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Prawn and BigAls A3 Track Car

Discussion in 'A3/S3 Forum (8L Chassis)' started by Prawn, Dec 29, 2010.

  1. Prawn
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    Prawn My other car is a MINI!!!!

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    And there was wood!

    [​IMG]
  2. Prawn
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    Prawn My other car is a MINI!!!!

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    Page 121 shall be the page of Plywood it seems.

    I started by getting the car up on the ramps, I need to remove the bumper to drive it up the ramps, so that came off first:

    [​IMG]

    And up she goes:

    [​IMG]

    I took a measurement along the sill line to see where the car was sitting, this will become my target angle for the splitter to ensure it's parallel to the ground when finished, or slightly nose down if anything.

    [​IMG]

    I marked up the centre line, and drew around my existing LCR splitter to get a rough outline shape.

    [​IMG]

    Then added 100mm all round for the splitter projection, this should suit, as the sides of the LCR splitter curve in tighter than the bumper, so total projection on the sides ends up around 50mm.

    [​IMG]

    [​IMG]

    And out came the Jigsaw:

    [​IMG]

    Next up came the rear piece, all cut out and finished:

    [​IMG]

    The idea of making it in 2 parts, is that the front section is fairly likely to get damaged at some point, and also, if it were a single piece, I'd be unable to remove it and take it home if it were damaged. By making it this way, it can be removed and put in the back of the car if needed.

    Like so: (hole is to clear the dog bone mount)

    [​IMG]


    Held up for a test fit:

    [​IMG]

    (angle not set here)

    [​IMG]

    Hinges fitted to join the two halves (these will be bolted up in the finished product)

    [​IMG]

    I left a 2mm gap between the sections, which is just enough to allow adjustment of the splitter angle without the two parts binding.

    Rear section test fitted, this is bolted through the two captive bolts that hold the lower subframe brace in place. it's absolutely solid here!

    [​IMG]

    But as an extra, I added tie rods hanging down from the chassis rails to take extra weight

    I welded M8 nuts to the end of the thread bar, then ground it all down so there's as little as possible sticking down to catch

    [​IMG]

    Getting there:

    [​IMG]

    [​IMG]

    More tomorrow :)
    Macky, JudderMan and StaceyS3 like this.
  3. Sam_
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    Sam_ Down under

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    Reminds me of Top Gear :)
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  4. jamiebennett81
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    jamiebennett81 Active Member

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    The beast up on ramps:happy:

    [​IMG]
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  5. badger5
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    badger5 RIP S3dave Site Sponsor

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    hopefully without the flames
  6. smurfworth
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    smurfworth Well-Known Member

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    Didn't topgear manage to set fire to their splitter?

    Im sure you've thought about keeping it as far away from any heat as possible though
  7. ScottD3
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    ScottD3 I want your faulty electronics

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    Prawny, That's a template to give to be given to a metal worker to create a nice shiny light weight version out some of exotic metal right or is it April the 1st?
  8. S3 Paul
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    S3 Paul Active Member

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    Ply wood is well known for this... looking good mr Prawn sir. keep it up
  9. ScottD3
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    ScottD3 I want your faulty electronics

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    Only ever seen it on BarryBoys.

    Surly it would be heavier than metal, chance of fire, warping when wet and its wood. lol
  10. Prawn
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    Prawn My other car is a MINI!!!!

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    I thought similar at first Scott, but believe it or not, every car on the BTCC grid apart from the honda runs 12mm plywood for the front splitter

    Splitters are considered disposable, so are made from something cheap, stiff, light, and easily replaced :)

    Once sealed, and painted black, it'll be fine
  11. Prawn
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    Prawn My other car is a MINI!!!!

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    More pics. Still a work in progress.

    Once finished it'll come off for more paint

    [​IMG]

    Made a start on the air dam, this is just a test piece to get an idea of how it'll work

    [​IMG]

    air dam will be attached to the splitter via tabs:

    [​IMG]
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  12. Jason.s
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    Jason.s Active Member

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    Can you not taper it back into the bumper line where it meets the arch instead of having it stick out so much on the side of the car? Would look much better and less likely to slice someones leg off in the eyes of the authorities lol.
  13. Prawn
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    Prawn My other car is a MINI!!!!

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    it's cut oversize for the minute, can be trimmed if required.

    Currently, it's exactly the width of the wheel track, and the visable frontal area of the wheels will be fenced off with an infill panel tapering out up the arch.

    Also, sides are needed on a splitter to stop displaced air from finding it's way back under the edges, at the moment it's all an experiment :)

    As for peoples legs, they shouldn't be standing on a race track, so that's for them to worry about :laugh:
    bigal 1 likes this.
  14. superkarl
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    superkarl MAN OF STEEL

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    will look good with the airdam in place.
    What does it all weigh? Estimate
  15. Jason.s
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    Jason.s Active Member

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    Yeah i remember reading all that business on Nige`s thread. Still doesnt make it look any better having the logic backing it up lol.
  16. Prawn
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    Prawn My other car is a MINI!!!!

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    Cheers SK.

    All up total with the fixings is around 7kg. so not too bad really.
  17. superkarl
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    superkarl MAN OF STEEL

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    be good if it gave 7kg of downforce.
    Do you find the car going light at high speeds?
  18. ScottD3
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    ScottD3 I want your faulty electronics

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    7kg?
    What would a suitable metal replacement weight?

    Just wondering for a comparison.

    I might have missed the bit about the hinge.
    Why is it hinged?
  19. jamiebennett81
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    jamiebennett81 Active Member

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    personally I would prefer on a road car a wood splitter. If for what ever reason it fails, shattering onto the road, wood option will be fair less hazardous than shards of metal going everywhere.
  20. Rainbird
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    Rainbird Member

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    Will you be leaving this on in daily use, Nick, or only fitting it for track use? Assuming from the wing and the fact that it's effort you'll be keeping it mounted?

    Looking good though, be good to see how much improvement you feel once running.
  21. Prawn
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    Prawn My other car is a MINI!!!!

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    Hinged so it can fit in the boot when I inevitably smash it on a kerb at Spa next week :laugh:

    Also allows for angle / height adjustment whilst retaining the rear section solidly mounted, and the replaceable front section can be made from a much smaller base sheet of ply that I can buy and transport home myself, whereas the 8x4 sheet I started out with here required the assistance of a mate with a people carrier to get home.

    As for downforce, I think it'll provide considerably more than 7kg of downforce, closer to 70Kg in all probability.

    Nige has been playing around with these for a few years now and has found they hugely effected the way the car drove at speed, combating the typical fwd wash out that you often suffer with, and making the whole thing more stable.

    I've not had any of the factory under trays for years, so air flow under the car would have been hideous at best. Covering the gaping hole under the front of the engine is the first step towards smoothing out airflow underneath.

    More than anything though, I just like experimenting, as there's not a lot else to do to it at this stage :)
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  22. Prawn
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    Prawn My other car is a MINI!!!!

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    I don't know to be honest mate, I've never seen a single metal splitter in my life though.

    They're all either plywood, or some form of composite (fibreglass or carbon)

    Quite often the very nicest splitters are made from a much thinner sheet of ply, and then wrapped top and bottom with a single skin of carbon, giving ultra light and ultra stiff.
  23. S3 Paul
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    S3 Paul Active Member

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    I think we did mates Honda with thin ply and then thin alu under it... as you say it does take quite a beating on a track day
  24. vroomtshh
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    vroomtshh Active Member

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    If it weighs 7kg in 12mm plywood, 3mm aluminium would weigh 7.5288888888kg.

    Ply is where its at
    bigal 1 and Prawn like this.
  25. Airs
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    Airs Member

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    this is revolution motorsports car from up my way, it has just recently set a new lap record at the nurnburg ring, its a quick machine!!

    and just for prawn i have done little reveal in my build thread ;)
  26. ScottD3
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    ScottD3 I want your faulty electronics

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    Prawn, Do you want me to get some Ikea and B&Q stickers made up? :ninja:
  27. Jason.s
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    Jason.s Active Member

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    Hows the front being supported? Tie bars or purely the screws into the bumper from the fence?
  28. ScottD3
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    ScottD3 I want your faulty electronics

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    With the extra down force on the front of the car, will it cause the back to go lighter?

    You added the rear wing to force the rear down to stop the 'ring happening again but adding a aero to the front would surly cause the front to push down forcing the back up and going ageist what the rear wing is doing?
    Or something like that. I guess.
  29. RobinJI
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    RobinJI Member

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    Looks great Nick! Good plan with closing in the frontal area of the wheels, looking forward to hearing how it feels, as you say, it should give a fair bit more than 7kg of downforce! (Well, probably considerably more than 7kg less lift, and then hopefully some downforce as an added bonus.)

    Must do something about the underside of the Scirocco sometime, just tricky to keep it looking subtle as the sump/wishbones sit a little lower than the front panel.

    Can't wait to have a poke around it at ADI.
  30. Prawn
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    Prawn My other car is a MINI!!!!

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    splitter isn't mounted to the bumper at all mate. It's totally independently hung off the chassis and subframe from 10 points, the bumper comes off and the splitter stays put :)


    whilst the splitter will act largely on the front end, it's part of a greater effect of getting air to flow better both above and below the car. The splitter will stop as mug air from getting under the car, so the effects are a tusk my felt across the whole chassis
  31. Jason.s
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    Jason.s Active Member

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    Ah right cool. Just couldn't really see and couldn't think of many points towards the bumper on the chassis/subframe it could be mounted to.
  32. Prawn
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    Prawn My other car is a MINI!!!!

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    A few pics just for interest :)

    Sam Tordofs MG:

    [​IMG]

    Nick Fosters Ebay Motors BMW:

    [​IMG]

    [​IMG]

    And Dan Welches NGTC Proton:

    [​IMG]

    Routed out to save some weight, but still 12mm plywood :)

    [​IMG]
  33. Prawn
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    Prawn My other car is a MINI!!!!

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    Air dam is finished.

    [​IMG]

    Hopefully bolt it up and see how it looks this evening.
    bigal 1 and Jason.s like this.
  34. badger5
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    badger5 RIP S3dave Site Sponsor

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    interesting stuff..
  35. Prawn
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    Prawn My other car is a MINI!!!!

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    It could be! or it could be absolutely rubbish, but there's only one way to find out :)
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  36. [Dave B]
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    [Dave B] Rrrrrrrr-tech

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    [​IMG]
    S3 Rav, Prawn and Rainbird like this.
  37. Prawn
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    Prawn My other car is a MINI!!!!

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    It's coming together, we're going to make it to Spa!

    Supports layed out and washers and nuts ready:

    [​IMG]

    Supports in the slam panel lower, metal bar behind these spreading load. I can hang my whole body weight off this, so I'm going to consider it strong enough.

    [​IMG]

    Side view of the supports from the chassis legs:

    [​IMG]

    I checked under the car for areas that would be most exposed to heat, amazingly, it's really not THAT exposed down there thanks to the enormous 6 speed box blocking half of it off :laugh:

    This was all I had, so for now I positioned it in the key area:

    [​IMG]

    And it's on!

    [​IMG]

    [​IMG]

    Bumper on:

    [​IMG]

    Airdam on, not enough light from my iphone flash now for a proper pic:

    [​IMG]

    Side panels still to make, but we're winning.
  38. bigal 1
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    bigal 1 Active Member

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    you are doing so well and when under so much pressure and with so little time to do it in. Very proud of you, just wish i was there to help. Someone has to soak up the sun and one volunteer is worth ten pressed man. Back soon.
  39. Prawn
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    Prawn My other car is a MINI!!!!

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    Side panels made:

    [​IMG]

    [​IMG]

    [​IMG]
  40. Jason.s
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    Jason.s Active Member

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    That looks better now.

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