Here is the splitter off the car:

Attachment 191752

^The tape on the passenger side is an outline of what I may trim off of the splitter...

The pink lines are marks from the bottom of the lip:

Attachment 191753

Attachment 191754

The 3x nut/bolts on the sides that hold the tire deflectors underneath also will be the mounting point for rubber truck splash guards, bolted to the outer exposed mounting point (that is outside of the bumper) and sharing a mounting point with the piece of flat aluminum that bolts to the frame.

Here is the underside view:

Attachment 191755

Will not be working on those until I have the protrusion length figured out. There is only about 1.25-1.50" surface area in front of the lip, but in excess of 3-4" sticking out past the sides to cover the tire, but I've been advised to have the protrusion equi-length all around, but no data / reasoning behind that. I will probably shorten the sides, so the final dimensions are not set yet, so I cannot do the tire spats just yet.

Overkill or not, the L bracket sizes were determined by the hardware size I wanted to use. The 2x bolts that bolt the L bracket to the splitter are M8x1.25, which uses a 12mm socket... all other mounting points/bolts are M6x1.00-- do you think 10mm hardware would be sufficient, even for the main support L brackets?

Here's what scraped off so far in 1-week of cautious daily driving:

Attachment 191756

How do you guyys think the eproduction body pane;ls (fenders and front bumper) are aero-wise?

http://farm4.static.flickr.com/3228/...f5776d79_z.jpg
http://farm4.static.flickr.com/3157/...c03538.jpg?v=0
http://www.scca.com/ImageLibrary/Master/1641.jpg


Flyin miata's eprod

http://www.flyinmiata.com/images/mis...dy/FPMiata.jpg

Low to the ground, less psi underneath = more vacuum to the ground. No windshield for less drag?

I was thinking body panel-wise (edited that post for clarification) I'd have to keep the canopy for what I run - but the body kit in general seems gtg I'm waiting on my mazdaspeed account to be activated - then I can see how much they cost

About $400 per fender IIRC, plus whatever the nose costs. It's been a while since I looked though.

The brackets hanging and fasteners hanging below the plywood will constantly be scraped off. I have 4 button head Allen bolts on mine that most every time I have to pull the thing off the heads are ground to where I can’t get an Allen wrench to work on them and end up grinding away at them. I need to make it so everything is countersunk on the bottom. scraping just the plywood with the fiberglass over it dosn't do much damage. the metal bits really dont like it though.

Bob

Thanks for the reply. I had M6x1.00 buttonhead allen bolts laying around in case I run into that issue... but I guess they'd scrape away too, along with the alum angle pieces would scrape too.

For the 4x M8x1.25 hardware for the main support braces, I have some hardware that looks like wheel studs but in M8x1.25 that I can use if need be... or do you think M8x1.25 is too much?

Attachment 191751

I can make everything M6x1.00 (10mm bolt size), including for the L brackets, but I figured it would need the extra strength of the larger M8 hardware.

I'll see if I can find pics of the aero on my FFR. 1/2" birch with layer of glass on both sides. I used carriage bolts from the bottom. Strong but will tear right off if you hit something solid. That's exactly what you want...don't want to pull the whole structue off.

one issue i see is that it looks like your splitter doesn't stick out further than the beltline on the bumper. loses effiency big time. it still does something, but when i put the larger birch splitter on mine it was a huge difference.

By belt-line do you mean the front-most part of the bumper? How exactly is it losing efficiency? More drag? I'd imagine a longer splitter, creating a higher psi differential above the splitter, therefore more downforce...

yeah, front most part of bumper. just what the aero phd from the article in grassroots motorsports mag. said. i also know because i had a small aluminum splitter and it made a big difference, but when i went to a birch splitter that went just a inch and a half past the bumper it made a huge difference. i also added a drop vent hood and had to trim the splitter down a little so i could get back to the frt./rr balance i wanted. i didn't have enough wing! it's now even in the front with the front most part of the bumper.

aluminum
Attachment 191679

don't have a good pic of the birch splitter
Attachment 191680

Why dont you guys use the carriage bolts? Cheap and available at any local hardware store. Also the bigger rectangle part will bite into the wood better than the wheel studs.

http://myword.info/images/ca_bolt_1b.jpg

I have a piece of wood that you can bite on.

i use all-thread, cut to a length that i can use the small or large splitter by loosening a couple nuts and moving the all-thread up or down in the bracket.
i have never had a bolt or all-thread rub or scrape under the splitter.
2 all-thread bolts and 2 oem bolt locations at the corners.
simple and works and i bolt it up tight against the bumper and it's solid.

Attachment 191677

Attachment 191678

+1. I am using carriage bolts on my splitter and it works great. Track tested to 140 MPH, no problems. Easy to mount up as well.

So I've always wondered about the shape of the leading edge of on a splitter. Some are curved like a section of a circle, some are pretty square, and some are like greeenteeee's with flat sections on either side. Anyone know the reasoning for this?

Material size? It isn't nearly as important as moving air away from the front tires.

Maybe more surface area (if that's what you mean by material size), could have something to do with more downforce.
As jacob300zx said, covering the tires are important, and is planned for my splitter. That is part of the reason why the sides are long and straight on the sides, I will be covering the tire, with something like what Savington posted. That, as well as the fact that it is easier to cut off than add material if I wanted. (considering some end plates, following the theory behind the use of endplates on wings...they help keep air from spilling over).

Here are some examples I use in designing mine:

Attachment 191589
^Note the outsides are pretty straight/squarish if you will. The EVASIVE S2000 has the same shape.

Here's some Miata-specific examples:
Satisaii (he entire undercarriage was covered)
Attachment 191590

Attachment 191591

Attachment 191592

Attachment 191593

We are almost finished with spoolin2bars front bumper. Need to trim out the radiator/Ic area and finish the pass side canard. Its hard to see in black but the bumper comes straight down with aluminum now from the center line/farthest point forward. No more pack man mouth to catch air.
https://cimg0.ibsrv.net/gimg/www.mia...4c50761aac.jpg

http://inlinethumb02.webshots.com/48...600x600Q85.jpg

https://cimg6.ibsrv.net/gimg/www.mia...6928ea489a.jpg


Like this... < = fail l = win

or

http://www.cosworthusa.com/store/pc/...aws-103web.jpg

Added some aero to our STU car and it gave us enough addtional speed to set an STU track record at California Speedway. It was fun testing the aero changes..
Attachment 19643
Attachment 19644
We only did a splitter and wing but man did they make a difference.

You should look at pics of the back of it:
Attachment 191159

awesome pics, cant wait to do my splitter and get a wing

I thew on some deflectors on the sides of my splitter before buttonwillow, the rain pics showed how well they worked, canards are next.
[IMG]http://i391.photobucket.com/albums/o...Picture002.jpg[/IMG]

Ive seen this car at willow springs, who's car is it?

Matt Andrews, last time I checked he was trying to sell it.

Mind posting up the rain pictures?

Had some spare time, so made up some aero to go with the new GTC 200 wing, copied a few ideas seen on this post. Ran the car last week at the track (on crappy Tyres), made the car so stable. Hard to say how much faster it was, the temp on the day was 100+ degrees, I only have 68 degree days to compare it too, most of the cars were running 2-3 seconds a lap slower then normal. I managed a time within .3 of my previous P.B. track is 2.2 km long. Will be fitting some 15x9's with semi slicks for the next session in two weeks. I know it looks a bit goofy sitting that high off the ground, but we have some rough tracks here, and every time I have lowered it , it is not as nice to drive and no faster

^ You have a youtube channel?

sorry no you tube channel, will work on that

http://a1.sphotos.ak.fbcdn.net/hphot..._5102899_n.jpg
WSIR is a holy place:
http://a5.sphotos.ak.fbcdn.net/hphot..._6141946_n.jpg

Wow, that is an extensive underbody aero treatment. The brace connecting the front and rear subframes is also of complex construction. You certainly have been busy. I wouldn't mind seeing pics and videos of some of your racing from NSW if you get a chance.

My car's aero equipment wants to be just like your car's aero equipment when it grows up. Nice work.

Wow, that under tray is perfect. Have you had any problem with engine, trans, diff temps?

yeah, love the tray. diff. looks like it might be suffocated, maybe throw a temp sticker on there, or use a laser temp gun to chaeck after a track session.

sorry I didn't buy them from the photographer, the pics I posted my brother in law took with my camera.

I will get some temp sensors happening for the diff and gearbox , engine oil and water temps were a fraction cooler even with the extreme temps on the day.
This is some race footage at Bathurst, not to many races held here as it is a public road, but it is the Holly place of Australian Motor sport. http://www.youtube.com/watch?v=UrPtUYeng0U It's not me in the car , but someone with much greater testicular fortitude, It's a demaning 3.9 mile circuit, with Conrod Straight 1.2miles long, off camber corners, 1 in 6 gradients, and a few blind bends. There is only about 4 endurance races there a year, so it takes some time to really know the track.



EDIT: only copy what's after the "=" in the youtube link for our YT embedding feature, kthxbye.
~curly

Holy crap. That footage was awesome.

i will NEVER be able to drive that close to other people

Amazing driving. Seriously.

Is that under tray attached via po rivits or dzeus screws? Also what material is it constructed with? Looks fantastic. Perhaps a few naca ducts will help ensure temps stay down on your diff and transmission with a few openings in the bumper for the hot air to exhaust from.

That is one of my favorite videos of Bathurst. Found it like 4-5 years ago and then lost the link. Can you explain any of your under aero? It looks like your center section is lower than the rest of the car due to the bracing? It also looks like center exhaust? How steep is that angle from the piece near the diff to the diffuser?

Why dont we have racing like this on the tv every sunday instead of NASCAR?

We did before SPEED Channel went to hell and became "mainstream."

Two iterations of aero on William's car. The "mustache" piece was eventually deleted.
http://949racing.com/server/william/..._diveplane.jpg

This picture was from the day we set the lap record at Buttonwillow 13CW (still stands). Cooler so we blocked off the rad opening to get a bit more downforce and cut some drag. The dive planes and splitter were made from corrugated plastic and .125 sheet ABS riveted together. The whole splitter and dive plane assembly were held on by 4 quick release pins for easier trailer loading. Splitter/dive plane thing weighed about 5 lbs. That's me driving in this shot. It would bow down on the ends at speed from downforce. Doing about 50mph at the apex of this slow turn.

http://949racing.com/server/william/WC_BW_red_aero.jpg

What about those spats running from the front to rear wheel?

Ive wanted to see that car in person but have had no luck.

The spliter is made from 3/8 ply, I cut voids in it, and then used a PU adhesive to skin the under side with some thin alloy sheet. attaching it to the car, I made some plates that mounted where the oem under tray was, and some thin alloy braces foward and out to the sides. I have used riv nuts and button head bolts to attach all the under body parts.
The under tray is alloy sheet, in three pieces, attached to the full lenght brace, I bent the edges up to meet the chassic rails as the brace sits 1/2'' lower then these, It is pretty level from the spliter to the rear. the diffuser drops away alittle steep at first (10 deg) but then levels out to 7, there is a 1 1/2'' gap between the rear bumper and diffuser to let the heat out .
Used Abs plastic to make the dive plates and the side skirts are plastic garden edging.
I will look at making some quick release devices, to many bolts
My car sits to high to create any real down force, I was looking more at smoothing out the air flow under the car

Did you use rubber sheet to cover the control arms (with it attached to the front and rear of the wheel wells)?

Brett, what brake calipers are those in your picture?

Not to muddle up the thread but might I suggest an alternative to hardware for those concerned.

VHB some threaded bosses/blocks to the top side on your splitter so the bottom side is perfectly flat and scraping on the pavement is a non-issue.

Your splitter will break before the VHB will ever fail.

We use it with some regularity at work and it truly lives up to its claims.

http://solutions.3m.com/wps/portal/3...apes/VHB-Tape/

-Zach

William's idea. Helps keep air flowing down side from getting sucked under car. Theory goes if any low pressure is developed (car had a diffuser) underneath, you want to keep it acting upon underside of car and not sucking down the higher pressure air mass from sides of the car. Same principle as skirts. I'm a bit dubious as to the effectiveness of his HD Motorsports solution with PVC garden divider but as he likes to point out, the car set several lap records with about 125whp less than all the other fast F/I Miatas in Cali. I think BW13CW is the only one that still stands now.

because in NASCAR, driver quality and car potential are a lot closer than the Lotus race.

my bet is that the driver was in a faster class. he somehow qualified at the back due to issues during qualifying. He is clearly 10 seconds per lap faster than some other Lotus.

FTW. I am using garden edging on my splitter, same way you are judging from your photo. Very cheap, durable, easy to bend and fasten. A little heavy but not a big deal in the grand scheme of things.

Speaking of which, I found and successfully used a method for making adhesive stick to that stuff (polypropylene IIRC). I may have posted this before but will post again just in case. Normally polypropylene is a terrible surface for adhesives. BUT if it is flame treated with a simple butane torch then it changes the chemistry of the surface layer. Adhesives will stick much better. I am using 3M trim tape to hold a skirt to that piece (low load) and it sticks very well after flame treating. There are writeups on how to do this that can be found via google. The guys that build model airplanes from coroplast (also polyethylene) have to do this as part of the construction procedure. In fact, I also flame treated a piece of coroplast (other side of the aforementioned 3M tape) and it works. You can tell when you are there because it loses a little sheen and water will no longer bead on the surface.

Lowe's Racing Supply aero construction supplies and techniques, gotta love them.

On the rear, attached to the floor at the front of the wheel well, zip tied to the control arm, heated and bent the abs at the rear so it rubbs on the alloy at the rear. Front abs plastic bolted to the crossmember and zip tied out at the wheel end.

Look like RX-7 calipers.

FD rx7 calipers 290mm rotors, work very well, not worth effort now, they are mounted on a simple dog bone mount, machining the out side radius of the caliper is required to fit inside 15'' wheels, and wheels have become an issue how, would really like some 9'' 6UL's but the caliper is to bulky and hits the back of the wheel spokes, would need 1'' spacer, it's just not going to work. I can see a Willwood kit happening soon

You need to tell everyone who wants to try that brake swap.

Its not a question of failure or not, The tape is very strong however the problem is how do you pull off your splitter and quickly replace it when time is short such as on a track day? In reality the paint will come off the wood and the splitter will fly down the road.

Where do you guys get your turnbuckle hardware for the front splitter supports?

Lowe's Racing Supply. There are many sizes and types of turnbuckles in the hardware section. My whole front splitter is built out of items from the hardware store.

Are you talking about Lowe's/Home Depot type of stores? Or is this an actual car shop? We always joke about Home Depot/Canadian Tire Motorsports up here. I haven't seen any turnbuckles, but I'll give it another go.