Splitter and undertray - work in progress w/pics
 

First track day in a couple of weeks and I'm fabbing up an splitter/undertray.
Need to do alu brackets to hold it to the car.
Idealy I want it to be removable... not sure yet how.

This is poplar multiplex - very light!

https://lh5.googleusercontent.com/-A...0/IMAG0530.jpg

https://lh5.googleusercontent.com/-x...0/IMAG0529.jpg

https://lh4.googleusercontent.com/-t...0/IMAG0528.jpg

https://lh3.googleusercontent.com/-U...0/IMAG0527.jpg

Need to decide on the overal width and yes, it will be flat black in the end.

Nice! How much does it stick out at the nose?

Post pics of how you mount it, please. I have a similar finished piece sitting in the garage, I haven't worked on the mounts for it yet.

Shape looks familiar ;)

Looks good and I take it you will be making some kind of spats for the tires from the width. Give me some info on those lights you have in the turn signals. We have a 24 hour race coming up and they look perfect for lighting apexes.

Those are the Aurora LED DRL's from RING Automotive
http://www.ringautomotive.co.uk/prod....asp?prod=2060

I use them purely for getting noticed on track and they are *very* bright, even in bright sun light. They mount nicely to the vertical metal stub in the turn signal area. I want some clear lenses over them but can't find any.

Slightly off your topic but on miata forum or here a guy melted the glue holding the original lenses from the backs in his oven, I imagine the original item would be perfect.

you can do that ^^^ or simply cut the plastic out from behind. you want to leave the grey plastic where the screws go thru the clear lense to hold it secure. For the splitter, use new, slightly longer screws in the fenderwell area that go to the factory support brackets just in front of the tires. i used aluminum brackets up front where my bumper support used to be holding allthread rods to support the front of the splitter. works great, takes 3-4 minutes to take off, and has been crash tested at a few tracks. lol

front/center supports
https://www.miataturbo.net/attachmen...ine=1329889683

https://www.miataturbo.net/attachmen...ine=1329889683

rear/side supports
https://www.miataturbo.net/attachmen...ine=1329889683

at the time i had a smaller aluminum splitter, but the same thing holds my birch splitter now. super simple, but it works with only 4 mounting points.

+1 to what Rharris19 said. I would add dive planes that start maybe 250-300cm ahead of wheel opening. Slope upward at 55° angle all the way to bumper skin.
The one in the video is a bit small. Your car could use something taller. Blocking the air stream from hitting the front wheels has a huge effect of drag/lift.

We don't uses rigid turnbuckles for splitters any longer. We find a small cable is easier to work with and will collapse upward if the splitter is pushed where a rigid rod will force something to break somewhere.

Some pics from 2010 showing our dive planes. ABS plastic and aluminum pop rivets. Whole splitter/undertray/diveplane assembly was quick replease, would hold 150lbs weight yet weighed maybe 9lbs and would flex upward if hit.

For undertrays we like coroplast or other corrugated plastic as used in temporary signs. Sign supply stores will have the corrugated plastic in big sheets and it's not expensive.
https://www.miataturbo.net/attachmen...ine=1329935760

How do you guys seal off the wheels from the engine bay? use the stock undertray? and what about area in the front bumper where the fog lights usually are on an NB (spoolin2bar's 3rd picture)?

Thanks for all the valuable input, I will be shopping for some mounts tomorrow.
Oh, BTW stick to imperial, 250-300cm would lead to some crazy trailer loading scenes. You mean 25-30 :)

:rofl:

Thank you guys for the additional details. I think the small cable vs rigid turnbuckle in particular should be helpful moving forward.

What do you think about coroplast for a small (street and driveway friendly) splitter that would go under a R lip? Ribs front to back for strength under aero load (and seal off the edge so spiders don't live in it). The coroplast would not be very strong under impact and buckle, thereby sacrificing itself for sake of the lip and bumper cover.

Guess I could just try it since the cost of materials is not much.

Pick the thinnest coroplast and double/triple/quadruple it. also make sure you cross the ridges. And you will need to fill it in or atleast seal entrance to the ridges.

While humungous still 50-60cm tops, not 250-300 :party:

I am 183cm tall. So yeah, Emilio... check you measurements :P.. I doubt a splitter will stick out 6 feet from the wheel well unless its one of these.

https://www.miataturbo.net/attachmen...ine=1330004874

Emilio, are you using cables exclusively, or solid braces at the back and cables at the front?

The picture was a joke. mm, not cm. Rear mount is not cable. Either tabs or brackets depending on the application. Figure out what works best for you.

Guess I've been posting in the wrong thread:

I've only got the middle of the car to finish up, but everything between the rear wall to the rear subframe is covered (could have been wider).

Started like this:
http://www.tumblr.com/photo/1280/gre...h7lrdwW1r31zr5

More pictures here:

https://www.miataturbo.net/showthrea...t=60805&page=4

Does anyone know what kind of diff casing temps I should avoid seeing? I've only measured after a 25-30 minute drive, it was 170 degrees.