I haven't had the full size spare in the back of my '80 for a few years now, but I recently moved my 12' sub back there. My question is this, I already knocked off the bracket to level it out some, but I would like to know if I can cut the entire raised center section out. The gas tank and things I can't see worry me, I'd rather not start a barbeque with myself as the main course.
Will I be able to cut it, or will the rest of it have to be brought up to the level of the bump. I know, I know..audio section...but 1st gen guys rule, and they actually know what under their cars , thanks. -George

 

Yeah, I'd call that a slight fire & explosion situation.

What I would do:
1) Under the car: paint-mark and undo the little hoses and level sensor. Careful, you will get gasoline on you.
2) Outside the car: unbolt the filler neck from the car
3) Back under the car: carefully undo the straps, let the tank down easy - it's heavy if full. I use my body to support it. Put it far, far away.
4) Tie off the little hoses on the car with tight rubber bands and baggies, then severely duct tape a coffee can or something over them. AIR THE AREA OUT, THEN SNIFF FOR GAS FUMES!
5) If no fumes, cut away. What do you have? Torch or sawzall?
6) What are you going to use to seal up the hole? Water from rain driving will splash up there, that's how my '85 got it's tank rusted out.

As always, keep us posted!

 

And take pics

 

Dose your car have the boxes behinde the seats ? If not, why not just install some subs there. Its so ez and the sub will sound better. Fiber glass the inside,seal it off ,cut your holes, port it and use the car as the box. I dont think any 12'' sub will give you the deep note your looking for in the spare spot.
good luck

 

How big of a hole are you thinking of cutting? Remember that the spare tire well is part of the unibody and provides some measure of strength and rigidity to the rear of the car. -Mike

 

well if your putting a bolt or whatever though the hole the ridigity should still be there.

 

Thanks for the detailed reply JEC-31. Now I'm not sure what I want to do, I'm a weight reduction freak at heart. However, during the winter months I care less about all out speed, as the weather usually prohibits it. Right now the sub in sitting loosely in the well firing at the hatch, the angle of the sub and the hatch are parallel. The sound is much better than the previous position, the reason I wanted to cut out the raised center section was to lower the sub 4-6 inches, creating a more concealed look and a stable base for the box to sit on. I was planning on putting metal base across the hole and securing it with pot rivots

JEC-31 is your suggestion to remove the tank a safety measure against using power tools? Would it be possible to drill a few pilot holes and use heavy duty tin snips or a hack saw to remove the offending section, or would i be risking component damage? Something I really don't want to do seeing as how they don't make my tank anymore.

HIMNI Racing, my SA didn't come with storage bins, but I've already hacked the sheet metal and installed 6 x 9 boxes that are nearly flush with the carpet, and the amp is bolted down in the center.

Did I miss any questions? Bcty and I have to go halfers on a good digital camera soon, how many megapixels will give good pics? I've seen alot in the 2 MP range. Thanks again.

 

I'd go with at least 3 Megapixels for decent pictures.

 

For the amout of work required I may just go with a round metal base attached to the high point. Is it safe to cautiosly drill through it, or would I still have to drop the tank to accomplish this. Going this route would also let me bolt the sub down to the new metal base plate without worry about hitting underlying components. The only worry is the holes for the base. TIA -George

 

I always take the power-tool route, it's just more fun. If you drill, DO NOT go straight down or you'll hole your tank as it's flush up against the unibody's bottom (little peices of foam won't stop a drill!) I can't picture how you'd get any kind of saw blade in unless you sawed off the "offending section" in a horizontal kind of way, which is how you'd have to drill anyway.
Considering the age of our cars, taking the tank off for cleaning isn't a bad idea, and then you can just borrow (if you know anybody who's willing to lend) a torch or sawzall and have fun lightening you car all over the place!
On another note, I need a digi-cam too. And a computer at home...

 

How about a dremel with a cut-off blade, or a more purpose orientated die grinder with a cut-off wheel. Obviously doing this very carefully, cutting in horizontally. You definitely should drop the tank though.

 

Right on - my little weakened-with-age dremel can still throw mean sparks and all it takes is one...
...but a dremel cutting through a few inches of car body is at least 4000 hours. It'll even take a while with a die grinder.
What Nanaimo needs is an electric sawzall with a blade specifically for metal work, and a pair of fully-enclosed goggles. Then the air-powered die grinder, or electric 4" wheel grinder, to dress up the jagged hole.

 

Only in compression, not in tension. It is concievable that the body may recieve tensile loads. As a matter of fact, this is the most likely form of stress to the bottom of the body.

Think of a wooden beam, like a 2X4. Imagine that beam is supported at each end, say on saw horses. Now apply a load (weight) uniformly allong the length of the beam. Notice that it bends downward. The bottom of the beam is now in tension, and the top of the beam is in compressive stress.

Now imagine your car as that beam, supported at each end by the wheels. Any hole you cut is now a stress riser, and since it is on the bottom under tension, putting a bolt in it won't mitigate that stress riser.

 

I have a Milwaukee SawZall, but it seems a bit big to fit in there. I'll check it out with a short bi-metal blade....if I do go through with this I'll definately be dropping the tank, not worth the risk.

 

Excellent idea! I would recommend welding the patch back in to recover the structural integrity though.