Scion xA aero mods
 

Greetings,

I've been testing some aero mods -- using good old duct tape, for the moment.
http://img.photobucket.com/albums/v7...eroMods-02.jpg
http://img.photobucket.com/albums/v7...eroMods-04.jpg
http://img.photobucket.com/albums/v7...eroMods-06.jpg
http://img.photobucket.com/albums/v7...eroMods-03.jpg
http://img.photobucket.com/albums/v7...eroMods-05.jpg
Simple stuff so far, and it seems to be quite effective: my best tankful average last year was 41.8mpg, and with some improved driving techniques, I got 43.5mpg on a tank. After covering the upper grill, I've got a new best of 45.5mpg. Then I covered the fog light recesses, and it's looking much better still!

The 45.5mpg tank was ~239 miles at the half tank -- and this tank is sitting at ~275 miles at a half a tank left! :D So if I do only 200 miles on the second half tank, that could be ~47.5mpg! Heck -- I might be on course to do almost 50mpg?! Incredible, if that's how it turns out.

[Edit: I ended up with 46.4mpg, partly because my last commute up Route 3/93/95 and on Route 117 was pretty clogged with stop and go traffic...]

So, I'm going to be trying to construct an even sleeker nose -- if I can form some planes to kick the air flow out and around the front wheels, and keep the required cooling (today was very hot -- near 100F and it worked fine!), then I could be exceeding what I thought this car was capable of.

The truth will come out in 4-5 tanks.

My mileage swings up and down by almost 10mpg on each tank, depending on when the bloody pump shuts off the nozzle. I don't take the risk of topping off repeatedly like some. I do slow the pump down when I know it's nearing the top though - makes for a little more consistency.

I'm quite interested to see what sort of improvements you can make. I've got an xB and may be in the market for a replacement car for my aging civic.

Can't wait to hear what the next tank is Neil. Looks like its comming along well.

Thats some huge variance millenniumtree! My tanks in my Matrix vary about 3 mpg (40-43) and there are two different people driving it.

Neil: that's encouraging. A 1.7 mpg gain works out to a 3.9% increase.

I did a number of non-rigorous "A" (5 controls) - "B" (2 grille block) runs and saw an average 2.9% gain @ highway speeds.

looking good, I think I will just tape over my fog light spots like you for now.

I got a little bump with the upper grill block too, wonder if it will last

I didn't see much improvement on my grill block but that could be for many reasons. One questions I have is this, is it better to block the upper grill or lower grill? I have a Subaru Outback with the lower grill blocked and the upper grill open. I chose to do the lower one cause it was a bigger opening but it may be at the stagnant point anyhow so the blocking the upper grill may be better for smoothing flow over the hood. any thoughts?

Thats the general consensus. If your going to block one, the upper helps more with aero.

You're right on: all else being equal, better to block the upper opening and send air that's already above the stagnation point over/around the car where there's less drag. Feed air that's below the stagnation point through the radiator, since it was going to end up in the turbulence underneath the car anyway.

sweet, i'll have to try that. I think it will make for a prettier mod too.

Hi,

I blocked the upper one because it is flush (the lower one is recessed) and it helps the air flow up over the hood. Also, the standard upper grill is more closed than mine is, so I felt more confident going without the cooling air. And there is the slot just above the bumper, too.

It worked perfectly well today in very slow/stopped traffic on Route 128 with the temps in the upper 90's.

Hi,

A quick update: I added a bit more duct tape to seal the hood joint with the top of the headlights. This tank is looking very good: ~370 miles with ~1/4 tank left = ~490 miles on the tank (!!!) = ~49mpg! Woohooo! That is simply amazing...these front end aero mods have added ~65-70 miles per tank, and they will have added ~5mpg to my pre-mod best!

[Edit: This is on my regular commute, so it is a round trip -- all the downhills are uphills in the other direction; and traffic is hardly ideal. There is no way I could do any pulse + glide...]

My lifetime average is 37+mpg -- and this tank looks like it will be 10-12mpg better than that. I'm still flabbergasted...

My working theory is that covering the fog lights has smoothed the air flow coming off the sides of the chin spoiler; possibly helping air to flow out an around the front wheels?

I want to make a pan for the rear undercarriage behind the axle -- ideally, this could be structural, and the new space would add a fair amount of volume to this car's Achilles Heel -- storage space. Both the rear bumper fascia and part of the metal frame hang down an form sharp edges across the air flow.

NeilBlanchard Do you have a scangauge? Just wondering what the water temp got to? I've been thinking of doing so aero mods to my echo but am wondering if that will cause the cooling fan to kick on more taking all the saved gas from the mod?

Hello,

I do not have a Scangauge -- yet. The coolant did not get too hot -- the electric fan only ever comes on when I'm stuck in traffic. The red warning light never came on.

My mileage has improved with these mods -- so, the answer to your question is the mods save gas; and the car does not overheat. It was nearly 100F yesterday, and all was fine.

Mechanically, the Echo is very similar to the xA (and the xB and the Spectrum). Are the grill openings similar? (Post some pictures.) Try blocking only the top of the grill with one strip of duct tape (and seal the edge of the hood), and see how it goes.

I did similarly to my Camry recently and have yet to see any gains from it, but my last tank was an oddball because I drove in the rain for about half of it unfortunately so less is to be expected. However, as of right now with my lower grill blocks (upper is going to be tricky to cover because of it's shape) I haven't noticed the fans kicking in more (I would hear them, one makes a sound like a frog) and my temps haven't moved at all (and I'm actually very low on coolant right now, which reminds me I need to fill it up). It will be interesting, once I put the partial belly pan in to bridge the gap from the bumper to the chassis, if the heat builds up in any exponential fashion or if there are any real aero gains made.

That should be your next move though, once you're sure everything is ok where it is with the grill blocks, made a panel to cover the underside of the front of the car to seal the gap that is usually between where the radiator is and the bottom of the bumper.

Hello,

Actually, on the xA there is already a couple of plastic panels extending back to below the radiator -- there are some holes in it, and the two pieces move around a bit. This would concentrate the air flow through the radiator, and if anything, it will improve the cooling.

Another aero mod I want to do is to improve the air intake for the ventilation system. It is pretty anemic and a lot of warm air leaks into it from under the hood -- but now I've got the hood taped shut! :p

G'Day,

Well, I filled the tank today:

458.8 miles (a new high)
9.882 gallons ($4.04.9/gallon = $40.01)
46.4mpg -- a new high as well, but less than I'd hoped...there was about 15-18 miles of stop and go traffic on Rt. 3/93/95, and on Rt 117 -- very thick. There were a few accidents along the way, so I'll see how things go on the next tank. Things are trending in the right direction!

I may try (partially) covering the slot just above the bumper...

dude 46 is great! you got me beat

don't you just hate it when you know your getting awesome MPG then you get stuck someplace and you are all "oh noes!" this is going to hurt

Hello,

A further modification test; I've filled in a pretty deep inset between the A-pillar and the windshield:
http://img362.imageshack.us/img362/1...hield01xv7.jpg
http://img362.imageshack.us/img362/4...hield02lk8.jpg
I'll see how these go...

You mean you filled the rain channels on the sides of the windshield?

The 1995+ Metro doesn't have any A pillar rain channels, or drip rails. Good for aero, bad when it rains (water streams freely into the side windows even if they're just cracked open a little).

I've wondered about that area of my Civic.

As you can see, the air slams right into those cannels causing a lot of drag ( I assume )

http://farm3.static.flickr.com/2094/...ca1f61e6_o.jpg

Now I know why they are designed like that . Thanks for clearing that up Metro !

Congratulations on your progress Neil ! You have some cool stickers BTW.

I just noticed you have some mini mud guards in back of your front wheels. Would you perhaps think of moving them in front of the wheels ?


I'm a little worried that you are going to screw up your paint job with that tape.
Does it come off easily ?

Hello,

Those are stock mud guards and so it would be hard to move them.

I have not noticed any residue on the paint when pulling off the tape. It is "transparent" 3M duct tape, btw.

Quote:

You mean you filled the rain channels on the sides of the windshield?

Yes, that's exactly what I did -- I didn't fill it all in, but I smoothed it out and "increased the radius". I didn't put the tape into the visible glass; just over the blacked out edge -- and I didn't cover the VIN or the inspection sticker.

Neil, I like your go-get'em style. Any plans for the wipers or mirrors? There is some intrigue in your idea for the structural storage undertray. I am looking at a tray for my truck but hadn't thought about that.

On an Outback Sport I didn't get any noticeable mpg difference with the lower grill blocked, but it also didn't hurt the cooling. Haven't tried the upper. I figure any air was going under the car instead of through the grill and under. With an undertray it may make a bigger difference. Try tucking in your mirrors.

Hello,

Yes, I'm thinking on how to best deflect air up over the wipers -- and I can put a "scoop" on the air intake for the interior vent intake, so I get better air flow w/o using the fan. See it in the upper left center:

http://img.photobucket.com/albums/v7...eroMods-04.jpg

And yes, I would love to try some video cameras and inside LCD screens for the side view mirrors (a la Aptera), or add some fairing to the existing mirrors. A clear plastic "pyramid" on the trailing side (so I can still see through it); and/or a leading face cone, would let me keep the existing mirrors intact. But if video cameras can work in the dark and in low visibility situations (fog, snow), then I think that is the better way to go. I doubt that their electrical use is very significant -- certainly much less than the stereo, and way more than enough to offset the aero gains.

They already make backup cameras -- what company will make side view cameras with some 7-9 inch LCD screens?

And yes, I would love to be able to have a body shop weld in a new floor to the hatch area -- the spare and jack could be put lower down and the volume of the storage would about double AND the aerodynamics of the rear would be greatly improved. I might have to wait until my 100K warranty expires before I attempt anything like this, though.

Check out http://www.bluedevilproducts.com/Hom...20Frameset.htm for cameras. I'm sure there are others out there, too.

Hello,

I guess I'll have to visit that web site when booted to Windows -- 'cuz in Ubuntu, NONE of the links work...:confused:

The xB's top grille does not let air pass through luckily,
but by looking at the steepness of the windshield, aero mods like this would be futile!


However, I was wondering how your tape does under all that heat from the engine?
Or could I cover a bit of my lower grill without worrying about it melting or sticking to the plastic grill?

Hello & welcome,

The tape doesn't melt -- the heat goes back, so the tape really doesn't get very hot.

BTW, I've taken the tape up onto the hood off, and replaced it with a foam gasket to seal out the air (so I can open my hood again!). I had called my local Toyota dealer about getting a proper rubber gasket (like the Camry and the Prius have), but they don't sell it as a separate item.

I also got some 1/8" "Plexiglass" to make proper covers for the fog lights -- I'm going to mark the oval onto the tape, and then stick the tape on the Plexiglass, and cut it out so it fits flush. I'll probably use tap to hold it on, but at least I'll be able to use the lights.

Hello,

I'm contemplating how one would use something to decrease the drag at the back of my xA (or any hatchback\stationwagon)? Ditto for improving the stock mirrors?

Would a row of tabs or fins along the roof and down the sides (at least down to the rear wheel openings) be the way to go? (I probably can be helped a lot by some rear wheel skirts!)

Cool. Been thinking about some mods to my xA and was worried about covering the grille. I'll get a SGII to doublecheck on potential overheating. In California, the summer heat is unforgiveable (100-103 is the norm as of late) here but I like what I'm hearing on the gains.

One guy on the scionlife forum had, for a time, a set of small round mirrors on his xB instead of the big stock ones. He made some plexi blanks to cover the holes on the door, and used some little mirrors like this: https://www.mooneyesusa.com/Store/pr...15a1d608275263

I can't recall if he specifically mentioned FE gains, but he did say that the wind noise was cut immensely, and a reduction of frontal area and drag is obvious.

Hey Neil,
What about closing off some of that lower intake?
Insert some coroplas on each side, leaving the center 1/3 open..?.

I covered up a lot of mine and it still runs about 185 as usual.
http://i46.photobucket.com/albums/f1.../Skidplate.jpg
http://i46.photobucket.com/albums/f1.../CRV/M018s.jpg

I think my air intake is about 1/5 of what it was.. :thumbup:

Hello,

I am getting consistent anyway: another tank, and ~46.5mpg again. Same thing for the last three tankfuls.

I don't think the A-pillar mod has done anything appreciable. I will pull off that tape and see how things go.

I need to put plexiglass over my fog lights -- in case I need to use them. Oh, I put some 5/16" thick foam "rubber" gasket under the front edge of the hood, so I could open the hood!

Hello,

I now have my ScanGauge II -- the highest coolant temp that I have seen is 184F -- typical is 181F. No problem at all with cooling with the upper grill blocked.

[Edit: today when stuck in traffic (sitting still!) I did see 198F -- but the fan kicked on and kept it under control -- the blocked grill has virtually no effect when the car is sitting still anyway. Once I got moving again, it came back down to ~180F.

I averaged 55mpg for my round trip commute, BTW -- even with the stop and go crap! ]

Someone could make a pretty penny with a business constructing lightweight aero pieces. I would concentrate on rear skirts for Metro generations 2 and 3.

And, there are a lot of Honda Gen1 CRVs out there that could use better MPG..:turtle:

Hello,

As you might have noticed (in my signature) my wife is now driving a Scion xD -- and the very first tankful has equaled my 90 day average. The car is ~310 pounds heavier, and has a 1.8 liter engine, a 4-speed automatic, and a slightly worse 0.32 Cd (vs 0.31 or my xA), and the EPA Combined estimate is lower at 29mpg -- and all I did was pump up the tires a little (~37psi vs the 32 recommended) and seal (most) of the hood joint to the top of the grill....

Now at 55mpg, the engine only turns at ~2,050RPM, so that may be most of how it does it. I hope to do similar front end aero mods -- esp covering the pockets where the fog light would go, and the upper grill is only for show -- and this car could be hitting 50mpg real soon.

The factory MPG gauge is a little optimistic, BTW -- it said we did 44mpg, while we actually did ~42mpg. But for the first tankful, I am quite impressed!

Hello,

I'm posting a coupla' pictures showing the current mods to my xA. I now have a foam "rubber" gasket under the leading edge of the hood -- so I can now actually open the hood. And I've made flush lens for the fog lights out of 1/8" acrylic glass (aka PlexiGlas or Perspex) -- so I can actually use the lights!
http://img.photobucket.com/albums/v7...ntAeroMods.jpg
http://img.photobucket.com/albums/v7...gLightLens.jpg

Nice looking lamp covers..
 

Should be a bit smoother now.

That tape looks like packing tape (little lines in it).
You might want to try some long lasting clear tape.

FROST KING T96H Clear Plastic Weatherseal Tape, 2" X 100'

This stuff is not thin like packing tape and works at all kinds of temperatures.
It's flexible and has a little stretch to it. Great stuff for outdoor use.
I use it to hold the Ailerons on my RC airplanes and a lot of other stuff.
I get it at hardware stores like Lowes and Homedepot.
You need a sharp tool to cut it, since there is no way you can tear it by hand.

Hello,

That sounds like it might be something I should try out.

The tape I'm using is actually "transparent" 3M Duct tape. Very sticky, and quite strong, but it does dry out and lose grip over time.