Comments from other sites about basjoos' Aerocivic
 

For your eavesdropping entertainment: comments about the aero mods on basjoos' car from the Honda-Tech forum ...

• " umm..."

• " hahah, silly. "

• " pretty cool http://images.honda-tech.com/set1/smile/emthup.gif "

• " oh wow. "

• " no way he is getting 90mpg in that thing, if so i will do mine tomorrow! "

• " hahah, i would die laughing seeing that thing driving down the road. but, it's practical with gas so expensive so http://images.honda-tech.com/set1/smile/emthup.gif http://images.honda-tech.com/set1/smile/emthup.gif"

• " lol... "

• " He's spending all the money he saved on crack."

• " just wrong in so many ways......."

http://www.honda-tech.com/zerothread/2180202

Sweeeet. Way to hit the mainstream, juice.

I figured it bounced around the net a bit because of home many views the thread had.

I'm not so sure I'd call the responses mainstream. HT is an enthusiast site, as is this one...

http://sacforcefed.com/phpBB2/viewtopic.php?t=3597 (reg'n required to view)...

• " Ummmm....no words..."

• " my god... "

• " okay... it looks half assed. if ti was polished up and painted then may I'd give ti props, but so far it just makes him looks like a cheap *******. "

• " omfg... gayest s**t ive ever seen. wtf. "

• " i'm doing that on my car. it's final "

• " better then a big ricer wing IMOA "

• " I already started on my car but the elmers glue isnt keeping things together enough. I think its too cold out.?? "

• " So he cut down on drag, but how much weight does that boat tail add on? I hope he doesn't have to parallel park anywhere, that thing looks longer than an Excursion http://sacforcefed.com/phpBB2/images...s/icon_lol.gif"

The workmanship doesn't bother me. It's a "50/50" job. (Looks fine from 50 feet or going by at 50 mph. :)) The results impress me more.

(Then again, this is coming from someone whose car currently has wheel skirts duct taped on ...)

That mimics real life. You get a few thumbs up, a lot of laughs, and a few mouth-breathing feces-throwing types doing what they do best. But the landscape IS changing.

I get the feeling that the FE revolution will be more permanent than the 1970s, simply because it's so much easier to do the research these days thanks to the internet, and the general feeling that it's not OPEC forcing the change this time.

There's more... the car is going viral:

http://carolinahondas.com/forums/showthread.php?t=43429

• This is soo funny looking but he is getting some good gas mileage.

• Lololololol...

• imho 40-50 mpg is a decent amount, why drive a piece of poo to get a little more

• funny as s**t...

• cool as heck

• holy s**t.. thats about retarded. look at his odometer! 440k!!

Luckily, that dude's opinion doesn't count :p The difference between basjoos mpg and 40-50mpg is more than some cars get from the factory :p On par with some crazy hybrid SUV even :p

I don't know why the performance types were making negative comments about my car. Many of the mods on my car are the same as the ones they use on the Bonneville Salt Flat unlimited speed cars to increase their maximum speeds. And the max speed of my car is considerably higher than it used to be (about 40mph higher) and the performance in the quasi-legal 70-90mph speed range is much improved over stock dispite no changes made to the engine.

Sadly, most of the "performance types" don't understand aerodynamics and tend to think that weight is more important.

Also: "different is bad."

They'll all remember that car when gas hits $6/gallon.

If you've seen "I am Legend" you'll see the gas prices. 6.30 something? Wouldn't the aerocivic create lift though at high speeds? that can be bad if your on the German Autobahn.

I suspect it would create more downforce at the back, because there's going to be suction going on underneath the back, more so than at the top of the vehicle, because air can only come from the sides. I'd be surprised if lift was an issue.

Basjoos has answered this one before, and if I remember, his impression was the car felt just as stable at 90 as at lower speeds.

I've had it up to 100mph with no stability issues.

Most "performance types" are fixated on 0-60mph, 1/4 mile times, and the maximum speed at which you can still get wheel spin. Hence the focus on weight, power and low end gearing, to the exclusion of everything else.

What he mean "a little more", I'd would need to cruise at over 90mph to get my mpg's down into the 40-50mpg range. On those few times when (mileage be damned) I do cut loose and cruise in the fast lane with the speeders, its amazing how effortlessly it cuts through the air. But normally I avoid speedng since my car is enough of a cop curiousity magnet without giving them an obvious reasong (speeding) to pull me over.

And I don't imagine they'd have much patience waiting for you to coast down to a stop. "But officer, think of the kinetic energy you've made me waste!"

well, I was just thinking of the lift problem because the whole car is shaped like an airplane wing, and since there is more down force towards the rear of the vehicle, this would lessen the weight on the front end, that could result in the front catching a wind gust and lifting the front end off of the ground. As I recall the Ferrari F430 has no lift at all, but creates around 360ish lbs of downforce at 100mph, even more weight at 180. But the downside is it's drag coefficient is like .32, which isn't real bad at all.

Most every car creates lift because of it's similar shape to an airplane wing, uneven raised surface on top, flat surface on bottom. The air going over the top has to go a lot faster than over the bottom so that the air meets up at the back at the same time as the bottom. This creates a high speed, low pressure on top and a low speed, high pressure on bottom, creating lift.

Now this only becomes a factor when you go at speeds up past 100mph, depending on the vehicle. A boxy high off the ground oddly shaped vehicle at 100 will have more lift than a low to the ground low slope windshield vehicle with front lip spoilers and rear inverted wings. Most lift is only felt at speeds of 150ish and up. Which is why most normal vehicles traveling on the autobahn at 120ish can without problem.

A vehicle that is symmetrical in every aspect will have an equal distribution of down force and lift, resulting in an equilibrium that makes no lift, and no down force. Sports cars try and speed the air on the bottom of the vehicle and slow the top by using flat bottomed vehicles to try and reduce drag and add things to make the incoming air speed up, and as it goes out the rear to speed up, they also add spoilers and pieces that cause drag over the top of the vehicle, resulting in the opposite of an airplane wing, even though it was originally in the shape of one.

Amerikans have been culturally conditioned to see "image" as all important. At the risk of quoting Mick Jagger, I just find that so unsatisfying.

And then there's the comments about the cost of the mods vs. the savings in gas: 1) at 440K, I bet the car has returned a pretty good value already; and 2) who says it's all about short-term savings?

Every time I hear about another life lost in the oil war, I feel guilty for my contribution by driving at all.

America is so retarded sometimes. We're probably gonna be the reason for the end of the world. Especially this new upcoming election with Hillary Clinton... buh. We're so gonna be a wreck soon.

If anything happens, that is the most likely of anything. But in most vehicles, there is downforce generated at the front of the vehicle (because the majority of air is pushed up especially with basjoos' car, and that generates an equal but opposite force on the front of the car downward. Because of that, it would be unlikely to tip over that way IMO. It might get equal, but there is also the weight of the car (remember that the rear wheel would be the pivot point, and most of the mass of the car is right at the front end, exerting larger torque).

Most cars generate lift at the back, because there is a low pressure area from the rear window backwards, and that rear window is pointed primarily in an upwards direction, so that component of force (Force = Pressure * Area) is large. I thought this was what you were getting at, but evidently not.

Third grade (and often, unfortunately, higher) level science textbooks have a lot to answer for in their attempts to teach aerodynamics by their mangled interpretation of Bernoulli.

There is no miraculous force that tells one molecule next to another molecule that it must somehow meet up at the other side of a vehicle at exactly the same time. None. To carry that meme to its logical conclusion, consider an inverted "T" shape - pretty much the ideal wing, because of all that distance and hence speed the air must travel around the top to reach the other side at the same time. Well no.

Please note that my ridicule is not aimed at you, it is aimed at ignorant publishers, science writers and teachers that credulously parrot these explanations. To help understand aero, spend a few hours googling "Newton" "Bernoulli", and aerodynamics in general.

^^ Both cases of lift and down force aren't really of any significance :D Basjoos has already given a thumb up for high speed stability :D

That detail really pisses me off.... Especially when that's taught in flight schools - to greater than third graders.

I really like the look of the aeromods basjoos has made, maybe you guys have covered this already, but, I've looked and not found it. Are their any pics of the mods before, during, and after that might give a newbee some helpful ideas? Thanx.

Pictures of my car at different stages of the modification process and photos of various cars and aircraft that provided models and ideas are at the site below.

http://smg.photobucket.com/albums/v4...Honda%20Civic/

AutoblogGreen picked up the Aerocivic thread today:

Aerocivic's mods combine great aerodynamics and a, um, stunning look in 95 mpg Civic

Besides one guy who apparently hasn't heard of coast-down testing and disputes the calculated Cd, this positive comment:

• With that kind of MPG, who cares what the drag is?
  
  Someday, all cars will look like this. Well, maybe not _exactly_ like this, but similar :)

^^ Classic case of falling on ones sword - taking care not to miss the point. Some people just need to cling onto insignificant points - insignificant to the grand scheme of things :/ Makes their bitter morning coffee more palatable...

Why use physniks when ya can use good ol'merican injunuity. http://forums.beyondunreal.com/image.../shakehead.gif

'cause even fiziks is on his side :p Less weight is only beneficial (FE wise) during positive accelerating (including while going up hill). The rest of the time, aero takes over as the primary factor :thumbup: I'm not saying it's not important - but weight reduction only does so much (really great when you have a lot of extra crap) :thumbup:

I wouldn't even go as far as to say uphill, unless the driver never goes downhill. ;) Crr>W. There, I said it. :thumbup:

Only of you coast uphill :p Otherwise, wasted power :/

Crr does indeed go up with weight... But we're talking of a scalar on the order of hundredths (Crr) that is used in linear a linear equation with respect to a constant (weight) versus a scalar in the tenths (cD) which is used in a quadratic equation with respect to a variable (velocity).

So lets say the car weights 2500lb and cRR is ~.01 (partially arbitrary). That gives us a RR of 25 pounds. This is constant. So, we can linearly reduce that value until we have no wieght in the car whatsoever (not possible - but just for discussion's sake).

So lets say the car originally had a cD of .3 and an area around 25 square feet. That's a cDA of 7.75ft.^2....


That means - given a cD of .3 versus .17.... A difference of 25 pounds is had at 53mph. Of course, we can't remove all of the car from the car... So lets take 500lb off. The even breakpoint would then be at ~24mph (5lbs).

Lets say he goes crazy - and pulls out 900 pounds of car off the car.... He'd then have to go ~32mph to get an equivalent difference in gains (9lbs)


Now, I made some assumptions on cRR, A and original cD. I know they're somewhere - I just used handy numbers from the coast down instructable and an estimated weight of 2500 lbs. I'll eventually come across the more correct numbers and throw it into a spreadsheet :p

I can also post the converse if you'd like (what reduction in cD is require to break even at some given velocity)...


------
To reiterate - removing weight is good (and shouldn't be overlooked)... But reducing aero losses has the potential for greater gains in drag reduction. The biggest (and cheapest), of course, is just driving slower :p

And finally - an example case... Basjoos' car :p

If ya go uphill, ya gotta go downhill. Anyway, bad, bad trebuchet03, Crrn it isn't linear. And I didn't mean that Crr goes up with weight, I mean it's easier to address than weight. What's going to be easier, slapping a set of RE92s for a halving of Crr or gutting 1000lbs out of a 2000lb car? If ya do both then it's a matter of diminishing returns and like ya said, ya might as well address aero. :thumbup:

^^ F_rr=cRR*Normal

Seems rather linear to me :p

I agree - easier to address... And less gains to be had while cruising :p

Page two under road load parameters. :thumbup:

Ahh, I thought you'd bring that up... cRR typically refers to the lower wieght simplification (as in, weights less than 2000kg). Keep in mind that these terms, as measured are an infinite sum with each term having a power of n-1 (one, theoretically could argue it's a "googtuple" :)

In any case, I can factor that in - but doing so, aero resistance becomes a cubic as this is looking at power.

Overall, we increase (very slightly) the velocity in which the break even point occurs. Check out page 4, figure 2. The dominating point occurs between 34 and 55mph. Make aero better - the locus shifts and those velocities slightly incease. I guess it's worth noting - the CR2 factor is on the order of hundredthousandths - .0000522. Much more significant when one speaks of a vehicle weight in terms of tons (~4+ short tons), rather than pounds (3000lb) :p

Lets apply their equations to a 1500kg car....

Term1 (crr*N) = 0.0678
Term3(excluding aero) = .0000355

Although, we shouldn't compare these directly as they don't have the same units....

Given the low comparative weights - it's really not incredibly necessary to include the expanded series. Stock coast down tests have come very very close to the factory advertised cD - even when cRR must be calculated...

I still stand that we have more potential gains from aero improvements given our high starting cD. Weight is important too - but when it comes to reducing a 20 pound load over a 60 pound load... I'll take 5% of 50 over 5% of 20 :D


Thanks for the link though - very good read. It's pretty interesting that ~6% of a semi trucks energy is in the rotating bits of the axles...

But I was talking about Crr not cRR! ;) I also think that Taylor series of a function is common compared to googtuple, but I guess that's just another Crr cRR. :thumbup:

P.S. This reminds me of that SAE study where the authors estimated flaps on the back of trailers would save the trucking industry something like three quarters of a billion bucks per year. Not to mention the reduction in externalities like pollution...

I think a lot of the reason for the ricers to complain about basjoos fine work is simply because it's "rough" and unconventional. It definitely shows what aero can do for fuel economy, but it also doesn't have the spit and polish look of a professional engineer with a team of highly trained machinists at his beck and call.

It's homebrew in it's appearance and has function (great function) but the form seems lacking.

I'm not bashing basjoos at all, in fact this has inspired me to look at what I can do with my Jetta to break above my 25MPG handicap.

I'm not sure what basjoos' qualifications are, but I wouldn't be surprised if he is an engineer. I'm an engineer, and a lot (well, all) of my mods are pretty rough and homebrew in appearance.

The difference is the equipment, the machinists, the professional paint facilities and painters, etc.

Given time, a whole industry will spring up around this, just as there has around the performance industry. Well, acceleration + appearance, as that was all the ricer crowd were about.

My name's Kuma, and I 100% approve the above message. :thumbup::D

I myself would not be surprised if basjoos is an engineer, I was more aiming my comments at the lack of "professional machinist" quality of the mods. Again not knocking basjoos he's done some incredible work, but the ricer community is fixated on that spit and polish look.

To be honest I'll be surprised if my own efforts look half as nice as basjoos, I drive a sedan so I know that my boat tail won't have quite as aerodynamically correct of a shape, but I'll do what testing and solidifying of my designs as I can.