1997 Ford Aspire
 

Hey Ecomodders,
It has been a long time since my last posts (the dodge caravan) a two second update on that, i built a permanent kammback and wheel skirts and underbody pannel, and was getting mid thirties (@55-60 on highway) on the dodge for about 70,000 miles. but alas, as tends to happen with cars, they eventually reach the end of their useful lives. after 215,000 the car eventually threw a rod, and i had to retire it.

I went for 7 months with no car and felt great about it, but a recent change in jobs has required me to get a vehicle. so I bought a 1997 Ford Aspire, with only 77,000 miles on it! cost me just $1000 and it runs like a champ. i have been getting great mileage pre mod, with just hypermiling techniques. the last it I did the math on I was getting about 50. at any rate, this car is my new project. The ultimate goal is to get this car to 70 MPG. I have taken up a hobby of fiberglassing, and plan on building some fiberglass body pannels.
So far my plans include:
-Complete rear end (Boat tail and wheel skirts) made from fibberglass with a steel DOM tube skeleton
-Complete belly pan, (I learned a lot from my las one and have a pretty good idea what i want to do here.)
-Front grille block
-passenger mirror delete
-Smooth wheel Covers
-Directed airflow system to avoid compression and flow separation around wheels as much as possible
- back seat delete
- interior weight staging
any suggestions?

Aspires, from what I can tell, have their own sort of kammback built in. If I was in your position, I'd say my best bet would be to begin with getting a feel for the car, while beginning to consider the mods.

Making a more pronounced kammback would be good, as you could then consider a boat tail. Grille block, belly pan, and wheel covers are also good investments.

You mentioned making a boat tail from DOM steel tubing. Might I suggest EMT (or any sort of thicker walled, aluminum variant) conduit? For me, it's cheaper, lighter, and a lot easier to work with. It's rigid, self-supporting, and forgiving; for me, permanence would be bad if the tail sustains enough damage.

Ha ha, no fuel logging, and cherry picking a number from the car's fe computer- know what that does to your claims?

@frank, Sorry my claims seem un supported to you. i was simply trying to give a recap to my last thread. you can brush up on how i was doing before if you'd like:
http://ecomodder.com/forum/showthrea...avan-7166.html
thanks.

@ Ecofreak. Thanks for the advice, i am planning on taking it slowly. the kammback that is on the stock aspire is designed to promote a cleaner separation at the roof/ rear hatch transition. this is a pretty good technique for cleaning up a location where sharp changes in direction are inevitable, however a boat tail system would significantly clean the rearward flow. I am planning on replacing the rear hatch with a boat tail, so the DOM skeleton is for rigidity, I work with DOM at my job, and can readily get scrap for my project, so it is super strong, safe (we use it to make roll cages) and for the most part free for me. I'm working on making some models of the car to test it in a mini wind tunnel, to prove my theories in scale. the reason for this is my last project, the van has made me want to lean towards a more scientific method of testing and a more finished style of construction.

OK I brushed up. Didn't change anything.

Cd 0.072
 

Going from 50,to 70 mpg is a 40% mpg increase.
To do that at 55 mph would require an 80% drag reduction.
If your original drag coefficient is 0.36,and if you did nothing to the cars frontal area you'd need to cut the Cd to 0.072.
That's below NUNA-3.
Looks like you'd need to chop off the roof and do a single bubble canopy.And its windshield would need to be laminated safety glass.Like James Bede's old Litestar of the early 1980s.

phil, im glad you said that. Its an interesting thought. You're totally right it would take a huge improvement in resistance. I guess I had such a big improvement on the MV I thought I might be able to get a similar result from the aspire (percentage wise). what do you think is a reasonable goal then?

Cd 0.151
 

bteck,if you retain the roof and go quite insane with the car I think Cd 0.151 would be doable without a trailer.
I would do everything basjoos has done with AeroCivic.
I'd stick to the 'Template' for the aft-body.Extend the rear pillars with integral wing spoilers,(top and midway at least),then pickup on the 'Template' out to the 50% mark.
You'd be looking at 65.5 mpg HWY and you'd still have a roof big enough for friends.

so my car is similar size to aerocivic when it started, so why would i not see similar mileage as basjoos gets? just curious if there is more going on with his car than he states on his website?
--Either way, I'm planning on going a bit insane with this car, as I didn't spend much on the car and it is already ugly as sin, so i'm thinking at least I might get some efficiency gains out of it.
also, aerocivic has quite an upsweep on his boat tail, is this ideal? wouldn't it be better to "return the flow" to the level it was at before it was forced over the car? such as on the schor?
http://www.dlr.de/100Jahre/en/Portal...tenansicht.jpg

There's a few threads on boat-tail construction, and for what I can tell, they all support the idea of an upswept boattail between 4-7 degrees as a preference, while until about 15 degrees in upsweep there is serious Cd increase. If you were conscious about the length of the boat tail, I'd say push 7 degrees in upsweep.

Also, with a small car like yours it might be wisest to focus on weight. Reductions in weight on your car will go farther than deletions on a truck. I had initially suggested conduit for the build because not only is it forgiving, but lightweight. You'd might be interested in switching from steel rims on your car, and increasing air pressure in your tires, also.

I appreciate your ambition, nonetheless. Good luck and happy modding!

i eas thinking of refacing mot of the car with a fiberglass body and removing the stock steel body panels because it might do both for me eco. any thoughts on this for a horozontal profile?http://4.bp.blogspot.com/-wXaTstGgWj...ed-profile.jpg

more going on
 

I think AeroCivic has a little better Cd going into the mods,and I believe it also has a smaller frontal area.AeroCivic also has the V-tec engine I believe and Mike has been very careful about his choice in tires.Friends had the Honda Civic V-tec and were seeing real world 55-mpg with a bone stock car.So maybe there is a powertrain advantage.
I haven't a clue about gearing but you can bet that it's been highly scrutinized.
The OBD-II tech that he has also allows him real-time data acquisition with respect to lean-burn and he can really optimize his driving for mpgs.
With other than aero mods you most certainly could push beyond the mid-sixties mpg.
I won't be able to tell you anything about the trailer yet as it remains an unknown quantity.Encouraging results so far.
As far as the diffuser angle,it was modeled after an aircraft he's fond of.The steeper angle no doubt protects it from ground-strikes with steep driveways and such,and with the length and top/side camber of the boat-tail the car is realizing really great pressure recovery.

That nmakes sense, V-tec is scary cool. I was considering some other potential mods, however my lack of car-specific knowledge makes it difficult for me to assume i would be able to do much to the engine. as far as base line mileage I can get about fifty, driving hyper mile status, but not as good as the magestic V tec. I might do some tire pressure testing, I've only had the car for about a week, which means my absolute baseline is not as good as it could be. I'm really curious about the boat tail angles, i just got a high CFM fan for a mini wind tunnel I want to build, that should help me know what shape might be best. Also just a question, but would weight staging the car only increase mileage in acceleration situations correct? It should have almost no affect on highway, or am I mistaken?

Aspire
 

If you'll leave the powertrain alone during the aero mods you won't upset your baseline,and any change to your mpg will have to have come from the streamlining.
You'll also be able to know your new Cd at any point based on your mpg at a given constant speed.
As far as the boat tail 'angles' are concerned,that's been worked out with the 'Aerodynamic Streamlining Template'.If you'll use it with the Aspire it will show you proper curvature for attached flow as far as you dare to go.
You can use it for the sides as well after locating the point of maximum body camber along the sides of the car.It will be the same curvature as for the roof,only it will probably begin in a different location.Don't know where it is on your car.
The thing about the 'Template' is that if you will stay 'on the curve',at a later date,if you want to add more savings,you just extend the curvature from where you left off.
With a very light 1-wheel trailer you could have the entire tail and around Cd 0.12 if you'll fair in all the wheels.
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You'll have to help me out with 'weight staging',it's a term I'm not familiar with.
Weight is kind of a non-issue in purely constant-speed highway travel.I pushed my CRX up to 3,300-pounds ( Ford Taurus ) and still managed 50 mpg.Only a 2-mpg loss from the sub-1,900 lb original weight.
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Minimizing stops will have the greatest affect on your urban driving.My truck will get 39 mpg at a constant 45 mph.But with traffic,and traffic lights it drops to low 20s.Yes,there is a perpetual supply of oil buried beneath every un-synchronized traffic signal.

Here's a thread to get you started: AM's '96 Aspire Mod Thread

hey all,
quick update on the aspire. I have been working on getting a few things fixed in order to make it registerable. it needs a headlight fix, some new relays (common issue if any of you have aspire/festivas). meanwhile i am trying to get a good baseline mileage. I drove my first tank of gas like a jerk (trying to drive exactly as inefficient traffic does). This yeilded the following results:
297.2 miles
7.4 gallons
40.16 MPG (pretty good for trying to not hyper mile at all)
I am currently testing a tank of gas with tire pressure up (at 44, tires rated at 44) and hypermiling all the way.

The reason for this test, is with the van, I started hypermiling as I did the aero mods, and I think I may have falsely attributed some fuel savings to the aero mods. in the effort of being as scientific as possible I am trying to get some good base idea of what kind of mileage this car is really capable of.

After this tank i'll be doing the following mods this weekend:
smooth wheels
air dam

You still don't have enough baseline for meaningful results of mod tests.

Today I purchased 2 4'x8' sheets of HDPE for starting some front end aero mods. Should arrive in about five days. has anyone had experience with this material?

Also, it is really hot in utah, around 100 degrees, and the aspire, as nice as it is, does not come with A/C. Any ideas on how I can keep cool in my car without the aero cost of windows down driving?