Prawn and BigAls A3 Track Car

And there was wood!

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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:



And up she goes:



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.



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



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.





And out came the Jigsaw:



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



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)




Held up for a test fit:



(angle not set here)



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



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!



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



Getting there:





More tomorrow :)
 
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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
 
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?
 
Ply wood is well known for this... looking good mr Prawn sir. keep it up
 
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
 
More pics. Still a work in progress.

Once finished it'll come off for more paint



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



air dam will be attached to the splitter via tabs:

 
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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.
 
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:
 
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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.
 
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?
 
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.
 
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.
 
ScottB5 said:
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?
Click to expand...

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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ScottB5 said:
7kg?
What would a suitable metal replacement weight?

Just wondering for a comparison.
Click to expand...

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.
 
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
 
Prawn said:
Awesome shot Curtis! haha.

I love that whilst exiting the right hand bend, the scoob is turning right as you'd expect and I'm steering left :laugh:
Click to expand...

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 ;)
 
Hows the front being supported? Tie bars or purely the screws into the bumper from the fence?
 
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.
 
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.
 
Jason.s said:
Hows the front being supported? Tie bars or purely the screws into the bumper from the fence?
Click to expand...

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
 
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.
 
A few pics just for interest :)

Sam Tordofs MG:



Nick Fosters Ebay Motors BMW:





And Dan Welches NGTC Proton:



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

 
Air dam is finished.



Hopefully bolt it up and see how it looks this evening.
 
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It's coming together, we're going to make it to Spa!

Supports layed out and washers and nuts ready:



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.



Side view of the supports from the chassis legs:



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:



And it's on!





Bumper on:



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



Side panels still to make, but we're winning.
 
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.
 
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