Maxing out Fuel Efficiency

[mikeyjd]

So I have had a few days off work and have been studying and playing with the idea of just about each and every engine swap that I've found reference to on here. And frankly I think I would probably enjoy trying each one. But for now I haven't yet reached my initial goal with the Festiva which was to absolutely maximize fuel economy. I know there are quite a few mpg's still on the table and that this car has more to offer in this area. I am wondering if anyone has suggestions for possible fuel efficiency upgrades that I could do to a stock engine b3 engine or tranny that would net me any noticeable gain. I have several ideas as it pertains to Aerodynamics that I am entertaining, but I've tackled most of the low hanging fruit in that department. Any sound ideas are appreciated and advice as to how to go about it even more so. Thanks.

Michael~

[crazyrog17]

A ported and polished head/intake/exhaust would allow easier breathing. With the addition of a different profile on the cam, accentuating low end torque, you could keep the revs down low and not be as bogged.

Other ideas:
Propane conversion?
Lightest/tallest wheel and tire combo for less unsprung weight and lower cruising rpm.

[FestYboy]

more compression

[Rocketman]

The Festiva is light with a good powerplant, but it lacks certain aerodynamics...

This guy was getting nearly 70mpg in his Civic



I believe he has much more than just Aero mods, though. http://www.aerocivic.com/photo.php?i...%20boat%20tail

[mikeyjd]

The Festiva is light with a good powerplant, but it lacks certain aerodynamics...

This guy was getting nearly 70mpg in his Civic



I believe he has much more than just Aero mods, though. http://www.aerocivic.com/photo.php?i...%20boat%20tail

I know all about Mike's civic. He is one of the reasons I got into hypermiling. I am looking at doing some more serious aero mods but have wanted to maintain as much of a stock look as possible for as long as possible.

He did swap out a civic vx lean burn engine for his stock one once it pooped on him.

[mikeyjd]

more compression

How do I add that?

[mikeyjd]

A ported and polished head/intake/exhaust would allow easier breathing. With the addition of a different profile on the cam, accentuating low end torque, you could keep the revs down low and not be as bogged.

Other ideas:
Propane conversion?
Lightest/tallest wheel and tire combo for less unsprung weight and lower cruising rpm.

Thanks for those ideas. I will look into them.

[sketchman]

+comp = shave the head. Pretty sure I remember Mattdickmeyer got somewhere around 11:1 with just head shaving and his flat "faced" valves, but don't quote me on that.

The "better" way to do it would be to ask Matt for some raised comp pistons. OR go 'to the wall with some raised comp flat tops and give up your non-interference crutch for a better CC design easy as pie. Won't be cheap, though.

I know everyone just loves the non-interference design, but plenty of engines use an interference design, and it's not as big a deal as it's made out to be, IMHO. Valve reliefs are not your friend when it comes to 100% focus on a good design rather than an idiot proof one.

[mikeyjd]

+comp = shave the head. Pretty sure I remember Mattdickmeyer got somewhere around 11:1 with just head shaving and his flat "faced" valves, but don't quote me on that.

The "better" way to do it would be to ask Matt for some raised comp pistons. OR go 'to the wall with some raised comp flat tops and give up your non-interference crutch for a better CC design easy as pie. Won't be cheap, though.

I know everyone just loves the non-interference design, but plenty of engines use an interference design, and it's not as big a deal as it's made out to be, IMHO. Valve reliefs are not your friend when it comes to 100% focus on a good design rather than an idiot proof one.

I shot Matt a pm last night to see if he had any good ideas. What you're saying sounds good. I wonder how much $$$ we're talking O.o

[Prafeston]

You could always do the Kammback idea...it's kind of like the Aerocivic, but not so severe. Someone on the forum did it with theirs for awhile. I think the cardboard was just duct taped on...

Here's a Geo that did it.

http://ecomodder.com/forum/showthread.php/project-making-permanent-metro-kammback-extension-3518.html

Found the Festiva that had done it. Rear skirts for the wheel wells and the Kammback for the back.

http://www.fordfestiva.com/forums/showthread.php?37873-KAMM-BACK-Festiva!-WHAT&highlight=Kammback

[Bert]

A ported and polished head/intake/exhaust would allow easier breathing. With the addition of a different profile on the cam, accentuating low end torque, you could keep the revs down low and not be as bogged. Other ideas:
Propane conversion?
Lightest/tallest wheel and tire combo for less unsprung weight and lower cruising rpm.

I'd agree with the swap to 155/80-13s via Metro/Swift/Firefly rims to improve mileage but not the suggestion to switch to propane. Propane has considerably fewer BTUs (ie less inherent energy) per gallon than gasoline. People only switched to that stuff because it was clean and was much cheaper at one time. Make sure you use non-ethanol blend fuel (In Canada only Premium is ethanol-free) when you're doing runs; ethanol also has fewer BTUs per unit volume.

[sketchman]

Haha, memory serves!

http://www.fordfestiva.com/forums/showthread.php?27805-Matts-B3-build-step-1-N-A

Cliff notes: 11:1, stock bottom end including pistons, shaved head, and over-sized valves.

[Aaronbrook37]

What it all really depends on is how much you're willing to spend. A high quality economy camshaft regrind would do wonders towards this goal as would increased engine compression, but those modifications don't come cheap. It's worth starting out ensuring that you do have a well-functioning motor with good compression, excellent recent tune-up parts, and the necessary pre-requisites to having good fuel economy. As Rocketman states, we've got the aerodynamics of a brick... so there's plenty of room for improvement in that regard worth examining.

[crazyrog17]

Alternator cut out/delete. I've heard of significant gains with this modification.
A 100% duty cycle 50A solenoid, knock off arduino and a little electrical/programming know how could net a few MPG.
I read somewhere this system was used in the xfi metro. The micro controller would monitor a few things likebattery voltage, load on the system and engine rpm to decide when to suck power from the crankshaft.

[Movin]

Mix a high explosive in small amounts into the combustion . The safest way is to make hydrogen from water and let it mix with the air charge going in. There is no advantage from extra fuel but this starts the flame front in many places instead of just the spark plug. This enables complete combustion of a lean mixture and lowers hydrocarbons ( unburned fuel ).
Because long flame fronts are stopped more compression and timing are possible without detonation, even on lean mixtures. The combustion pressures have less of a spike and more of a broad hump on top, the kind that makes more torque.

These improvements are not going to be as big as most claims and involve a lot of tinkering.
The amount of work and money to obtain the a increase in mileage is not worth it. BUT if you want to be at the top or love to do it yourself it is a lot of fun.

You need the lightest weight to win in town mpg, you need the stretched teardrop look for faster more constant speeds. You need both for mountain driving.