an exact 2 lb less equation. a 2 lb will add some boost since its going to be a bigger diameter than the stock lower pulley since its the same size lower as a L's lower, but it wont add the same 2 lbs of boost it will on a L, but it has to add something since its a bigger pulley.

    there was a chart somewhere's on here with the exact math figured out. ken800 on the boards years ago was great for doing the nitty gritty calculations for all that kind of stuff to find out the EXACT answers lol

  11. #26
    PiMpInDaSoUtH!
    Name:

    DATS TTRAH!'s Avatar
    Join Date
    Sep 2008
    Location
    laffy, louisiana
    Posts
    1,660
    Like
    0
    Liked 0 Times in 0 Posts
    would it be safe to put a blower pulley on with my 6lb that is on now or would it blow?

  12. #27
    PiMpInDaSoUtH!
    Name:

    DATS TTRAH!'s Avatar
    Join Date
    Sep 2008
    Location
    laffy, louisiana
    Posts
    1,660
    Like
    0
    Liked 0 Times in 0 Posts
    i have the #6 and was thinkin about putting the snout pulley from a lightning stock eaton what is my best bet as far as getting the most reliable most usable power








    pulley

  13. #28
    Over The Pond
    Name:

    Adam's Avatar
    Join Date
    Dec 2004
    Location
    Gt Yarmouth, UK
    Posts
    1,436
    Like
    0
    Liked 6 Times in 4 Posts
    I have a 6# Lower, Lightning Upper and a Port.

    Hasn't blown up yet

  14. #29
    World's Fastest Street HD
    Name: Josh

    Harley#356's Avatar
    Join Date
    Jan 2003
    Location
    NJ
    Posts
    31,073
    Like
    0
    Liked 6 Times in 6 Posts
    I'd swap the lower to an 8 before swapping the upper to a L pulley. More belt wrap keeping the stock upper and going with a bigger lower = less belt slip.

    I'd port the blower before adding even more boost though. I only had a 6 lb lower, stock upper, full ported intake setup (C&L, ported TB, smooth elbow, JLP ram air, S/C Spacer) and i'd see 18 lbs on the dyno, 16-17 on the track

  15. #30
    Registered User
    Name: richard

    v jet's Avatar
    Join Date
    Mar 2006
    Location
    augusta
    Posts
    23
    Like
    0
    Liked 0 Times in 0 Posts

    What lenght belt?

    I switched upper pulley to lightning pulley, but I have the 8lb pulley. I was running a 70 inch belt and from what I have researched I should continue to use the same belt. Help, it seems it would be too loose. GDY Goodyear/Gates Belt 70.00 inch Long Belt GDY-4080700

Page 2 of 3 FirstFirst 1 2 3 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
  •