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  1. #1
    Lee Goodall's Avatar
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    S4 with VR6 big turbo (I want!!)..


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  3. #2
    jcb
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    saw this the other day.
    I was looking at one of their Fluidampers but they don't fit the 058 block.

  4. #3
    Lee Goodall's Avatar
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    Quote Originally Posted by jcb View Post
    saw this the other day.
    I was looking at one of their Fluidampers but they don't fit the 058 block.
    Shame.. I'd imagine their kit is top notch judging by the clips!

  5. #4
    Lee Goodall's Avatar
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    Link for anyone who's interested..

    http://uspmotorsports.com/index.php

  6. #5
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    Very nice, though it ain't an S4. It's got a standard rear bumper and no S4 engine. :P


    A4 1.8TQS

  7. #6
    Lee Goodall's Avatar
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    Must be a Golf then

  8. #7
    twostrokepower's Avatar
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    quite clear its a polo

  9. #8
    Nez
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    A4 with VR6 big turbo I would call it
    (Audi S4 351.9 PS, 603 Nm, MRC Custom Remap XS Power DP's, Cat Back Exhaust, Forge DV, RS4 Intercoolers, RS4 Breaks and Induction kit)



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  10. #9
    CraigG's Avatar
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    US s4's didnt get a different rear bumper to A4's hence euro bumpers fetch such a premium over there, so im gonna say that it is an S4 with a VR6 engine, like the video says

    034 motorsport have one aswell, and sell a bell housing conversion plate to fit a VR6 engine into your own S4 aswell
    http://www.034motorsport.com/product...roducts_id=665
    Imola S4 - Bilstein B6 + Eibach Prokit, Anthracite BBS Pescara 18x7.5"

  11. #10
    Geeman's Avatar
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    I'm sorry... but why fit a VR6 to your S4...? Surely the standard V6 twin turbo can outpace a VR6 in standard form...?

  12. #11
    CraigG's Avatar
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    standard yes, but you fit a VR6 so you can slap a stonking great single turbo on the side of it for huge power. VR6 turbos have had much more in the way of engine development than the 2.7tt, much easier to get big power from them
    Imola S4 - Bilstein B6 + Eibach Prokit, Anthracite BBS Pescara 18x7.5"

  13. #12
    Lee Goodall's Avatar
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    I'd imagine not having to remove the engine to swap the turbo would be a big bonus too.

  14. #13
    docurley's Avatar
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    Standard form yes but a tricked up VR6 no not unless they spend a hell of a lot of money.
    Black Audi RS4 2006 Exclusive edition, Black optic option (stock for now)

  15. #14
    docurley's Avatar
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    got beat to it had to take a call.
    Black Audi RS4 2006 Exclusive edition, Black optic option (stock for now)

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    docurley's Avatar
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    Quote Originally Posted by Lee Goodall View Post
    I'd imagine not having to remove the engine to swap the turbo would be a big bonus too.
    Running cost would be way cheaper after the install and nearly everything can be done whist the engine is still in the car.
    Black Audi RS4 2006 Exclusive edition, Black optic option (stock for now)

  17. #16
    jcb
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    I am all for ease of use and in situ engine development,
    (Its the reason I went for the 1.8t vs the S4 (plus being of a Scottish persuasion I am tighter than a duck's arse!)

    but a stock S4/rs4 lump can take waaay more abuse out of the box without being built/rebuilt than a stock VR6 block.

    you start looking at 400bhp + on a VR6 lump and you can cost in rods, pistons, fully rebuilt oversized head and some serious hardware.

    standard S4/RS4 blocks knock out 450-500 all day long before requiring bottom end components

  18. #17
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    I know of a couple of RS4 engines which run around the 600bhp+ on standard block and heads!!

  19. #18
    jcb
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    550 ftlbs is the accepted threshold before you start bending rods.
    foolish not to swap them.

    lots of 1.8t's running over 350ftlbs but it is very risky

  20. #19
    "Stick a V8 in it!"

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    Or just limit the torque with the map...

    550lbft at 7000rpm is 733hp.

    You just need a turbo big enough to hold onto the boost until 7k, and map the engine to ensure it doesnt exceed 550lbft.

    You say 350 is risky on a 1.8T, but thats 87lbft per rod, compared with 91lbft/rod or the 550 on the S4...

    Are the rods on the 1.8T worse than the S4 items?

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  21. #20
    jcb
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    Quote Originally Posted by aragorn View Post
    550lbft at 7000rpm is 733hp.
    how do you figure?
    I have seen dynos of K04'd motors producing a high of 300+ ftlbs with power peaking at 290ish.

    550ftlbs on a twin turboed V6 could produce power as low as 500bhp
    easy to get torque higher than power.
    check the spike on this APR S4. similar spike on a curve of a 1.8t could kill it that low down the rev range



    Quote Originally Posted by aragorn View Post

    You say 350 is risky on a 1.8T, but thats 87lbft per rod, compared with 91lbft/rod or the 550 on the S4...

    Are the rods on the 1.8T worse than the S4 items?
    no, if I am correct they are virtually identical. (if not completely so)
    But you have a totally different pulse cycle and dynamic to the V6 vs. I4 rotating assembly.
    I don't think it is as simple as dividing by four or six.
    Its the reason it is usually the rod in cyl 2 or 3 that ****s itself on a KO4 (or similar) maxed out 1.8t producing spikey torque over 300+.
    Last edited by jcb; 5th December 2009 at 22:20.

  22. #21
    "Stick a V8 in it!"

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    i meant if you can hold the 550lbft until 7000rpm you've just made 733hp.

    power = torque * RPM / constant

    constant = 5252 for lbft and bhp


    What i'm saying is that for big power on stock rods all you need to do is map the engine to ensure the torque doesnt exceed 550lbft.

    If the boost curve etc is carefully controlled and the turbos are large enough, you can have an engine that develops exactly 550lbft from it coming on boost until the red line with the correct mapping.

    Quite similar how audi control the torque on the V10 TFSI in the RS6 (probably to protect the transmission), it makes a constant 650nm from 1500 to 6250rpm, and quite a few of their modern engines do the same.

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  23. #22
    jcb
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    I know there is a rough calculation that exists to guestimate power from torque but it is not accurate at all.

    i fixed the dyno sheet so you can see it now. that spike at 3000rpm is horrible in MAP terms/
    its not so much the figure at the top of the curve than the way it arrives at that figure.
    its the reason 350ftlbs from a 50trim or 2871 turbo can be run all day on a stock 1.8t but try to run the same numbers at high boost from a Ko4'd Gti and you will ventilate the block sooner rather than later.

    the larger turbo is well within it's effeciency curve and the power delivery is smooth and steady.
    the smaller turbo is outside its efficiency curve and delivers spikes of torque which on an effectively 2 pulse 4 cylinder engine is going to break something.

    yes you can restrict torque with the map but you are basically creating something that is working against itself. overfuelling or boost leaking to keep a figure down.

    but to get back on topic my point was the VR6 needs lots of internal hardware to support the same levels of power the 2.7 V6 can achieve comfortably on stock internals.

  24. #23
    "Stick a V8 in it!"

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    Erm, its a mathematical formula mate, not a guestimate.

    HP = LBFT * RPM / 5252

    Thats physics. If you have either of HP, LBFT for any given RPM you can calculate the other value.
    Take your power plot above and run the numbers and you'll see what i mean. 3500rpm for example its making 360lbft. if we do 360 * 3500 /5252 we get 239.9, which matches what the graph shows.

    I dont see why restricting the torque would require overfuelling or leaking boost?

    You control the boost level, with the N75 valve just like normal, to remove the torque spikes.
    Like this:
    http://www.jesperdk.com/etomic/powercurve.jpeg

    Audi doesnt produce that by overfuelling, they control the boost level, to produce the desired torque map. If they went full boost at 2000rpm, you'd get a huge spike. Instead they peg the torque at 550nm (in that example) to protect the transmission.

    Proper mapping can produce a result like that with any turbocharged engine, by limiting the boost at lower revs, then ramping it up as the VE drops as the revs increase.

    The reason a 2871r doesnt produce the same dangerous torque spikes, is because it spools further up the rev range.

    I'm not disagreeing with you on the stock internals. I'm agreeing, and saying that even with a torque limit of 550lbft, if you have a well crafted map and a turbo capable of it, you can make 700+ hp.


    A mate of mine is building a Volvo T5 engine for his locost. The torque limit on those is around 300lbft and the rods are a particular weak point. Hes aiming for 300lbft from when the engine comes on boost at 3000rpm until the rev limit of 7000, giving him 400hp. Hes specced up a 400hp turbo, and will be using some mappable engine management to control the boost using something like an N75 valve, with low boost coming in at 3000rpm, and scaling up as the revs climb to keep the motor producing 300lbft all the way thru the revs.

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