Binky the Civic Build Thread
 

Hey all, if this is a thread that doesn’t need to be started feel free to remove.

I’ve recently got a 250,000+km 1997 Civic Si in decent shape which I’m currently working on. Having been a cyclist commuter for more than 3 years, I’m always thinking about aerodynamics (in fact, as I work on this car, my velomobile project is sitting on the back burner). I got my license this September (still only 19) and I’m already disappointed with the design and economy of the cars I’ve tried. I want something sleeker, and more efficient.

I’m here to ask for opinions/ideas about aero mods that won’t compromise my ability to get through the harsh conditions here. Namely, snow. About a foot of it here currently, and I swear it’s just getting taller and taller. The ground clearance of Civic makes it hard enough already to get through, so I can’t imagine how things like an air dam or front scoop would react. Maybe it’ll work? Let me know any experiences/advice/opinions on this.

A grill block might be a good thing -- keep the snow out of your radiator. As long as there's something behind it (the grill) there, little reason it would buckle under pressure.

Most people seem to use lawn edger for their air dam/skirt...it would just give way if it scraped on anything, like hard/deep snow, and then return to it's normal shape after. I suppose the cold might make it brittle enough to potentially break, but better that than tearing your front bumper off.

As to anything else...if you design/build it to take a beating. it will. If you make it out of papier-mâché, it's going to crumble at the first sneeze.

If you can get one, and the shape works, you can try bolting a trimmed-down bumper - from the same make and model - upside-down to your current bumper, to make a chin spoiler. It'll be just as tough, since it's the same material. All depends on the shape/design of the one on there.

Have fun!

Thanks for the tips. A grille block is something I’ll definitely be doing. I’d like to use Coroplast to make a nice scoop of my own design, but the bumper idea is clever. The Aerocivic’s nose/dam/thing shape (a scoop) seems like it would easily dig down into a snow pile, so I’m considering a front nose with a bit more upward sweep, like that of a Mustang I prototype or a classic Daytona. Would this shape be less efficient?

Durability is a priority, and I’ll for sure be covering the engine right up. They salt the roads here recklessly and I want that out. Moon discs, wheel skirts, and an underbody panel are on my to-do list.

Welcome. So say we all.

What you have here is a use case. The Ecomodder folk wisdom here doesn't necessarily apply to your situation. I would look to, say, the Gambler 500.

ecomodder.com/forum/showthread.php/eco-off-road-budget-destroying-prius-you-decide-38366

From Permalink #2 there:

jalopnik.com/this-lifted-prius-trolls-jeeps

There's no problem with a lot of air under the car +belly pan -airdam. The ideal is a central air jet with spats shrouding the wheels*. Conveyor belting is your best bet, but keep the fabrication simple, just drilling a hole in it is hard.

https://ecomodder.com/forum/member-f...42-mudflap.jpg

This suggestion has two pieces — a U-shaped metal bracket and a piece of belting with two angled cuts. Leave the short end open so the belting can deform with impacts.


*See Aerocivic

edit:
The point (no pun!) is the stagnation point. It determines how much air goes over or under the vehicle. Or in the case of the Cybertruck, down the sides.

Here's an example of a metal clip that would grip conveyor belt by the edge:

http://wpc.ac62.edgecastcdn.net/00AC..._PROD01_lg.jpg
http://wpc.ac62.edgecastcdn.net/00AC..._PROD01_lg.jpg

2-door or 4-door?

Post some photos including a side profile and something explaining the front grille.

There is a sticky on grille-blocks, I forget if it's the top or bottom one you should try first.

Driving style has a lot to with mpg.

Front chin spoilers only really improve aerodynamics if they hang no lower than the dangley parts under the car.

I suspect your Honda is not serious offender in that area, but a few belly shots should confirm.

NOTE:
Conveyor belt material is much better than lawn edging, but more expensive too.

In short, most aero in this forum deals with drag, drag forms on the aft part of the car after the highest part of the roof.

Suggestions will follow photos.

Definitely a grille block.

2 in 1 in terms of benefits as it allows for faster warm-up times and provides an aerodynamic advantage.

Just make sure to consider all the variables when determining the grille block area. Such considerations can be : ambient temperature, cooling requirements (engine, transmission, etc). Choose a durable material as it will get beaten up, especially in the Winter.

kachi22, I don't mean to single you out here, but at the same time this needs to be addressed: This is way too simplistic, but it's one of those "rules of thumb" that get thrown around here constantly. Drag is one of the three components of the aerodynamic force resultant that forms from pressures acting on the entire surface of a car.

As I posted about in another thread recently, a well-shaped car can have a lot of forward-facing surface area subject to negative pressure differential from atmospheric--the implications of which (that this reduces overall drag because of the contribution of thrust) appeared to go over the heads of nearly everyone who subsequently commented in the thread.

Incidentally, Julian Edgar later told me that Rob Palin, former Tesla aerodynamicist, said that lowering pressures on forward-facing surfaces by careful shaping was a key strategy for reducing drag in the development of the Model S. This runs counter to the prevailing wisdom here that beyond a certain amount of rounding--just enough to support attached flow--shaping of the front of a car has little to no effect on drag and everything important happens at the back because the prevailing wisdom is overly simplistic to the point that it is not true.

The conversation is already in the weeds.

OP is only nineteen and this is their first post. (Hi again. Did you lurk much?)

I can't find a picture, and it's torn out of my example; but the Audi 80/Passat/Dasher has an offset radiator and should have a sliding fiberboard panel in the radiator ducting that was apparently controlled by a wire cable. A variable grille block if you will.

As important as some blockage is a proper bell-mouth intake and well-thought out venting (back corners of the hood vs wheelwells).

So rather that try to give him (and others) correct information, it's better than we continue to spread misinformation? And trying to correct that misinformation is a conversation that's "in the weeds"?

How pathetic.

No wonder I've stopped 99 per cent of my postings - what's the point?

Hi there, JulianEdgar.

While we wait to see if the OP has been scared off, my point was that the information, correct or not, is overly [non-]specific.

kach22i probed for a use case. Another user [couch]Tyrant at large[cough], took up your torch. I think it was a strawman argument.

Irrespective of the merits of any particular suggestion, it needs to be pertinent to a specific case. Surely you appreciate case-by-case A-B-A testing.

I am not interested in (re)joining your semantic games.

Some people want the correct information to be disseminated, others just want to play sophisms.

I don't know if this is an option for you right now, but what I currently do is I drive my car (the mercury) when the roads are clear and there is no forecasted snow/ice. If there is I drive my van. If having 2 vehicles is an option, now or eventually, you won't have to worry about snow and aero mods.

I can get a decent amount of snow where I am, but not as much as you describe. I won't be able to be much more help.

Good luck with it.:thumbup:

I think it wise to Keep It Simple Stupid (KISS-Method) for this young man.

Suggestions (good ones) have been made.

If anyone here is proposing some advanced fix for a problem that probably doesn't exist such as forward body positive pressure design flaws in the Honda Civic SI, then please post what you have. Your solution? Net gain?

Aft body and trailing edge extensions seemed to have worked before, but not sure if this body style will be very welcoming to it.

For instance, a rear deck-lid Bonneville style horizontal extension is probably just going to be a big snow shelf possibly.

https://ecomodder.com/forum/showthre...any-10434.html
http://www.seriouswheels.com/pics-20...e-1280x960.jpg

https://ecomodder.com/forum/showthre...lty-10468.html
https://farm3.static.flickr.com/2284...8c695430_o.jpg

https://www.dragzine.com/project-car...iting-bullitt/
https://www.dragzine.com/image/2014/07/MG4_8045.jpg

A little more info, some argue that it's about refilling the Aerotemplate- Part-C (or against).

https://ecomodder.com/forum/showthre...nit-33989.html

Do the grille block but keep an eye on your temperatures, warping your heads by overheating will total this car. I personally do not like grill blocks, because it is cooling system dependent and most of my cars/trucks have not been friendly to this (antiquated cooling systems).

The wheel spats are cool, but getting into where the snow is, maybe not right for this project.

Buy a big push broom and do the rear deck-lid extension, and report back. Just don't cover up your rear bake lights.

I was doing my best to keep it as simple as possible and acknowledge that front end, middle body and aft section are all part of a complete composite picture.

What changes (eco-mods) do you propose to "positive pressure" the front of a 1997 Honda Civic SI?

Lol, sorry for not replying quick, I’m either at work or in the shop. I made a response post but it must not have uploaded. I’ll go and do it again, I guess.

I’m young, but I’m not a stranger to aerodynamics. I’m good friends with an engineer who flies planes and is currently working on both a diesel aircraft engine and a world record attempt HPA streamliner. He’s passed much of his knowledge to me as I design a velomobile. A car is definitely a different animal, but the basic principles are still at play. I know from my time as a cyclist just how much faster you can get by tucking in, to reduce frontal area. The magpies outside my window sure aren’t shaped like cones, that’s all I gotta say.

On my list currently: Grille Block (adjustability is a good idea), underbody panel, wheel discs, wheel skirts, a wiper deflector, and some gap filling work here and there. I may leave the bigger modifications for when the cycling season comes around, as the car won’t need to be driven.

I sometimes have the option of other vehicles, maybe I’ll consider that. My mom’s Ford Flex is around, but the brakes are problematic, apparently.

I think wheel covering will actually be beneficial in snow. From my experiences growing up in snow, I’ve gained a pretty solid understanding of how it likes to stop a car. Discs would keep it from getting inside the rim, which normally make the wheels wobble like hell. Skirts would help keep it out of the wheel wells, and with disc covers I doubt any snow could build up enough to push the skirts off. If it helps to streamline air, it should help with streamlining powdery snow. Unless I hit packed and frozen snow, but thankfully things get plowed before the roads become a foot taller, lmao.

That shelf is interesting, and could be a perfect option for my trunk. The rear windshield angle and it’s transition to the trunk is a problem area, and the Canadian regulations are restrictive of heavy modification, so working around a boat tail that doesn’t compromise the trunk’s lighting and functions is kind of an ordeal. On the other hand, I tend to be really obsessive with cosmetic appearance and just can’t figure out a slick design for the rear.
Bonneville cars are something I’ll be studying, thanks for the links and photos.

My friend was joking with me that with a paneled underbody and a slightly upswept curve below the stagnation point of the nose, my car could go sledding. Not serious, but I do wonder if a nose can be shaped to maintain good airflow while keeping snow from being scooped up. A nose like the Aerocivic’s would be like using an upside-down chisel. On that note, I’m weary of trying those wheel deflectors you pictures. I know mudflaps pack up with snow immediately and it loves to turn to ice. To the detriment of possible aero gains, I’m planning to keep all mods above the current ground clearance, except the underbody. For snow, but also for the terrible roads here, and curbs, etc. When I drive more in it and really see if the underbody gets scraped, I’ll consider mods below it.

Thank you all, lots of replies, and probably the fastest forum I’ve seen. I’m a busy guy and I’m very scatterbrained as well so expect me to answer sporadically.

The car is a ‘97 2 door Civic, standard transmission with a 4 cylinder engine.

I’ll try to figure out how to post pictures on here and get some up.

https://ecomodder.com/forum/attachme...1&d=1605106011
https://ecomodder.com/forum/attachme...1&d=1605106011

I don’t have a computer and struggle with tech stuff in general so expect these to come out sideways or upside-down, haha. The body isn’t much different from stock. Sorry for my forge and other junk being in the way, sure ain’t feeling like moving it.

Actually, the rear wing recommendation led me to Progress Auto’s 205MPH Civic.
It’s pretty much my car, with a lot of aero work and engine tuning, etc. Wonder if it could be a good reference.

http://www.pure-tuning.com/pages/news/landspeed.html

Besides the lower skirting, all the rest is quite doable and useable, though I sill think a nosecone is cooler and could possibly be better in the snow. I mainly just love concept cars from the Rocket Age, and would love to have a front like the Mustang I. A rear wing seems like a very solid idea.

I'm in Michigan, and we get a lot of slush with our rapid Freeze/Thaw cycles.

I've never lived with wheel covers, but have to periodically remove chucks of ice built-up in he wheel wells similar to the below photo.

https://nbcmontana.com/news/local/ga...202329#photo-1
https://nbcmontana.com/resources/med...?1514398277841

By all means research wheel covers and wheel opening covers.

I'd like to know if your initial intuition is accurate as it runs counter to mine.

Thank you for posting images of your car.

There are different solutions for hatchbacks and sedan/coupes in my opinion.

An aft greenhouse addition is out of the question because of Canadian law?

Good thing you know that ahead of time.

Linky no worky.

Actually, you’re right about that. I’ll rethink the covers. We get that same exact problem. Discs will still be beneficial, but it will indeed be annoying to clean up, no doubt.

The police here abuse their power and ticket you for made-up laws, and then stick you in legal limbo if you try to stick up for yourself. I gotta pick up a subpoena today for a trial I was the victim in a whole year ago now. The justice system is a failure here, but I digress. So far as I can tell, there are no real regulations on modifications to the body paneling, only on safety-related equipment. Were I to make a boat-tail, I’d need to make it from Lexan to keep the lights shining through it and in view at all angles. Same goes for the nose, but that one is a bit easier to work with. The trunk shape is kind of hard. But if by aft greenhouse you mean a rear wing like the pictures you’ve sent, that should be fine legally as it doesn’t obstruct any real functions of the car. I’ll probably go down that route.

PURE Tuning Racing Progress Auto 205 mph Land Speed Civic

Try that. Really like that car’s shape, looks straightforward to do. I’m not sure about the front, though.

runs counter
 

* The Model S isn't necessarily the poster child for low drag. The are a dozen ICE automobiles on the road today with as low a Cd if 'electrified.' Some lower.
* As to the forebody, and it's effect on aft-body, you may recall Hucho discussing aerodynamic 'saturation,' a situation in which, at some degree of radius, any further 'softening' results in zero gain as to drag. This was 1976. SAE Paper No. 760185, Hucho et al..
* Drag reduction is the most important aspect of road vehicle aerodynamics, which makes the aft-body the most important area of the vehicle.
* And it may seem 'simplistic', because it is 'simple,' unless you introduce 'complex' body shapes, as Bearman discusses in his July 23, 1979 paper. Or Glenn D. Thompson, Standards Development and Support Branch, U.S. E.P.A., Figure 5, Page 11, ' Prediction of Dynamometer Power Absorption to Simulate Light Duty Vehicle Road Load,' shares in his 'template' advocacy.
* One can make aerodynamics as complicated as they like, however, since 1922, there's been no need. It's a 'Paris Dressmaker' issue.

To add, I imagine it was a key strategy because of safety standards limiting a lot of rearward streamlining. Just a hunch, seems like cars are required to have a tall and flat rear end for “visibility”. If you’re limited like that, the importance of the front section becomes more important. Similar to cycling, the focus shifts to frontal area because the rear can’t really be improved under UCI rules. I could be wrong, though.

rear wing
 

If you want to open a hornet's nest, get a copy of the book, ' Modifying the AERODYNAMICS of Your Road Car, by Julian Edgar, and look at Chapter 7, page 186.
*the text discusses SAE Paper 2011-01-0175, having to do with the 2010 Audi A7 Sportback ( fastback ).
* this car has rear body flow separation, including the entire backlight, which increases both drag and rear lift.
* Audi's solution is to add a deployable rear pocket spoiler, which reaches 72.5 mm upwards to the 'template' contour to cancel the separation-induced lift, then reaches a bit further ( 30 cm ) to add 'direct downforce.'
* the 2018 Audi A7 spoiler only goes as high as the 'template.' And it's Cd 0.26, vs Cd 0.28 for the 2010 model.
------------------------------------------------------------------------------------
When weather permits, you might construct a cardboard and duct tape rear wing for testing, and see if the performance gain ( if there is any ) justifies the trouble to fabricate a durable version.
The Tesla X, dual-position, active rear spoiler was quietly discontinued when it was found that snow and ice would build up below the 'wing', then cause problems when it attempted to lower, and stow itself back inside the hatch.:(

visibility
 

Rear visibility has certainly been an issue over the decades.
When General Motors did their Aero X concept car, the key personnel involved, mentioned GM's stringent rear vision standards which limited how streamlined the backlight area could be.
Soon, the Department of Transportation in the USA may allow 'camera' vehicles, with only synthetic, high-resolution, side and rear vision technology, like Volkswagen's XL1.

If I can find a source, will do, thank you for the info. A deployable wing...why? For parking space? I don’t see much an issue with a static wing, but around here I’d agree on the ice. I’ll be purchasing lots of coroplast for the underbody, so I’ll snag some cardboard for tests like you say.

I think I’ve building up would be fine on a fixed wing. I can take my car into my heated shop and let it melt down every now and then, so I’m not that worried about ice. I think it should work okay.

What Id like to know currently is opinions on a boat tail design. With clear Lexan, I think I can keep the visibility, but the junction between the top of the trunk and rear windshield makes me feel like this is a lipstick-on-a-pig situation. I’d like to know the shape to use to make shortest (and preferably least strange looking) boat tail that still helps to streamline the airflow. For now it’s purely conceptual, but it’s something I’d like to know.

The Xl1 reminds me somewhat of the EV1, interesting. I personally haven’t been convinced I can trust a very technological car, which is why I’ve got a civic. I’m very mechanically-enclined. I know my mom’s flex has a rear camera, and I can’t stand it. I meant moreso visibility in terms of another person seeing your car. It seems like cars are mandated to be very visible in both front and rear.

Were the Civic wired for trailer lights, it would be possible to add new lights in the boat tail.

For visibility you have the Military Theme thread ecomodder.com/forum/showthread.php/military-theme-fun-function-22468

http://i1072.photobucket.com/albums/...flyingturd.jpg

I think I’ll stick to the wing for now, until whenever my velo is done. From then on, I’ll tackle a boat tail, and nose, for there’s a lot more work involved. That’s a sweet looking machine. A hinge and piston for the top section would be coolest of cool. I think if I were to go through the steps of making a boat tail, I’d go through the steps of changing the angle of the rear windshield, so I don’t have to trail the tail out as much. The other idea is Lexan behind the current windshield, but I’m not sure how I feel of that. Good information and pictures, though, I’ll be saving these.

I’ve changed my mind on the skirts, for the rear wheels anyways. I’ll do some cardboard testing driving through snow, but I think they might work in the rear. Hinges at the top can make for easier access to clean them.

deployable why ?
 

I believe that the actual reason has less to do with aerodynamics, and more to do with commercial car washes, which could damage a structure like Tesla produced.
Hyundai / Kia recess their car's windshield wipers for this very reason.
You'll notice also that modern cars don't have exposed radio antenna as in the past.
Vortex generators would also to subject to damage unless 'Touchless' systems were used exclusively in lieu of hand washing.
--------------------------------------------------------------------------------------
As to the boat-tail, as far as aerodynamics, all I can recommend is the 'template' for the side elevation contour. For the sides of the car, it would be the same in plan-view, as it's highly modelled after W. A. Mair's boat-tail research. You'll have to integrate onto the existing contour, and go from there. All compound surfaces, the most difficult to fabricate. Or 'planar' surfaces, like the Chevy VOLT, maintaining all the 'character' lines original to the car. Still a complicated build.
Rear visibility efficacy will fall on your improvisation.
I drove commercial vehicles in the military , had a commercial drivers license for a couple decades after, and drove with my side mirrors, so direct rear vision issues weren't 'issues.'
If you thought you had to, you could construct flying buttresses, with a vertical backlight embedded. I've done this with my truck. It has a captured separation bubble which travels along, air flowing over as if it's solid. Plan-B. :)

visibility to other motorists
 

GOOGLE might be a source for ' high-conspicuity' color and reflector schemes.
In the early 1970s, BMW experimented with paint jobs which were so visibly arresting, that to the viewer, they couldn't do anything but 'look' at the car. :)

Does anybody know if there are members on this forum who have done aero mods in Canada? I’d like to find some more clarity on regulations regarding heavy modification.

mods in Canada
 

MetroMPG the Grand Poobah of EcoModder.com will be a font of aero info for Canada.
He coined CAD ( cardboard and duct- tape ) construction technique. His aero creations should be in museums! :D

Thanks again, I'll drop him a message maybe. Elaborate on this flying buttress idea, if you can, as I can't quite picture it right. It sounds interesting.

I'll check out that template generator when I get home from work. Looks like a good starting point for designing the future body shape. Waiting until I'm done my velomobile is a good idea, as it'll introduce me to careful body work and structure design, which will help a ton with future work on the car.

Ford GT:
https://www.carscoops.com/wp-content...d-gt-mecum.jpg

Chevy Ridgeline :)
https://cars.typepad.com/.a/6a00d834...136c970c-800wi
https://cars.typepad.com/.a/6a00d834...136c970c-800wi

My favorite is the VW GTI w-650:

https://www.carscoops.com/wp-content...d-gt-mecum.jpg
https://ecomodder.com/forum/member-f...w12-650-16.jpg

Here in Upstate New York we are very familiar with driving in deep snow. A smooth under carriage with at least 9 inches (230 mm) of ground clearance is recommended. A radiator block system is good and a modest chin spoiler of rigid material is helpful. Controlling the air flow over the roof and rear window is important. Ice build up behind the tires is common. If one gets stuck it is important to be able to clear snow away from the wheels and put down some type of traction material. Also remember the top speed will be less in winter conditions.

I assume you mean to have buttresses with Lexan panels? If they were like those on the Ridgeline, I feel like they wouldn’t do anything for aerodynamics. Certainly look cool though, that Volkswagen is pretty sleek.

That’s a good note, snow clearing is of importance. I’ll take your word for the mods you listed, especially the underbody. What chin spoiler shape do you use?

Good point about snow buildup. Electric spat heaters?

Those are examples of external ducts. Here's an external duct that is not a flying buttress on a Ferrari.

https://i.imgur.com/Z8q8D.jpg

They can be effective, the Ford GT reduces the effective cross section of the body toward the rear.

The GTI W-650 has an effective wing and a top speed of 300mph. It is essentially a bubble-top coupe with a buttressed wing that doesn't exceed the stock Golf envelope.

I think aerohead's example had sail panels instead of flying buttressses, pending his confirmation. Sail panels are like a shorty Kamm-back.

Huh, maybe I’m wrong, then. I assumed having the body split out into a buttress like that would create turbulence within the gaps, vs having a buttressed frame with panel covers. That’s an interesting idea.

Electrically-heated wheel spats seem like a good way to complicate a simple thing, no offence. I’m going to really study how and where snow builds up in the wheelwells and decide from there. It seems like there’s usually more buildup near the drive wheels, as they tend to spin out when losing traction. The rear wheels *seem* like they have less buildup. I want to determine just how much gets in there between the sides and the openings in front of and behind the wheels.

Is there a good thread available discussing grille block how-tos? I’d like to design a sliding block with a sheet of plastic and some spare bicycle shifter parts, but I’m not sure how to determine where the car needs most air.

Completely far-out, but I had a dream last night about a concept car. Single seater with a motorcycle engine, shaped like a wider velomobile meets a Cunningham C-4, but with a crazy airplane style cockpit. It had a variable height lift, which I used to ride up and out of the deep snow, and came back down to the lowest height after hitting the clean pavement. Maybe in 10 years I’ll pull that off, lol. Safety regulations be damned.