Ok guys. I'm putting this in the build thread because, well, its a build, damn it.

Some one double check my math on this; because, if I'm right, I just built a 45 GALLON TANK!!!!!

Here was my plan:

I wanted to keep as much of the OEM stuff as I could. So, I had to make the tank quite a bit deeper than I wanted to, but I think I did it in a very good way.



The length of the tank, front to back, is 24". The width of the tank, between the frame rails, is 35 7/8".

I'll explain this now....

The easiest way to figure out the volume of this tank was to break it down into basic shapes. Hence the areas 1, 2, and 3.

As I said before, I wanted to put the tank in the stock spare location. Well, If I were to do that, I would loose the ability to run the stock fuel pump. I really didn't want to loose that, and have to dump more momey into this tank. SO, what I did was make the tank drop behind the rear axle, and slope up to the frame rails. I figure the axle and tires will protect the long portion of the tank. The slope goes up to right inbetween the frame rails, so it'll be good and protected. I also plan on running an; at least; 3/16" skid plate over the tank.

So, on to the math.

To find the volume of a square, section 1, the formula is LWH. To find the gallons, you divide the volume by 231. THIS IS FOR INCHES!!!! The formula is different for feet. Therefore, we get the formula:

8"x6.5"x35.875(7/8)=1865.5" cubed. Divide that by 231 and you get 8.0757575...Gal.

To find the volume of a rectangle, section 2, the same formula is applied; LWH/231. Therefore, for section 2, we get:

7"x24"x35.875=6027" cubed, divided by 231=26.090909.....Gal

To find the volume of an extruded triangle, section 3, the formula is 1/2(LWH). Therefore, for section 3, we get:

1/2(8"x17.5"x35.875") =2511.25" cubed, divided by 231=10.871212.. Gal

Those numbers, rounded down just for the heck of it, are:

8+26+4(the only one that was above 0)=38 Gal.

Another way to do this would be to take all the volumes, in inches, add them up, and then divide them all by 231. Such as:

1865.5+6027+2511.25/231=45.03787878...

Now, for the pictures!!!!

I made this tank out of 16ga steel. I'm in the air of coating it with something, because as long as I keep gas in the tank, which I will, then there shouldn't be any rusting. I still might get some of that stuff to coat it with, the POR-15 or what ever it is....

The front, bottom, and back are all one peice, with bends in the necessary places. The sides are tac-welded for right now, as are the two baffles that are in the center. There will be one more baffle going across the width of the tank, right in the middle, to give it more stability, and then the top will be welded on once it's all cleaned up on the inside.

(Sorry for the ****ty pictures. My iPhone case was nasty at the time.....)


















SOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO?

Whatcha think??

Put a baffle bracing from the bottom to the sides. It should help keep 200# of fuel from bowing it out.


Looks good. I did not check the math but looks well thought out.

Get it welded up and let see it completed.

Cool looking tank.

I believe your formula for the triangular piece is incorrect. If I am seeing it correctly, it is not a prism, but just an extruded triangular section. The formula should be 1/2(LWH). This would result in a total of 45 gallons.

I also quickly modeled the shape in CAD and it calculated 45 gallons too.

Well sh!t!!! THAT'S EVEN BETTER!!!!! Thanks Bandit. That's why I put all of that up there, so someone such as your self could check it for me.

So, it's been a while since I've updated this thread. Nothing really significant going on, just some much needed stuff.

Got the speedo working, the front shaft installed, all the 4wd stuff working. Had a problem with getting her into 4LO, but figured it out. Also got a new wiring harness installed. Got it out of a '99 SR5.

Can someone tell me what the point of having the O2 sensors different on these things are? I mean really? The front O2 sensor doesn't plug into the harness, yet the rear pops right in. Maybe not, but the sensor I got does. Just seems like the O2 sensors would be the same for all the same year 4Runner. Guess Toyota wanted to make sh!t difficult. Go figure....

The speedo is 16% off, so when I'm going 50 on the speedo, I'm really doing 42. and when I'm going 80, I'll be doing 67.2. Need to get the speedo corrector from Dakota Digital ordered and installed so I can have a functioning speedo.


I took these Pics Saturday when I went to get the VSS and the O2 sensor from a guy up in Washington, NC that has nothing but Yodas... He's also got a little bit of some stuff in the back that he built. A bunch of tires, some concrete pipes, hills, and a mud pit. Definately didn't hit the Mud, but did get up on the pipe. Also had a nice little hill that a Taco with 36's couldn't get up, but I did with the rear locked.

The little girl is my Girlfriends kid. figured I'd be nice and let the GF sleep in a little....









Also got a few things that I'm planning on working on this weekend with the rack and such. Going to finish up welding it up, strip it down, and paint it to match the truck. If I have the money, I might add some metal in there to make the rack a little stiffer.

I also plan on attempting to fill the holes left from the panneling. That should be interesting to do....

Here's a couple other pics of stuff I've done/am working on.

As you can see, I'm about to be inducted into the Umbrella Corperation...




And then there's this one...



I'll update more this weekend when I get the rest of her done.

Ok guys.

Here's a little update. Been chasing around a damn CEL, but got some of this stuff done along the way.

See above post for the before pics. See all the holes? Yeah, I took care of those.

First, I cleaned up the paint a little bit, then welded the holes up.






Then, ground them smooth, taped off the truck, covered it with newspaper, and Bondo'd and sanded it smooth.
















After sanding:













Then sprayed with Rubberized under coat:






And, the finished result:








Honestly, it looks really good.

The durability, not so good.

I've noticed that when she sits in the sun, the undercoat gets tacky, and then scratches very easily.

Hell, it scratches easily anyway.

I should've done it right the first time, and used the bed liner, but I got tired of looking at all those holes, and the ugly ass green paint that was all over the side of her.

The next thing on my list:

Figure out that damn CEL, then to finish up the gas tank, mount shocks, and build bumpers.

Then, I'll find something else to do to her.


Oh, just for the hell of it, a couple Pics from Daniel when Rudy97 and I went two weeks ago:

I like the look of those half doors. Any reason why you kept the top half of the doors?

Because I'm going to eventually make an insert out of some vinyl or waterproof canvas to cover the area where the doors have been cut out.

That way, when I decide to go wheeling, and there's a drastic change in weather, I can just put those in there, and stay warm/dry.

That, and it keeps the doors stiffer, I don't have to worry about sharp edged when I have my son in there, and it keeps the flow of the body.

Got myself a present a little early this year: A 1st Gen Roll Bar.

Actually, I got two. One for me, and one for Rudy97.

I didn't take pics doing any of the cutting, so when I help Rudy out with his, I'll be sure to snap some.

Here's the roll bars, and mine put in.

I know, I know. The back of my truck is a mess. Trust me. I plan on cleaning it while I'm off of work for the next few days.

more info/updates on the tank,,,, back when I had my 3rd gen I talked to to 2 fab guys about building a tank just like you started, and IIRC it would have been about $600 OTD but the was with a built in skid, that would be strong enough for a tank in that place (spare tire) I never did it, glad you are going forward with it.
I may have to look into for my 4th gen

x2 on this fuel tank business... I was planning putting an F-150 fuel tank behind my rear axle as an aux tank but that would still only net me 36 gallons with my stock fuel tank. Take lots of pictures when you install it. I may just do something around the same idea.

I'm working on the tank guys.

Ok. I've been stalling on the tank for a while. The tank is currently here in Hickory. I've been down in Jacksonville, and haven't been able to get back here. Thank you Christmas, for giving me a reason to take leave and getting back here! LOL.

I'm going to be bringing the tank back with me, and I plan on working on the tank while I'm back in J-ville.

I too looked into the F-250 swap, but you need to do a whole bunch of modifying to get the stock fuel sender to work with it. That, and you'd still have about the same, if not a little less, capicity than the stock fuel tank.

With the tank I'm making, I'm going to have to extend the wires for the fuel pump/sender, but it's going to be worth it to have the stock stuff in there.

This tank is so I can go COMPLETE flat belly. I've already got a custom transmission crossmember, lifting the tranny up 1.5", a custom 1.5" engine lift to keep the drive train straight, the BudBuilt clocking ring to get the t-case between the frame rails.

And, with the 63" swap in the back, all I really need to do is add a leaf or two to the pack so it won't sag. 45 Gallons, plus the take, is going to be about 300lbs.

The only thing that's left to get rid of to make the belly flat is the freaking gas tank. I looked into EVERY viable option, none just seemed as easy as this one is.

Merry Christmas Doc. When are you going back home?

Same to you Sing.

I'm in Hickory right now. Gonna be RTB tomorrow. I'm gonna swing in and see ya if you're not busy.

Alrighty.

So, a few things I've been doing every now and then.

You've seen the Pics of @Rudy97 's Bar. Here's mine.

Started off using his bar. Made myself a "bracket" to add my drawers in. Just tacked them to the bar, and cut them off later.





Then, I figured out a way to make the box removeable. More pics and explination of that later.

Next, I took the bar, and cut two holes in it, one on each side. I then welded a sleeve of 3/4" square into the holes I cut. Ended up with this:






AAAAAAAAANNNNNNNNDDDDDD that's as far as I've gotten so far. This process will be repeated 4 more times, twice on each other bar that's touching the roll bar. Should be nice and stiff. Tehehe.

Here she is all mocked up, and some pics of the way I have the system in place to make it removable.









The slide is some 3/4" angle that I got from Home Depot. Put it in, drilled some holes, welded the nuts to the back side of the angle so I wouldn't have to mess with a wrench in there, slid them into the box, and added screws.

As I said before, the process of cutting the roll bar will be repeated four more times: Twice on the back part, and twice on the front bottom part of the box.

Then I will smooth the welds, and work on the supports and drawer system for the box.

You're probably asking why I'm making it so difficult for myself.

Well, the reason is that I like the space in the back of the 4Runner. Hence why I'm adding my two 10" Rockford Fosgate R2D2s to the top of the roll bar, like @blcktpgsr did. The drawer system is going to be removable incase I decide to go on a long trip. At some point in the future I'd like to get a dog, and with the kids, the dog would have to be in the back. The first thing that came to mind was sharp metal objects sticking out and impaling the dog, or ripping our luggage up. Definately DON'T want that. So, I came up with this idea.

I'm going to be working on the bar more Wednesday and Thursday, so I'll keep the process updated as I go along.