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Large Plenum Intake

Discussion in 'A3/S3 Forum (8L Chassis)' started by s3dave, Oct 11, 2012.

  1. Jason.s
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    Jason.s Active Member

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    Do that and also just weld in a section in the middle of the plenum like the Americans love doing on the A4`s.

    Obviously its an AEB inlet but you get the idea...

    2coo502.jpg
    #81
  2. Sam_
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    Sam_ Down under

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    I've not really had time to finish it off, just skim read a few sections, one of which covered inlet manifold design funnily enough. I was reading it when I was building a GT30'd 2.0 16v GTi6 lump for a 306 track car.

    Seems like getting a decent WMI setup is a bit like getting a decent hybrid K04...
    #82
  3. badger5
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    badger5 RIP S3dave Site Sponsor

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    I have a mani here from Berks to do just that... I just need to weld it back together.
    AGU runners onto S3 plenum
    #83
  4. Jason.s
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    Jason.s Active Member

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    Be interesting to see what happens with that...Got an AEB inlet sat in the garage doing nothing thats just ripe for something like that.
    #84
  5. S3 Paul
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    S3 Paul Active Member

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    Likely to get shot to bits... or ignored,
    Would fitting a better flowing less restricted inlet not be over kill? or hinder say a car running nothing bigger than a K04 hybrid?
    Im only asking as people fit large port inlets and R32 throttle bodys to cars with less.
    I understand how and why the B5 tip helps , I understand the free flow air filter...
    But these are intake mods that help get air into the turbo. not move it from there onwards to the cylinder head.
    #85
  6. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    Its all relative... overall free flow will mean the turbo has less work to do to achieve the same power... in context of the B5 TIP the restriction was that no matter how hard the K04 tried it couldn't draw air in fast enough for that top en peak in power... larger intake allowed the turbo to perform better within the limits of its capabilities...

    Same with the inlet... on my setup for example... GT30, 15psi of boost (actuator) I gained power and torque by fitting the manifold from the same boost which means to drop it to the power levels of the previous manifold I would have to turn the boost down... I was getting roughly 10hp per 1psi of boost increase when we started to map properly...

    Arguably if I fit a larger TB (R32 or other) its plausible I will see another increase for the same boost level...

    In context of the K04 then there of course will be a limit... strapping a K04 to my setup for example will shift the curves for sure... will be interesting to see the affect of one of these inlets on the curve and how much top end you may gain (as thats arguably where the gains of fitting more free flowing gear lay)... I suspect that just fitting it is only part of the picture though... as you can see from my graph I lost lower down initially... that was no change in mapping just hardware... this was picked back up through mapping though... I also suspect that some of the low rpm and mid range losses you may get from going to a large port/plenum intake can be mostly brought back through creative mapping too...

    <tuffty/>
    #86
  7. S3 Paul
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    S3 Paul Active Member

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    Thankyou for that,
    I just wondered wether these gains/ mods for big spec set ups would actualy filter down to us small fries,
    My car for instance is hybrid'd, FMIC, 3 inch DP decat... jetex...
    Will need bigger injectors to make good use of a B5 tip and im guessing this would also push me past my fueling limit, R32 throttle body... is this the same story?
    I would think each and every stage would need a map tweak to be safe ?
    #87
  8. superkarl
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    superkarl MAN OF STEEL

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    thing is with your car paul is youd a combination of mods to take the car to the next level.
    B5 tip might result in needing the injectors which will then need a map.
    Its the same for stage 2 ko4 cars tho, they are at the top end of injector duty, so any other improvement in flow will no doubt push them over the edge, resulting in injectors etc etc.
    tufftys case, and daves, and westys for that matter, can bolt on something like a large port mani, and see instant gains, with no REAL need to adjust mapping. as their specs are quite extensive, and there is headroom in it.

    as with most things, improve one small area, and you highlight weaknesses elsewhere. you need to know how to reach a balance, and the parts needed.
    #88
  9. Yohan87
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    Yohan87 Member

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    Fixed that for you :)
    #89
  10. superkarl
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    superkarl MAN OF STEEL

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    lol. too right!
    #90
  11. S3 Paul
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    S3 Paul Active Member

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    I agree with the ive reached a point where its alot of outlay to achieve a little or save and go mad.
    If the car stays which i think it will for the next year i will probably go for injectors ( is the VXR ones a bad idea)? and the a B5 tip and map to suite.
    But even that will be probably £400 +
    #91
  12. Westy
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    Westy Double Dark Side! Diesel & 8P

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    Just buy Bosch 550cc injectors. They're easy to get, not too expensive, fit the inlet mani injector seats, and theres lots of mapping info for them about.
    #92
  13. Yohan87
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    Yohan87 Member

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    I'm at a similar crossroads.

    Next logical step would be a relentless manifold for me, but I'd need rods doing to make the most of it, and if the head is coming off to fit rods/relentless then I'd be as well sticking a large port back on. Assuming I do all the work myself then that not too expensive relentless soon clears the 4x figure mark.

    The question is, does the increase in performance from the aforementioned modifications justify the cost when the car is currently making 280bhp / 290lb-ft?

    Who the hell knows.
    #93
  14. Westy
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    Westy Double Dark Side! Diesel & 8P

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    For a K04 it's a lot of money for very little gain, trust me ;) For a hybrid it's going to be a bit more worth it.

    I went to all the trouble I did because I'd just purchased a brand new K04 and wanted to see what it could do. I don't intend on ever selling the car and now it's built up with rods and all the other goodies it's in a position to make the transition to hybrid one day. Even if I decide to go BT one day at least I know the engine is man enough for it.

    So dont see this as a huge outlay to get a tiny bit more performance, see it as "future proofing".
    #94
  15. Prawn
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    Prawn My other car is a MINI!!!!

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    Yup, VXR ones are a very bad idea. Welly tried a set at first, and despite the claimed size, they were maxxing out before 300bhp on his car. Not good at all.

    The bosch 550's arn't too expensive at all, and are plenty for your needs :)
    #95
  16. Yohan87
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    Yohan87 Member

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    Westy you're a bad influence.

    Lol great, so that's injectors to add to the list as well now. Where does one buy the 550's from?
    Last edited: Oct 18, 2012
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  17. Westy
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    Westy Double Dark Side! Diesel & 8P

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    It's Westy not Welly ;)

    Injectors can be bought online or I'd expect also your friendly ASN tuner Badger Bill :thumbsup

    Back onto the subject of Plenums I can only expect a larger one to finish off the nearly maxed OE injectors on a stage 2 car.
    #97
  18. Yohan87
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    Yohan87 Member

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    Now you're splitting hairs, you've both got fast Audis :p

    I would've thought so too.
    #98
  19. badger5
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    badger5 RIP S3dave Site Sponsor

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    4bar reggy should nett 15% more fuel delivery.. on a healthy fuel pump
    #99

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