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Vtec & Boost

Discussion in 'Forced Induction' started by TurboRex90, Jun 1, 2009.

  1. TurboRex90

    TurboRex90 Golden EG

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    Ok me and my brother were talking. When Vtec engages it allows a larger airflow right? And with a vtec controller you can change the RPM in which it engages right? And if engaged too low in the power band you would lose power right?

    Well what if you had a turbo, would lowering the RPM in which vtec engages around when the turbo begins to spool wouldnt that allow for a quicker spool due to the engine opening up and allowing in more air. I mean wouldnt that make sense?

    This would be on a SOHC Vtec engine so i dont think that it would potential LOOSE as much power as it would help the spool of a turbo because Vtec doesnt hit as hard as it would in a Bseries?

    Whats your all's two cents, do you think this sounds plausible??
     
  2. Briansol

    Briansol Admins Admin VIP

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    sometimes lowering vtec engagement makes more power
    sometimes raising vtec engagement point makes more power

    it's a case by case basis that can only be found on a dyno with tuning software on your lap.
     
  3. TurboRex90

    TurboRex90 Golden EG

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    Well im not looking to gain power from Vtec alone, im talkin about using Vtec to spool my turbo faster. Is that technically possible?
     
  4. Briansol

    Briansol Admins Admin VIP

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    vtec doesn't do anything to effect spool. unless you're running a rediculous turbo (like a t88), you'll be fully spooled well before its time for vtec
     
  5. TurboRex90

    TurboRex90 Golden EG

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    No no no no no, i dont think you understand my point. You understand when Vtec engages it allows for more air to pass through the engine right? Ok well if Vtec engaged early enough wouldnt that allow for alot more air to pass through the engine and in theory spool the turbo quicker? Because a turbo is spooled by exhaust gas.. the excess gas from vtec engaged would create a quicker spool? Understand?
     
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  6. Matts96HB

    Matts96HB . Moderator VIP

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    I think that you could see some gain from this if you strap it on a dyno while doing it. It's going to be extremely difficult to tell on the street. But yeah, good idea.. worth a try I'd say. :thumbsup:
     
  7. Briansol

    Briansol Admins Admin VIP

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    :bash:

    just get a right sized turbo and spool won't be an issue anyway
     
  8. DESPAIN

    DESPAIN yep....mmhhm.......yep...

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    :concur: I dont think its that much exhaust gas to make a large diff. But it would be cool to check out if you had axcess to a dyno.
     
  9. DESPAIN

    DESPAIN yep....mmhhm.......yep...

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    :concur: I dont think its that much exhaust gas to make a large diff. But it would be cool to check out if you had axcess to a dyno.
     
  10. TurboRex90

    TurboRex90 Golden EG

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    :eek:... I have a T3/T4 .57 trim turbo. Problem is i dont start to spool til about 3500rpm, and dont hit peak boost until about 4800rpm. Instead of buying a new turbo.. which i admit i plan on doing anyways in the near future, i'd rather help this one spool faster.
    Yeah right now i do have turbo lag and before boost i have low power so the sooner it spools the sooner ill be happier.

    DESPAIN: Well if you do any research on Vtec, the difference in air flow before and after engagement is actually more then you'd expect.

    But yeah, ill talk to my tuner about it and try to get dyno time within the next couple weeks to test this theory out.
     
  11. Matts96HB

    Matts96HB . Moderator VIP

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    I can't help but think that your spool time is slow because of the compression you are running. What headgasket are you running? You could get a thinner one to bump up the compression a bit, that'd help spool a bit.
     
  12. TurboRex90

    TurboRex90 Golden EG

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    current compression is 8.1:1... Bleh.. thats also why i have to push 19psi to compensate.
    But as you i told you in another thread i plan to bump the compression to somewhere in the 9:1-10:1 range.

    I have a triple layer head gasket on.
     
  13. Briansol

    Briansol Admins Admin VIP

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    throw a 20 shot on.
     
  14. TurboRex90

    TurboRex90 Golden EG

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    Noooo thank you.

    As my DD i am never messing with spray on this car.
     
  15. Matts96HB

    Matts96HB . Moderator VIP

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    See if you can snag a thinner gasket. I know they make em, just not sure about your engine. Call up Cometic or something, that'd be a pretty cheap way to bump up the compression without having to open the motor up
     
  16. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    lowering vtec to much will make it worse
     
  17. 95b16coupe

    95b16coupe New Member

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    i think to answer his question....no, it wont do anything. you do not want to set your vtec to 2000-2500 rpm, is that what you were considering?
     
  18. 97hatch

    97hatch ?

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    if you are afraid of runing nitrous on your daily driver i highly doubt that you are runing 19lbs of boost. What are using to tune with you could play with timing and antilag settings to decrease spool time. By the way if you are afraid of nirous you have watched to many F&F movies. N2O is sefe when setup properly i ran over 200 bottles thru a D16Y7 in my ek went to the track twice a week with a 100hp and pulled the engine to do a Bswap and my old sohc still runs today tunning is yor friend
     
  19. DESPAIN

    DESPAIN yep....mmhhm.......yep...

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    as i said. imo: it will not make a huge differance. but it would be fun to play eith on a dyno. but i wouldnt pay for dyno time to test it. i would just ask your tuner...
     
  20. TurboRex90

    TurboRex90 Golden EG

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    I mean if you'd like when i get my car back here in the next week from the paint shop ill film my boost gauge for you if you really dont believe me, but i'd rather be making power without always having to fill up a bottle, let alone pay for a kit and just to use a 20 shot.

    95b16coupe: Yeah i was talkin about doing that, my power isnt really made from Vtec, actually im pretty sure it was disconnected during my tune.. which i only later found out because when i redid my harness weeks later i saw the wire was cut.. but that a different story, so i wouldnt be really loosing power.

    Ill ask my tuner and see what he says.
     
    Last edited: Jun 2, 2009
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