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DeskTop Dyno 2000 - !! CALLING ALL EXPERTS !!

Discussion in 'The Garage' started by Greg72, Jan 21, 2007.

  1. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Need some help....

    I'm trying to teach myself how to use DD2000, specifically how to load custom cam profiles (custom head flow numbers are next!!! :wink1: )

    Here is the cam I'm trying to input specs for:

    http://www.compcams.com/Technical/Search/CamDetails.asp?PartNumber=01-535-8


    In DD2000, I entered the following data in these cells in the CAMSHAFT section:

    Lifter: Roller
    Cam Specs @: Seat-to-Seat
    Int Lift@Valve: .513 in
    Exh Lift@Valve: .507 in
    IVO: 17.0
    EVO: 69.0
    IVC: 65.0
    EVC: 21.0

    What I want to confirm is that I've entered the correct data in the correct places... The "Seat-to-Seat" is reportedly better to use, and I grabbed the data off the spec sheet that showed "Valve Timing at .006" which I believe is the spec for Seat-To-Seat measurement???

    Also, when I added the values for IVO, EVO, IVC and EVC, the values for things like "Lobe Separation", and "Int Duration" and "Exh Duration" are automatically calculated by DD2000 and seem to match the cam spec sheet correctly....so it seems like I've done it right.

    Am I supposed to use the Gross Valve lift values the way I did, or am I supposed to use only the Lobe Lift (no rocker arm ratio applied)???

    If I take a look at the actual .cam file created in MS Notepad, it looks like this: (annotations next to the items I understand)

    Comp Cams TPX 262HR-14.cam

    3.10 <- ???
    0 <- ???
    TPX 262HR-14 <- Cam file name
    6 <- ???
    Roller <- Cam type (roller, flat, hyd)
    3 <- ???
    Seat-To-Seat <- Type of measurement (.050" vs Seat to seat)
    1 <- ???
    1 0.000000 <- Cam advance or retard in degrees
    1 0.513000 <- Intake Lift
    1 0.507000 <- Exhaust Lift
    0 <- ???
    1 17.000000 <- IVO
    1 65.000000 <- IVC
    1 69.000000 <- EVO
    1 21.000000 <- EVC


    Does anyone know what the ??? values represent?

    Just looking for feedback to make sure that I'm entering the data in the correct cells in DD2000, so that the output I'm getting is believable....

    :usaflag:
     
  2. 1977k5

    1977k5 3/4 ton status Vendor

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    You have it right.

    On a side note, generally the duration numbers at .050" lift are considered more accurate, but I have also found that DD is closer with seat to seat numbers.
     
  3. 86haubs

    86haubs 1/2 ton status

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    If your interested I have the 2003 version....have the camdisk also
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

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    Not sure about DD2003, but keep the specs, change the cam to hydraulic flat tappet though. You will likely see what most others do, the difference with exact same cam specs flat tappet to roller are ridiculous.

    Typically proves to be more accurate that way.
     
  5. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Are you saying that the HP/TQ numbers are exaggerated with the setting at "Roller"?? So set the cam spec as a "Hydraulic Flat Tappet" even though that cam actually IS a roller cam???

    The difference looks to be about 40 Lb/Ft on a sample BBC engine I'm playing with..... :dunno:
     
  6. 1977k5

    1977k5 3/4 ton status Vendor

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    That's what some people think
     
  7. UPS

    UPS 1/2 ton status

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    Is anyone using this program on Windows XP? If so how did you get it to work properly?
    Thanks,
    Mike
     
  8. dyeager535

    dyeager535 1 ton status Premium Member

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    Actually, I've seen it proven. Calculated power from 1/4 mile, compared to DD2K numbers, roller vs. flat tappet were the difference between almost dead on and a fair bit off.

    Obviously DD2K can only do so much, (look at engine analyzer if you want to play with just about all variables) and I've seen articles where folks such as David Vizard have tried Desktop Dyno and found it to be correct, depending on what dyno was used to compare.

    So it MIGHT be accurate in some cases one way or the other, but as I've seen it proven, and don't have dyno numbers to back up my own combo, (which have also been proven to be inconsistent themselves) I'd certainly go with the lesser of the two.
     
  9. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    Yes, i'm using it on windows XP and it works perfectly. I just slipped the disk into the drive and loaded it on my computer.

    Greg, Comp cams are all ground with 4 degrees advance so you need to change the timing advance to represent +4 degrees. I'll show you when you get here in a few weeks how to work this thing.
     
  10. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    Dorian, regardless of how accurate the DD2000 is you can still input info and get an idea of what works to make more HP/TQ between different given changes.
     
  11. dyeager535

    dyeager535 1 ton status Premium Member

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    Yeah, I'm not saying DD2K can't be accurate, because I'm not the only one that has seen it work and be quite close.

    I'm just saying the roller numbers vs. flat tappet cannot always be trusted.

    I think it is one of the better tools to use for comparing changes as you say. :)
     
  12. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    The only way you'll be able to get fairly accurate numbers is if you have actual air flow numbers for the heads, and also know for certain what your final compression ratio is ( deck height CC's, piston CC's, head gasket CC's, and the combustion chambers CC's) to give you an accurate compression ratio. Also need to have ALL of the required cam spec's. Most people don't have ALL the required info so they have to use the given choices that DD2K offers which of course won't give you accurate numbers.
     
  13. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Does anybody out there have an accurate .dyn file for a BBC Crate motor?

    Something like the 454HO or 502HO would be great. I'd like to see how the entire file looks (all attributes, not just the cam profile) on a real engine setup.


    You can email them to me at:

    gregblanchette@gmail.com
     
  14. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Bump for the afternoon crowd....

    Anyone got some .dyn files???
     
  15. dyeager535

    dyeager535 1 ton status Premium Member

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