Official TOTM: AdFab Weight Loss Program

[Matt S.]

That's right folks, with out talking to any of the mods or people who run this place, I have decided to add spice to the AdFab forum with a Topic Of The Month. I will be doing this one time a month with no perfect interval. Just expect one every month!
This months topic is Weight Loss. In this thread, we will discuss the advantages/disadvantages, how to's/how not to's, and anything else that may come up. Hopefully this will be more than a success for you to understand weight loss, but for you to desire it. The only thing I ask is that this TOTM stay on topic and will get you to start other threads to spur more AdFab work.

First things first. A brief explanation of weight and the terms that you may see used.
Weight = The vertical force exerted by a mass as a result of gravity. If you do not know what weight is, please move yourself to a school where you can become educated:conceited
Unsprung Weight = The weight of all components not supported by the springs of the car. This includes the tires, wheels, axle assemblies, and ONE HALF of the springs, shocks, and control arms (suspension links).
Sprung Weight = The weight of the chassis. This includes the body, frame, engine, transmission, transfer case, all components mounted to these items, and ONE HALF of the springs, shocks, and control arms (suspension links).
Pig = Slang for a car that is very heavy
Balemic = Slang for a car that is very light.


Start with the advantages/disadvantages of weight loss.

Your Jeep slower now than it used to be? Got a winch and the kitchen sink with you? How about huge bumpers that are not only bullet proof but double as armor plating? Maybe you have to many stickers!Weight is obviously causing your stock motor to work much harder. Now you need a stroker motor or a v-8 just so you can get out of your own way. When you cut weight out of your Jeep, that straight 6 becomes a "v-8". You want speed? Lose weight folks.

So now your Jeep can go at least as fast as it did as stock. You say " I didn't get a Jeep to drive fast!" Well, how about this. You got that Dana 30 still? I do! Can't afford to swap to a Hi9 or 60? I can't! Problem solved! Lose weight! Regardless of what people say about axle strength, its all relative. Weight plays a large role in part failure. With less stress on your axle shafts, drive shafts, tcase, transmission, and motor... you're less apt to break things. Depending on the terrain you wheel and the driving style you develop, you could make weaker parts last just as long as the stronger parts.

Ok, so I have a better chance of not destroying my Dana TURDY, but how does all this help me off road? I thought the heavier you are, the better the traction? True, but think of this. You ever tried to push a person in a wheelchair up a steep hill? Sucks huh? Ever pushed an empty wheelchair up a steep hill? You can find ways to make it fun! Traction will become important by the tire choice, off road ability is largely effected by the ability to overcome an obstacle. The lighter you are, the better your vehicles ability to overcome obstacles.

Wow! So losing weight is just the greatest thing since sliced bread! But wait, what are the really bad sides of it? If you consider choosing to lead a more healthy lifestyle due to the Jeep weight, not taking your mom and your moms moms valuable kitchen, and thinking more liberal when it comes to tools and spares. The largest disadvantage of cutting weight is that levels of comfort are lost most of the time. A small price to pay in my mind.


How to lose weight on a full body rig: Start with carrying only the tools needed to change the spares you must have. Carry only the fluids you need to get you off the trail. Lose those oversize bumpers and winch cables. Switch to lighter and better designed bumpers and go with a synthetic cable for the winch. Ditch all the interior you can handle. Remove carpet, extra seats, panels, power windows, power locks, etc. DO NOT use bed liner as a carpet replacement! That stuff is heavy and black paint works just fine! Removing doors, dash, a/c, heater and hatch is a great way to lose extra weight, but may not be an option for some. Ditch the stock seats and seat mounts. Go with a good quality light weight seat and hard mount your sets safely to the floor or cage.

How to lose weight on a chopped rig: This is harder than it may seem. Get rid of all glass, ditch the dash, a/c, heater, all unnecessary comforts, lose body panels that bolt on and you don't think you need. I recommend keeping the hood:wierd: . Trim all extra brackets and mounts that are no longer used. Strip wiring harness down to the bare minimum. Do not go overkill with the tube. Use only whats needed to serve the purpose. Run air shocks or coil overs to help eliminate the coil and shock weight. Use aluminum rims. Get quality tires and ditch the spare. Switch to a plastic fuel cell and keep it around 10 to 15 gallons. Basically... be creative with it. Just don't sacrifice the safety of you and others.




Care to add anything? What did I miss? Need more details on it? Testimonials? Examples? Lets build this TOTM to a great tech source.

[vetteboy]

Excellent first topic, which I think is often overlooked in buildups. Mine included. :)

So in relation to strength vs. weight - what would you consider the 'minimum' requirements for reinforcing the unibody structure on something that already has heavy axles and tires, to keep it from fatiguing at critical points but not go over the top with plating everything?

[Ludakris]

this is a good topic..
I have a couple questions.. I still have a full body rig, no interior except dash and seats,
what are some good areas to remove weight now.. I would like better seats, but I am boney so I cant see me bouncing on plastic seats..
are there areas I can drill out to remove weight without sacrificing strenghth?
I have seen removing weight from the hood with a hole saw in the structure, where else can I do this? what about building bumpers with said holes, would they still be strong enough?

with relation to the A/C, has anyone removed the evaporator and kept heat? how much of a pain is this?
I hope to be doing alot of this work this winter.. so I will actually wheel it next year...

[ponyracer1]

this is a good topic..
I have a couple questions.. I still have a full body rig, no interior except dash and seats,
what are some good areas to remove weight now.. I would like better seats, but I am boney so I cant see me bouncing on plastic seats..
are there areas I can drill out to remove weight without sacrificing strenghth?
I have seen removing weight from the hood with a hole saw in the structure, where else can I do this? what about building bumpers with said holes, would they still be strong enough?

with relation to the A/C, has anyone removed the evaporator and kept heat? how much of a pain is this?
I hope to be doing alot of this work this winter.. so I will actually wheel it next year...

I wouldn't go drilling holes in a unibody vehicle, for the limited weight you'll save you'll be weakening the chassis ALOT. Look at replacing the side and rear glass with plastic, glass is HEAVY. Or just back half it and loose the roof all together.

[Menzenski]

this is a good topic..
I have a couple questions.. I still have a full body rig, no interior except dash and seats,
what are some good areas to remove weight now.. I would like better seats, but I am boney so I cant see me bouncing on plastic seats..
are there areas I can drill out to remove weight without sacrificing strenghth?
I have seen removing weight from the hood with a hole saw in the structure, where else can I do this? what about building bumpers with said holes, would they still be strong enough?
I have basically the same questions. I think I've taken out everything obvious. I don't have heavy aftermarket bumpers; I have stockers with tow hooks. I don't even have any sort of audio system, unless you count my CB. And mine is a two-door, so it's already lighter than most.

I can only think of two questions right now. I want to ditch most of my A/C to prepare for an eventual OBA system. Do I need to have the refrigerant professionally evacuated before I start removing stuff?

Also, my doors are removeable, and I'd like to replace the big side windows with Lexan or similar before I go wheeling again. But I don't know what to do about the hatch. Has anyone been able to make the hatch easily re-attachable? I haven't looked closely at the hinges/mounting, but how hard is it to put back on once it's been taken off?

[GSequoia]

tI would like better seats, but I am boney so I cant see me bouncing on plastic seats..

Beard Seats are comfy and very light. Check 'em out.

[cracker]

Thread is useless without pics. :D

I'm on the biggest looser program: :looser:

http://beta.propichosting.com/FileHandler.ashx?pa=450016572&sub=26&timecode=632976700809218750&checkref=1

I was about 4600 about two months ago. I am hoping to be 3900 or lighter when I am done. Yeah, thie winshield is coming out too ;)

[shortxjdoug]

Thread is useless without pics. :D

I'm on the biggest looser program: :looser:

http://beta.propichosting.com/FileHandler.ashx?pa=450016572&sub=26&timecode=632976700809218750&checkref=1

I was about 4600 about two months ago. I am hoping to be 3900 or lighter when I am done. Yeah, thie winshield is coming out too ;)

weld in some tube to keep her from folding and wheel her as she sits :thumbup:

[Capt. Nemo]

Thread is useless without pics. :D

I'm on the biggest looser program: :looser:

http://beta.propichosting.com/FileHandler.ashx?pa=450016572&sub=26&timecode=632976700809218750&checkref=1

I was about 4600 about two months ago. I am hoping to be 3900 or lighter when I am done. Yeah, thie winshield is coming out too ;)


I don't know man, I think the "Back to the Future" hover board mod is where it's at...

http://img.photobucket.com/albums/v202/muddyjeep1/wideshotfront.jpg

[shortxjdoug]

I don't know man, I think the "Back to the Future" hover board mod is where it's at...

http://img.photobucket.com/albums/v202/muddyjeep1/wideshotfront.jpg

i bet that makes for a fun tow :D

[Weasel]

If you have ever thing torn apart start looking where the factory ribbign anf reinforcemtns go. You should be able to cut the areas that have no ribbing or reinforcements out. Or section I would think atleast. Like the hood, think four holes and leave the bracing.

[BrettM]

If you have ever thing torn apart start looking where the factory ribbign anf reinforcemtns go. You should be able to cut the areas that have no ribbing or reinforcements out. Or section I would think atleast. Like the hood, think four holes and leave the bracing.
forget that, the hood isn't structural so cut out the bracing and leave the sheet. just don't stand on it.

[Ramsey]

anyone have some numbers they can post up. doors, windows, carpet, hvac etc...

[CW]

For a full bodied rig fieberglass fenders and hoods are available fairly cheaply, I'm not sure on the exact weight though. Dr. Dyno has numbers on what a few things weigh on his site if I remember right.

[BrettM]

my doors ('88 MJ, same as 4 door XJ, manual windows and locks) were 55 pounds each.

a lot of weights and rig-diet ideas were covered in this thread: http://www.naxja.org/forum/showthread.php?t=44176

[Matt S.]

I am working right now on getting a large amount of wieghts compiled. I wont let these threads die, but I started this one prior to research.:flipoff:

Good link Brett... forgot about that one.

[XJ_ranger]

anyone have some numbers they can post up. doors, windows, carpet, hvac etc...
the rear seat (both pieces) and rear carpit (for the cargo area) is good for 55lbs... in my 92...

[shortxjdoug]

97+ xj's are the ones cursed with the fat IMO, with the metal hatch and much heavier doors being the main problems. especially power doors, mine have to weigh 70-80 lbs each. usually before wheeling i lose the fronts but i'm heavy on spares (tire, front shafts, one rear, driveshafts, fluids, tools). next summer i'm looking at losing all four doors with tube doors replacing the rears (to keep my junk from falling out :D) as well as a basic rollcage added. She may be fat but that just means i have to go slower ;)

course all this is speculation: i don't know any exact difference in weight between 97+ and 96- but i would be intersted to find out, all the 96-'s i've owned have been faster on their feet than my 98

[XJ_ranger]

97+ xj's are the ones cursed with the fat IMO, with the metal hatch
IIRC - the steel hatch is lighter than the fiberglass...

[nhrocker]

the rear seat (both pieces) and rear carpit (for the cargo area) is good for 55lbs... in my 92...And if you're pulling the rear bench you might as well pull the seat belts. It may not seem like much, but all the different pieces add up fast.

[DirtyMJ]

Has anybody considered looking at that really heavy lump of cast iron under the hood? Yes, the 4.0. What's it weigh? I've never pulled mine, but, based on what I've heard others say, it probably weighs near to a BBC.



I'd suggest looking at a Chevy 4.3 or LS1 just for the whole options involving drivetran possibilities.


Or, if you're dead set on the 4.0, there's a fancy aluminum head for it out there. Just might be the excuse to buy one, eh?

[GSequoia]

Head probably weighs like 50 - 70 pounds, haven't weighed it but have one handy.

4.0 is nice and torquey, good for the trail. Most of the weight is in the block though, not the head.

What would be fun woould be to compare the weight of a 4.0 verses, say, an all aluminum LS1 (is that the alum. 350?).

[DirtyMJ]

What would be fun woould be to compare the weight of a 4.0 verses, say, an all aluminum LS1 (is that the alum. 350?).



Well, it's a 346ci actually... But yeah, it's the all aluminum 5.7L v8. Can't remember the HP/TQ specs on one, but it blows the 4.0 out of the water to say the least. And with a few bucks in mods you can easily be making 500/500 out of one.


And regardless of what people think, you can actually build an engine that is not an inline configuration that makes a decent amount of torque off idle...

[shortxjdoug]

And with a few bucks in mods you can easily be making 500/500 out of one.


do you realize how many expensive parts i could break with all that HP :D

[MJ_Chubs]

What would be fun woould be to compare the weight of a 4.0 verses, say, an all aluminum LS1 (is that the alum. 350?).

From Novak's website (estimated, accessory loaded weights):

4.0L: 515 lbs

Gen I&II SBC: 550lbs
Gen III SBC: 470lbs
LS1: 407lbs


From a Ford forum:

SBF 5.0L: approx 450lbs

[Gerr]

Id like to loose the ac compressor anyone know where I can get a pully to put in its place for a 93?

[XJ_ranger]

And if you're pulling the rear bench you might as well pull the seat belts. It may not seem like much, but all the different pieces add up fast.

also for me - they seat belts make great tie points for putting ratchet straps in, so im willing to keep them around just for that fact...

[csuxj]

Ok, adding to the topic: What amount of weight loss will actually lead to improved wheeling capabilities? I mean, if I get rid of my rear seat and carpet, it's not going to keep me from breaking my dana 30

On a full bodied rig, lets say I get moderately aggresive with this jeep diet and drop my 3900 pound rig to a 3600 pounder. Let's say I lose a few pounds myself even (hey, if it improves my wheeling) and I'm 350 pounds lighter than I was before. What benenfits can I expect from this amount of weight loss?

For me, this is the most important part of this topic. Before I start removing all of the comforts of my rig, I want to know what I can really expect to gain from weight loss.

Any thoughts?

[CRASH]

Defying graviy is really where the weight savings make the most difference.

Light, well designed rigs climb like no other!

[FatXJ]

When I was running my 87 XJ I did a total weight loss program for a DD. I removed the carpet, headliner, interior plastic, A/C condenser, foam padding under hood, useless lines and charcoal canister, body molding, rear seat, exhaust, and the doors for summer. I replaced the rear bumper with an aluminum one that was stronger and lighter. I noticed a huge difference in the way it handled off trail and even on the street. It was admittedly loud and cold in the winter but it was worth it.

[BlueGerbil]

I´ve just bought a set of aluminium rims w/ the correct b/s, so I can loose my steelies and the steel wheel spacers.

I´ll also replace the steel winch rope w/ a synthetic one and the roller fairlead with a hawse fairlead.

A friend of mine is just building his first carbon-something-fibre hood for his MJ, that should be the next step.

I´ve got a heavy rig (bumpers, roofrack, winch) - so I´ll try to save some weight where it´s possible without sacrifing any protection or functionality.

[Ludakris]

I took the time to remove the A/C condensor this weekend.. yeah, that is worth about 1 lb! :wierd:

I didnt realize it would be that small, its the size of a good trans cooler...

but I am sure a saved some OZ's by not re-installing all those screws and bolts...and the broken ones will save some too!

[Matt S.]

Cannot add much right now, but the AC compressor weights in at 20 lbs even.

[IntrepidXJ]

Id like to loose the ac compressor anyone know where I can get a pully to put in its place for a 93?

i would like to do the same. anyone?

[Matt S.]

i would like to do the same. anyone?


Yes, go to the dealership and buy the pully assymbly for non a/c units. :yelclap: Uses the same belt even.

[IntrepidXJ]

Yes, go to the dealership and buy the pully assymbly for non a/c units. :yelclap: Uses the same belt even.

sweet.....got a part number for us lazy peoples ;)

[Captain Ron]

...
I don't have heavy aftermarket bumpers; I have stockers with tow hooks.
...

I've had pretty good success doing this. The very first thing most folks do it seems, is add a whole lot of weight to the ends of the vehicle. Most of the aftermarket stuff is very heavy. The stockers do get damaged, but I've been able to keep 2 spares of both on hand, and all the end caps, in the right color with no problem.

I get them for free, and have an endless supply from the guys putting aftermarket bumpers on. :D

--ron

[CRASH]

I just got a set of MetWrenches (actually, cheap Indian knockoffs) for my tool bag. I just dropped 4.5 lbs from my tool bag because I have a single set of box wrenches instead of two, and I don't have to cuss when I grab a 9/16 to take off a 15mm.

Now I'm down to 4846.5 lbs.

[Ludakris]

Yes, go to the dealership and buy the pully assymbly for non a/c units. :yelclap: Uses the same belt even.


the pic looks like you may need a different idler pulley as well.. I have to look under the hood to make out what the pic in the EPC is showing...


What about plastic headlights vs the glass?

[Matt S.]

the pic looks like you may need a different idler pulley as well.. I have to look under the hood to make out what the pic in the EPC is showing...


What about plastic headlights vs the glass?


I just did this swap on Goatmans rig... no other pulley change needed. I also swaped his PS pump, and changed it to a smaller pully (for hydro) and did have to change the belt. But with the stock pump... its all good.

[Ludakris]

I just did this swap on Goatmans rig... no other pulley change needed. I also swaped his PS pump, and changed it to a smaller pully (for hydro) and did have to change the belt. But with the stock pump... its all good.

I might check into this.. I am having doubts that my OBA will ever materialize or be worth it...

[XJ_ranger]

Front carpet (the part under the seats, console, setblets, and all that) with pad and exhaust sheilding pad on the passenger side weighs in at a whoping 38lbs...

but mine had a little bit o water in it too...