Weight reduction

[oil pan 4]

I have been looking into weight reduction for my car and found this:
http://aluminumintransportation.org/...th%20cover.pdf
It starts to get very interesting once you get past the first 24 or so pages of filler.
It has lots of good info I think.

Top gear gave me the idea when they gutted an old jag and removed 400lb and trimmed 1.2 seconds off the "not to 60"mph time and 5 seconds off the "not to 100"mph times. Then I figured I would look into it for fuel economy reasons too.

I am not looking for mods that kill drive ability. Such as when I pulled the back carpet with pad out of my car to clean and store it. After a week the added road noise lead me to put the carpet and pad back with a little added sound deading material.

The EPA had there own numbers which I figured were overly optimistic.
I am sure every one has herd the one about 100lb meaning the difference between 1mpg. I always found that one hard to believe. In my truck it took more like 500lb to make a 1mpg difference.

[CigaR007]

The thing is, that weight will have the biggest impact on fuel economy in stop and go traffic. Highway fuel economy savings will be negligible in my opinion.

Weight reduction is good, but only to a certain extent. I would also be concerned about the weight distribution of the car being affected; if too much weight is removed, hence affecting the overall balance of the car.

[Frank Lee]

Fe gains from weight reduction mainly kick in when the drivetrain is downsized/optimized for the lower weight. Just pulling the weight out without doing that mainly helps acceleration.

[oil pan 4]

My car weighs 2050 pounds up front and 1450 in the back.
Any front wheel drive will suffer even worse weight distribution.
In a rear wheel drive car 50% 50% is ideal. Right now its pretty close to 60/40.

For me there is no threat of reducing and moving weight around having a negative effect on handling.

[Sven7]

Originally Posted by CigaR007

The thing is, that weight will have the biggest impact on fuel economy in stop and go traffic. Highway fuel economy savings will be negligible in my opinion.

Weight reduction is good, but only to a certain extent. I would also be concerned about the weight distribution of the car being affected; if too much weight is removed, hence affecting the overall balance of the car.

Yeah it throws the weight balance off, but a little FWD oversteer never hurt anyone On a truck it matters less.

I took the rear seats out of the Anal Probe. Since I never used them anyway it was a really effective mod, and netted me tons more cargo space. If you have AAA coverage, take the spare tire out- that's probably a good 50 lbs. With Suburban you could save a ton of weight by just removing the seat backs when not in use. I'm not sure what you're using the vehicle for but if it's a daily you won't need all those seats. If it's a work truck you could probably use the cargo space.

Lightweight alloy wheels will also net you some weight savings where it counts. It'll help with both acceleration and braking. Look on the internet for specs on different wheels with your bolt pattern. I'm sure those C/K's have plenty of wheel options, and there are probably some cheap, light stock wheels to be had.

[oil pan 4]

For the truck:
Yeah the back seat removal was truely the first mod, did that when I first got the truck back in 2006. Never had the seat in there since, I think I will sell it and try to get a few bucks for it.
I have always used the suburban as a covered pickup truck. I always need the cargo roomm not the seating capacity.
I pulled that 3rd row seat out and has to weigh well over 100lb.
The full size spare tire and jack are always gone unless I am going on a road trip.
My yokohama 31x10.5R15 AT-S tires weigh 44lb when new, plus another 15 to 20 for the steel rims.
I am not too worried about weight on the truck because it weighs 3 tons already gets very good fuel milage and there is still room to pick up 2 or 3 more MPG with motor mods and then another MPG or 2 to be had with mild aero modds.
My biggest consern about weight when dealing with the truck is when towing and hauling.
See this in reguards to tires and weight for my truck or anyones truck before you go sticking skinny tires on your machine to "save fuel":
http://ecomodder.com/forum/showthrea...tml#post258808
With big work trucks you just cant go all out for fuel ecomony, if you can then you should think about getting a car.

[oil pan 4]

For the car:
The car is where I would like to strip off a few hundred pounds and move some weight from the front to the rear to get closer to 50/50 weight distribution with out hurting drive ability or safety.
Mods that are out are:
Removing carpet and padding, been there done that, no thanks.
Relocating battery to the rear trunk area. For some reason my rear bumper attracts drunk or distracted drivers so there is no way I am putting the battery next to the fuel tank in what would be the "crush zone".
I am not cutting out support structures, such as the frame rail around the door.
Not replacing side windows or wind shield with lexan.

Planned mods for weight loss among other things:
Cast iron small block chevy to aluminum LSx engine swap, good for at least -120lb (and +200 hosepower, +5mpg)
PA racing tubular K-member for LS engine swaps, with coil over conversion, with rack and pinion conversion good for -50lb
Front lower control arms for a coil over conversion -20lb
Converting to rack and pinion -30lb (not sold on this one yet)

Weight loss and hail proofing:
Repairing T-tops with broken glass I have with carbon fiber, -10lb (each side) and it would look cool.
Swap the rear window to lexan, -20 to -30lb
(I hear the hail in NM breaks a lot of glass T-tops and rear windows, if I can sell the rear glass this could be very cheap to do)
Replace lead acid battery with a lithium starting battery and relocate under the rear seat for -30lb
Replace stock steel hood with Daytona IROC style fiber glass, its the only visual mod I have ever cared for and it would be good for at least -30lb
(The hood would also be nearly hail proof, plus I can sell my old hood making this a fairly cheap mod too)

[oil pan 4]

I was watching history channel, modern marvels: "Aluminum".
They had a GM engineer (who had an engineering PH.P) says that "a 10% reduction of mass gives you an 8% boost to fuel economy".

[gone-ot]

Originally Posted by oil pan 4

I was watching history channel, modern marvels: "Aluminum".
They had a GM engineer (who had an engineering Ph.d) says that "a 10% reduction of mass gives you an 8% boost to fuel economy".

I'd be VERY wary of anything regarding FE that came from GM mouths, regardless of their credentials.

[mechman600]

The GM engineer is right if he is talking only about city mpg.
Highway economy is all about Cd, not weight. Weight reduction, unless extreme enough to change rolling resistance, is unlikely to affect highway mpg.