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Thread: Upgrade Time..T or YS?

  1. #1
    Senior SCH Member
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    251

    Upgrade Time..T or YS?

    Well I've been running S-Trim for over 5 years, and it finally is time for a rebuild, but also the perfect time to upgrade.
    The current combo is
    331 8.5 c/r
    TFS TW 2.02s (300/230)
    Cam Motion Custom (564/239/114)
    Port matched Holley systemax
    1 3/4 LTs
    S-Trim 13psi
    60lb injs, dual 255inlines, -8feed, -6 return (in work)
    Alky inj
    TKO600

    The car made 588rw on 13psi running outta fuel at 5400rpm (on the 42lb injs and stock lines rails)

    Now I was only making 13psi but spinning the S-Trim for all its worth...I ran a 2.75/7" which obviously was over spinning the S.
    I'm sure you all are aware of the CFM ratings of the S/T/YS....and the reason I'm leaving the YSi out is Vortech doesnt rec. it on a curved volute (kills eff. they said) and said the YS performs better on the curved discharge.
    This car is a weekend cruiser/drive on nice days to work or whenever I feel like cruising..I'm looking for a blower that will give me room to grow, and I wont have to spin it so hard. Looking for 15-18psi w/o even thinking twice, and obviously some nice CFM.
    S-Trim 1000cfm 50,000 max impeller
    T-Trim 1200cfm 55,000 max impeller
    YS-Trim 1600cfm 65,000 max impeller

    And yes this car is driven on the street 98% of the time
    My goal is mid 10s

    Thanks
    Chris
    Last edited by eades5.0; 09-24-2005 at 04:32 AM.
    Stock Blocks are Unbreakable

  2. #2
    Senior SCH Member
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    May 2003
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    251
    bump
    Stock Blocks are Unbreakable

  3. #3
    I'd upgrade to a T-Trim, I'd go to the YSi if you were looking to go mid 9's. T-Trim is good for over 700rwhp at a minimum.
    1998 Pontiac Formula
    YSi, 348ci, 8.2:1, T400, TCT Converter, Moser 9"
    680-754rwhp
    9.40@143.7 | 1.35 | 3440 Raceweight 10.8.05
    Pics: www.psj.ls1tech.com

  4. #4
    SCH Moderator BLOWNBY's Avatar
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    Second that plus the T is easier to install since it is smaller. You will need to upgrade to the mini race bypass as well. Mondo is not necassary but will work as well. The mini is just smaller and cheaper.
    351 "stockshort block": -Vortech T-trim (21 psi), Trick Flow Heads, Lunati Cam, Weldon fuel system, Lentech AOD., 3.55 gears, 27" Hoosier QTP's, 3500# with me

    -545 rwhp
    -10.02 @ 135mph---Is 9.99 to much to ask?:freaks:
    -1.42-- 60'
    Quote Originally Posted by regattacoupe
    Since when do they let Homo's with 700rwhp that run 11's be a SCH mod? :shocked: :obscene: :D

  5. #5
    Senior SCH Member
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    Thanks guys
    Stock Blocks are Unbreakable

  6. #6
    Senior SCH Member
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    I still say the T-trim.

    Troy
    1995 Mustang Cobra
    302-10.77 @ 127.76
    new motor being built
    redsnk@yahoo.com

    owner/moderator
    http://www.stangtuning.com

  7. #7
    Junior SCH Member
    Join Date
    Aug 2005
    Posts
    5
    Vortech has a neat compressor map on their site that compares the efficiency of the S and T trim. But to make a decision you need to know where your engine's total system resistance lies on this map. You already know two points on this curve and it's easy enough to draw a curve between these two points.

    Based on your numbers, you are spinning the S-trim at about 47,500 RPM. If the belt is slipping deduct 5% from this number for 45,000 RPM. Intake boost is 13 psi but add 3 psi for losses through the ducting etc. for a pressure ratio of ~2.1. I have no idea how much to adjust the rwhp so I'm going to guess at 700 HP crank. That's about 70 lb/min of air flow. This defines the upper point of the curve. The lower point of the curve is basically (0,0).

    I marked up the compressor map and attached it. You can see that the S is running about 66% efficiency at your WOT operating point, where the T would be about 72%. More important you can see by extending the system resistance curve up to a pressure ratio of 2.4 you would gain about 100 HP. The curve is steep, so it's very much diminishing returns.

    The real answer is to make the curve less steep. You do this by installing better cylinder heads and a bigger cam. Then you need the YS, because you will be off to the right of the efficiency islands for the smaller blower.
    Attached Images Attached Images
    Last edited by tomcat; 09-26-2005 at 08:46 PM. Reason: Where's my attachment?

  8. #8
    The YSi can make over 1000hp but it would be overkill for low 10's unless your car is 5000 lbs. Plus the piping will have to be 4.00 in diameter.
    1998 Pontiac Formula
    YSi, 348ci, 8.2:1, T400, TCT Converter, Moser 9"
    680-754rwhp
    9.40@143.7 | 1.35 | 3440 Raceweight 10.8.05
    Pics: www.psj.ls1tech.com

  9. #9
    SCH Moderator BLOWNBY's Avatar
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    Your car will rock with the T and make some serious power. I wouldn't be suprised if your at least mid to upper 600's at the tire.

    Oh and I'd get the 8" 10 rib setup as well. Just so you don't have to worry as much with belt slip.
    Last edited by BLOWNBY; 09-27-2005 at 08:58 AM.
    351 "stockshort block": -Vortech T-trim (21 psi), Trick Flow Heads, Lunati Cam, Weldon fuel system, Lentech AOD., 3.55 gears, 27" Hoosier QTP's, 3500# with me

    -545 rwhp
    -10.02 @ 135mph---Is 9.99 to much to ask?:freaks:
    -1.42-- 60'
    Quote Originally Posted by regattacoupe
    Since when do they let Homo's with 700rwhp that run 11's be a SCH mod? :shocked: :obscene: :D

  10. #10
    Senior SCH Member
    Join Date
    May 2003
    Posts
    251
    Thanks guys!
    Stock Blocks are Unbreakable

  11. #11
    SCH Moderator BLOWNBY's Avatar
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    Mar 2004
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    1,380
    trying to post the compressor map for tomcat:
    Attached Images Attached Images
    351 "stockshort block": -Vortech T-trim (21 psi), Trick Flow Heads, Lunati Cam, Weldon fuel system, Lentech AOD., 3.55 gears, 27" Hoosier QTP's, 3500# with me

    -545 rwhp
    -10.02 @ 135mph---Is 9.99 to much to ask?:freaks:
    -1.42-- 60'
    Quote Originally Posted by regattacoupe
    Since when do they let Homo's with 700rwhp that run 11's be a SCH mod? :shocked: :obscene: :D

  12. #12
    SCH Member
    Join Date
    Nov 2004
    Posts
    74
    I agree the T is about the best all around blower there is in my opinnion it can be used as a strip only set up or a very mild street set up.

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