Post your DIY aero pics
 

Try to use this template if possible to help others learn (and copy)

Dollars spent:
Hours spent:
How effective:
0=slower, 1, no improvement, 2 =slightly better,3= big improvement
Materials used:
URL, brand name, material type
Size/thickness of materials:
.060", 3/16" etc
Bracket location:
Tracks tested on:
Race/TT class built for:

To keep the thread clean DO NOT QUOTE IMAGES.
No fuzzy, out of focus cel phone pics. It's 2012. If you can't take a decent digital image and post it on a forum, you lose man points.
Non-Miatas OK as long as it's DIY. Mixing OEM or aftermarket aero with DIY is fine. In other words, don't show us a pic of your new Garage Vary copy on your street car at stock ride height with daisies.

NASA 3 point NB air dam
 

~$60 spent
3 hours
3 for lowered drag, probably 2 for reduced lift
corrugated plastic and ABS sheet from www.sign-mart.com
coroplast was 3mm white for undertray. ABS sheet was .060 black
Air ducts from Aircraft Spruce

Machine thread screws into subframe though undertray for rear.
Dam had riv-nut inserts in OEM bumper skin then 3m machine screws through dam to hold it on. Ducts are zip tied in place through skin.

Testing this weekend at Auto Club Speedway in Fontana, CA. Looking for less drag than OEM dam we ran at T25 and most of last season.

NASA E1/PTC/TTC. 3 points. It's temporary until we get our complete race nose finished.

https://www.miataturbo.net/attachmen...ine=1330147248
https://www.miataturbo.net/attachmen...ine=1330147248
https://www.miataturbo.net/attachmen...ine=1330147248
https://www.miataturbo.net/attachmen...ine=1330147248
https://www.miataturbo.net/attachmen...ine=1330147248
https://www.miataturbo.net/attachmen...ine=1330147248

front undertray
 

~ $60 spent
5 hours or so spent
?drag, 3 for lift
made of 3 mm dibond

Mounting:

uses oem rear subframe brace bolts, oem belly pan mounting points at steering rack. in the front i have L brackets that mount to the AC condenser bracket and have Dzus fasteners holding the tray on.

havent gotten it on the track yet but it feels like the front is more planted on the highway 75mph+

my car is a DD/weekend track car.

https://www.miataturbo.net/attachmen...ine=1330292876

Emilio,

Are you using any sort of splitter in conjunction with that nose?

Perhaps an underbody tray?

I'm piecing something similar together for my NA and I'm curious.

Thanks bro

There's coroplast behind it in one of the shots.

mine started like this:
https://www.miataturbo.net/attachmen...ine=1330333382

eventually did more, aiming for drag redux, lift redux second. (stock B6 engine)
birch ply 1/4" splitter became undertray when i added an airdam in front of it (minimize air underneath, but to allow for bottoming out without damage)
at the rear end, 2' wide x 26" long diffuser @ 6.5* and 9.8*... strings of yarn were tested at various stages of development which led to corrugated plastic aft of the chassis floor to the end of rear subframe. Entire rear floor covering a span of 44" end to endNext is complete rear diffuser spanning bumper to bumper. Have also tried fins on the HT window, with plans towards fins from the windshield frame back.

https://www.miataturbo.net/attachmen...ine=1330333382

I've posted plenty pics in another thread, it might be redundant putting it here so here's my video of the end result so far.

MUTE MUSIC PER PREFERENCE
PAUSE AT:
0.39 for front end aero
1:05 for before/after rear end aero



doing coolant reroute and rad swap eventually, will replace oem undertray with corrugated plastic. currently have post-rad ducting as testing but no vent on hood yet.

total drag overall has decreased (objectively)
steering much heavier at speed, very balanced now, biased to slight understeer.
lift has drastically been reduced at speeds 80-90. anxious for another trip to BW 13CW to see how it does.

I dont have complete cost etc as it's been a long time project. (multiple revisions)
as such, can remove post if need be.

Just as you see it in the pictures.

Downforce on undertray
Saturday the one in the first set of pics didn't last at 130mph. It was .060 ABS and was too flexible, fllaped around and destroyed itself. The 6mm coroplast undertray got sucked down from under the dam and ground itself to bits on the T1-2 banking at ACS. So for Sunday we went back to the shop and made a new one from slightly thicker .090 ABS and it held up. We also increased the undertray to 10mm thick corrugated. We didn't brace the undertray and again, it got sucked down and ground on the pavement at about 130mph.

V3 of this dam has added attachment points all the way to the forward edge of the tray to help prevent it getting sucked down. The undertray meets the dam about 2" up from the bottom so it creates a little suction behind the dam. That was our intention but the forces were much more than we expected so it took a few tries to make the undertray rigid enough. Surprised us as there is no splitter at all. Having the undertray meet partway up the airdam also allows the bottom edge of the dam to flex a bit when loading/unloading the car.

Rad Inlet plenum
We then fashioned a plenum between the mouth in the dam and the radiator. Without it, the airflow was really disrupted as it goes through the mouth, with plenty of little leaks here and there. The plenum solves all that. Easy enough to cut and bend the plastic to make a simple smooth venturi shape that terminates at the rad core. Sorry I didn't get a pic of the plenum before we stuck the grill on there.

Grill and mesh choice
We typically make grills from three meshes of different open ratio. Basically cool and hot weather. With a reroute, it's easy to overcool the engine to the point that the oil doesn't get hot enough. The more closed it ism the less aero drag and more downforce on the front end.

Wire mesh from mcmaster.com
9217T41 81.5% open area hot weather (pictured)
9641T241 61.6% open area warm weather
9227T632 44.8% open area cold weather, what we ran at T25.

https://www.miataturbo.net/attachmen...ine=1330659533

Been keeping up with this thread and information about your NA front air dam for SuperMiata.

Curious to know if adding a front air dam to a mostly neutral car without adding a wing out back will create a car that is prone to oversteer? If so, will the balance be off far enough where I wouldn't be able to gain balance again through adjustments to sway bars, dampening, tire pressures, etc. Thanks.

Also, are there any other solutions that make a significant difference to positive rear downforce or negative rear lift other than a big wing? Thinking rear diffuser, AutoX type trunk spoiler, etc.

A functioning front air dam/ spoiler like our Supermiata will require a wing out back. Any compensations with mechanical grip will net out worse than just not running the front aero.

Dollars spent: 0
Hours spent: 2
How effective: not tested yet
Materials used: birch ply
Size/thickness of materials: 12mm
Bracket location: 5 10mm bolts on subframe holding factory undertray on, enlarged for 10mm bolts
Tracks tested on: non yet
Race/TT class built for: weekend lapping

The guy that cut this for me says the shape is better than following the curve of the bumper...wtf do I know, but we'll find out soon. Wish I had a water jet at home. I just have to attach the aircraft cables.

https://lh5.googleusercontent.com/-Z...2/IMG_2711.JPG

https://lh4.googleusercontent.com/-S...2/IMG_2712.JPG

Apparently the guy likes Nascar
https://www.miataturbo.net/attachmen...ine=1331138884

Subbed. Report to follow.

Dollars spent: $50

Hours spent: 20

How effective: 2 - balances the rear spoiler out and large enough that I can feel its effects at realistic speeds. Because it is DIY and I'm no engineer, I'm sure the design could be improved, so it doesn't get a 3.

Materials used: 1/16" MDF sandwiched between 2 layers of fiberglass, 3 layers in the angles

Bracket location: Mounts to bumper w/ little L brackets, and bolts to splitter

Tracks tested on: SOW and several autocrosses

Race/TT class built for: Miata Challenge, if any. Will be at Chuckwalla end of this month to try it out some more.

https://www.miataturbo.net/attachmen...ine=1331189251

https://www.miataturbo.net/attachmen...ine=1331189251

https://www.miataturbo.net/attachmen...ine=1331189251

https://www.miataturbo.net/attachmen...ine=1331189251

http://i175.photobucket.com/albums/w...t/DSC_2048.jpg

https://www.miataturbo.net/attachmen...ine=1331189251

https://www.miataturbo.net/attachmen...ine=1331189251

wow and i thought the aero on your car couldnt get any more bad ass. keep up the good work

Dollars spent: $110-ish
Hours spent: 10
How effective: 2 - did this before the canards, and it did enough to unbalance the car above 50mph. The canards balanced it out. Still, in many ways it could be improved.
Materials used: Alumalite, aluminum L bar stock, rivets, struts pieced together from hardware store materials
Size/thickness of materials: 6mm alumalite
Bracket location: attaches to trunk with triangular gate hinges
Tracks tested on: Chuckwalla, SOW, several autocrosses
Race/TT class built for: Miata Challenge, if any

https://www.miataturbo.net/attachmen...ine=1331189815

https://www.miataturbo.net/attachmen...ine=1331189815

https://www.miataturbo.net/attachmen...ine=1331189815

https://www.miataturbo.net/attachmen...ine=1331189815

Aren't those buckles on the bumper trashing airflow?

He is correct. More horizontal area of the splitter, means more positive pressure on the top side, means more down force.

Just make sure it is securely mounted to the frame of the vehicle not just a plastic portion of the bumper which will flex. If it's rigidly mounted and well supported then the downforce produced will be better translated as increased vertical load on the tires. I've seen many instances of folks attaching splitters in such a way that the majority of the possible downforce is likely lost in deflection of the mounting setup.

^Its interesting you mention deflection as bad, considering the whole last season or two of F1 people have been complaining that RB's front wing is deflecting beyond the minimum height and giving them more downforce. Care to explain further?

Perhaps the area of deflection is whats at question here?

It's hard to compare the aero of an F1 car to that of a diy miata setup. Totally different ball game. But to answer you question I'm talking about a different type of deflection.

The goal with the front wing deflection on the red bull was to get the front wing element closer to the ground which would produce more downforce. The mounting of the wing however was not designed to deflect. If it was, then the downforce produced would be wasted and not translated into increased vertical load on the tires.

This article actually explains it quite well.

http://scarbsf1.wordpress.com/2010/0...ls-front-wing/

So yes, deflection of the actual aerodynamic device can be used to your advantage, but if your goal is more vertical load on the tires, then the force it's generating has to be translated to the wheels effectively.

If your splitter makes actual downforce and that downforce is only used to bend your bumper, then it's really not helping you at all is it?

Well, strictly speaking, as long as the bumper eventually stops deflecting, then the downforce is still being translated to the wheels. Static loads. And nothing is completely rigid, so no matter how beefy your structure is, it still moves under load.

But, point made. Structurally speaking these aero devices should be well attached to the chassis.

How much does the angle of the splitter affect the performance? Is it better to have the nose slightly lower or is it better to keep it level with the ground?

Level with the ground.

I see, I figured it was something more specific than deflection in general. Thanks for the explanation.

Must be level with the ground. Unless you want tons of drag along with your downforce. Also messes up the other benefits of a splitter if its not level.

Dollars spent: < $100
Hours spent: 4-8
How effective: betwee 2=slightly better and 3=big improvement (too little testing)
Materials used: Poplar multiplex
Size/thickness of materials: 11mm (~ .43")
Bracket location: Rear of subframe (2), droplinks from crashbar (2), steering rack (1)
Tracks tested on: Assen, NL (-1s)

Last year I had just the GTC-200 and the rear became very stable (compared to no aero). With the wing slight understeer.

Now with the splitter, car turns in sharply and the rear is more loose. Needs more testing with more AOA in the rear.

Hey Emilio. I was just talking to you earlier about my wing (and how badly my lack of a hardtop will effect it). Thanks again for all the advice. This is why I need it so badly:

Dollars spent: $100
Hours spent: 15
How effective: I hesitate to say without real testing data, but enough to seriously unbalance the car. I spun at every event I've been at since putting it on. I'm finally getting my head out of my a$$ as putting a wing on to balance it out.
Materials used: Birch ply for the splitter. ABS plastic for the air dam.
Size/thickness of materials: 1/2" ply splitter (thicker than it needs to be, will use thinner material in the future), 1/4" abs airdam
Bracket location: 2 bolts @ back of subframe. 2 turnbuckles on the sides (in front of each wheel, just inside the air dam), 2 turnbuckles in front.
Tracks tested on: Jefferson Circuit @ Summit Point, Weatherly Hill Climb, Various autox's
Race/TT class built for: SCCA SSM Time Trails and Hill Climbs.

https://www.miataturbo.net/attachmen...ine=1315443451

A quick and dirty band-aid aero is a sheet of coroplast hose clamped between the roof and roll bar hoop. We tested it on a chump car in it had a bit more top end speed and back end was less loose. Also keeps the sun off you if nothing else. Maybe William or Sonny have a pic they can post.

Cool idea. Sadly, it wouldn't be legal for SSM. It turns out the Chaser top isn't legal either :/

Here's the top in question.

https://www.miataturbo.net/attachmen...ine=1331688712

For the guys with plywood splitters, do you do anything to it to help make them more water resistant? How would this hold up on a rain day?

heat, tar, oil resistant spray paint. Other than that I expect water to be the least of my worries.

I paint the top side with cheap solid black wood stain. I do not bother staining the bottom most of the time since there is a good chance it will be scraped off anyway. I've had my 3/8" birch plywood splitter at one really wet event and a couple of other damp events. So far, no problems. FWIW I do not leave it out in the rain. Mostly it is in the garage between races.

Spraying it with a water sealer like Thompson's might be worthwhile.

Mine has been soaked in rain more times than I can count and there are no significantly ill effects. It is covered in ~$3 worth of spraypaint.

I daily drive my splitter and i coated both sides with fiberglass resin then some black paint and other than some bottoming out on the street it has held up fine all last summer. see location im local to you so same weather.

Kris.

APR 2D wing mounts
 

APR Performance 2D wing. We made our own mounts. Not pretty but, functional.

Very interesting video, very well explained!
Thanks!

Awesome video!

i just want to add that my mpg went up about 2-3 mpg with my undertray from page one. testing was accurate as its gonna get.

We have seen the same thing on other cars. Front under tray is far more effective that most people my guess.

Is there a recommended height off of the ground a splitter should be?

doubt it

lower is better as less air can flow under the car. there is an optimal distance off the front of the car though.

As low as it will go on the track/suspension combo that you run. Mine is probably at 1.5-2" or something.

Mine's 4", but I do hill climbs which require a bit more clearance than most tracks

Thanks, right now I'm trying to figure out how low it should be mounted. As far as how far it extends it is about ~5 to 6in. from the point it leaves the car but sits pretty flush with the furthest leading edge part of the nose. That sound about right?




Wow this post could be taken so many different way:facepalm::jerkit:

IIRC for a splitter to work properly it has to be mounted front of the front most part of the bumper so it hits the air first. So I guess 6 inches but not from the point it leaves the car but from the front most point of the bumper nose.

Like this:

https://www.miataturbo.net/attachmen...ine=1333132539

https://www.miataturbo.net/attachmen...ine=1333132539

http://autorecordspeed.com/wp-conten...ew-600x449.jpg

https://www.miataturbo.net/attachmen...ine=1333132539

http://stwot.motortrend.com/files/20...er-623x389.jpg

So not to jack the thread, but I have seen some very thick front splitters on hill climb or Pike's Peak cars. Is this just for strength/durability, or is there an aerodynamic benefit?

Here is the GoPro Pikes Peak car. Look how thick the splitter is at the front. I cannot tell if that is just a front dam with a diffuser behind it or if the whole splitter is that thick.

https://www.miataturbo.net/attachmen...ine=1333148697

Do you guys use the stock plastic belly pan with your DIY splitter? Or do you fabricate something to close in the sides? My stock plastic belly pan is a mangled piece of junk. What would be a good material to use in order to close up the sides to mate it with my front splitter? I remember someone using plastic/canvas type of material, but I cannot find that thread or remember what it was called.

genesplicer did a pretty awesome job with his liner if that's what you're thinking of.

You could also use Thompsons water seal then paint

ZX-Tex: I'm not sure about Monster's. I can't think of any other reason to make it so thick. I'd bet its for strength, since pikes peak cars have so much riding on a single run, you don't want a random rock that happens to be laying in your line to ruin it.

Mine's .5" birch ply and has survived a few low speed hits on curbing and such. Most of the other door bangers I race with dont have aero (they mostly focus on POWA!). Of course the formula cars and hill climb specials just use wings on front to get serious down force.

Dgmorr: I don't use the plastic pan with mine, my splitter goes all the way back to the center line of the front wheels (as allowed by the rules for my class). It does make it heavier than it needs to be though. I might try replacing some of the non-load bearing area behind the bumper with a lighter removable material.

That's the one I'm thinking of, thanks.

3yrs in and it's still holding together. I do plan on some aero-updating this year, like these awesome ABS plastic dams with a splitter...

Has anyone ever done a touring car style aero for the miata?

https://www.miataturbo.net/attachmen...ine=1333372258

Or would it just be overkill?

Check out the "carbon time attack twins" in the build thread.

That Vodafone car gives me a boner.

Are you using the coroplast under the abs sheet for reinforcement? The black sheet up front is it just abs plastic? and if so.. did you need to make some kind of mounts for the bottom part to hold it up during high speeds?

Hey Emilio,

Nice video, always very insightful to see what you've done and why. Crusher's wing mount has inspired me to do the same with our Ciro Design wing for Senna. I'm glad I already have a 2D wing that'll benefit from more rearward/upward mounting. Plus, Scott R's neat idea for a DIY tire rack will fit better on Senna!

We're creating a 3/8" birchwood front splitter also, along the lines of what Savington and Bob have done. I'll post pictures once we have something concrete. The plastic aero work on Bellwilliam's car in this thread is very sexy though, but my modest aero intuition and reading suggests I want to make mistakes with thinner / break-away birchwood first (or just stick with it).

Primarly, I want to make the aero NASA TT/PT and Miata Challenge compliant, even if SCCA Solo XP rules may allow more. As Bob Bundy did, an alternate Solo splitter would make sense and different ride heights vs. track.

Shaikh

Class rules state nothing shall protrude beyond the bumper when viewed from above, so that pretty much does away with front splitter, airdam is okay. Also, we are not allowed a wing. So you don't want to add to much front grip.

Here are a few pics.
https://www.miataturbo.net/attachmen...ine=1334723017
https://www.miataturbo.net/attachmen...ine=1334723017
https://www.miataturbo.net/attachmen...ine=1334723017
https://www.miataturbo.net/attachmen...ine=1334723017

Looks good. Couple questions though. Are you going to cut away the lower part of the bumper, or at least remove that lip? Also, could you have made it any lower? Getting that air dam close to the ground will reduce drag and lift significantly. I'd even consider adding a "soft" plastic skirt that gets REALLY close to the ground if I couldn't run a splitter.

crazy idea:

could you tilt the airdam back as it heads down so that you get the benefit of a nearly vertical air dam PLUS a few inches of splitter?

like this: /

Would that not create lift?