about to get real aero dynamic
 

So im about to start collecting election signs and stuff and build a nice lil skid plate. ive got some other things already. right now i just have my grille and bumper covered up with some stickers i have.

my goal is to have this thing looking as good as possible. my car is currently pretty damn low. my front lip is about 3 inches off the ground. that helps right?? personally im not afraid to drive around a car that is practically touching the ground because of my racer mentality haha. ive been searching up all the aero threads already and found some civic stuff. one of the main questions i had is what is the best design for a wheel spat? direct the air under the car for less of an outside wake? ive seen the wind drawings how the sports cars direct the air to the brakes to cool them. that isnt a concern of ours though correct? so we want to keep the air that goes under the car moving straight back with no interference from wheels and suspension components. alos if i where to make side skirts that are under the car out of sight with lawn trim how much could that help?

I think you are on the right track, I like the idea you mentioned of directing the air off the tire by sending it under car.
I never thought about that before but it sounds like its going to be effective, that the air will more readily flow under the car with a belly pan rather than off to the side and away from it.

yah it makes sense. i dont exactly know the whole science of the spats but that is what i have gathered so far. of course most people on here have different opinions.

I am not sure how many people have contemplated that idea, I think it would win favor.
If your car has wishbone suspension a election sign would fill the space nicely, You should consider raising your front air dam/spoiler to near the same height of the planned belly pan, to avoid low pressure zones/ empty space.

Filling behind the rear wheels to the bumper well remove the parachute effect caused by the voids.
If you leave your air dam 3" off the ground then a front belly pan would need to drop down to near that level to be effective, or you could even not put a belly pan on since the air will be traveling below suspension parts.
I would add the rear belly pans if i was to keep the low front air dam, as a bonus its easier.

I snagged 5 courogated plastic signs from work and one that was laying in the street that just barely caught the corner of my eye when I pulled over cuz I was lost in the hill country lmao. I really want to get a giant one off the side of the road or something. So now I'm going to start on my belly pan. I'll be posting lots of pictures.

Finally, a good use for a Romney poster!

As for wheel spats, I think directing any air out away from under the car is better than sending it under the car. Once away from the car, it will have nearly no effect on your aero. If under the car, it will find whatever drag and interference there is down there. That's why a common recommendation is a low front lip PLUS thorough side skirts, to create a vacuum and maintain it as air flows rearward.

I'm not saying you need complete side skirts for spats to be useful. Just saying, I think getting the air away from there is a good thing.

Thats what my friend said about the romney ones!! Would it be better to make the spats parallel with the tread of the tire or to make long sweeping one that angles the air out away from the wheels?

My Infinti Q45 came from the factory with an underbelly pan and tire spats. Seach the treads in my post for pics. (front belly pan)
The spats angle in. Directed the air down the center of the car.

If you'd like to post political digs, please go to the lounge. 67% of Americans who watched think he won for a reason. (which means Romney lied...... He can get part of the 47%)

Yah on my moms Pontiac vibe they are like just slightly angled inward. That's why I'm not sure. When I searched everyone said different things.

What I am being to realize is that 'everything has a reason'.
While my spats point inward another car may point out. The infiniti guys might have wanted to cool the tranny!!!!! and not given a crap about aero!
When we try to look at small things in abstract, we sometimes miss the real reason or the bigger consideration.
another example is solid wheel covers. Some manfacturers have slots and vanes in the wheels to intentionally stir the air up and create flow over the bearings and brakes, others have cooling provided by....you guessed it!!!! NOT HAVING SPATS!!!!

As I stated a while back in other thread, the actually are engineers at these manufacturers who are earing their degrees. Some times it's just more obvious than others.

Political digs all in good fun.

In my opinion, don't even bother with a coroplast belly pan. It may get ripped off when you scrape. Just get a nice air dam (garden edging works well) that extends to the level of the lowest suspension/chassis component. You'll get most of the effectiveness with a fraction of the effort and cost. It'll bend out of the way when it hits the road and you can sticker bomb it as you have done with the grille block.

Spats also may be a lost cause with a car so low. I will suggest you just go for the low-hanging fruit, a Kammback or boat tail. Getting flush wheel fitment with a flat faced wheel up front should help aero, and tucking the rears as much as possible will give you clearance for full rear skirts.

Got any pics of this thing? The car I'm imagining (with all the mods) looks pretty badass. Wonder if stretching LRR tires would reduce their effectiveness.

I think belly pans a great way to smooth out the bottom of the car. An air dam increases frontal area and drags the air underneath along with the the car. I agree they are a pain for maintenance, but I have had them on for 8 years. The rear half lasts longer than the part under the engine, if they are made from coroplast. They keep the snow from packing up under the car when you ram through a snow bank. The main problem I have when off roading are branches or corn stalks ripping off the front skirt bungee cords under the car or if the front wheel is in a rut and the tire gets under the skirt it gets ripped off. Putting the bungees inside the belly pan and trimming the skirt would fix this. A belly pan is one aeromod that is stealth.

Haha great info sev7! Thanks a lot! I do have a real sweet front lip already from garage door trim. It's a little less then 3 inches from the ground. Also I'm in Texas so no snow, and I keep the rallying to a minimum, all though next month I plan on getting it a little dirty in Arizona :p.


Skid plate almost finished as we speak. BIG QUESTION! Will the oil pan melt couroplast?

Pics coming real soon!!

I do not think that the oil pan will get that hot.

I would swear I just answered this question last week.....
Understanding basic concepts will answer this question.
1. underbelly pans (reguardless of material) are mounted so they don't touch moving parts. engine is a 'moving part' ' tranny is a moving part, exhaust is a moving part
2. underbelly pans (reguardless of material) are mounted so they don't touch hot parts. engine is a 'hot part' ' tranny is a hot part, exhaust is a hot part
3. refer to previous bellypan threads for safe distance from hot objects.

So whether XXXXX can melt XXXX really is immaterial ....unless you don't follow the basic concepts.

Keep an inch between em just in case. Or, butt em up against each other and see if it starts on fire. I had some 'plast up against the downpipe on the Probe and all it did was melt out of the way. Then you cut away the melted parts. Not the best way to do it but it works well enough as long as the car doesn't burn down?

Some crappy pictures
http://i137.photobucket.com/albums/q...77E4163942.jpg
http://i137.photobucket.com/albums/q...77D6EB9EA0.jpg
http://i137.photobucket.com/albums/q...77DB74BB17.jpg
http://i137.photobucket.com/albums/q...77DFDD7DBB.jpg

Pics of lowness?

http://i137.photobucket.com/albums/q...77F1A1057E.jpg
http://i137.photobucket.com/albums/q...77E860B73D.jpg
http://i137.photobucket.com/albums/q...77D140F3BA.jpg

I had it about a half inch lower but it was on some HORIBLE springs and I took them off a couple days later. This set up is real comfy and it handles like a beast!

Looks beastly too. Now do rear skirts and smooth wheel covers!

Some air out to side, some air under... compromise spats
 

I have been wondering same thing, I decided on a compromise. I thought the Mercedes ML 350 (some models / recent year at least) has good factory spats. They seem to, at a minimum, keep the air off of front of tire, and they curve and taper inwards. Maybe a bit out too.

I mounted plastic PEX bend supports just in front of the front tires. Grainger item # 10A675.

I will be mounting lawn edging, maybe 2 or 3 inches down, in them using zip ties. Since it is 90 deg. curved, I angled them so they are pointing a bit back, not straight out the side. So I will have some air curved out into the side, and some inwards past my lower control arm.

I agree, without resources the aero engineers have, I am going on what SEEMS to work for other designs, and felt that getting air off of tire is good. I do not have a clean underside, so i figure some air each way is better then not.

2004 Malibu Maxx. Left front wheel well

http://ecomodder.com/forum/member-we...d-supports.jpg

http://ecomodder.com/forum/member-we...awn-edging.jpg

http://ecomodder.com/forum/member-we...front-tire.jpg

Hmm ok, I have not seen a spat like that. I think I might make them on the inside to try and angle the air away from the hole in my Bally pla that is cut out for steering. It seems like even though my car is low, having spats is better then not having spats. And it will be easy and fun to make. Soon once I aquier more signs. Ill finish off my belly pan. Even if these things make a small difference it is better then not Doing It at all. And seeing as my car likes to be driven around 60-75 good aero is goin to be important.

I'm thinking ill do some wheel skirts for my Arizona Vegas trip but I won't make them permanent. My friend is really pushing me to put them on. Ill have to figure out a way to mount them without using duct tape on my paint. AND I got a trunk for the trip for free that i am building into an aero bike rack and I can maybe build a boat tail on!

More pics - plus Mercedes ML 350 example
 

I will have to take better pics of the complete front view with them mounted, but this may help.

Essentially curved air dams in front of tire, like the Vibe, but a bit bigger left to right, and they come down a bit further.

ML350 - Look just in front of right front tire... I have seen them in person, they curve under the car and taper up a tad.

http://ecomodder.com/forum/member-we...nspiration.jpg


My Maxx splash shield mounting area... prior to install

http://ecomodder.com/forum/member-we...re-install.jpg

http://ecomodder.com/forum/member-we...tek-screws.jpg

Good luck, have fun, be safe.

That's what mcrews spats look like. I'm starting to think the engineers put it like that to help the wind clear the lower control arms and stuff (because that's a tall SUV a lot of it is exposed) Seeing as mine are covered now (and they are slanted up because its low anyways) I might just do a really small one like vibe to help with the tires. I still havnt slide code which direction in or out I want to go. Has anyone noticed some nice gains from shaving one of their wing mirrors?

Perhaps you might edit out your political comments. It's off topic.

Sorry I didn't know it was so offensive. I just need signs. I don't care care who's name is on them haha.

Do you guys think my front lip is big/ low enough? Or do I need to go with a larger lawn edging?

Installed pic of the ML 350 style spat on my Maxx. Not trying to hijack your thread... just sharing what i am trying. Still have to do right side... good luck on all your mods.

http://ecomodder.com/forum/member-we...left-front.jpg

http://ecomodder.com/forum/member-we...-installed.jpg

http://ecomodder.com/forum/member-we...39-lft-frt.jpg

:thumbup:

Nice that thing looks factory, the other thing that style spat would do is clear the hole in the belly pan that is cut out for steering.

Ok so I hit the jackpot on signs last night! I got 7 of the huge 8x4 or whatever they are. So now I can make a full belly pan for my car and probably at least 4 others lol. Really really excited. Idk if it was because of my new mpguino or my new front skid plate but I'm averaging like 4 mpg better AT LEAST right now. Ill have to fill up to be sure.

On a side off topic note. My dad has an ex civic same year as mine (crappy ex transmission) with a jdm d15b that I swapped in for him (converted the car to 1.5L non vtec) and he drives all over the state every day for his job and he is getting 41 mpg despite the fact he sucks at driving haha. But his car is all stock and ready for ecomodding so ill probably build him a belly pan too if he is nice and see what happens. Lots of potential.

So my friend has these wheels that are the same lug pattern as my civic. I feel like I can make these smoothe pretty easy, or at least they are more aero dynamic then my HX wheels. And they have a lower offset so the will be closser to the fender. Plus they are 2% taller then mine. But they are 195 rather than 185. What do yall think?http://forums.bimmerclassics.com/att...btlcap-rim.jpg

http://forums.bimmerclassics.com/att...btlcap-rim.jpg

Best if tire spats direct air away from, not under the vehicle. The way you have its better to not even have a tire spat because your directing more air under your car. I think no less than a 45 degree angle would work best. The idea is to keep that air from hitting other things under your vehicle. The more you hit it the more it slows you down.

Alright dudes!! I am very pleased to introduce my cars new mascot, Texas state representative hopeful Robert "big Bob" Thomas. At least that's what I call him.
http://i137.photobucket.com/albums/q...25BD4D4D52.jpg
He is going to make me get better gas milage
http://i137.photobucket.com/albums/q...25C557948F.jpg
http://i137.photobucket.com/albums/q...25CAC7B8AA.jpg
http://i137.photobucket.com/albums/q...25CF685B85.jpg

Sorry for te crappy pictures. I've even working on it for about 5 hours and its done now :) it looks way better in person. Yah it's touching the muffler. I probly should have consulted you guys before I did that but I figured it won't get that hot. We will see. I also raised the muffler way up like 4 inches, so it isn't even visible from standing behind the car and I cut the Tip of a couple months ago aswell.

I didn't want to start my own thread for this quick question, so please excuse the thread-jack.

Can clear packing tape effectively be used as a grill block? If not permanently, what about temporarily to gauge how effective a grill block would be?

I'm wanting to try an upper block on my TSX, but don't want something obvious such as white coroplast in there. And, honestly, I'm feeling lazy and don't want to take the time to fit it at the moment.

Do they have the same offset?

Yah packaging tape would totally work^^

I'm pretty sure the BMW wheels have a lower offset by like 8mm at the most. Same exact size though. My tires are 14/65/185 and the bmw tires are 14/65/195. 2% taller. Just a smoother face. Idk if those were ment to be aero dynamic or what

so if i were to do a Bonneville spoiler how should i go about the design? something like this?
is this long enough? are these even beneficial? by the way, this will be on my road trip trunk, not my every day trunk. i want to keep a stock appearance.

http://i137.photobucket.com/albums/q...templatec2.jpg

decklid extension
 

As of today,I've never seen any peer-reviewd report on these 'Bonneville' type modifications,so it's gonna be tough to assign any hard numbers to them.
Here are some talking points:
*many racers at Bonneville are aerodynamically drag limited speedwise,and are capable of wheelspin at very high speed,which can be a disaster if the car goes sideways.,lifts off and goes airborne.
*the decklid extension provides ample surface area for separated flow to re-attach which greatly increases rear downforce,which can positively affect wheelspin.
*the decklid extension also cleans up rear turbulence enough to allow the parachutes to deploy sooner which can be a life-saving difference in an impending spin.
*the decklid extension doesn't violate rulebook limitations for 'stock' body shape (even though it is technically 'cheating' when you use one).
*the decklid extension modifies any existing spanwise vortex to the good and allows streamlines further aft to recombine at nearer flow velocities and pressures,eliminating powerful longitudinal attached vortices.
*while the extension modifies the 'upper' flow,it does nothing about the separation point at the body sides and bottom,which will in turn determine the pressure of the entire wake (so the extension cannot provide the benefit of a boat tail which alters the entire separation point on the car).
*as you can see from your own graphic,it would require an enormous extension to reach out to the 'Template'.
*if you wanted to 'experiment',run your extension out to any length you can live with,and then go 'half-way' vertically to the 'Template' with a 30-degree upswept 'kicker.'
*I've observed a few high-performance cars which have done something like this.
*you buy some effective length by raising the trailing edge of the extension up.(it could be done with clear Plex. or Lexan bent on a gentle curve [when viewed from above],allowing you to 'see' through it when backing).
*if you extended your C-pillars out to the back of the extension as buttresses,you could additionally tailor the captured-vortex with these 'capping-plates.'
*also,if you go ahead and boat-tail the decklid extension it would be easy to do a follow-on box-cavity or proper tail extension at a later date.This is where your money is hiding.;)

So for the spoiler to actually work it has to reach the curve? I just don't feel comfortable angleing that thing up. It seems like it would be so wind resistant.

Well I must be doing something right because yesterday from my house to the Bmx competition down town I averaged 54 mpg! And that was including getting Lost and circling around finding parking. I got 57 just before that! That's the best I've ever done. I'm getting so excited and inspired to keep this bad boy going. This is all happening on some seriously low tire pressure because I didn't want to throw that into the mix yet (still testing my aero) and my cel came on too. It has always done it when I drive in 5th at like 1200 rpm. I'm guessing because the egr ports and intake mani are dirty. It never stays in lean burn for more than a second or two. So I got some sea foam to hopefully change that. Thanks for all the help dudes! I couldn't have done it without you all!

spats rock and look easy to install on my short list

No do not angle the spoiler up. The curve needs to follow the contour of your vehicle. Curve the spoiler down in the direction of that curve.