Weight reduction

[Baltothewolf]

My thing is, I have to Traverse 2 miles of 6% grade and 8 miles of 2% I think it is, I'm not 100% sure on that. It makes me drop into 4th gear and hover around 30-32mpg for those 8 miles, coming home is when I have to come up the 6% grade, thus me wanting to decrease weight. I will also most definitely be working on aero, I'm still searching for mud flaps for my wheel skirts and wheel covers. I plan on picking up lawn edging today for the front air dam, my dad said he found me a bumper to a semi, so I may be able to make an even better air-dam.

[cowmeat]

Every day I pass an automotive shop that has had two junk plastic front bumpers piled in the trash, and every day I wonder if I could somehow use the lower part of one for an air dam.
But I know if I pulled into the driveway with one of the bumpers in the back of the Festiva, my wife would NOT appreciate the aero opportunity it would represent!

[Baltothewolf]

Originally Posted by cowmeat

Every day I pass an automotive shop that has had two junk plastic front bumpers piled in the trash, and every day I wonder if I could somehow use the lower part of one for an air dam.
But I know if I pulled into the driveway with one of the bumpers in the back of the Festiva, my wife would NOT appreciate the aero opportunity it would represent!

LOL. My dad thinks me wanting to mod my car for mpg, and the way I drive 'stupid' but he still supports it. Haha, I guess I'm blessed with understanding parents.

[oil pan 4]

Originally Posted by serialk11r

Wow, your front axle has almost more weight than my entire car weighs on it.

I think rearward bias is better because it improves traction, not 50/50 split.

That's nothing. The suburban can easily have over 2,000 pounds per tire on the rear axle (2ton RAW).
That's why I am keeping 31'' load range C tires on the back.

[oil pan 4]

Originally Posted by cowmeat

Every day I pass an automotive shop that has had two junk plastic front bumpers piled in the trash, and every day I wonder if I could somehow use the lower part of one for an air dam.
But I know if I pulled into the driveway with one of the bumpers in the back of the Festiva, my wife would NOT appreciate the aero opportunity it would represent!

Parts of other vehicles make very good aero mod part that can keep the vehicle looking stock.
You could use a large air dam off the truck or SUV on your car, it would look stock. You could build grill block plates out of other vehicles plastic bumpers, it would start to look less OEM at that point.
If you know the air dam is going to drag, better stick with lawn edging or conveyer belt.

[oldtamiyaphile]

Whenever I remove a part from a car, I see what I can do to lighten it. It might only be grams here and there but they'll add up to kilos eventually. I have a spreadsheet that records weight saved down to 0.01grams. I'm up to about 34kg from the Fiat thus far without turning it into a stripper at all. The goal is to save 10% of the car's original 915kg.

[backpacker3]

Originally Posted by Baltothewolf

No cruise control, and I have no idea about the ECU, I'm probably going to check to make sure it's the FED ECU today. As for nit picking the little things, I'm sure I will get to it all eventually. I do want to get a list compiled though.

The reason I ask about the ECU is because on some cars (mine included they're held on by a steel bracket that is pretty heavy for the size. But if you relocate the ECU to inside the car via the rubber firewall plug you can get rid of the bracket altogether. It's worth looking into.

Originally Posted by cowmeat

Weight reduction in such small increments doesn't make sense if you're having to buy replacements. If there was a way to do the actual math, and I'm sure there is, it would show you that even replacing a ten dollar shift knob would never pay for itself in that car's life.
I would stick to removing the basics, and only replace any item you already need to replace with lighter materials.
In fact, I'd work on aero and driver habits before I would even bother with weight reduction, they will pay off quicker.

That depends on how you look at it. A shift knob can be found for a buck or two if you look around for one and making one is pretty easy and can be done for just about free with stuff you can find around the house. I was actually talking about the whole shifter assembly being replaced in my previous post with a short shifter which is usually lighter and can be found for ~$30 for many cars.

While I agree that spending exorbitant amounts of money on parts that reduce weight by mere ounces or grams spending some money on parts that reduce weight is worthwhile because even though it may not be a ton of weight each time it will add up. Someone on here has in their signature " don't look for one place to lose 100 lbs look for 1600 places to lose an oz" it makes sense when you look at it that way doesn't it?

[oil pan 4]

I have finely decided on some weight reduction mods for the Camaro.
1 a fabricated tubular front cross member, it also makes room for funky engine, oil pan and exhaust combos.
2 I would like to replace the back glass with lexan because I am in an extreme hail threat area. It should have been busted out by the last 2 hail storms.
3 fiber glass hood. Its lighter and gives more room under the hood.
4 A moser made ford 9 inch, with disc brakes and aluminum 3rd member. It replaces hulking GM cast iron diff and drum brakes with stamped, fabricated steel and cast aluminum.
5 fabricated rear control arms. My old stamped GM iron is pretty rusty, as if they were equipped with rust at the factory. These fabricated units are stronger, lighter and relatively cheap.
6 Replace the old 2 core copper/brass radiator with aluminum.

What I am not doing,
Fabricated front lower control arms. They cost around $550 and they only save about "5 pounds" according to the manufacture and some of them use a funky looking ball joint setup.

Already done.
I replaced the lead acid with LiFePO4 a long time ago.

[sendler]

Does a lighter battery save fuel? What is the payback on the Lithium battery? Or thousands of dollars of rear end pieces?

[oldtamiyaphile]

Originally Posted by sendler

Does a lighter battery save fuel? What is the payback on the Lithium battery? Or thousands of dollars of rear end pieces?

In theory it does. But unless your car is particularly weight sensitive (like my 2 cyl turbo Fiat), then the gains are tiny.

For my conventional 1.6L Renault, I see a deficit of 0.0018L/ 100km per pound of weight in 100% city use (20 MPH AVG speed). That figure comes from towing a trailer that no doubt also adds aero drag (it's slightly taller than the tow vehicle) and there's rolling drag from an extra axle.

So best case for a NA engine you might gain 0.2L/100km per hundred pounds.