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  1. #76
    Quote Originally Posted by Dan Cragin View Post
    The Drag Pack cars made 800hp with unported gen 4 heads.

    Unported gen 4 heads with 2.08'' valve = 312 CFM @ 0.500'' lift and 327 CFM @ 0.600'' lift (passed that it drops)

    it's not that far from the numbers I have with my ported gen 3 heads and I kept the 2.02'' valve diameter (for few reasons) so I think my target of 750 crank HP is reasonnable


    Edit: Sorry I think the numbers here are with stock valves and the ported one with 2.08'':
    http://www.speedstore.ca/VP4_flow_sheet.html
    Last edited by Aevus; 05-18-2022 at 03:43 PM.

  2. #77
    Quote Originally Posted by Dan Cragin View Post
    With a 114 LSA the cam it should be tuneable with those numbers. We had issues with the 107-110 LSA cams.
    I have found, that unless your heads are really flowing well, the bigger cam does not make more power and
    driveabilty suffers.

    Gen 4 heads on a Gen 3 motor with the dragpack intake, you can make big power.

    In fact, all in all, there is not that much to gain with a N/A engine. It's basically always between 700 and 800hp (more or less 85hp difference at the wheels) from the ''basic'' Roe Racing's 710R kit to the somewhat extreme dragpack w/gen4 heads you mention. No wonder why big N/A projects are not very popular... I'm doing it for fun but frankly speaking if someones is looking for best bang for the bucks, it's not very good.

  3. #78
    With a 114 LSA the cam it should be tuneable with those numbers. We had issues with the 107-110 LSA cams.
    Yeah I wouldnt dare going that tight. 710R cam is 14 deg valve overlap, I'm pushing it to 23 deg on mine, and that's only because I'll have 11.7:1 CR to compensate. And that will require 93-94 oct all the time and dyno-tune

  4. #79
    They couldnt grind exactly what I wanted so that's the cam I'll finally get:

    246/256 @ .050
    .596/.554
    114+4

    It leaves some room for timing adjustments (retard by few degrees, if needed) and also for future shaft mount rockers upgrade with 1.75 ratio (again, if needed)

    Not sure if the shaft rockers would be that important, since the valvetrain is now very light and spring lift moderate. Also not gonna spin the thing to 7,500rpm... But at least, there is a possible upgrade.
    Last edited by Aevus; 05-19-2022 at 01:01 PM.

  5. #80
    How does the drag pack intake compare to the Gen 5 intake?

  6. #81
    VOA Member
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    Dan Cragin's Avatar
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    The drag pack intake works with the Gen 3 throttle controls and engine controller, but allows you to use Gen 4-5 heads. It has a much larger upper plenum than
    the factory Gen 3 intake, as well as provisions to get more air to the rear cylinders.
    specialtyperformanceteam.com
    310-597-6295

  7. #82
    Going with Gen 5 heads on a 9L gen 2 block. I do have a gen 5 intake in possession, but wonder if it'd be worth it to go with the drag pak instead. Sorry for going off topic

  8. #83
    VOA Member
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    I'm doing the same thing on a Gen 2 currently, but we are using electronic throttle bodies and a Motec. Much more complicated.
    You can use Mechanical throttle bodies on the Gen 5 intake as well. That would be the best my second choice.
    specialtyperformanceteam.com
    310-597-6295

  9. #84
    Doesnt AZ Viper spin his 9L to 7k?

  10. #85
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    ITB is the way to go, unfortunately not cheap, but super easy to work with and pretty dang economical when you calc dollar per HP and reliability gain.

  11. #86
    Quote Originally Posted by SRT_BluByU View Post
    Doesnt AZ Viper spin his 9L to 7k?
    Indeed he does:


    (if it doesn't skip then go to 8 minutes and 40 seconds)


 
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