Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

Homemade intake

Discussion in 'VE Holden Commodore (2006 - 2013)' started by monkeyboy, Aug 2, 2011.

  1. Grennan

    Grennan Slayer of Stupid Threads

    Messages:
    2,512
    Likes Received:
    74
    Trophy Points:
    0
    Joined:
    Mar 13, 2007
    Location:
    Glen Waverley, Victoria
    Members Ride:
    VE SSV G8 Sportswagon
    You wont notice any gains, you might get 5 kw if you are really lucky and did a service on the car before it went on the dyno but a good air intake shines on the track.

    Also the bad bend I am referring to is the 80 degree bend from the TB. Sure thats how it is stock, but that is massively restrictive.

    Did you modify the airbox at all? Thats where the gains will come from.
     
  2. wraith

    wraith Hand over the dog bikkies

    Messages:
    5,009
    Likes Received:
    105
    Trophy Points:
    63
    Joined:
    Sep 17, 2008
    Location:
    Demonicaland
    Members Ride:
    VX V6 Berlina. 2003 VW Passat
    Has growler intake which replaces airbox.
     
  3. monkeyboy

    monkeyboy New Member

    Messages:
    119
    Likes Received:
    1
    Trophy Points:
    0
    Joined:
    May 23, 2005
    Members Ride:
    2010 VE SV6 SIDI
    Well each to their own I guess. Hose clamps give me raging horn actually and just thinking about them takes me on a one way trip to stiffy town. What would you suggest? Sticky tape? Blu-tac? I want the thing to be rigid, not flop around like some old codgers' johnson.

    A 90 degree bend is the only way to get from the throttle body to the airbox. How could a 90 degree bend in a 90mm pipe be 'massively restrictive' anyway? Air is quite good at going through pipes that have bends in them and doesn't have to move in straight lines to get from A to B...especially when it's only travelling about 4 inches. A restriction is something that impedes airflow...a 90 degree bend isn't a restriction...it's just a bend that redirects the air. And yes I replaced the airbox with a growler, the standard headers with Pacemakers and the standard exhaust with a full 2.5" X-Force setup. If you can produce a bench flow result that demonstrates what you're basing your 'massive' restriction idea on I'd be happy to be proven wrong. But anyway, the angle from the TB to the airbox is more than 90 degrees...so a 90 degree bend is mandatory to connect the two together.
     
  4. wraith

    wraith Hand over the dog bikkies

    Messages:
    5,009
    Likes Received:
    105
    Trophy Points:
    63
    Joined:
    Sep 17, 2008
    Location:
    Demonicaland
    Members Ride:
    VX V6 Berlina. 2003 VW Passat
    Spend the money get a bit of pipe made up to suit reduce the hose clamps. Wonder what a cop will think when they pop the bonnet and see that many hose clamps.
     
  5. monkeyboy

    monkeyboy New Member

    Messages:
    119
    Likes Received:
    1
    Trophy Points:
    0
    Joined:
    May 23, 2005
    Members Ride:
    2010 VE SV6 SIDI
    ^^^I've been driving for 21 years now and have never had a cop look under my bonnet and I'm assuming that won't suddenly change...although one did try to juggle by ball bag during a pat down once, which was kind of a turn-on actually.

    I guess I don't share your aversion to the humble hose clamp. But if a cop is ever overcome with a burning desire to poke his snout under my bonnet I'll just tell him they're Optimus Primes' leftover c*ckrings.

    Sorted!
     
  6. Ron Burgundy

    Ron Burgundy Well-Known Member

    Messages:
    2,385
    Likes Received:
    1,176
    Trophy Points:
    113
    Joined:
    Jun 3, 2004
    Location:
    NSW
    Members Ride:
    VF II SS
    at least it's not radiator hose pieces (Type S cai for l67 by FIT) that are too ugly to advertise and yet you still get charged in excess of 300 bucks for it...

    you fork out the money and then you get nasty surprise when it shows up in the box :)

    I'm all for DIY and creative mods...
    Over time these things improve...

    I used VN/VP air intake pipe for my old VT on side of the airbox and it was cheap, effective and looked factory...
    Many people jumped on board and gave it a go back in the day

    I prefer this look than some nasty shiny chrome pipe that will get hot as hell and remain hot as hell, defeating the purpose of CAI
     
  7. thestig

    thestig resident misanthrope

    Messages:
    299
    Likes Received:
    124
    Trophy Points:
    43
    Joined:
    Jan 19, 2008
    Location:
    Melbourne's South East
    Members Ride:
    E34 535i M - E70 X5 M - E60 M5 - No Fear
    And

    OK.

    The facts:

    Your engine: 210kW@6400rpm. 3564cc (217.5cu)

    217.5 * 6400 / 3456 = 402.7

    @ 90% Volumetric Efficiency (a guess)

    402.7 * 0.9 = 362.4cfm

    Therefore drinks about 362.4cfm at max power,

    Lots of calculations not included mean that a 4inch radius bend in 90mm piping is equivalent to the same level of flow restriction as 10ft of straight piping of the same diameter.

    If your driving around on your typical August day:

    Temp = 15 deg C.
    Density of Air = 1.225 kg/m3
    Dynamic Viscosity of Air = 1.15 mPa.s

    To feed your engine 362.4cfm the air velocity through 90mm piping is 26.88 m/s (88.2 ft/s)

    More calculations not included here mean that the pressure drop caused through flow restrictions encountered during the journey through 10ft of 90mm piping with an average internal surface roughness of 0.2mm would be 0.0643psi

    Assuming a volumetric efficiency of around 90% under these conditions (again, a aguess, I can't find the actual figure quoted anywhere) internal engine pressure for wide open throttle would be 14.7 *0.9 = 13.23psi

    removing the 90 degree bend would increase this by 0.0643psi or:

    0.0643/13.23 = 0.49%

    Making your engine that much more efficient. At most it will generate:

    0.0049 * 210 = 1.029 more kW

    So, conclusion:

    Is the 90degree bend a restriction?
    Yes.

    Is it massive?
    Not really.

    Would you remove if you could?
    Depends on how much money your willing to part with for 1kW gain.

    Have Holden already done these calculations?
    Yes.

    What was Holdens conclusion?
    Leave the fụcker there, if the customer is that cashed up and anal about power they can pay us a lot more money for a GTS/Senator/W427.

    Now! Let the flamage continue.

    L8r
     
  8. RUF-60L

    RUF-60L Donating Member

    Messages:
    467
    Likes Received:
    2
    Trophy Points:
    0
    Joined:
    Nov 25, 2010
    Location:
    Sydney
    Members Ride:
    2008 VE SS
    i wish i were smart :(
     
  9. wraith

    wraith Hand over the dog bikkies

    Messages:
    5,009
    Likes Received:
    105
    Trophy Points:
    63
    Joined:
    Sep 17, 2008
    Location:
    Demonicaland
    Members Ride:
    VX V6 Berlina. 2003 VW Passat
    My brain just exploded.
     
  10. Jarp

    Jarp Surely You Jest

    Messages:
    1,087
    Likes Received:
    7
    Trophy Points:
    38
    Joined:
    Dec 22, 2009
    Location:
    Canberra
    Members Ride:
    VFII SSV A6 W375
    LOL Stig....nice piece of math. We'll all assume this is correct and that air and indeed even sewrage will flow correctly through this piping. Nice doozering Monkey.
     
  11. monkeyboy

    monkeyboy New Member

    Messages:
    119
    Likes Received:
    1
    Trophy Points:
    0
    Joined:
    May 23, 2005
    Members Ride:
    2010 VE SV6 SIDI
    I read on some physics website that a 90 deg bend creates a restriction equal to 2.5 feet of straight pipe. So if I'm reading your post correctly Stig you're saying that the 90 degree bend is costing me a whopping 1kw compared to a straight pipe?
    If that's the case I can happily live with that.
     
  12. Grennan

    Grennan Slayer of Stupid Threads

    Messages:
    2,512
    Likes Received:
    74
    Trophy Points:
    0
    Joined:
    Mar 13, 2007
    Location:
    Glen Waverley, Victoria
    Members Ride:
    VE SSV G8 Sportswagon
    If you aren't concerned with a 1kw difference, why did you do it in the first place because realistically.....that's probably the gain you got from doing it.

    Either way, I do applaud the effort, Ive seen some good homemade intakes made from Bunnings pipe re directed towards the bottom of the front bar. Perhaps that is your next step - redirecting the stock intake from behind the headlight to a gap in the front bar.
     
  13. monkeyboy

    monkeyboy New Member

    Messages:
    119
    Likes Received:
    1
    Trophy Points:
    0
    Joined:
    May 23, 2005
    Members Ride:
    2010 VE SV6 SIDI
    ^^^Unless you've got some tech/maths proof to back that one up I'll have to take your word for it...or not. Myself and a few others have mentioned the standard airbox was tossed and replaced with a growler several times now...don't the mods here read the posts they moderate?

    And I'm not having a crack at you or trying to limbo Hermes Conrad style under the ban stick...it's just an observation :)

    And the Stig obviously has a head for maths and could probably calculate a ball park kw gain figure, which may confirm you 1kw gain statement...or not. Either way it's mostly about increased throttle response and a whistlier intake noise rather than trying to get some badass kw gains.
     
  14. Sabbath'

    Sabbath' Redblock Jesus

    Messages:
    6,117
    Likes Received:
    1,109
    Trophy Points:
    113
    Joined:
    Jul 3, 2006
    Location:
    Vic
    Members Ride:
    80 Series// MK5 GTi//
    Your original comments may have been removed, but every one that was quoted is still there. Fail.
     
  15. Grennan

    Grennan Slayer of Stupid Threads

    Messages:
    2,512
    Likes Received:
    74
    Trophy Points:
    0
    Joined:
    Mar 13, 2007
    Location:
    Glen Waverley, Victoria
    Members Ride:
    VE SSV G8 Sportswagon
    Meh probably skipped like 3 pages. *Shrug*
     
  16. radrat085

    radrat085 New Member

    Messages:
    6
    Likes Received:
    0
    Trophy Points:
    0
    Joined:
    Jan 21, 2007
    Location:
    Adelaide
    Members Ride:
    10' VE SV6 SIDI 3.6L
    Got bored this weekend and thought Ill make my own intake pipe.

    Well here it is.
     

    Attached Files:

  17. monkeyboy

    monkeyboy New Member

    Messages:
    119
    Likes Received:
    1
    Trophy Points:
    0
    Joined:
    May 23, 2005
    Members Ride:
    2010 VE SV6 SIDI
    ^^^Looks the goods man. What angles did you use...starting with the TB and ending at the airbox. I might make a few alterations to mine after seeing yours :)
     
  18. bigjim92

    bigjim92 Active Member

    Messages:
    929
    Likes Received:
    25
    Trophy Points:
    28
    Joined:
    Nov 29, 2009
    Location:
    Victoria
    Members Ride:
    2016 VF SSVR
    If you're in glen waverley the closest dyno would probs be Autotechnique, that's what I've used in the past
    Where's the one in Blackburn?

     
  19. radrat085

    radrat085 New Member

    Messages:
    6
    Likes Received:
    0
    Trophy Points:
    0
    Joined:
    Jan 21, 2007
    Location:
    Adelaide
    Members Ride:
    10' VE SV6 SIDI 3.6L
    hey mate thanks, i used 2x 45s and a 15.
     
  20. IW.45.NT

    IW.45.NT New Member

    Messages:
    27
    Likes Received:
    0
    Trophy Points:
    0
    Joined:
    May 20, 2011
    Location:
    richmond NSW
    Members Ride:
    '07 VE SV6 manual, ignition.
    Monkeyboy great post, I just did one on the weekend. I used your idea but only used a 90 and 22 degree pipes and a bit more rubber joiners.
    Anyway I noticed I had a bit of oil inside my old pipe coming out of the breather hose... Do you or anyone else have any idea why?
    Cheers
     

Share This Page