Noticed this when browsing through photos recently. Shot with a zoom lens from far off. Endplates making the most of the wing; bowing inwards at the lower tips - higher pressure on outside of endplate, low pressure on the inside under the wing.

https://www.miataturbo.net/attachmen...ine=1431683687

-Ryan

Wow, that's pretty stout

Wow.

So spam.

Such truck.

Wow.

Ryan, I thought the endplates were part of the support? How are they bowing in? Also, I still cant get over how good your front end paint looks.

Why thank you :)

Nope the wing has standard upgrights, the endplates are just endplates, just very effective ones (these were my test units that lead to the development of our high-efficiency endplates).

The endplates are bowing in due to the pressure differential between the outside of the endplate and the inside.

Faster moving air = low pressure and vice versa. The air on the outer side of the endplate is basically at atmospheric pressure, so for the endplates to be bowing inwards indicates that the air inwards of the endplate under the wing is being significantly accelerated and thus at a lower pressure. (i.e. more downforce). With small/basic endplates the wing loses much more effectiveness on the outer sides of the wing as the air mixes much more with the stationary air outwards of the endplate. Well designed/larger endplates isolate the air under the wing much more so the wing can get its groove on.

-Ryan

This leads to a question i have always wondered...

So why does bigger not always mean better.....?

Because drag becomes a limiting factor. Needs more power to overcome greater drag or the car will be slower on the long straights. If it is a slow, curvy course the bigger wing is a plus, but if it is a course like many of the F1 tracks that are just long straights punctuated by slow, tight corners and then another long straight, too much wing could yield a slower time. It's always a balancing act.

Any obstacle in the airstream creates drag, and that increases with size. So with endplates, the largest/most basic priority is just to know where material is important for the performance of the wing and where to remove material so that you're getting the most performance you can for the cost in drag. Just going large without that knowledge usually results in excess surface area where it is not best utilized.

However, as a broad statement, the cost in drag from endplates is lower than the cost in drag from aggressive AOA, so 10 out of 10 times I would choose larger endplates and less AOA rather than small endplates and more AOA.

The significance of endplates is why endplate surface area is limited by the rules in almost all professional racing.

-Ryan

Yep sorry was talking about endplates only....does the side surface area have much drag or is it mostly the edge facing the air flow that is the factor....

I could only ever come up with cross wind instability or an increased resistance to turn as being the biggest possible reason but rules is something didn't think about....

For most of us running in track days and non sanctioned (in an aero manner anyway) events, larger end plates would likely be beneficial?

The total surface area is a factor due to surface friction drag.

Yep.

And while I would even say that as a blanket statement for very basic oversized endplates, cleverly designed endplates can further reduce drag by manipulating the vortex that is shed at the ends of the wing (this is a large portion of the drag created by the wing). This can more than offset the additional drag from the increased surface area of the endplate itself.

-Ryan

This technology is above my pay grade.

https://www.miataturbo.net/attachmen...ine=1431820936

Read the plaque:

http://www.airlinereporter.com/wp-co...ax-winglet.jpg

https://www.miataturbo.net/attachmen...ine=1431820936

That plane stuff is interesting, i was trying to compare the loss in the middle with the gain outside thinking the winglet area might be less but it would have less drag and (i think) higher leverage of lift.....maybe. Drag probably the biggest thing as it relates to fuel cost.

Anyway, the new slats in F1 versus the old slots caught my eye the other day and the pass's info made me remember to look it up....its probably not especially relelvant to us (too subtle for our heavy cars and we don't have a huge rear tyre messing with our wing aero zone) but interesting none the less.

The top forward part (slots) of the end plate might have some relevance....

Analysis: Rear Wing Endplates | theWPTformula

I've actually played with applying most of the endplate features covered in that article to production car applications. Some only apply to an open wheel car or need fine tuning in CFD.. But interestingly, not all of them are wasted on the cars owned by us mere mortals.

We applied some of those elements with success to a set of custom endplates for a special project on a C6R wing recently.

Speaking of F1, I had the wing from the 2010 Williams car - specifically Hulkenberg's - in front of me this morning. Very cool:

https://www.miataturbo.net/attachmen...ine=1431828043

neet!

Hey Guys, trying to design a splitter for my GV lip on the NB. I'm going toward a form follows function approach but I still want the splitter to be athletically pleasing toward the lines of the car. Any suggestions on the options I came up with?

https://www.miataturbo.net/attachmen...ine=1433862038

<p>Option 2.</p>

2.

I can help with grammar but as all those options look okay to me, i'll let people better than me work on the aero!


"Aesthetically" ...... ;)

Mo' surface area, mo' betta.

-Ryan

Apologies, double post.

The aircraft winglet case is a little bit different than what we are playing with for our wings.

The goal with winglets is to get better fuel burn through increasing the effective aspect ratio of the wing (wingspan / wing chord) without physically increasing it to stay within gating sizes. Additionally they are operating in a region where the business cased doesn't benefit quickly from increasing flight speeds due to the supercritical airfoils performance degrading quickly, but rather minimizing the drag at a specific cruise condition that the majority of time is spent at.

If you imagine a wing section in a wind tunnel that spans from wall to wall the effective aspect ratio is infinite, and the sectional properties match that of the 2d analysis case of the airfoil. As you move away from that case the span efficiency term drops due to the mixing of the low and high pressure zones.

We're trying to get the greatest amount of downforce with a minimal drag penalty from our wings, where the optimal configuration will be track dependent. As has likely been mentioned before the end plate shape is usually driven by the thicker boundary layer on the upper side of the airfoil (closer to the ground in our case) cause by the low pressure region driving a taller endplate on the low pressure side relative to the high pressure side (3:1 ratio). The distance that the endplate projects forward into flow being a smaller fraction (less than .1) of the chord, with the optimal varying based on the loading & Re of the section, and aft driven to around .15 of the chord.

For our design points the induced drag (drag due to downforce) is substantially larger than the parasitic drag (skin friction drag) from the wetted surface area of the wing and endplates, with this trade growing quickly at increasing velocities.

Bit of a rant but I hope the info helps somebody make a logical choice with their DIY aero work!

I have made 3 splitters to date. The mounts I use are here KazeSpec Engineering splitter hardware kits - MiataRoadster - High-performance customer service...and parts for Roadsters

Version 1 - 9.7 kg (ABS Plastic)

Version 2 - 7.2 kg was made from ply 10mm with 2 layers of fibreglass on the bottom and 1 on the top. It has lasted quite well to be honest.

Version 3 - 5 kg is made from 17mm Monopan Sandwich Panel ? MonoPan » Lavender CE Pty Ltd. This stuff is strong and light! However the edge does not take drilling too well. I'm getting some 1.6mm x 17mm U channel aluminium to put around the leading edge to protect it. Enough Monopan to make 2 splitters cost about $250. It is easy to cut but a bit painful to shape and trim. In the end I got an air angle grinder out and this worked well. Note this is also a bit bigger than the other 2 but weights LESS.

Version 3...

Monopan under the front after V2 splitter removed
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2609 by Eipeip, on Flickr

Version 2 - after about 18 months of use.
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2607 by Eipeip, on Flickr

Starting to mark out (the red dot in the middle is in the flash shadow)
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2613 by Eipeip, on Flickr

https://www.miataturbo.net/attachmen...ine=1436690571DSCN2612 by Eipeip, on Flickr

https://www.miataturbo.net/attachmen...ine=1436690571DSCN2615 by Eipeip, on Flickr

Cutting Plan. Made some changes to this version, an arch for the wheel turn radius.
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2606 by Eipeip, on Flickr

https://www.miataturbo.net/attachmen...ine=1436690571DSCN2608 by Eipeip, on Flickr

Cut out (used an air panel saw, like a knife through butter)
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2616 by Eipeip, on Flickr

https://www.miataturbo.net/attachmen...ine=1436690571DSCN2617 by Eipeip, on Flickr

https://www.miataturbo.net/attachmen...ine=1436690571DSCN2610 by Eipeip, on Flickr

https://www.miataturbo.net/attachmen...ine=1436690571DSCN2611 by Eipeip, on Flickr

https://www.miataturbo.net/attachmen...ine=1436690571DSCN2619 by Eipeip, on Flickr

Close up of edge after a bit of a clean up. Started with a die grinder, not very effective. Then a 3" grinder that worked a treat. I used more clark rubber foam to fill up the air gap. A more permanent solution is needed, a work in progress. The gap is caused by the GV Lip not being perfectly flat/level.
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2626 by Eipeip, on Flickr

A great tool to clean up the edges after the grinder.
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2625 by Eipeip, on Flickr

This is what the edge looks like close up with a bit of flat black paint.
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2624 by Eipeip, on Flickr

This is where it stayed for a few weeks, until I could do the edge protection. I attached some rubber seal from Clark Rubber to protect it a bit. Monopan does not hold very well to screws put into the honeycomb middle structure. Fastners need to go perpendicular to the surface not horizontal.

https://www.miataturbo.net/attachmen...ine=1436690571DSCN2665 by Eipeip, on Flickr

How to bend the aluminium U channel that I planned on using. After loots of attempts I got a sheet of 18mm marine ply and cut out 1/2 of the splitter. I also attached a few hold down points to help it keep its shape.
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2667 by Eipeip, on Flickr

After heating the aluminium and 'tapping, it against the mould, a test piece.
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2669 by Eipeip, on Flickr

https://www.miataturbo.net/attachmen...ine=1436690571DSCN2666 by Eipeip, on Flickr

Final version. It is held on with Sikaflex and riveted from the underside. I would have preferred to use peel rivets however they are not available over the counter in my area.
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2675 by Eipeip, on Flickr

A closeup of the edge inside the wheel well. A nice neat fit.
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2676 by Eipeip, on Flickr

Finished
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2680 by Eipeip, on Flickr

https://www.miataturbo.net/attachmen...ine=1436690571DSCN2679 by Eipeip, on Flickr

A few creases, I'll get better at shaping the aluminium, or sand it flat next time.
https://www.miataturbo.net/attachmen...ine=1436690571DSCN2681 by Eipeip, on Flickr

Is that a standard GV lip with optional side panels?


I don't think I've seen those in the States...

got this NASA splitter installed over the weekend. i remember someone telling me they won't fit.

https://www.miataturbo.net/attachmen...ine=1436809699

https://www.miataturbo.net/attachmen...ine=1436809699

I got the diagram from a buddy that works in the nationwide series. used 1"x1" .083 wall square stock. thing came out beef i would say it's close to 20 lbs. but i could use it as a bumper.

Johnny - looks like you're actually using at least a portion of the original NASCAR splitter frame?

Looks good. Obviously need to cut off the rear portion that extends into the wheel well, but don't trim any of the width down to make it narrower.

-Ryan

Yes it is. By the way the car is in Australia and I have not seen the side panels here yet either. Car also has the GV bonnet.

I just started to coppy the original nascar diagram. i'll post more pictures when i can get the car on the ground. Also i found out this is a cup car splitter, the nation wide splitters are larger. next time i order one i'll get the nation wide option. i trimmed the wheel wells with a sawzaw.

I have used a similar material for another project. I drilled small holes around the mount area, injected them with epeoxy, and then drilled the final size hole after it dried. Held fasteners much better. Cost some weight though....

Then I realized that I could drill the hole I wanted, then put a small Allen wrench in a drill and used it to sweep out the honeycomb around the hole. Then I filled that area with epoxy and micro balloon. Made a super strong hole/mount area. Then I used carbon tube on the leading edges to close that. Again removing the honeycomb in the way, and epoxy the tube in place.

Ryansmoneypit, thanks for the advice. I have another splitter to make so I will use your advice.

Random pic that popped up on my facebook. This was done by a cone. Aluminum splitter FTL. Birch splitter would have beheaded the cone, with nothing more than a smudge mark to show for it. I know, I've mowed down my fair share ;)


https://www.miataturbo.net/attachmen...ine=1438485341

I really like all of these splitter/undertray projects. I'm already taking advice from this thread to make a splitter for my miata, but I was wondering if my daily driven RSX would benefit from it considering gas mileage predominantly (mostly interstate) and maybe a little handling? For the return on investment, would it be an all or nothing kind of thing? For instance would you need to make a splitter, full flat undertray, and diffuser to make it worth it or would a splitter that extends to about the front axle be worth the time and money?

Post your DIY aero pics
 

In true MT fashion, you would need to run ALLOFIT.

says the guy currently running NONEOFIT :giggle:

a quick update i ran road Atlanta. it was 15* hotter then when i ran before and almost matched my best time. 1.39.5 vs 1:39.2. i think the splitter is too high off the ground. i'm going to lower it one inch.
i didn't notice much difference in the butt dyno, according to my Aim Solo i still pulled a peak of 1.2G.

What i did notice was in the braking zone, holy molly i could get way more into the pedal. I was straining at the harness. that's what leads me to think it needs to get lower. i noticed it when it got close to the ground.

The BRZ guys are seeing 2-4mpg increases in highway driving with just diffusers.

This sounds like....a 10-15% increase in fuel economy, fromantic a single part. Wouldn't every manufacturer put them on cars, with an increainincrease in mileage like that? I'm not sold on those numbers.

The only numbers on a brz that matter are the ones where the tq drops off like 20lb/ft.

Then don't be? I won't be able to report back until I get mine and see how it works. Keep in mind this is with a diffuser behind the diff and also panel/(s) that cover up all space between the control arms, in front of the diff up to the rear of the floor pan.

The BRZ has a relatively flat floor pan to begin with so.....no idea?

I could believe 2-4mpgs. From what I can gather, the biggest percentage of drag, after frontal area, is the suction produced by the car ending abruptly and disturbing laminar flow. Thats is why these exist:


https://www.miataturbo.net/attachmen...ine=1438904060

That's 2-4 mpg on a flying brick, with straight sides and a square end. Not an already aerodynamic car.

Yeah and finding 2-4 MPG on something that gets 8MPG is enormously harder than finding it on something that gets 28MPG.

My understanding is that you can get TOO low. When it touches, it loses d/f, the front pops up and regains d/f, nose drops and it touches again, loses d/f ... rinse and repeat. Known as porpoising I believe. We had a 4 litre 911 doing it in the braking area at the last sprint meeting, clearly audible from the viewing platform.

The splitter needs airflow to work, so when it is cut off it no longer works. It would be dependent on how much of the splitter is touching too I guess, if you have a relatively pointy splitter shape only the extreme tip may be touching and that may not be such a problem, whereas a straighter splitter may be touching along a greater length.

From your description, it sounds like the height under brakes is already very effective. Maybe dropping it a bit more will improve both braking and cornering. I have been thinking about ways to limit the dive under brakes so that the splitter height change can be managed - heave spring anyone? Or maybe a skid which would 'protect' the splitter, and keep it a few mils off the track ... hmmm

I look forward to hearing how you go.

https://scontent-cdg2-1.xx.fbcdn.net...ce&oe=563BD44A

the effect was so strong on my car is actually damaged the wing by trying to pull the aluminium end section out of the wing, had to run a carbon rod from the bottom of the endplate to the wing upright in the end, you can see it best on the right hand side

IME, nothing survives cones forever. We use alumalite for our dedicated autocross car, and it has been surprisingly durable.

A REALLY big hit at high speed will put a small dent in the leading edge, but won't destroy it like the aluminum sheet in your pic. We run it pretty low, so it slowly starts grinding off the lower sheet of aluminum.

We're still perfecting the design/height/etc. The biggest area that needs improvement is in the mounting brackets. But our first alumalite blade lasted one full season of heavy autocrossing with three/four drivers per event.

A Subaru I drove for a while had a custom splitter that was two layers of carbon on either side of an aluminum honeycomb core. For durability it had a wood leading edge and a layer of kevlar on the bottom. It was really awesome, and super light. But for the cost/trouble to fabricate (expensive materials and very labor-intensive to build), it was probably not worth it over alumalite.

Neal

Uhhhhhhhhh can i get some details on your car? :drool:

yeh sure,

I spend alot of time reading miataturbo as its great for technical info whether it be aero, chassis or engine/tuning development(i do all my own mapping so looking at the megasquirt ignition tables really helped)

My car started off as a series 1 lotus elise(wasnt avaliable in the US) I then added a special lightweight exige body(my own mix of composites)

It weighs 715kg(1573lbs) runs 16x8(225) and 17x9(255)

Aero wise its a complete flat floor from front to rear, underbody and diffuser is aluminum, side skirts are 3mm dibond(aluminum/plastic) with 5mm rubber skirts, splitter is 1mm carbon each side with a 10mm nomex honeycomb core(hardest bit is getting it stiff enough to take the downforce when being attached to a composite crash structure.

the front wheel arches are vented from the top to release pressure and all of the sill behind the front tyre is removed to again reduce pressure

the splitter also has diffusers and end fences, the diffusers are set at 10 degrees relative to the ground when the car runs a rake of 1.5 degrees.

The diffuser is raked at 12 degrees to the ground at again 1.5 degrees of rake.

the wing is a simon mcbeath 183 dual element wing attached to home made pure carbon fibre uprights

the front splitter leading edge is 70mm from the ground and will start to skim the ground at 130mph, i havent had to hit the brakes hard at that speed yet as most UK tracks dont have long enough straights, i will probbaly have to up the spring rates to avoid the splitter grounding hard when braking.

I run 700lb front springs and 900lb rears

One of the reasons I like this forum is the engine info everyone is very open to give, I run the OEM Rover 1.8 twin cam engine which is a very lightweight engine(the block weigns 8.5kg) it is known over here for blowing head gaskets and cracking the very thin liners(its basically a 1.1 engine designed to be 75bhp but massively stroked and bored) so I thought it would make the perfect engine to throw a big turbo onto it and a load of boost.

At 22psi peak and 20psi hold its around 320bhp and 300ftlbs, im still running OEM engine components, the muffler bolts directly onto the turbine housing and sticks out of the lefthand side quarter panel

Here are a few pics, sorry for hijacking your thread but I do enjoy aero and make all the components for mine myself with whatever I can find lying about.

I would like to maybe chat to The Pass on facebook one day about his aero but hes never popped on my suggested friends list yet.

https://scontent-lhr3-1.xx.fbcdn.net...e1&oe=5651581D
https://scontent-lhr3-1.xx.fbcdn.net...23&oe=5638B81E

you can see the cut away sill and door to expose more of the front tyre
https://scontent-lhr3-1.xx.fbcdn.net...02&oe=56823174

rear mounted intercooler ive just installed
https://scontent-lhr3-1.xx.fbcdn.net...5f&oe=5651F88C

https://scontent-lhr3-1.xx.fbcdn.net...53&oe=563DB466

The car infront on the picture earlier is a lancer evolution which had its body cut off and a 205 T16 Group B body but on, its 400bhp 4x4 and weighs 1000kg.

Holy crap, that's cool !

Menacing, that's the word for that thing.

:drool:

That lotus is so rad!!

Definitely not a problem.

Why haven't you put end plates on the canards? Seems like an all-out car like this would have them, especially on canards with that much surface area.

Lee I have been following your lotus for some time, aren't you running a Simon Macbeth Aero?

Another splitter
 

Just made a new splitter/air dam.

As you can see from the pictures there is a reason I made a new one, I decided to run out of talent on a lap and tested the snow plow potential.

Original splitter/air dam was constructed from 3mm aluminum, and held by 3mm ally brackets to the rails, and some of those thingies you can see at the front. It was also had a set of the large garage vary canards, and custom end plates either side.

Splitter 1

Dollars spent: $200
Hours spent: 5
How effective: 3
0=slower, 1, no improvement, 2 =slightly better,3= big improvement
Materials used: aluminum
Size/thickness of materials: 3mm
Bracket location: rails, screw holes for undertray and front stays
Tracks tested on:Lakeside QLD and QLD Raceway
Race/TT class built for: TT/TA

Splitter 2

Dollars spent: $200/$300
Hours spent: 20
How effective: to be tested tomorrow
0=slower, 1, no improvement, 2 =slightly better,3= big improvement
Materials used: Coreflut centre, 3 x Layers Fibreglass, 2 x Layers Carbon CF in places, 4mm Aluminum bracks, That plastic roll stuff 3mm
Bracket location: Rails and front stays just behind dam
Tracks tested on: tba
Race/TT class built for: Fun

Brake ducts are SINGULAR with a custom set of 3D printed bellmouths from a friend at Dreamfarm.

Endplates to be finished and added. Diffuser parts to be made on another splitter and swapped out (with more CF).

Its on the list of things to do, just havent got around to it yet, since the canards are curved I will probably just mould a vertical section each side in carbon.

Interesting that alot of race cars dont have the vertical section and allow spill off to travel around the outside flanks of the car to energize and keep the air attached rather than forcing the turbulent air over the car into the clean air heading to the wing with reduces air wing efficiency and downforce

rear wing is a simon mcbeath 183 dual element wing with my own endplates.

that video is of me but wasnt made in the way I wanted and was more about youtube controversy than actually giving the information i wanted to get across.

the wing in that video was moulded off a 2004 honda BAR monza spec f1 wing then extended out to 1750mm, its still in my shed as im not sure what to do with it.

Where did you source the turnbuckles from?

From Bunnings, which is a hardware warehouse. Also boating places seemed to have the same.

Looks good Tim, hopefully see you on the track soon.

Passey - how would you go about getting front downforce on the Eliminator? I'll be starting one soon and was thinking about adding a wing to the front - Indy style.


https://www.miataturbo.net/attachmen...ine=1439812553

https://www.miataturbo.net/attachmen...ine=1439820167

This is how, obviously.

Funny, I just came across an ad for these last night surfing craigslist..

That thing is so aerodynamically challenged you're better off focusing on mechanical grip. :giggle:
A front wing could be effective, but this is a street car - you really don't want to be driving around with a wing acting as your curb feeler. And you'll never match it with rear downforce - there's pretty much no way to put an effective rear wing on that thing unless you mount it two feet above the cage tubes.

-Ryan

Loving this car.