My attempt @ more front aero. How can i make these better?
 

Attachment 193458

Attachment 193459

Attachment 193460

Attachment 193461

Attachment 193462

Attachment 193463

Thoughts/comments/suggestions all welcome

Specifically interested in support and if you guys think this will even hold up. Anyone else have any pictures of how they supported their front spats/canards?

Doesn't attaching them to the splitter negate any part of the splitter they're covering?

Splitters work by smoothing out airflow UNDER them, and thus creating higher velocity and lower pressure. You jut them out from the bumper a bit in order to disallow the high pressure air at the very bottom of the bumper from flooding under the car and negating the benefits of the high pressure - same reason why you use endplates on a wing (and why larger endplates are slightly beneficial, to a point). There's a small amount of high-pressure component on top, but the big thing is the vacuum pulled by the increased velocity.

Gotcha, ignore me then. What's the outside row of brackets for?

Take a closer look at pic #5.

I was trying to think of something to do in that same local too... except I have flares that stick out a good 2" too. Looks like it'd work pretty good... in for testing - then copying :) It sure the hell aint going anywhere with it bolted down like that!

Do you have it such that the front clip pops right off? Saw the buckle and was wondering - not that's sweet.

Good stuff, you followed John's advice and he's help build aero on a couple cars now for the guy who did the aero on this:
http://blog.kw-suspension.com/wp-con...6/3E4H0807.jpg

buy some time in a wind tunnel.

Looks good. iirc the biggest effect of the canards is as a tire spat, ie shielding the un-aero tire parts from the wind. If so, you've got it covered pretty well.

Looks like a good straight forward and proven design. I don't know much about spats, but would it work better if the bottom was closer to the tire? I don't know if the air would be able to come around that and try to hit the tire or if it will do it's job just fine. Again, I know very little and was the only thing I saw.

I really dig the latches holding the bumpe to the fender. I may steal that.

I'm sticking mine inside the fender and pulling the bumper "back". They also fit under the hood on the factory metal bumper attachment.

What do you guys think about support, and having them only attached to the bumper via 7-8 bolts on L brackets?
Does the angle look to aggressive?

I am thinking that the design will be "better" than nothing there but i am yet to take a fluid dynamics class so I am just looking at this with common sense.

On a side note, found a fog machine in the garage while digging out Halloween stuff, I wonder if there is some way i can rig up a really really basic wind tunnel to see whats happening to the air on these things.

i've been under the impression that reasonable angle of attack would be similar to wings - IE: 15* max. perhaps keep < 15* and do 2 or 3 elements like a multi element wing? (by cutting up a cheap ebay aluminum wing).

do you have a smooth airflow under the car? anything which reduces the speed of the air under the car will hurt your aero...

Only to the end of the front subframe, some sort of flatbottom is an idea Ive been toying with alot lately. Mike @ GST motorsports and his L gave me a great idea on how to do it.

Look at the canards in Hustler's pic. I can't tell from your pic if your side fill plate extends up as an upright spat to direct airflow.

1. Fluid dynamics (at least sub-sonic) is pretty much common sense with some math thrown in.

2. Do the fog thing with one of those giant shop fans. It could actually give you some good insights into what is and isn't working. If you can, try and rig up the fog machine to a thin tube so can focus the fog in specific areas the way they do in wind tunnels.

i was just thinkin.... maybe ask mike if you can use his corner weight scales? put your front tires on them. get yourself a pretty good size fan and watch the scales while changing the AoA. find the angle where you start to get diminishing returns. now you have a range.

then you just need to know your drag penalty to figure where your sweet spot is. to find drag, you could just take the thing up to say 100mph, put the clutch in, and time how long to drop to 70 at various AoA. when your drag goes up but your weight didn't change, you've gone too far.

same thing for the rear wing, just harder to measure if you keep it on the car.

Decided to build a wind tunnel and test the aero on a few things. Enjoy.

Sweet video.. the diy wind tunnel looks like it gives some nice results. Your aero work seems to be working very well too. I especially like how that illustrates the airflow coming out of the wheel wells.

Not bad for DIY, that's kinda cool haha.

Is your car still road legal/registered? I'm wondering if you can make a longer probe for that fog machine and have someone drive your car on the highway while you stick the fog machine pipe out the window of another car in the next lane and video tape it. Impress us with that next.

After thinking about this for several months, for us South Texas guys. While looking at your first pictures it looked fairly good. Now that its boxed in I see some problems. The whole point of this canard/spat is to get air to ramp up over the tire smoothly and keep it out of the wheel well. It seems that you might have traded an abrupt tire for an abrupt spat. The front of the spat is now the aero obstruction. Blow the smoke from dead on in front of the tire and see what it does on the lower portion.

Love your work/vid sorry to be a downer.

Edit: Where did you get the material for the canard? What is that?

Very nice work and great info, but what material did you use? Is it ABS plastic?

http://compositeenvisions.com/images...nversion18.jpg

Thought this might help your thought process out a bit, doesn't seem like a bad start to me, then again I don't know anything about aerodynamics

like it. i think it looks like its working. as far as wing, doesn't really show anything spraying it right in front like that. you need to see what happens after the air goes over your hardtop. as far as angle of attack, i attached small brightly colored yarn strings all over the wing. since i didn't have anyone to help, i attached my gopro to my back window and filmed what the yarn did at 4 different levels of attack. watched the video, it was at max downforce at pos. 3 and started stalling at pos. 4. you could do the same for the canards if your worried about drag.

looks like abs. we have small sheets here at the shop. i'm sold on alumalite after seeing matt andrews car in person. it's way stiffer than i imagined. if it's too much, i have thin aluminum sheet at home that'll work.

I learned a lot while wrenching on that car last season, alumalite is awesome. I also learned a lot from looking at the big $$$ Commiefornia cars.

cool old video:

http://www.youtube.com/watch?v=HpwPTyDC4do

by the looks of the water, it appears that they are doing some good:

http://sphotos.ak.fbcdn.net/hphotos-..._3684366_n.jpg

impressive!

Cobb?!

That DIY wind tunnel is a good idea. I don't think it illustrates the exhaust air coming out of the radiator very well though because yeah a large amount of smoke left through the wheel well. but correct me if I'm wrong but because you were only pushing air into the bumper opening and not across the whole front end and over the hood, wouldn't the Bernoulli effect of the hood vent not work because there is little to no air traveling over the hood to create that vacuum to cause extraction.

Great idea though. I'll have to try that in the future.

I honestly couldn't tell you. My knowledge is very limited in this. The smoke coming out of the wheel well's was to see if the brake ducts moved any air, which I would say does, and does very well.

As for the hood, I couldn't tell you a thing about the Bernoulli effect, but ill do some reading up on it and see what I can find.

Or even from the bed of a truck infront of the car... line up a few of those machines...

Anyway, before getting to absurd here... thanks for the video.

Nice DIY wind tunnel! Did you happen to test how the air separates from the hardtop roof? Are you using a rear window on the hardtop? I've read that others have found that no window provides the cleanest air to the wing.

We did not, the fan couldn't generate enough flow to really see whats going on over the hardtop. I run a factory rear glass on an oem hardtop for a few reasons. Main reason is because I like to wash the car on a regular basis, and having the rear glass and side windows in makes its 10x easier. Second reason is because I can't get myself to remove a perfectly good oem hardtop w/ oem glass. No one locally has a silver top with even remotely the same paint and busted glass and wanting to trade.

looks great!

haha I just thought his fender to front bumper clasp was pretty cool.

Instead of starting a new aero thread - thought I'd tag it with yours -

IF you could replace the front bumper with flare combinations for better track aero, what aftermarket combinations would you go with? I've been thinnking of an altered Bomex front bumper with some Autokonexion N2 flares - with some canards.

I'm dumb when it comes to aero, but would the best bumper drop straight down from the support and not recess back in like our oem bumpers? - as much as I hate to say it, like the wizdom bumper, but with a MUCH smaller opening

Yes a straight down bumper is ideal.

I wouldn't run flares on the track unless you ABSOLUTELY have to - they increase frontal area and thus increase drag.

I know strait down would be more aerodynamic, but with the stock bumper tilting back it would cause more high pressure on top of the splitter, if you have one. Would it not?

It would/will have a splitter - my splitter is currently supported from the bumper support and hangers - nothing to tug/pull down on the bumper cover itself, and that's the way it'd be if I changed bumper covers

No flares? - Well, seeing how I'll have 275/35s on - the tires already do a pretty good job of adding frontal drag - shit, my 225 nto1s + 20mm spacer already stick way out with the oem bumper - was just trying to 'smoothly' deflect the air around better than letting it slam into the front tires - same with the rears too

absoultely want to cover those tires. they're worse than drag, exposed spinning tires supposedly create lift. you would want the flares/bumper assembly to cover the entire front/exposed part of the tire.

These are the flares I was thinking about molding into another bumper - still wish they were smoother in design... kinda like rharris's N2 flares but stick out more at the bottom instead of curving back in. Someone just needs to come up with a functional aero kit not based on just looks.
http://ep.yimg.com/ca/I/gomiata_2139_47383489

+1. 54% of the drag that an Indy car creates is caused by exposed tires.

Every bit of unshrouded tire below the hub line is not only frontal area, but it's also angled to catch air and funnel it under the tire - the high pressure that creates is going to act to lift the tire up off the ground. Worst yet, MOST of the unshrouded tire on a Miata is under the hub line.

The more you can shroud the front tire, the better.

http://farm6.static.flickr.com/5163/...b4d613dc_b.jpg

Here's my attempt. Still not done, but first time mounting it on the car and driving it on the street.

Attachment 191844

Attachment 191845
^ There is a slight gap on pax side only, btwn the lip and splitter. Probably due to the mounting points for the lip, as the driver side does not have a gap. Can fix this by widening the hole to move the mounting point of the lip further back a little bit.

Attachment 191846

The nut/bolt on the sides are 1 of 3 nut/bolts... it has an aluminum L bracket to block the tire, found in OEM vehicles. It is also supported to a 10mm bolt to the frame. It only extends down 1/4", didn't want to overdo it. These affect drag, and lift (front and rear) with different configurations. On a DIY w/o a wind tunnel, I think it is all a guess... Here is the article I referenced for this:
http://autospeed.com.au/cms/article.html?&A=2456

Attachment 191847

So the "tire deflector" serves for that purpose, as well as support for the sides of the splitter, and will be incorporated into the tire spats to be added. I will bolt it onto that point and curve up following the contour of the lip/bumper. Probably will make it out of rubber (truck mudguards).

Attachment 191848

^The view underneath looking straight back. At the very back, it is mounted to the 2x 10mm bolts in front of the subframe, right below the steering rack. I should probably add some spacers btwn the splitter and the sub frame so it does not bow/mushroom the way it does, tho very minimally.

Attachment 191849

^Here is the inside mounting points. Box aluminum frames extend from a 10mm mounting point to the chassis, M8x1.25 hardware holding the splitter to steel 5" L-bracket, with a box alum running horizontally from front-most of L bracket to each side, for some extra support.

Attachment 191850

View of the box alum to L bracket through the duct. Will add brake ducts eventually. Take note the clevis pin/bolts for quick release. :laugh: I need to make the bumper easier to remove first for it to be "quick release" -- it was a PITA to get the car on the ground as it is.

Attachment 191851

^ Also an aluminum L bracket running fore and aft from the rear to the front, it ties into the box alum that ties both steel L brackets and is lengthened further out front to give some extra support.

1/4" Birch Plywood, no fiberglass, yes I am taking a risk taking it out in the rain. I wanted something thicker, but they had either 1/4" or 1/2"... the 1/2" was pretty heavy, so I went with this for now. It's not as thick as others, which is why I added the extra supports that I did. Though as I was fabbing it up, even if I went with a thicker Ply next time around, I probably would still do the same supports.

Chose not to fiberglass for cost, and I may not use it on the streets anyway. Only sticks out maybe 1 to 1.5" from the GV-style lip. After much research and feedback, my main priority is to reduce drag and have a flat bottom. I can also trim it shorter if need be to further tune it. Already looking to what I can do to smoothen the underside of the car, and finish it off with a simple diffuser.

http://farm6.static.flickr.com/5288/...2db54757_z.jpg

It is for this car, and I have since raised it to 4.375" front pinch, 4 11/16" rear pinch (about 11.5" F 12.25" R hub to fender)... may need to raise it more as my old lip hits the bowl of Streets of Willow at 4.125" front pinch height, but I don't like wheel gap.

I've been thinking a lot about deflectors and how much they should go down. I would go with longer than 1/4 of an inch if you have some power to compensate for drag (I don't think there would be too much to worry about if you went with 1/2").

My car was really scary over 120mph with the stock bumper, can't use much brake pressure, can't steer at all on the back-stretch at ECR:
http://sphotos.ak.fbcdn.net/hphotos-..._1480432_n.jpg
With the RB bumper it's much more planted, brakes work, I can steer at 140mph at TWS
http://sphotos.ak.fbcdn.net/hphotos-..._1213292_n.jpg
I never knew those figures, but it makes sense.

Good splitter greentee. Now add some aluminium going from the top of the front fender curving down to the splitter, it should follow the outside edge of the tire if you were to look from the front of the car. Off the car it would look like a triangle that had been curved over a 55gal barrel. I'd also ease up on the thickness of your bottom L brackets, it might be a bit over kill using 3/8 alum.

That vent in the hood makes a huge difference in lift at speed. At 140 mph the stock hood has so much more pressure on the bottom side of it than the top side it will almost bend with the stock latch trying to hold it down. With a properly placed vent the lift forces go away.

I think my Eribuni hood made a bigger difference than the splitter.

Bob

+1 ^^^^ i doubt his bumper made much of a difference at all. any reduction of lift was probably all due to the hood.

Why must you always come down upon me and pick on me!!!

I'm not sure that hood has a big-enough hump to make a difference but you guys know more than I do. I've considered adding an aluminium foil/flap to increase the pressure differential...not because I need it really, but because Matt's oil temps were so much lower than mine with the same heat exchanger. With all that said, the hood and bumper made a huge difference at speed.

I wonder if you could put a gurney flap on it.

not picking on you. just have gone through that stuff before. bumper probably helps a little since some people report the r lip makes a slight difference, and your rb style bumper is probably a little better than that. the hood that we have is another story. robert made that mold from the carbontrix vents that everyone uses and has reported on making a huge difference. it made a big enough difference on my car that i had to trim down my splitter to compensate for the added grip up front. plus you said at tws that your car was scary on the front straight like you need more downforce. it might be time to bite the bullett and buy a secondary trunk with a spoiler or a small wing, and a splitter. even the little aluminum splitter i had on my car made a big difference above 100mph on the track. when you drove tws you already had your bumper and hood so i wouldn't expect you to know which helped the most. that's kinda the problem i had all last year. i did so many mods throughout the year that i was chasing my tail trying to get back the balance that i had at the end of 2009. my car got faster, but not as much as it should have. sorry, i don't hate.. i educate... besides i like you!

I'm jacking with you.
Part of my fear may have been never driving my car that fast with others around it; I was able to steer and brake the car pretty well. However compared to the backstreatch at ECR, the car was definitely more planted with the new body parts.
I already have a painted spare trunk in the garage; I would have bought-up Savington's spoiler if I had the money but last year was a hard year. Hell, I have a $4000 tooth, not including the two crowns from last year.
I'm trying to leave the car the same this season and change nothing, but the reality of TTA hit me yesterday.

Hey Hustler - I'm in the same boat getting into TT this year and with the passing rules - might as well be racing. Still trying to have Greg tell me what I'll be classing - I can check everything off a list, but when it's turboed, it has a different base weight which only he has some magical/wonderful formula to let you know. He says I could very well end up being TTA - which would suck ass at places like RA. Has he (Greg) been responsive to gettign you classed? I know the man is the freakin national director - but dam, my first event is early march, and hasn't been much help getting started/classed. I'm in for 4, but with check ride should get the provisional license and run TT. It's the ** that kills us - 14pts right there.

Unfortunatly, Greg is a very buisy man and we too have our first event in march. Hell I have a hard time getting a answres to my questions when I am talking face to face. All year miatas have taken a hit this year.

BTW Gene there are many people that are dealing with his magical formula to fgure out classing and I feel for all of you. I will be going throough it later this year. I honestly think it needs to be a set formula. Welcome to 4I was forced out of 3 by the instructor and am glad that he did so. I have improved so much as a driver its not funny. This class is considered to be a competetive class. So yes it may feel like racing. I dont know how the people out there are, but I have a great group of people that I get to run with. The passing issue for me is a non issue. We are not door to door racing like Spec Miata.

have a gerat day,
Jared

that's wierd, i had my tt classing within a week or so of emailing him. less than that on our crx turbo. maybe he's extra busy or you didn't give him the info needed. all you need to tell him is what your whp is (dyno based) tell him what kind of dyno was used (dynojet, or mustang etc..) and what your competition weight will be. (weight of car with you in it after exiting the track) so you might wanna add a few hp and a few lbs. to your actual #'s to make sure you don't come in under weight or over whp due to weather, amount of fuel in tank, etc.. how much does your car weigh? my car with 230whp and 2500lbs comp. weight was classed ttb* in 09. i never ran that much power so i lowered it to 204whp (9psi) and lightened my car to 2400lbs comp. weight and was classed ttc** but after points i'm at the top of ttb.

one other thing, once your base classed, you don't take any points for any power mods or weight reduction. it doesn't matter what you do in regards to those things as long as you don't exceed your stated whp, or go below your stated comp. weight. lmk if you have any questions, i've helped 4 of my friends get their tt classing figured out this past year. or you can go to your regions tt section here: www.nasaforums.com
good luck this year

I believe Ken Brewer does classing for my regions. It's easy to see if you will be in A or B just how Spoolin said, divide actual weight by actual peak whp, hopefully you're over 10.25, I'm literally 2hp away from TTA. After that, our tires are skinny enough to give lots of head room for mods.

I used a Cat trucker scale so I'm a little concerned with accuracy. I guess I'll class it and hope for the best at the first event. I suppose that I can enter TTB, then find myself in TTA hopefully without a gay penalty.

Jared - 4 is like PBOC supersolo - absolutely awesome, keps you focused at what you're doing. I might have pissed off one vette in 3 - I didn't give him a PB for like 3 laps, figuring he'd notice the Nasa4 sticker on the bumper - guess he missed/skipped class and didn't know about it - that's his own dam fault. The instructor was all in my favor when I told him about it!

Last fall at 1/2 tank, I was 2420 comp weight on their cert scales at Nasa. Just got the extinguisher and that weights 16pds - I put a comp weight of 2450. If I have to add ballast or back off the boost, no problem. What I did was fill out the older 2010 form, checked all that apply, make notes to vague mods, - scanned and emailed it to him and also my dyno sheet. That was about a week ago and haven't heard anything back - yet. I still had quesitons before filling out the classer, but just went ahead with it anyway. Maybe we should start a TT miata classifer thread to help us out?

Currently, I'm at 92 mod points. What did he say was your turbo base weight. He did say it will not be the 2182 listed in the rules. My my shady math; my P/W ratio ends up at 10.65:1 - can up the ponies to 239 if the min base weight is 2358 - I "think" that's what he said it was/would be but without his "base weight" calculations, I'm lost.

It'd sure be easier to just run power:weight in TTS/TTU That way I can build the car to whatever is fun as a DE car and not feel like I "have" to stay within certain power and point ranges. Prob 1/2 of my track weekends will be TT - other will be just fun DE days. Hell - if I drop in the 1.8 wanting to make 350 at the wheels - I'll be in TTU - competitively speaking, not a chance at tracks with long straights unless I do something about gearing.