Audi A4 BTCC / STW engine specs - 305 bhp from an N/A valver.

Discussion in '16-valve' started by A.N. Other, Mar 23, 2009.

  1. A.N. Other Banned after significant club disruption Dec 5th 2

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    Chatting to infinity recently, he mentioned that the old BTCC Audi A4s used to use 16 valve 2.0 engines.

    Which of course can be traced straight back through, via ACE/6A/9A, to the original 1986 Golf GTI 16V KR-engine.

    From here:




    Strange looking cam cover under that carbon - are the cam covers Audi V8?
    post-2404-1205076926.jpg

    inifinity's been scouting for info on these and will chime in soon.

    They're seriously modified bits of kit, but nevertheless interesting [:D]


    Update 4/11/2010, specification sheet gained so far:


    Car

    Length 4.48m
    Race weight 1040kg
    Engine

    Component Supplier Detail
    Engine block Audi Cast stamping: 05? 103 021 J, 86mm bore spacing
    Sump Combined dry sump / lower half of main bearing girdle
    Cylinder head Audi
    Crank Omega 88.1mm, cross drilled
    Pistons Mahle 85mm, 18mm pin (definitely in V8). Step 5 engine: 0,4- 0,6 mm above deck
    Piston rings Goetze
    Piston squirters Eight instead of four
    Conrods Oral 153mm
    Valves Del West Inlet: 34mm, Exhaust 29.5mm (some late engines 30.0mm) with long hollow stems.
    Valve springs Scherdel
    Cams SCAM straight cut toothwheel interconnecting drive
    Step 5 engine: Inlet > 14.87 mm lift / 4.2mm lift @ TDC / 107 degree / valve clearance 0,13-0,18 mm
    Step 8/9 engine: 15,4 mm lift
    Inlet exhaust 13 mm lift / 4.65 mm lift @ TDC / 107 degree / valve clearance 0,18-0,23 mm
    Cam followers Individually sized to adjust valve lash - no caps
    Throttle inlet MTK slide throttle 44mm
    Airbox ROC
    Injectors Bosch B 280 431 128/1 (128 is a motorsport injector)
    Fuel regulator Bosch B 280 550 113 (runs at 5 bar)
    Spark plugs Bosch H3CS; Step 5 engine: F2cs ( heatgrade 300)
    ECU Bosch Motronic MP 1.8
    Electrical harness Bosch
    Battery WKG
    Alternator TAG
    Exhaust Mecom
    Catalyst Prototechnik
    Fuel cell Uniroyal
    Fuel pump Bosch
    Dry sump tank Mecom
    Oil pump Audi
    Oil pressure 4-6 bar
    Water temp 75 C
    Engine weight 89 kg dry without clutch and air box
    Output See 16 valve engine race outputs here

    Note: all above data covers the 1995/6 seasons.


    Brakes

    Component Supplier Detail
    Discs (front) Alcon 343x32mm
    Discs (rear) Alcon 330x28mm
    Calipers Alcon
    Brake pads Performance Friction
    Master cylinders Alcon

    Transmission

    Component Supplier Detail
    Gearbox & gears Audi
    Diff internals Audi, ZF, FFD & Torsen
    Driveshafts Lobro
    Propshaft Lobro
    CVs Lobro
    Flywheel: Titanium, steel outer ring
    Clutch Fichtel & Sachs Carbon

    Chassis

    Component Supplier Detail
    Bodyshell fabrication Audi Sport & Matter
    Composites Divi
    Front suspension double wishbone
    Rear suspension ?
    Dampers Koni
    Springs Eibach
    Ground clearance 45mm (min)
    Rear wing Side profile < 150mm x 150mm, no closer than 100mm from the car
    Wheels OZ magnesium 8.2 x 19" forged
    Tyres Dunlop 215/650 19

    -----------------------------------------

    Valvetrain - DTM V8 spec for ref

    Component Measurement Weight
    Valves - inlet 32.9mm / 108.55 x 7mm 55 grams
    Valves - exhaust 28.0mm / 110.55 x 7mm 43 grams
    Bucket 35 x 28.6mm 53 grams
    Double springs free length 41.65 mm 60 grams /78 grams with retainer
    Valve lift 12.9 mm
     
    Last edited by a moderator: Oct 24, 2015
  2. mk1. Forum Junkie

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    Last edited by a moderator: Oct 30, 2017
  3. sambo Paid Member Paid Member

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    Oh hell yea!!!!

    Mmmmmmm......
     
  4. Mike_H Forum Addict

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    8 bolt crank pulley - I wonder how many 4-bolt ones they broke before they went that way?

    I'd love to see a pic of the head porting (and get it on Mr Hillclimber's flowbench).
     
  5. badger5 Club GTI Sponsor and Supporter Trader

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    I remember seeing some pix of these engines, and the porting work was not porting but physical machining out of the head, inserting new blocks so angles and geometry was totally different.
     
  6. Mike_H Forum Addict

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    Sounds a similar method to the Judd/Brabham heads - major surgery on the casting before they started.
     
  7. A.N. Other Banned after significant club disruption Dec 5th 2

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    I suspect a total re-work of the compression chamber shape, from the peculiar 16V design, valve angles being the regs restriction.
     
  8. infinity

    infinity Forum Member

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    Thanks for starting the thread Chris!!

    As Chris was saying, I've been trying to document as much info about these engines as possible, i.e tech spec's what parts were taken from VAG bins etc etc and to try and un-ravel the mystery of how they achieved >300 hp from a VAG 16v motor.

    Although the A4 engine wasn't the most powerful on the grid (with that trophy going to the Volvo 5 cyl 850, also rumoured to have some Audi genes in its engine and the Nissan primera with a whopping 330 hp from a 2 Ltr!!)


    That crank pulley looks very similar to the one found on an A4 2.8 V6 from the same era?? its also 8 bolt!!

    I can only image the vibrations these engines have to go through, every component was superlight for maximum acceleration. Lets see what we find:thumbup:

    anyone know how I can put pic's from ETKA up on the forum??
     
  9. A.N. Other Banned after significant club disruption Dec 5th 2

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    Which bits? I have some TWR BTCC Volvo engine drawings [:D]

    Press "PrtSc" and drop it into Paint. Cut it about, and pop in photobucket.
     
  10. infinity

    infinity Forum Member

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    The original castings were rumoured to be from the old Audi 5 Cyl, 10v and 20v, but Volvo had cast them from ali?? The volvo needed a a strong lump, its a massive car!! Been snooping around my own volvo, an 850 T5R volvo's attempt at homologating splitters and spoilers into there race cars and the old quattro stuff is similar? can't confirm it though?? maybe some of the quattro guy's may know


    Cheers Chris!

    V8 Cam cover, similar but def not the one,

    [​IMG]
     
    Last edited by a moderator: Oct 30, 2017
  11. A.N. Other Banned after significant club disruption Dec 5th 2

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    Ah, it's got to be a bespoke cast cover then - dry sumped motor etc
     
  12. RobT

    RobT Forum Junkie

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    maybe it was for cam lobe clearance
     
  13. drunkenalan Paid Member Paid Member

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    the early volvo engines were very similar to the original Audi 5 pots, however they were quicker than Audi at developing the design, into what now powers the focus RS

    awesome looking engine, are these the highest powered NA valvers ever produced?
     
    Last edited: Mar 24, 2009
  14. A.N. Other Banned after significant club disruption Dec 5th 2

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    So were they copied under licence, or just similar?
     
  15. RobT

    RobT Forum Junkie

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    kit cars were realistically 260-270hp so these must be the most powerful vag valvers using the original engine design - they are likely to have an aweful powerband though - IF thats right, its one hell of an output with the design they have if they cannot move the valve centers
     
  16. Brookster

    Brookster Paid Member Paid Member

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    Well done with the information some very good stuff .

    what cam spec's would they have been running ?
     
  17. A.N. Other Banned after significant club disruption Dec 5th 2

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    Virtually impossible info to get a confirm of, I would have thought?

    I'm going to rake this TWR BTCC Volvo info I've got, get that on the table too. Never realised I'd do anything with it.
     
  18. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    VCC 5 pot was a Reno engine with an extra cylinder.
     
  19. infinity

    infinity Forum Member

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    They certainly were a higher spec, than the kit cars, dry sump, big valve, high compression etc etc. But then the kit car was built for rallying, much longer engine life is required.

    Although valve location was fixed. they may have got around that by moving the head around on the block...... elongated head bolt holes anyone!!:)

    To my knowledge these are the most powerful valvers made, the Audi 80 STW was also raced somewhere I think Italy so i'm presuming the engine was a development from that!?

    some pics

    Audi 80 STW
    80_quattro_16v_fia2_1994.jpg
     
  20. mk1. Forum Junkie

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    any thoughts on why the drivecouplings are not in the normal place or am I looking at something different?

    [​IMG]
     
    Last edited by a moderator: Oct 30, 2017

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