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DragBean 12-05-2015 07:35 PM

The DragBean
 
3 Attachment(s)
I've been checking out Ecomodder to the point where it's now a hobby. I figured i should share with everybody my project/commuter car.

I've got a 88 Toyota Corolla that got 30 mpg when i first got it. My record tank was 38 mpg, but that's probably going to change this tank.

So far I've done these things in order
1. Tire Pressure Increase
2. Passenger Mirror delete
3. Power Steering Unbelt
4. Front Air Dam
5. FrontvAir Dam optimization
6. Mini Drivers side mirror with panoramic mirror
7. Lot's of combustion chamber cleaning
I'll probably make a video on that
7b. Ok out of order, but rad innovattive cheapo air filter cleaning process
8.Advanced timing
9. Hot air intake insulation with manual cold air intake switch

Right now I'm trying to figure out my pizzarimboy wheels, i gotta screw them into the rims with higher grade screws

I also want to figure out my front tapered air damn better so it aerodynamically meets the hood.

Ive got a 300 mile drive Monday, so tomorrow is the perfect time to figure it out. I'll post pictures here in a minute.

Later when the signal board arrives I'm going to solder together some amps and with it, and make myself a 3 phase BLDC motor controller to allow myself to disconnect the alternator and water pump, powering the water pump with the alternator.

The goal here is to beat 50 mpg and keep going after that.

O also my current tank (with the HAI switch and pizzaboyrims) could beat 38 mpg and that's with 1/4 tank being averaged at 85 mph (on a closed course highway of course) and getting stuck in LA traffic and several cold starts. I've seemed to be in hurry more often lately, so I intend to drive a bit fastly. Oddly enough the car seemed not to get better mpg when I first got it driving 60 mph vs. 70 mph. Maybe the timing is too advanced? Plus the thing only seems to have 3 gears (Maybe there's a fourth one I'm feeling kick in for a microsecond when I accelerate) and the sucker is also AutoMagic (it's spell casting ability is really off).

Definitely would prefer a manual, but I got this car for so cheap its perfect for doing whatever too.

Yeah Yeah!

DragBean 12-05-2015 08:05 PM

https://goo.gl/photos/Gcg5suPDwSHmWDKW6


Ok this ain't working. Whats a good website to generate urls for pictures?

NeilBlanchard 12-05-2015 08:51 PM

I use Photobucket, but there are others. You may have to have some more posts to be able to post pictures?

DragBean 12-05-2015 08:56 PM

I was thinking that. I was able to post one picture to the original post by sending the picture to myself and using my desktop... I guess this forum is not very smartphone friendly.

Update... Sweet I got the pictures of the air dam up...
Basically I took a piece of 1/4 redwood plywood and wrapped it around the front. I did cut the corners of the bumper and added some pvc to give the front a nice taper in the side view dimension. I did some neutral coasting tests involving cut and try as well as continual driving and figure out a little more clearance in the middle of the thing is better. (side edge clearance is 5.5")

Now I'm trying to figure out if I should stay with the redwood, which holds up, but it's cracked on one side from bottoming out, and the first thin layer of it is delaminating on the edge.

Also I need figure out how to wrap the air dam up to the bumper.
I was looking at Andrew J's modded Civic Hatchback and the PVC sheet hot molding turns out great and holds up well.

Problem is that looks expensive and hard to find.

I'm kinda thinking I'm going to fiberglass it... Then I could leave the original headlamps in place cuz cured fiberglass is decently transparent.

niky 12-06-2015 07:34 PM

That is absolutely ghetto-tastic.

That is a complement, mind. :D

-

Let us know what results you get with that thing!

DragBean 12-06-2015 08:06 PM

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@Niky
TY. It's funny driving it around areas like Oceanside. The real Gs don't know what to think about it.

Anyways I started the front end aero egging a little too late in the day, but i think my fiberglass should still be able to dry even though it's dark. I did have to use 2 cans of expanding foam :/ I'm sure i could have found a more environmentally friendly way to do this, but i did use a bunch of newspaper to mitigate the use of expendable foam.

freebeard 12-06-2015 10:30 PM

Quote:

Then I could leave the original headlamps in place cuz cured fiberglass is decently transparent.
It's translucent. I can't think of anything fiberglass that is optically-clear transparent. This will affect the headlight beam.

My car also has a 30mpg specification, and my bestest ever tank was 37mpg (burned the whole tank in one go with the engine and transmission already warmed up).

Fat Charlie 12-07-2015 09:01 AM

That is absolutely disgusting. You're awesome!

aerohead 12-07-2015 04:59 PM

headlamps
 
If you can release the glass and dig out all the foam,after dark,turning on the headlamps will illuminate the light pattern on the glass.With a Sharpie,you can trace the perimeter of the pattern,and later cut out this portion with a sabre saw/with hacksaw-type blade.Then,with a heat gun you can hot-bend Plexiglas to create legal,clear covers.

DragBean 12-09-2015 10:18 PM

Pic difficulties
 
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Sorry having technical difficulties again. I cant close the upload page on my smartphone so i can't bundle all the pics from today together..

Anyways the fiberglass works! I'm able to take off the entire front. The headlamps kinda suck right now cuz i was in a super hurry Monday when i pulled the front off and i havnt polished it or even got the newspaper off where the light goes through. I made my record Monday - 41 mpg! And that was with a radiator flush and 80 mph averaging for half the tank! I think i could easily get 45 maybe even 50 if i drove 65 instead of 80.

DragBean 12-09-2015 10:20 PM

Another pic
 
1 Attachment(s)
So i had to drive to LA today and while on the 5 North a semi sent a huge chunk of concrete into the air. It clipped the car in front of me one lane over on the passenger side and exploded into a bunch of chunks of debri. Luckily i hit the brakes in a split second and didn't end up with a caved in windshield. But a huge chuck went through the passenger side of my front body kit and popped my tire :\ Thankfully no one got hurt but a total of 5 cars got popped tires. What's crazy is after i pulled over i ran back down the freeway waving my hands in a stopping motion so i could get the cinder block size of concrete that hit me in the middle of the freeway. I did this for 5 minutes and people hardly slowed down so i gave up and later 3 more cars to make 5 were on the side of the freeway with popped tires.

DragBean 12-09-2015 10:47 PM

Not exaggerating
 
2 Attachment(s)
Here's the chunk after it got hit 5 times and crushed down

BabyDiesel 12-10-2015 01:48 PM

Hate that for your ride, DragBean. I know you are looking for replacements already, let us know if we can help.

Also, I love the way your pizza pans look. Except the front passenger side one, "looked" :D

Cd 12-11-2015 03:53 PM

So........um.....what about the back of the car where the drag is ?

freebeard 12-11-2015 11:01 PM

I'd call that a successful stress test. :) Did the concrete fall off the truck or was is dislodged from the roadside?

You said you need better fasteners on the wheel covers. But these seem to have done their job. Are they threaded into the rim itself or the wheel studs? And the fiberglass appears to have survived. Was it only the curved paneling that was shredded?

DragBean 12-11-2015 11:42 PM

@freebeard

I replaced the #8 screws with 1/8"x3/4" self-tapping screws with 3/8 hex heads and rubber washers.

The pizza tray saved the rim for getted scouged up, although the rim got a little bit where the concrete impacted it.

And yes the concrete was from the road, it got dislodged and sent up by the semi. The curved redwood cut a chunk tore out right on the edge where the wood curves the most. I'll probably have to figure out how to separate the fiberglass from the existing wood and re-do it. Or I might be able to backplate it and fiberglass it.

@CD How do you recommend I deal with the back? I'm going to put side squirts on, but I'm at a loss as to figure out the back. Maybe a little Nascar thing on the trunk?

freebeard 12-12-2015 02:22 AM

Make a patch that looks like a riveted gusset plate and add another on the driver side.

I think the wheelwells and floor-pan offer as much potential as the tail, and Cd will have suggestions; but there are
  • fixes—like spoilers, vortex generators and Gurney flaps
  • mods—Kamm-backs, skirts, spats and difussers
  • boat tails—extend the overall length by the wheelbase and wonderful things happen to the Cd. If you can live with the aggravation.

The really exotic stuff includes Coanda nozzles and Plasma actuators.

Cd 12-12-2015 05:39 AM

I don't mean to disrespect what you are doing. I just see a lot of folks here recently concentrating on the front of the car.
If you are trying to decrease drag, the best place for that is at the back of the car.
There is plenty of information here on E.M. from user " Aerohead " on the subject.

Your car had attached airflow on the front of the car from day one. You have rounded the front end and possibly sent the airflow around the sides of the car. This may, or may not decrease drag. Yor modification has also plugged the grille and added a section that is lower - much the same as a spoiler, so this will certainly decrease drag and you will see MPG gains....but as you can see from the attached image, there is no need to extend the nose of the car. A simple grille block, and a front spoiler will do the same thing.

You asked about what to do at the back of the car. This guy did a wonderful job of taking a '3-box' design, such as yours, and streamlining it : http://img.photobucket.com/albums/v4...RunSE-R009.jpg
http://img.photobucket.com/albums/v4...RunSE-R018.jpg

The only thing he might improve on is to round out the sharp edges on the rear extension.

Disclaimer : I am just an 'armchair' aero enthusiast. I just repeat things I have read. I am constantly surprised at new things that I learn about aerodynamics. I know nothing. Carry on .

freebeard 12-12-2015 01:46 PM

Cd's disclaimer applies to me as well. :)

That's a good example for the build quality.

christofoo posted this picture (in 2013) at http://ecomodder.com/forum/showthrea...tml#post394186 I had suggested a 4-bar linkage at Permalink #171, but he improved on the idea by eliminating two. The bars are bolted to the holes for the license plate.
http://ecomodder.com/forum/member-ch...back-moves.jpg

DragBean 12-12-2015 11:57 PM

??
 
@CD

So why would rounding the front NOT decrease the overall drag? Pretty much in any sub-sonic application a rounded approach will allow air to slip around the object far better than a flat face.

Maybe it could create unwanted flow separation on the sides but that would definitely already be there.

Aerospaceweb.org | Ask Us - Drag of Cylinders & Cones

And I did the front fiberglass part (originally there was an air gap between the rounded word part and the hood- that was hardly a 1 mpg improvement) and pizza rims on my tires both at the same time and my mpg went from 31-36 to now I have at 38.7 tank and a 41 mpg tank. Pizza Rims were probably only about 25% of the gains because other people would see 10% gains with terribly unaerodynamic rims.

But this is good news. It looks like if I do the back I'll get some huge improvements.

I also have a panoramic mirror that relies on the back not being obstructed... That means I would have to make the rear panel out of bended plexiglass to still have the benefit of essentially no mirrors. A little bit of a curve might be a tad better than a flat panel.

Cd 12-13-2015 08:33 AM

Quote:

Originally Posted by DragBean (Post 501886)
@CD

So why would rounding the front NOT decrease the overall drag? Pretty much in any sub-sonic application a rounded approach will allow air to slip around the object far better than a flat face.

.

Air works in crazy ways. This car had a Cd of .19 : http://www.oldcarbrochures.com/stati...M%20EV1-04.jpg
The figure was later brought up to .20-.21 i believe.

This car tested out at .201 ...with the hood scoop :
http://image.hotrod.com/f/10214133+w...front_view.jpg

Source : http://www.hotrod.com/how-to/paint-b...-aerodynamics/

Gm tested the EV-1 at their tunnel that gives a reading lower Cd reading than the example I just gave with the Camaro.
So ...That Camaro has a better drag coefficient than the EV-1.

Oh - and an interesting factoid : The guy that tests the Camaro in that article worked at GM on the aerodynamics of the EV-1.

:confused: Boggles the mind doesn't it ?

Rounding the corners does decrease drag, but only a slight amount is needed to retain attached flow.

http://www.myrideisme.com/Blog/wp-co...s-race-car.JPG

Other times though, a sharp edge is better. You see a lot of new vehicles with fake scoops at the corners of the front ends. Air forms a pocket there and skips around the wheels of the vehicles creating an " air curtain"

It all makes a person just throw their hands up and say " whatevah ! "

DragBean 12-13-2015 12:44 PM

@Cd

Sweet article. I never would have guessed that the 362 HotRod has as low of a Cd as it does. Although it still has a higher Cd than the EV1 - I can see your point - it has a scoop which is most likely creating more drag (maybe 5% for 100 clicks and you get 0.19).

I think comparing the EV1 and the 362 is like comparing apples and oranges. The EV1 has side mirrors which if taken off the Cd for it would drop probably over 100 clicks. Also it doesn't have moon covers - another 50 clicks easily from the production Cd rating.

The 362 also is extremely low. It looks like it 3-6 inches lower than the EV1. There's no way you could run it on anything but salt flats and a flat track. I think that is having a considerable effect on bringing its Cd down to around the EV1.

One big thing worth noting is that Cd changes as your Reynolds number changes. I think comparing Cds of passenger cars works because the airflow that it was measured in is similar. The 362 got its at 250 mph - way different airflow than what the EV1 is operating at.

"The HRM Spl. walked in the door to A2 with a very good Cd of 0.229 with 762 pounds of front lift and 65 pounds of rear downforce at 250 mph. With all the tricks, we got a legal Cd of an incredible 0.201, the front lift reduced to 430 pounds, and the rear downforce increased to 180 pounds. Thats all in the right direction, and it helped us run 261 mph at Bonneville with about 1,000 STP-corrected flywheel horsepower. Now its off to Australia and racing at Lake Gairdner."

Also Cd goes down as speed increases

https://en.wikipedia.org/wiki/File:Drag_sphere_nasa.svg

Another thing to note is that it gets harder to lower the Cd once it's already lower. For example a 100 click reduction in a car originally at 0.4 cd versus 0.2 is going to be way easier to do. This isn't called diminishing returns, but similar concept.

Also the 362's cD was measured head-on. If there's any crosswind or you are turning, there goes your magneficient Cd. I don't even think I need to supply evidence that a curved front is going to be better from different approach angles.

So although you might be able to design an aerodyanmic flat front, rounding it like a teardrop is going to be better.

PS When did Walter White get into Drag Racing?

freebeard 12-13-2015 02:18 PM

The aphorism on the Salt Flats is: "It's not how big a hole you punch in the air, it's how big a hole you leave in the air".

Rounding the nose reduces the size of the stagnation point and mitigates leeward separation in cross-wind conditions. But the maximum width on The Template is biased toward the front to give more time for things to settle out downstream.

In some cases features can affect airflow 'upstream' from themselves; for instance base pressure being transmitted forward in recirculating pockets.

Fat Charlie 12-13-2015 07:04 PM

I'd think that windshield would tuck conveniently in that hood scoop's wake.

freebeard 12-13-2015 07:28 PM

Plus it would keep the bugs off. :thumbup:

DragBean 03-03-2016 12:21 AM

Update
 
I've been very demotivated to post any results after changing my tires and not getting improvements. In fact my mpg started going to low 30s. But then i realizedseafoamed my car and charged the sparkplugs. Now I'm back to upper 30s. Looks like there is hope afterall. I'll post a pic of the old plugs soon. (Well and gas prices are so low too saving money on gas hasnt been as high of a priority)


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