bolt ons that help/hurt fuel economy?

[trebuchet03]

Originally Posted by LostCause

Aluminum Flywheel:
I'd like to know. I'd assume lowering reciprocating mass would lower friction/energy consumed, but it kills the idle and makes it easier to stall. Some first had testing would be nice...


High-Output Alternator:
Not too sure on this. I don't know whether a larger alternator could charge a battery faster than one smaller...which is the only area I could see a decrease in engine load.

- LostCause

Car Flywheels don't reciprocate

And I agree about the alternator issue... The rating for an alternator is max output - not nominal. Being able to charge faster isn't necessary a good thing - and even then, it's more load over for a shorter duration...

[Chris D.]

Originally Posted by diesel_john

electric fan only

http://farmindustrynews.com/tractors...-new-products/

what does this john deere link have to do with what this post is about?

typo?

Originally Posted by LostCause

I can't imagine mechanical fans working on anything but longitudinally mounted engines, which are really only common to trucks, SUV's, sports cars, and classic cars. They are probably still being used because they are cheap, and with a fluid clutch can still be effective/efficient.

Thats what I have, a front engined rear wheel drive truck..
they use em on just about every rwd truck out there..

Headers:
Any aftermarket exhaust is going to be interested in high-hp, which is not useful for hypermiling. Headers that are "tuned" to shift the torque band into lower rpm's would be useful, but they would probably have to be custom made and mated to higher gearing to be useful.

so a direct fitment mite not be the way to roll then?

Freeflow Exhaust:
I don't see much of a benefit as under hypermiling conditions the exhaust shouldn't be much of a constriction.

I can see it from that point of view, but what about in reguards to FE and low end torque?

Electrical --> Mechanical Fan:
Beneficial, especially if the fan is not clutched (unlikely). I've seen people switch from clutched fans to electric fans and record a mpg/hp improvement, but I bet the improvement is less than moving from an unclutched fan.

I'm not sure if its clutched or not..
but I'll find out..

Aluminum Flywheel:
I'd like to know. I'd assume lowering reciprocating mass would lower friction/energy consumed, but it kills the idle and makes it easier to stall. Some first had testing would be nice...

reciprocating? maybe rotational.. thats a new one to me..

google a "reciprocating saw" and compaire that to what a flywheel does..

In terms of street/driveability, takes a little bit to get used to it ,
but it was very daily drivable.. made a great deal of difference in acceleration and hp difference in a race vehicle i had, not sure about FE goals tho

Underdrive Pulley:
I would expect a marginal improvement in mileage, but I have no idea of the impact on the cooling or oil pump. An underpullied alternator will probably make up the speed difference by increasing field current (i.e. no MPG gain). Removing items from the circuit (alternator delete, electric coolant pump, etc.) will see bigger gains.

alternator delete? how far would ya get till you kill the battery then the ecu looses proper voltage and your DOA.. I donno about that.

High-Output Alternator:
Not too sure on this. I don't know whether a larger alternator could charge a battery faster than one smaller...which is the only area I could see a decrease in engine load.

Its something I want to do for stereo equipment and having an onboard compressor setup..

- LostCause

Chris D.

[Ryland]

Originally Posted by WTFM8

Is it just large pickups and SUVs that come with belt-driven fans anymore? I'm wondering why this design hasn't been phased out, since the electric just makes more sense. I suppose this can be likened to air-cooled vs. water-cooled motorcycle designs.

In the case your car came with an engine-propelled fan, I do think the electrical replace would help.

They have the mechanical driven fan because it's more efficient if the fan is running most of the time, like in a truck! trucks are designed to be under load, as I said before, it's less efficient to convert mechanical to electrical and back to mechanical if it's going to be running 80% of the time that the vehicle is running, my cars fan rarely comes on, the fan on the truck at work is almost always on, why? because it's a truck, and is normally hauling a 5,000+ pound trailer.

If you are using the truck as a sales vehicle, or to tote the kids around, then yes, go with an electric fan, if you use it for it's intended perpus, then stick with the direct drive fan.

[Daox]

I'd definitly agree with Ryland, and most of what LostCause said.

A header properly designed for economy (which eliminates 99% of the headers out there) will give you more more low rpm torque instead of high rpm torque. If you are driving for fuel economy you will never use high rpms so that extra high rpm torque is completely wasted. As mentioned, you'd have to have one custom designed and fabricated. Last I checked this costs upwards of $1000+.

A free flowing exhaust does exactly the same thing, more high rpm torque which you will never use if driving for fuel economy.

I agree with Rylands comments on the E-fan and aluminum flywheel.

Underdrive pulleys can provide benefits, but you have to live with reduced output from your water pump and alternator then. That means you'll lower your towing capacity due to not being able to disperse enough heat, and you won't be able to use that nice big ol sterio that you want.


Personally, the only one I'd even look into on your list is an electric fan.

[WTFM8]

Originally Posted by Ryland

They have the mechanical driven fan because it's more efficient if the fan is running most of the time, like in a truck! trucks are designed to be under load, as I said before, it's less efficient to convert mechanical to electrical and back to mechanical if it's going to be running 80% of the time that the vehicle is running, my cars fan rarely comes on, the fan on the truck at work is almost always on, why? because it's a truck, and is normally hauling a 5,000+ pound trailer.

If you are using the truck as a sales vehicle, or to tote the kids around, then yes, go with an electric fan, if you use it for it's intended perpus, then stick with the direct drive fan.

You know, I've only ever open my truck's hood during oil changes. I really should take a look at that design. I suppose the fan design goes along with most of the other engineering in the truck, which seems to be absolute overkill for commuting, but comes in handy when you're pull a trailer with a loaded bed, which is what these vehicles were meant for.

[LostCause]

Originally Posted by trebuchet03

Car Flywheels don't reciprocate

Good point...

Originally Posted by Chris D.

alternator delete? how far would ya get till you kill the battery then the ecu looses proper voltage and your DOA.. I donno about that.

MetroMPG did an alternator delete awhile ago and saw a 10% mileage increase. He used a deep cycle battery and topped it up at home with a trickle charger, I believe. As a safety measure, he kept a custom serpentine belt in the car so the alternator could be reattached if needed.

You run the risk of destroying batteries if you deeply discharge them (depends on commute length), but the potential savings are large.

Its something I want to do for stereo equipment and having an onboard compressor setup...

This will probably work against you since subs, amps, and heavy gauge wiring are all pretty heavy. A large alternator will encourage you to add more extravagence (weight) to your car. The compressor might be useful if it allows your to vary your ride height, but your car is already lowered.

- LostCause

[Chris D.]

I'd kill it with my stereo..

what good is a vehicle without some somfort features..

if I wanted a super ultra mega commuter I'd gut out a festiva so it only had a steering wheel and pedels..

My vehicle makes me money, thats about the only difference
between mine and the majority of other people on here..

[WTFM8]

Originally Posted by Chris D.

My vehicle makes me money, thats about the only difference
between mine and the majority of other people on here..

Oh really? I work as a courier part-time, so my car pays for itself and then some.

Plus, I'd say that anyone who drives to work in a car has a vehicle that "makes them money."

[LostCause]

I drive to school in my car, so does that mean my vehicle helps me lose money x 2?

- LostCause

[Chris D.]

Originally Posted by WTFM8

Oh really? I work as a courier part-time, so my car pays for itself and then some.

Plus, I'd say that anyone who drives to work in a car has a vehicle that "makes them money."

you know what I mean..