1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

I cut my roof off. *Pics*

Old May 26, 2006 | 10:14 PM
  #26  
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Originally Posted by 3rd and final 7
looks pretty decent true targa huh?! you going to see if you can fab something up for a cover or you going leave it as is? you need to see about adding the strucural integrity back too the frame!!!! there was a thread about 4-6 months back about an under body brace for miata's that goes under the drive shaft i will see if i can find it for you.
This is made by Flyin Miata, however it fits over the frame and will not fit RX-7s I dont think. Your could box the drivetrain tunnel but this would help mostly with torsional stiffness. To add bending stiffness you would have to add some material oriented vertically instead of horizontally.
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Old May 26, 2006 | 10:52 PM
  #27  
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looks wicked shame its a neccary to strengen the frame
as fourm members have said it well be a nessacery saftey item if it was my car ild be pretty dead right now
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Old May 26, 2006 | 11:37 PM
  #28  
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after a few months of sitting and driving it's going to start sagging. You'll believe me once you start to notice it's harder and harder to open and close your doors.
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Old May 27, 2006 | 04:49 AM
  #29  
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not really my taste, but i try not to knock another man's sauce. it looks like you did a good job, but i'll parrot the sentiments to reinforce it. weld the doors and have a roll bar built with strategic floorpan points tied together.
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Old May 27, 2006 | 12:54 PM
  #30  
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ya since the roof is already off just weld the doors and jump in and out of the car.
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Old May 27, 2006 | 05:46 PM
  #31  
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Originally posted by rotary_sex

might as well scrap that car...
It's one thing to critique a car and another to be a jerk....lighten up.

I'm not too keen on the doors still having their complete frames with the Targa look. When the windows roll down, there shouldn't be anything to visually "tie" the a and b pillars, aesthetically speaking.

And, oh...........he's got a camera that can take pictures from the future!!...might want to change the time stamp there, chief...lol...

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Old May 27, 2006 | 08:14 PM
  #32  
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Yeh, I agree with Mar3 on that one. If you want to cut the roof off your car, that's your perogative. Still, I'm trying to figure out what you do when it rains...

In other words, I think the Mazda engineers had it right in the first place, stock is good, and however creative and novel your approach might be (like cutting off your roof), it's probably not a good idea for your average 7 owner (Unless your 7 is headed for the scrap heap which is I guess what's happening to yours).

Check out the car next time before buying it on ebay, for $1000-1500 you can get a real nice 1st gen (I've bought two real nice GSLs on ebay, each about $1500 each, and I sure wouldn't cut the tops off these).

I love driving first gens, it's a good thing they made about 500,000 of these babies!

Ray
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Old May 27, 2006 | 08:24 PM
  #33  
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Originally Posted by aussiesmg
I think unless you reinforce the underbody it will fold up if you ever have a wreck and will twist like a pretzel on corners
One of the local kids did this to a 1st-gen Probe. It lasted almost five days before the doors wouldn't open anymore, until one day they hit the brakes hard enough and the car folded "up" and the doors popped open, permanently. Yeah, scrap metal.

Fortunately, RX-7s are nowhere near as stiff as a Probe. (Oh wait, that's bad)


Basically, what we see here is the imminent destruction of an RX-7.

Last edited by peejay; May 27, 2006 at 08:27 PM.
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Old May 27, 2006 | 08:33 PM
  #34  
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Just recently, someone posted a pic of the Pacific Avatar vert conversion. I suggest that the original poster contact him for pics of the structural mods that PA did to the body to strengthen it.

If I were to go this route, I would cut off the top of the window frame and design a targa insert for those foul weather days. With proper re-inforceing, this mod could be a viable DD with longevity potential.

The 2nd gen verts have an extra 'K' brace underneath to stiffen the chassis. They also have the biggest front sway bars of the 2nd gens to counteract unibody twist. Rear bar is the same size as the TII.
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Old May 27, 2006 | 08:38 PM
  #35  
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Looks nice dont let those people deture you from doing what you want to your car. Just because he cuts the top off doesnt mean its going straight to the trash heap, Im willing to bet money his car will be fine in 2 months. and to the person that said what does he do in the rain? He said that he kept it in the garage 24/7

Last edited by Rx7Roger; May 27, 2006 at 08:40 PM.
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Old May 27, 2006 | 08:47 PM
  #36  
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hey man, i really like this. i wasnt too sure i would when i read your thread title but i actually think it looks really nice. not too fond of the louvers but hey, thats just my opinion. still tho, nice stuff man
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Old May 27, 2006 | 09:56 PM
  #37  
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Originally Posted by Rx7Roger
Looks nice dont let those people deture you from doing what you want to your car.
Nobody is "deture"ing him. He already did it. We're just (accurately) predicting what will happen.

Just because he cuts the top off doesnt mean its going straight to the trash heap
Well, given that the roof provides more than half of the torsional and beaming strength of the chassis, yeah it probably does mean it. The floor is *remarkably* flexible, you can easily flex the U-channel upwards a few inches with a prybar against the heat shield attaching points. That's not even permanently bending, that's just the *flex*, in the strongest part of the floor....


Life is not group hugs and credit for thinking creatively. Deal with it.

Last edited by peejay; May 27, 2006 at 09:58 PM.
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Old May 27, 2006 | 11:04 PM
  #38  
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If any of you gents watch the Sat/Sun morning automotive 'How To' shows, you will see that the first thing one does before making a radical change to the body structure is to weld in braces, BEFORE any cutting is done. This is done to hold and keep the original shape of the body/unibody so that when the needed structural and a stiffening braces are added in, the original shape is maintained.

The door area is THE most critical area that this needs to be done in. Prior to cutting the roof, the doors should have been removed and a X brace welded in place on both sides to prevent the unibody from sagging.

I'll bet that when the original poster cut the roof out, he noticed that as he neared the ends of the cuts, the blade began binding on him. That's why he used so many blades. I have cut up enough 1st and 2nd gen bodies for scrap to know where and when they will bind. I can cut either gen into small enough pieces that I can load them myself for the trip to the recycler, and it takes no more than 2 blades to do this, unless I get one pinched and it breaks.
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Old May 27, 2006 | 11:13 PM
  #39  
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A sunroof would have done pretty much the same job. But good effort. Its different
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Old May 27, 2006 | 11:17 PM
  #40  
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I really love this pic, it illustrates beautifully the thread title
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Old May 27, 2006 | 11:32 PM
  #41  
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LOL, my thoughts exactly.
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Old May 27, 2006 | 11:54 PM
  #42  
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I know first hand about how weak the first gen frame is.... Notice the RIP on my sig!!

I like what you did, however I'm sure everybody is wondering what are you gonna do now?

My car on a hoist, would flex enough to have problems closing the doors and it had a roof.

I'd get some C-channel welded over the stock frame rails and an X-brace in the center. A roll cage would be a good addition aswell.

Don't take any chances, park it until you can strenghten it up. That would suck to see all that hard work go down the drain.
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Old May 28, 2006 | 02:36 AM
  #43  
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The next thing I am doing is having a roll cage profesionally installed, A friend of a friend that I buy parts from Installs Roll cages in Rx7's that he puts Ls1's in, hes going to hook me up for about $700 to make the cars structure somewhat decent, He is going to reinforce the roof area where I cut the 2 main supports and elsewhere he see's fit.

I was goign to try and fabricate a fiberglass top for it, But i have been so busy with my other projects that I havent been able to work on it yet :-(.
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Old May 28, 2006 | 02:55 AM
  #44  
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that seven is done... looked nice till you hacked it up.. hope ur happy with your TARGA . lol
if u want a targa buy one, if you want a seven buy one, its that simple.....
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Old May 28, 2006 | 03:11 AM
  #45  
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Originally Posted by trochoid
If any of you gents watch the Sat/Sun morning automotive 'How To' shows, you will see that the first thing one does before making a radical change to the body structure is to weld in braces, BEFORE any cutting is done. This is done to hold and keep the original shape of the body/unibody so that when the needed structural and a stiffening braces are added in, the original shape is maintained.

The door area is THE most critical area that this needs to be done in. Prior to cutting the roof, the doors should have been removed and a X brace welded in place on both sides to prevent the unibody from sagging.

I'll bet that when the original poster cut the roof out, he noticed that as he neared the ends of the cuts, the blade began binding on him. That's why he used so many blades. I have cut up enough 1st and 2nd gen bodies for scrap to know where and when they will bind. I can cut either gen into small enough pieces that I can load them myself for the trip to the recycler, and it takes no more than 2 blades to do this, unless I get one pinched and it breaks.

Wow, somebody finally said it... I was wondering why it hadnt been covered 2 pages ago. Some preliminary *thinking* would have been excellent here. Even if you do brace the frame or add a roll cage, you have already caused a measurable amount of flex. The frame is no longer straight, I can also attest that my 7 when on a lift can cause trouble opening and closing the doors. Your doors are pretty much all that is keeping your car from folding in half. If you were to have both open at the same time you might not be able to close them again.

When professionals chop tops, or cut tops off, they weld in random braces inside the car to hold the cars frame in place so it doesnt move, or flex, between the time that the cut the roof off and weld it back on. And If I were you I would have tore out the headliner and AT LEAST welded in some mean bracing between the front and back halves of the roof. There is SO much more that goes into severe body changes as this. What you did was the easy part....
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Old May 28, 2006 | 06:07 AM
  #46  
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Easy part, and the last part that should have been done, other than, the cosmetics to finish off the hack.
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Old May 29, 2006 | 10:58 AM
  #47  
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Seriously, you had better jack up the underbody now, take some measurements and see how much the roof gap has closed, it may be too late for the cage already, think about it, every bump or shake on the road is transfering pressure into your suspension, forcing the ends up. The roof is a structural section which resists this motion, you removed the only part of the car stopping the ends folding towards each other.

For everyone ever considering this, this is a major modofication requiring lots of knowledge, skills and additional weight to a car that doesn't need it, hell my sunroof isn't much smaller.
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Old May 29, 2006 | 01:14 PM
  #48  
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time for a batmobile!!
Attached Thumbnails I cut my roof off. *Pics*-batmo01.jpg   I cut my roof off. *Pics*-batmo032.jpg  
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Old May 29, 2006 | 01:40 PM
  #49  
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So you restore a car from terrible condition into a pretty decent looking car... then cut the roof off. Hmmm...
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Old May 30, 2006 | 06:54 PM
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Cars going in soon to get a Roll Cage installed, We are going to do the following. Reinforce the area where the 2 supports used to be on each side. And soemthing along the lines of this picture, I Will post actual Pics later. when its finished.
Attached Thumbnails I cut my roof off. *Pics*-roll_cage.jpg  
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