Page 2 of 10 FirstFirst 1 2 3 4 5 6 7 8 9 10 LastLast
Results 11 to 20 of 99

Thread: Intake tuning for your quads

  1. #11
    Oldschool Member
    Join Date
    Jul 2006
    Posts
    102

    Default

    There is certainly some interest. Im about to embark on a trumpet making exercise with a pile of pre-fab trumpet ends and some torroids to make bent ones to fit under the bonnet. Just waiting till after this weekend, which is when the last NSW Supersprint round is on before I go pulling the car apart again.

    The T3 ones are also tapered which has an additional effect on airflows into the engine.


  2. #12
    Elite rthy's Avatar
    Join Date
    Dec 2008
    Name
    Leo
    State
    VIC
    Location
    Tulla
    Country
    Australia
    Posts
    7,305

    Default

    Gilly: the idea of changing trumpets on the conditions is a sound idea, however you may find that the engine may well need a retune between changes. However if you have an ecu that accepts twin maps then your well ahead and the power is there for your taking. You could also tune it for some better fuel while your at it too

    As for the taper of inlet trupets I am still looking into it, I know it’s a very complex thing and the subject of countless man hours on a dyno for race teams. The theory is that it speeds the air up with a taped inlet, I don’t know myself.

    The inlet opening is a little more clear-cut though, a pipe with a flared end will flow 30% more than just a straight pipe or just an opening. This is why anyone who just takes the trumpets off and slaps an airbox on is doing a very bad thing. Going from a flared end to a full curled bellmouth gains another 3% of flow.

    The debate is this: have a full bellhouth on the inside of an airbox or have a curved taped inlet in the side wall of an airbox. I have heard various opinions on this and I am staying out of it.




    Drift-pig: Brendon what you can is make a set of trumpets that are adjustable without too much effort, well that is assuming my idea would work! What you do is get a flange plate for the throttles (chopped out from the stock airbox is great). Then weld some 2 inch exhaust pipe stubs on it about 20mm long. That will let you slide a piece of stiff rubber hose over each and clamp on, then at the other end have a set of bell-mouths with a short pipe on each at that end again to let you slide a piece of rubber over. Chop some 2 inch rubber pipe to the longest length that you can practially have the trumpets, do this again till you have 4 equal size pieces. Now what you can do is have the rubber lengths acting as a pipe between the flange and the bellmouths. Adjustments can easly be made from here by chopping pieces off at a time.


    Oly ae86: assuming that your talking about a 20v then the tuned rpm for your two setups are as follows:

    20mm: 9200rpm
    70mm: 7500rpm

    did you find that you lost any top end with the longer trumpets? because you shouldnt of


    Riojin: I don’t think a modified 7afe would like short trumpets, simply because unless some costly internal work is done then you wont be able to rev it hard enough reliably to make use of it. From what I hear peak power with a 4age head is at around 5500rpm and I can only assume that with a high modded 7afe head it would be the same with mild cams. It would be different with more aggresive cams but then theres the rods and crank issue again. For me personally with that engine I would have a resonance at 5000rpm or so.

    What you talk about with staggered trumpets its somewhat interesting so let me explain what I make of it: First up the theory is great, instead of a single point in the rev range that all the pipes work in resonance it is spread over the rev range as the shorter pipes resonate at the higher revs and the longer ones at lower revs. Reality is very different, on every engine I have seen with multiple cylinders the load metering with the ecu is done over the whole engine and that’s where the problem is. You see if at for example the longest trumpets start resonating at 4000rpm and the rest are not because the are shorter then it means that those two cylinders are getting more air in them that the rest. This does sound so bad till you consider the way the ecu works. It just measures and works out a total load of an engine, every ecu that I know of assumes that every cylinder of an engine is equal and if it isn’t like out example earlier it would get an average reading of all the air going in. So the cylinders that are sucking a this-proportionate amount of air less compared to the longer trumpets will run richer. Again not so bad but the pipes that are flowing better than the rest will run lean and then is very bad news indeed. So yeah unless it had carbies which may work its just for looks, make sense?
    30kw club

  3. #13
    Veteran
    Join Date
    Nov 2008
    Name
    David
    State
    QLD
    Location
    Ferny Grove
    Country
    Australia
    Posts
    3,670

    Default

    hmmm i'll have to check the twin map thing, would be a wicked score if it does

    i will definately be getting a retune as its copping some different gear compared to its current setup, mainly the longer trumpets, slight CR bump, and some nicer extractors (again one of your strong points )

    always a good read Sam, thanks for the words

  4. #14
    Elite rthy's Avatar
    Join Date
    Dec 2008
    Name
    Leo
    State
    VIC
    Location
    Tulla
    Country
    Australia
    Posts
    7,305

    Default

    the pleasure is mine Gilly,

    just a few more things to keep in mind:

    for max speed it might be best to have your resonance tuned to or just above your normal max power, that way you would have a real decent acceleration.

    and make sure your extractors are tuned for the right rpm too! although thats so much easier said than done
    30kw club

  5. #15
    Veteran
    Join Date
    Nov 2008
    Name
    David
    State
    QLD
    Location
    Ferny Grove
    Country
    Australia
    Posts
    3,670

    Default

    i'll have to find the specs on them, they are Fujitsubo items, i have specs somewhere..

    i might have to pm you some questions closer to the time it all comes together, if you don't mind of course!!

    just want to ensure i optimise what i've got

  6. #16
    Elite rthy's Avatar
    Join Date
    Dec 2008
    Name
    Leo
    State
    VIC
    Location
    Tulla
    Country
    Australia
    Posts
    7,305

    Default

    feel free its not like I am going anywhere
    30kw club

  7. #17
    Elite rthy's Avatar
    Join Date
    Dec 2008
    Name
    Leo
    State
    VIC
    Location
    Tulla
    Country
    Australia
    Posts
    7,305

    Default

    I thought you guys might be interested to also know for a while I have been dsigning a system of a variable intake system that uses a set of sliding tubes. But now I am instead thinking of making just a dual stage system to improve my power and economy.
    30kw club

  8. #18
    Senior Member
    Join Date
    Jun 2010
    Name
    Will
    State
    VIC
    Location
    Melbourne
    Country
    Australia
    Posts
    623

    Default

    I'm going to look in to this in the (hopefully near) future, dunno how much the tuning will need to be adjusted to find the new peak torque RPM, but im at least hoping to get a few points to make sme assumptions (hopefully the relationship is reasonably linear)

    i'm planning on using a fixed length, was going to use two short and two long to flatten out the torque curve a bit, but decided i want all the cylinders tuned to the same RPM instead.

    I have heard that people are generally dissapointed with very short lengths (haha) and the best thing to do most of the time is to make them quite long, as sam has said nothing beats dyno tuning, as you could find making them longer will actually give you MORE top end, as other things come in to play.

    another important thing to look at is the distance from the butterfly to the inlet valve, this affects power, throttle response and drivability.

    from dummying stuff up, you can get an 80mm trumpet length (not effective length) on a set of silvertop quads and angled T3 adapter on a smallport head without going outside the confines of the original manifold, but this doesnt allow for a plenum outside the trumpets, and i don;t want to use individual filters, so more work is needed.

    sam, i think the dual length is the way to go, you might want to look at using 4 of 6 runners from a EL-BA falcon as they use a pretty simple system. you could look at seperated chamber pulse tuning as well, but i havent seen it used on 4 engines before. a variable length system would take too much effort to tune IMO

  9. #19
    Elite rthy's Avatar
    Join Date
    Dec 2008
    Name
    Leo
    State
    VIC
    Location
    Tulla
    Country
    Australia
    Posts
    7,305

    Default

    I would strongly recomend having all equal lengths for the reasons I said earlier

    yeah I have heard that the falcon engine does what I want mine to do: and this is that it acheives the first long runner resonance at the same rpm at which the engine sits on the freeway helping fuel economy. I will have a look at the setup and see how they did it, thanks for the tip.
    30kw club

  10. #20
    Elite rthy's Avatar
    Join Date
    Dec 2008
    Name
    Leo
    State
    VIC
    Location
    Tulla
    Country
    Australia
    Posts
    7,305

    Default

    I forgot to post pics of my own intake:







    more information in my worklog

    also I sujest to be very wary of going wthin a few cm of the brake booster it will affect flow.
    30kw club

Page 2 of 10 FirstFirst 1 2 3 4 5 6 7 8 9 10 LastLast

Similar Threads

  1. WTB: Cash to go - Techno Toy Tuning Quads to Small Port
    By amaroo66 in forum Cars or Parts Wanted
    Replies: 4
    Last Post: 21st October 2009, 04:24 PM
  2. Replies: 20
    Last Post: 21st February 2009, 12:52 AM
  3. 4ac intake to 4afe intake
    By FUTO_GT in forum Technical - Questions
    Replies: 4
    Last Post: 30th December 2008, 03:12 PM
  4. putting 20v quads on 4age quads
    By w84me in forum Technical - Questions
    Replies: 1
    Last Post: 24th September 2007, 09:33 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •