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Prawn and BigAls A3 Track Car

Prawn Dec 29, 2010

  1. Prawn

    Prawn My other car is a MINI!!!!

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    I think this is the key point.

    Weight distribution on my car, and also relative available braking force at each end, is so vastly different to stock, that the system is operating so far outside of normal parameters that it no longer does it's job properly.

    Given the size of my front brakes, and the extensive cooling setup I've installed, I really shouldn't be suffering from these issues. There are others with smaller brakes and no cooling that have no issues since an ABS delete, so I'm fairly hopeful it'll be a resolution to my problem.

    If not, then it's something I'd need to do to go racing anyway, so it's not wasted effort :)
     
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  3. Sandra

    Sandra Administrator Staff Member Administrator Platinum Supporter Audi Main Dealer

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    @Prawn congratulations to both you and Victoria. :) x
     
    Prawn likes this.
  4. snowy

    snowy Registered User

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    weight balance vs brake balance though

    Even that weight out, sling some sandbags in the boot ;)
     
    Last edited: Nov 8, 2016
  5. StaceyS3

    StaceyS3 Registered User

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    Could always move fluids power steering etc to the rear to adjust the weight?

    Got my battery, wmi, screen wash and power steering where the rear seat was, just a thought?
     
  6. Prawn

    Prawn My other car is a MINI!!!!

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    Battery and WMI are already in the back, so that's the main bulk of the above.

    PSF and screen wash are such small items I just don't see it making a huge difference.

    Agree with the concept though certainly.

    Everything at the back is fairly redundant, so easily removed (and already gone)

    Everything up front is fairly essential, so it's pretty tough to lose any great deal from the front end
     
  7. Dubster5

    Dubster5 Registered User

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    adding a diff at the back would balance the weight out a bit :)
     
    Sam_, StaceyS3 and superkarl like this.
  8. Rainbird

    Rainbird Registered User

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    Might rattle around a bit in the boot though. Better strap it down well.
     
    craigt1985, Sam_ and fanta like this.
  9. Prawn

    Prawn My other car is a MINI!!!!

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    :iagree:

    Altering weight distribution is about all the rear diff would be good for :laugh:

    FWD and proud!

    :racer:
     
    VAG-Slag likes this.
  10. Dubster5

    Dubster5 Registered User

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    admittedly I don't track either of my cars and they're not set up for handling the way yours is so it's a different situation but I own a fwd Ibiza cupra and a haldex S3. Even though the Ibiza is lighter, lower and probably slightly more powerful I much prefer driving the S3, it just has so much more grip........ maybe I'm getting old! :laugh:
     
  11. snowy

    snowy Registered User

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    Rear fuel cell, mounted behind the rear axle
     
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  13. Prawn

    Prawn My other car is a MINI!!!!

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    I must admit, a fuel cell is something that's never appealed to me for the A3.

    The stock system is mounted as low as it could possibly be, and is fairly far back towards the rear axle. it's well baffled, reasonably light weight, and has a decent built in swirl pot system which doesn't suffer from fuel starvation.

    Any gain by moving the tank backward is potentially offset by mounting it 2-300mm higher up in the boot floor. I'm also not keen on the idea of mounting it inside the car due to the need for a firewall etc when doing so. I also need the full 54L capacity, as I use that amount 3x over on a single trackday sometimes!

    In other news, I'm sick and tired of waiting on the few small valve parts I need that I ordered from a supplier in America.

    I've now taken an £80 hit and ordered the bits direct from Supertech, and they should be here next week, so I'll FINALLY be able to get the ball rolling!

    Once those bits are here, I'll book a week off work, and make some real progress towards getting the thing running again!
     
    bigal 1 and Broken Byzan like this.
  14. Prawn

    Prawn My other car is a MINI!!!!

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    Ordered a set of head stands this morning, and will be ordering some valve spring compressors shortly too so I can swap these valves over myself.

    For too long I've relied on the help and generosity of others on some of the more complex aspects of the car (and been incredibly thankful for it too), but I've gotten so frustrated waiting for these few small parts to complete that I've decided this last leg is going to be 100% driven by me. No way it can slip back then. No relying on others.

    Once all the bits arrive, there should be no excuses to not get it running again this side of Christmas.

    I really am starting to lose the plot having it sat in the garage broken.

    In related news, these arrived a few weeks ago:

    [​IMG]

    So they'll replace the 18 year old original hoses. Once they're on I'll measure up and order JCS clips throughout also. Any hoses not covered in the kit I'll replace with straight lengths and bends to suit.

    I also had another go at the adapter plate last weekend.

    I wasn't happy with the amount of thread left in the hole at all, so I got out the drill and decided to see what I could do with it, fully accepting it may well end up scrap.

    To my surprise, after just a few seconds with a small drill bit, I started getting what looked like shards of thread coming out.

    [​IMG]

    A few minutes later, and I got out what was actually the end of the original stud!

    [​IMG]

    I then found a spare M8 tap, and cut it off at half length to create a plug tap.

    I ran this down every M8 hold in the adapter plate, with good results. Including the wonderful damaged hole I've struggled with so much, and to my delight, it appears I now have 5 fully intact useable threads, which matches the other angled stud holes.

    I'm now confident I can use this without issue, and without the additional of a helicoil.

    IF, when I come to tightening it all up, I find it pulls through again, I have also considered overdrilling to M10 and using one of these:

    [​IMG]

    I think it's all heading in a positive direction.
     
    snowy, craigt1985, bigal 1 and 3 others like this.
  15. bigal 1

    bigal 1 Registered User

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    Your engineering prowess started at the age of eight when I gave you, for your eight birthday a 24" version of a Ridgeback mountain bike. Which at the time was close to the best you could have.

    Any problems that occured were overcome by buying the tools for you to rectify what needed to be done. Failure was NOT an option. There was always a solution. That continued with the Mini, when at the age of twelve you made your own tools to overcome ones you did not have. Changing a gearbox and clutch , with no previous knowledge or intruction manual was unbeliveable , but you did it. No jacks, hoists or any other mechanical aids. A lesson to others, repair it, don't bin it.
    BBD
     
  16. Prawn

    Prawn My other car is a MINI!!!!

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    Thanks Big Bad :yes:

    We WILL be going for a drive in the A3 on Christmas day.

    This target isn't optional. It's been down too long, and we've lost another year of trackdays. Next year will be fairly busy too with Baby Prawn arriving, so the car MUST be sorted this year and ready to go.
     
    fanta, StaceyS3 and bigal 1 like this.
  17. fanta

    fanta Registered User

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    As well as celebrating Xmas day with family I'm looking forward to checking back here for a video of you starting her back up :) I'm glad you didn't give up, it inspires me to keep plodding on. I've got a 2 year old so know how busy life gets when little legs arrive.

    Sent from my XT1572 using Tapatalk
     
    Prawn likes this.
  18. Sam_

    Sam_ Down under

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    With the hose kit - do you know what is included in the 12 hose kit that's missing from the 7?
     
  19. Prawn

    Prawn My other car is a MINI!!!!

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    From what I could work out, the 12 hose kit had a few extras for the over run pump, and I couple I couldn't figure out that certainly arnt on my car.

    I decided to go with the 7 piece after @Tabsy said his were decent quality and fitted well. Anything missing I'll make up in silicon myself I think.

    In other news I think we'll be ordering new springs shortly, after talking about them for over a year :laugh:
    This will be an interim measure to stiffen the car up, and won't be the ideal end solution as the rates I would ideally run will be WAY beyond what my v3 shocks can handle. And there's no point in overspringing the car to the point where it's no good.

    Current thoughts based on experience of others is to go 10kg front and 8kg rear.
     
    snowy likes this.
  20. Tabsy

    Tabsy Registered User

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    [​IMG]

    [​IMG]

    Aye can confirm its a decent kit. I had a forge coolant kit before the fire and these are just as good if a little more forgiving with custom pipework runs

    I'm also running their generic hoses for boost and intake. They've got loads of funky sizes.

    Sent from my Nexus 6P using Tapatalk
     
  21. Prawn

    Prawn My other car is a MINI!!!!

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    Good stuff Mark.

    What spring rates are you running on the Bora also?
     
  22. Tabsy

    Tabsy Registered User

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    Slightly stiffer than what shipped as standard from bilstein on their B16's. The kit was also from a Leon Cupra R which I'd imagine is a tad lighter to lean a Bora, specially at the back end.

    It's one those things on the to do list. Certainly going to need looking at once we get out on slicks....

    Sent from my Nexus 6P using Tapatalk
     
  23. SHUk

    SHUk Once Bitten Forever Smitten =]

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    Hello Mate

    I am trying to find a cage for my a3, same setup as yours would be ideal. Can you please let me know where you brought yours from.

    Thanks =]
     
  24. Prawn

    Prawn My other car is a MINI!!!!

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    SHUk likes this.
  25. ben4866

    ben4866 Registered User

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    Prawn is there a specific reason you linked to a 5 door cage or did you mean to link the 3 door? I'm at a similar stage with my car and want to get the cage sorted out.

    Cheers mate.
     
  26. Prawn

    Prawn My other car is a MINI!!!!

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    Simply because that's what's in mine Ben.

    At the time there wasn't a 3 door option, and the only difference is the tab to tie into the upper belt mount, which I ground off.

    If there's a 3 door version I see no reason why it wouldn't fit, but I'd be surprised if the upper belt mount was in an identical location from the mk4 golf to a3 also.
     
  27. Prawn

    Prawn My other car is a MINI!!!!

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    I've actually done some work on the car today too!

    Not much, but it's a start!

    More on that later.
     
  28. Gops

    Gops Badger 5 Edition VCDS Map User

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    Watchaaa been dooooooing? I surprised an RS3 today kept with him in cold dampish weather and had him on the straights. Wasn't easy though rwd!
     
  29. Prawn

    Prawn My other car is a MINI!!!!

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    I've finally started working on it again!

    First up, the bulkhead.

    I stripped down my heatshielding, to reveal the mass of brake pipework behind.

    I still had the original bulkhead sound deadening installed also, which had seen so many driveshaft failures, oil leaks, coolant leaks, and road debris, it weighed about 5kg and was probably a huge fire hazzard!

    Obviously that had to go!

    [​IMG]

    After removing the ABS pump and lines, i cleaned up the bulkhead, then set to work on the first brake line.

    I mounted the T piece for the front split in an appropriate location, cut and bent the first pipe, flared both ends, and offered it up.

    It didn't fit!

    Argh.

    [​IMG]

    It turns out, all the threads on the car are m10x1, apart from the 2 into the master cylinder! These appear to be m12 fine.

    I cut the end off, and refitted one of the original fittings:

    [​IMG]

    With a bit of practise the flares all seem to be coming out very well. I've found a drop of brake fluid on the pipe before flaring really helps get good results :)

    So, attempt 1:

    [​IMG]

    And it looked absolutely *****!

    :laugh:

    Lets try again:

    [​IMG]

    Similar profile, but far less messy. That'll do.

    Next up the front left wheel.
    I started at the wheel arch end, replicating the factory shape as closely as I could:

    [​IMG]

    Then moved onboard, trying to retain the stock pipe clips the whole way across the engine bay:

    [​IMG]

    2 things to note when making brake lines:

    If using copper, it absolutely MUST be clipped every ~200mm. Copper work gardens with vibration, and it allowed to vibrate around too much it can go brittle and crack.

    You should also avoid a straight run between 2 fixed points, as it won't allow for any expansion or contraction with changes in temperature. S bends or similar before fittings are always a good idea to allow the pipe a little movement if required.

    In this case, I'm using Kunifer, which is copper / nickel, rather than pure copper.
    Kunifer is easier to work on my opinion, and nowhere near as prone to work hardening / cracking as pure copper.

    Next up was the drivers side line.

    I'd have loved to do this in straights and bends, but the space available just allow it, despite how it appears in the pic!

    [​IMG]


    With it all back in and connected, everything fits, and everything clears without touching. There is 15mm between the two lines beneath the servo.

    [​IMG]

    Last up for today I decided to mount the bias lever.

    I wanted it within easy reach whilst strapped in. I had thought it'd end up back near the handbrake, but it just wasn't natural or comfortable to adjust when back that far.

    I found there was a gap to the side of the gear lever that my leg could not get to as the seat stops it, so it can't be knocked.

    I made up a quick bracket from some thick ali angle I had, drilled and tapped to m6 for bias lever, and mounted to the side of the shifter tower:

    [​IMG]

    It's easily adjusted whilst strapped in, doesn't interfere with the gear lever in any gear, and I cannot knock it with my leg no matter how hard I try, so I think it's a winner.

    You can see the lever position here:

    [​IMG]

    I've rotated the lever, so quite literally, you pull the lever backward to bias the brakes backward.
    Push the lever forward to push brake bias forward. I've mounted the lever high enough that is easily reached and not lower than the side of the seat, and it also allows me to form an S bend both to and from the lever for expansion purposes.

    Busy week ahead, but next weekend I'll be back on it. Hopefully finishing the rear lines and making up new heat shields for the back of the engine bay.

    I also need to make up a sealing plate / gromit for the gaping hole I gouged in the bulkhead all those years ago for the shift cables :laugh:

    Even though it's only small steps, it feels really good to finally be making progress on the car again :)

    I'll be back!

    :racer:
     
    snowy, <tuffty/>, bigal 1 and 4 others like this.
  30. g60leigh

    g60leigh Registered User

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    I'm so glad you re did the pipe after first attempt. I don't have OCD but badly laid brake lines really do bug me.
    I've been playing with brakes today too after my exhaust blow melted my one way valve. -[​IMG]
    Upgrade fitted - [​IMG]

    May be worth you checking all the vacuum lines while your in there.


    Sent from my iPhone using Tapatalk
     
    Prawn likes this.
  31. bigal 1

    bigal 1 Registered User

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    Already done
     
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  32. Lavis89

    Lavis89 Well-Known Member Regional Rep

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    When laying pipe lines (useful for brakes or plumbing around the house) it's pretty easy to work out the amount of expansion over a given distance. Cuni pipework you are using for your brake lines will have a very similar coefficient of thermal expension as normal copper (but as you said, doesnt work harden quite so easily)

    Coefficient of copper: 0.000017
    You need to X the length of the run in meters by the change in temperature. for example
    0.000017 X 1.5 X 100 = 0.00255

    Over a 1.5 meter run of pipe going from 10-110 celcius the pipe will expand 2.55 millimeters.

    Lets you know if it's worth putting in a expansion loop/S/U bend etc and how many.
     
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  34. Chris90

    Chris90 Active Member VCDS Map User

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    Surprised the tank in the A3 is baffled. Had a mk4 tank off before and theres no baffles inside...just a empty tank with a pump to sit in.
     
  35. Prawn

    Prawn My other car is a MINI!!!!

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    So, it genuinely feels like I've waited a lifetime for this:

    [​IMG]

    A whopping £112.58 later, these finally arrived:

    [​IMG]

    Not even angry that I ended up buying them again from a different seller.

    Money down the drain perhaps, but worth it now that I can finally make some progress!
     
  36. badger5

    badger5 www.badger5.co.uk Site Sponsor

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    and you bought from abroad.........................
     
  37. Prawn

    Prawn My other car is a MINI!!!!

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    Yes.

    Pm'd you my reasoning. It makes zero sense now. I'm an idiot at times, and I know it :bye:
     
    daz-20vt likes this.
  38. Prawn

    Prawn My other car is a MINI!!!!

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    More progress today by way of postman pat!

    [​IMG]

    Clutch disc is back and ready to go :racer:

    [​IMG]

    And I've found my supertech valves and springs to double check the collects and retainer are correct :)

    [​IMG]

    Hopefully have a day on it tomorrow.

    Plan is to make more progress on the brake lines, and if that goes well, I'll pull the head and make a start on the valve swap :)

    Progress at last feels good!
     
    sparrow, Gops and g60leigh like this.
  39. Chris90

    Chris90 Active Member VCDS Map User

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    What valves are you doing Nick?
     
  40. Prawn

    Prawn My other car is a MINI!!!!

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    4x inlets to swap for supertech.

    The rest are done already :)
     
    craigt1985 likes this.
  41. Prawn

    Prawn My other car is a MINI!!!!

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    Argh.
     
    Rainbird likes this.
  42. daz-20vt

    daz-20vt Registered User

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    This statement is unclear.
    It would suggest there are times that you arent an idiot
     
    scotty_24 and Prawn like this.
  43. Prawn

    Prawn My other car is a MINI!!!!

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    So, some more work was done, and visually, things went backwards again :laugh:

    The seats are out. the fuel pump is currently off, it's in more bits than it was on Friday!

    I think I'm reaching the end of the doom and gloom phase, and soon I'll start to see progress and cheer up again.

    I may even begin to take more pictures once I've got something worth of taking a picture!

    Over the weekend I addressed lots of small jobs, mainly related to the brake lines.

    So, Saturday started with finishing off the lines in the engine bay.

    With the fronts complete, all that was left was to route the single line to the rear through the bulkhead.

    Much care was taken to find a decent passage through the bulkhead, that'd bring the pipe out in a sensible location in the car that can't be kicked or knocked by either my foot, or my passengers.

    Care was also taken to ensure that none of the pipes in the engine bay touched the bodywork anywhere other than the clip locations, and none of them touch each other at all.

    it's not the most Pro looking job, but it's not 100% **** :laugh:

    [​IMG]

    This then runs inside to a joiner up on the tunnel. I didn't want a single piece all the way to the bias valve, because if the internal pipe is ever knocked or damaged, I'd need to remove the engine to replace the line in the engine bay! Adding a joiner gives me the option to replace either end independantly.

    This hose actually looks neater in real life. I kinked it inboard immediately after the console so there's no change of my leg ever pressing on it, but it just looks odd from the angle of this pic!

    [​IMG]

    Under the car to the rear axle, and time to plan the pipe runs back there.

    First pipe to remove, the hardline on the rear beam:

    [​IMG]

    Yay!

    Not to worry, I've got a spare beam in the other garage, I'll go and get the pipe off that:

    [​IMG]

    Yay (x2) These things are Sh!t.

    So, 2x new rear hard pipes ordered with the ECP 30% code this weekend.

    Next up, to fit the orange braided hoses I got YEARS ago but never fitted. This gives me a solid termination point to aim for when bending up the hard lines.

    I offered the pass side braided hose up, only to find the stainless fittings don't go through the standard 14mm bracket holes!

    D'oh!

    Thankfully, I had a countersink bit which took it out to exactly 16mm, and the hose fitted fine:

    [​IMG]

    On to the other side, and the standard connection location is facing up, and backwards, to meet the brake pipe that's run across the top of the fuel tank. it was also rusted SOLID.

    Now, I didn't want to keep this location, for what I thought were 2 good reasons.

    Reason 1: I didn't want to drop the fuel tank to get the new brake lines in. This seemed like an awful lot of work for what started out as a 'quick job'

    Reason 2: Should I need to replace / retighten the lines ever in the future, I didn't really want them being in a totally unaccessible location. the 2 connections on the passengers side were easy to reach, but the standard location on the drivers side would have been impossible to get at should it need intention in the future, without dropping the tank again.

    So, I looked at ways of modifying things to move the connection point downwards to a better location.

    This is what I came up with:

    [​IMG]

    I re-drilled the hole in the beam mount to fit vertically like the passengers side, then made a bracket that piggybacks onto the rear beam pivot point. it's still well up out of harms way, doesn't interfer with the fuel tank or pump, and brings the connection to a much more accessible location. All I'll need to do is 'massage' the new hardline to suit the new downward fitting position.

    It's amazing just how much time these things take! Little things like working out the best route for the pipes. Finding ways to clip the pipes whilst drilling as few additional holes in the car as possible etc.

    I'm now at a stage where both rear lines are installed from the beam connection, through the seat squab, and jointed at a T piece near the handbrake.

    Final brake pipe to run this evening is from the Bias valve back to the T piece, then the new hardpipes arrive tomorrow, and hopefully I can get some fluid through it and see if any of my flares leak! That'll be the next nervous moment!
     

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