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Building a new front splitter - a work in progress...

Discussion in 'General Discussion' started by MattC, Dec 21, 2011.

  1. MattC

    MattC Well-Known Member Donated!

    Partly inspired by Stigs comment in another thread, "I still can't believe nobody makes a solid 1 piece fiberglass spoiler", and partly inspired by my need for same, I'm building one :D My fibreglassing experience thus far extends only to patching go kart bodywork, I've never actually built anything from scratch with the stuff, however after a bit of research via Google and YouTube, to quote that great modern philosopher Clarkson, how hard can it be? :hehe

    SO, my splitter, like most of them, is looking pretty sad - the three pieces don't join together any more (though it seems previous owners have tried in vain to re-connect it all with varying combinations of self-tappers), and most of the fussy vertical bits in the middle section are busted. I'm going to paint it when I respray the body, so any imperfections or further bodgy repairs will really stand out. The best solution I feel is to use the old splitter as a template for building a new one. I'm going to fuse it into one piece, use that as a plug to build a fibreglass mould, then use the mould to make the new splitter

    First up, here's what you'll need to build one:


    First job is to join the three pieces of your old splitter solidly together. Make sure you do this while it is still bolted to the car, that way it stays rigid when you remove it and you know the new one you build will line up with your bumper and guards properly. I used Selleys Araldite two-part epoxy to bond everything together, but you can use whatever you prefer or have lying around. As I mentioned, whatever clips and tabs that Toyota used to join the bits together have long since been destroyed, so I needed to make a couple of temporary backing pieces to join each side to the middle. I used some heavy gauge cardboard for the backing, but once again you can use whatever you have lying around that is pliable enough to be pressed roughly into the shape of the back side of the splitter but still retain a reasonable amount of rigidity. It looks a bit dodgy (probably because it is :lachtot ), but remember this is just a template, your end product will contain no badly cut bits of cardboard :hehe . Epoxy the cardboard pieces to the back of the splitter (use plenty, you want to make sure the pieces won't move when you remove it as one piece), and clamp them in place with a couple of clothes pegs or whatever else you have that might be suitable. Let the epoxy cure for a few hours, then you can unbolt the splitter from the car. It will look something like this at the back:


    Now fill in the gaps between the pieces with more epoxy. Don't be shy with it, use a lot, at this stage don't worry too much about it being messy, you want to make sure that sucker is one solid piece!


    Next up, I decided I don't want to keep all those vertical struts (they'll be a PITA to re-mould and will probably only break again anyway), so I've gutted the centre section. I used a box-cutter with a brand new blade to cut them out and shave all of the mounting points down flush. Now it looks like this:


    With no support it's very flexy in the middle, so the next job will be to build a single thick centre pillar. The finished product will have mesh inserts either side which should help with rigidity too.

    That's as far as I got today. Once I've got that centre support made, I'll sand or shave off the excess epoxy from earlier as well as any other dags, then give the whole thing a light sand, a thin coat of body filler to give it a smooth uniform surface, then a good wax with the mould release wax, and that will be the plug for our mould finished. Stay tuned...
  2. Spiderman

    Spiderman Well-Known Member

    Gotta love Araldite............... I remember Stig talking about this last month.
    How did you know my spoiler has broken verticle bars and self tappers :mrgreen ......... I'm tuned :popcorn
  3. Stig

    Stig ST162 Guru Donated!

    How cool is this?

    You could use small boxes to fill the hole at intervals or cut it horizontally and make it longer.
    The grille is pretty big so I don't think it needs much (if any) airflow through the spoiler

    Pity it's not in the bodywork section
  4. MattC

    MattC Well-Known Member Donated!

    Sorry, I wan't paying attention to what section I put this in :eek:ops . Feel free to move it to the bodywork section though, I don't mind.

    Simplicity is the aim of the game here my friend, so just one centre post it will be for now. I like your idea of making little boxes though, will use that :thumbsup: You're right, it doesn't need the airflow, I just think it'll look cool :D If, howver, it proves to be too weak then I'll add more supports or just make the whole thing one smooth piece.

    Today sanded all the goops of epoxy down, and gave the whole thing a good sand so the body filler that will go on next will stick to it nicely. Not sure if I'm going to get any more done before Christmas though :cry
  5. Thaifighter

    Thaifighter Well-Known Member

    This is gonna be exciting. :D
    I'm doing a similar thing with mine, except I'm actually extending my front lip. :p


    I'm not too happy on how mine looks so far, but we'll see... :/ still gotta fill in some areas with spot filler since it's not super smooth yet but I haven't had the time lately... :( (My lip's been sitting around for at least two months now...)

    Anyone know if it's ok if you put the epoxy and fiber glass on top of the bondo? Debating on whether I wanna stick a fiberglass cloth on top to give it a carbon fiber look. :p

    So this means that I can block off the other side of the spoiler without any worries of decrease in performance? (So that the lip will actually look symmetrical. Know what I mean?)
  6. ST165-2765

    ST165-2765 Well-Known Member Donated!

    the epoxy and fiberglass will definetely stick to the bondo no problem but the epoxy may not bond well with the black plastic
    rough sand the black plastic with 50 or lower grit sandpaper to make it as rough as possible.
  7. Thaifighter

    Thaifighter Well-Known Member

    Awesome. :)
    Thanks for the tip!
  8. MattC

    MattC Well-Known Member Donated!

    +1 for sanding first, otherwise the epoxy will lift off easily. Also make sure you clean everything thoroughly before you start, nothing is ever going to stick very well to 25-odd years worth of accumulated dirt, car wash detergent, tar and oil! I used a pressure-washer on mine, even though it looked fairly clean to start with, you should have seen the crap coming out of it!
  9. Thaifighter

    Thaifighter Well-Known Member

    Now, another thing I'm wondering: how sensitive is fiberglass when it comes to how smooth the surface you're applying it on is. (Like if the surface is a tad rough, if all the little imperfect areas will show up) In other words, should I try to make my lip anymore smooth before putting resin and fiberglass cloth on, or should I not bother?

    Thanks. :)
  10. ST165-2765

    ST165-2765 Well-Known Member Donated!

    You guys should check out my Dirty Deeds topic.
    Pages 22,23 I'm working on skull mirrors

    Plastic and fiberglass just don't stick together, I could easilly remove the plastic skull from the fiberglass
    after it had dried and I didn't use any release agent, they just don't like to stick to each other




    Page 11 I'm working on the overhead visor and somewhere in there I did the side window louvers
  11. Spiderman

    Spiderman Well-Known Member

    Good idea and this is the first thing I'll do when I start fixing mine :thumbsup:
  12. MattC

    MattC Well-Known Member Donated!

    :lol2 I have the same OCD, having just one side blocked off has always bugged me, but instead of blocking the other side off to match, I cut the blocked section out :thumbsup:
  13. eNtraxGT88

    eNtraxGT88 Well-Known Member Donated!

    with that you can cool your windshield washer fluid :D :hehe
  14. Spiderman

    Spiderman Well-Known Member

    Not if you live in alaska :hehe ................ Here's a question for you all............... do our cars really need the vents/gaps in the front lip/spoiler and why ????........... The Toyota design team obviously thought so.

    I do understand downforce and drag and air flow and I'v seen a few cars on here with the lip replaced or the vents filled in.

    One side blocked has always made me question why and of course the number plate blocks 3 vents as well............. my 2 left vents have a 'tube' directing air onto the gearbox.
  15. MattC

    MattC Well-Known Member Donated!

    I very much doubt the splitter has any aerodynamic effect at the road-legal speeds we normally get about at, and at higher speeds I suspect it would actually produce lift instead of downforce. And as Stig noted earlier, the grill is plenty big enough to supply air to the radiator, also the gaps in the lower half of the front bumper would contribute to the cooling as well.

    My money would be on two reasons why Toyota made it that way -
    1) it's cheaper to manufacture when you replace about 40% of the plastic with holes
    2) it was the 1980's, chintzy design details like asymmetrical vents and slats were fashionable
  16. lone wolf

    lone wolf Well-Known Member Donated!

    If I'm not mistaken the wholes are ment to guide air in the duct to your transmission for cooling purposes ;)
  17. Stig

    Stig ST162 Guru Donated!

    Yes Matt, I'm inclined to agree

    The holes normally have nothing to do the gearbox, there are supposed to be covers fitted (see pics below)
    which prevent airflow into the bay

    No - The 162 Corona and the 4 door 162's don't have the holes.
    They are mechanically identical to the GE auto and manual versions.

    Personally I think there's too much air going to the engine bay which leads to increased drag and slows the car down,
    new cars (ie Merc) are bragging about variable grilles which limit the amount of air at higher speeds and improve aerodynamics. (fuel efficiency & speed)
    I have run for years with the solid spoiler and stock covers with no ill effects.

    I believe fuel efficiency did increase with the solid spoiler, but I have no proof so
    time for somebody to prove it either way

    The number plate does not block the holes - the air does a fantastic job of flowing around it
    I think you have the GT4 gen1 gearbox cooler fitted? -
    later GT4 models were all fitted with oil coolers but there is no provision for cooling the S53/4 other than fitting the GT4 vent.
    I'm confused as to whether some 162 models were fitted with this extra vent as stock,
    but I do know that the GT4 cover does not fit the 162 without re-drilling holes etc.
    My testing shows the S53 box and starter temps normally range between 85-95 deg C, which is pretty high.


    We don't have the luxury of wind tunnels to prove this, the next best is to look at cars that did - ie the IMSA Celica and the WRC cars

    The IMSA Celicas actually had a dummy grille which blocked all airflow and only air from the air dam was allowed in
    The side vents were used to feed air directly onto the front brakes and intake air was cleverly taken from
    a high pressure area at the bottom of the windscreen

    The WRC cars had a metal bash plate/splitter installed which seperated the engine from airflow under it and cleverly sucked hot air out.

    Unfortunately most of the cars on the site have lost most of the plastic ducting and engine covers over the years,

    I think they are important and should be substituted with a plate/splitter which keeps junk out and and helps "suck" hot air out behind the motor/box
    I have designed a splitter to do this as well as strengthen the front bumper.
    Switching to a GT4 bumper last year put the experiment on hold for a while but I still have it lying in the shed.
  18. Thaifighter

    Thaifighter Well-Known Member

    ^hmmm kinda tempted to just cover up all the holes, and make a DIY Corona lip now. haha.

    Thanks for the info! :)
  19. MattC

    MattC Well-Known Member Donated!

    OK, update time. I abandoned my original idea of having a centre post as it was proving too fiddly to build, so now the centre section will be completely filled in, and will look remarkably like the one on Stig's white car, only all one piece.

    I used a can of expanding foam to fill the gap. I covered the gap at the front of the spoiler with strips of duct tape to contain the foam when it expanded, then laid the foam in the cavity in the back. Leave it overnight to fully expand and cure, and it ends up looking like this:

    Take the tape off the front and roughly trim and sand the foam into shape. It sands easy, so don't go too hard on it. Next you want to fill and smooth it. Here's a tip - fibreglass resin breaks down foam. I was tossing up whether to use body filler or resin, I went with resin thinking that as it would go on in more of a liquid state it'd pour and shape easier, and those things are actually true, but it also breaks the foam down and it's left rougher than it started. Sigh, rip it out and start again. Second time, after trimming and sanding the foam I covered it in bog. Much better. Sets faster too.

    When you fill it, you want to make sure that you keep the profile of the splitter consistant the whole width of the piece. To do this, you'll need to make a buck to spread the filler with. To get the right shape, I laid a piece of cling-wrap over a part of the splitter that so far hasn't had any filling or sanding (and thus has retained it's original shape). Then I poured some body filler onto the cling wrap and held the corners up so the bog didn't just run everyehere. While it was still in that plasticine-like state just before setting, I cut a neat slice out of it, and hey presto, a piece of bog with the same contour of the splitter:

    Next I traced the shape of the splitter profile onto a piece of ply, then cut it out with a jigsaw:

    ...and now I have a wooden buck which I used to spread the filler over the splitter and ensure it stayed the right shape:

    So now, after a few more rounds of filling and sanding my splitter looks like this:

    It's still not perfect, but should only need a tiny little bit more filler and a final sand and it will be ready to hit with some primer.

    Remember, all this work so far is just to build the PLUG so I can make a mould and THEN i can make a new spltter :ack2 I have a newfound respect for people who build stuff out of fibreglass from scratch :bowdown
    Last edited: Jan 13, 2012
  20. Stig

    Stig ST162 Guru Donated!

    Looking good, I think this is a better idea
    1)It's stronger
    2)It gives you the option to put lights etc wherever you want

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