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Sunroofs. Extra weight, less rigidity.


Killtodie
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There's exceptions to every rule, but for the most part...

 

 

The roofs on OEM sunroof cars are typically as strong/rigid if not moreso than the same car without a sunroof. They add extra structural support around the sunroof that's tied into the rest of the structural support for the roof.

 

 

Aftermarket sunroofs can take a little of the strength out of the roof since some of the structure is carried in the roof skin itself. However, most of the structural support for the roof is in the underlying framework, so making a hole in the skin has VERY minimal negative effect, if any.

 

That being said, an aftermarket sunroof can majorly weaken the roof if not installed properly. Since the underlying structural supports carry most of the rigidity, if you cut any of that stuff out while making the hole for the aftermarket sunroof you will pretty much ruin the strength in the roof.

Edited by Burton
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Some cars, even from the factory, I would say YES.

 

These cars, I would not. If you remove the headlining from a hardtop car, it's very easy to see the amount of bracing that Mitsubishi designed into the car. The portion of the roof that the sunroof sits in on these cars is inside of all of this bracing, so when you factor in the way in which the roof panel itself is designed as to allow the sunroof, there is actually a bit of extra material there making the roof panel stronger, but not the roof itself.

 

The roof bracing is actually very nicely done, with a nice square around the roof, which ties into the A, B, and C pillars nicely.

 

The sunroof mechanism itself is quite light, the heaviest piece being the glass itself. The deflector weighs nothing, and the drain piping is also very negligible in weight. There may be just a couple of extra pounds, and that is being generous, with how the roof panel is formed with regards to the sunroof pan.

 

Having owned both hardtop and sunroof Starions, both from the same year, and month of production even, I can say that the sunroof car is no less rigid, with no extra cowl shake. Nothing in the the interior on the sunroof equipped car rattles or squeaks any more than the hardtop car. Both cars doors slam with the same Diebold-quality slam.

 

This observation applies ONLY to factory sunroof equipped Starions, as I have seen plenty of aftermarket sunroofs in Starions, and since all they do is cut a large hole in an otherwise unsupported expanse of sheetmetal, I tend to see fit and finish issues, such as the rear section of the sunroof actually "weighing down" the roof, and causing a noticeable warp in the roof panel, and since the rearward section of the sunroof is also where the action is, you tend to get rattles, and sometimes, leaks from this area.

 

Tim

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The roof is a vital support in these cars. Sunroof cars are stronger. I've jumped repeatedly on the roof of a parts car and wasn't able to cave it in. I'm 250 lbs so I was hitting it with some force.

 

 

The roof supports our cars more than most realize. I know someone who made a convertable starion by cutting the roof off. Once the roof was gone the doors didn't line up and were hard to close. Going into a driveway at an angle made the whole car twist. The car acted like a giant leaf spring and was unsafe to drive.

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The roof is a vital support in these cars. Sunroof cars are stronger. I've jumped repeatedly on the roof of a parts car and wasn't able to cave it in. I'm 250 lbs so I was hitting it with some force.

 

 

The roof supports our cars more than most realize. I know someone who made a convertable starion by cutting the roof off. Once the roof was gone the doors didn't line up and were hard to close. Going into a driveway at an angle made the whole car twist. The car acted like a giant leaf spring and was unsafe to drive.

 

Yes, I can see that. Personally, no sunroof for me. It's just another number of parts that can go bad. Though on a daily driver, sunroofs are great, specially in a nice sedan with a big roof. On a nice sunny Cali day, is as close to a convertible as you'll get.

 

on a seperate note, from the top of my tow truck, sunroofs make for interesting days, specially if the lady driving with one open is hot and wearing a skirt. :lol:

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http://i998.photobucket.com/albums/af108/scooterdude92/crash6.jpg

...very low speed roll over...i have to say i personally like hardtop starions, now that ive had one of each

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Yes, I can see that. Personally, no sunroof for me. It's just another number of parts that can go bad. Though on a daily driver, sunroofs are great, specially in a nice sedan with a big roof. On a nice sunny Cali day, is as close to a convertible as you'll get.

 

on a seperate note, from the top of my tow truck, sunroofs make for interesting days, specially if the lady driving with one open is hot and wearing a skirt. :lol:

 

 

i think that is part of what i miss about having a 4x4 truck the most. i used to see all sorts of crazy stuff looking in windows and sunroofs.

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My question was in general, not specifically to these cars.

 

I always see people trying to diss sunroofs cause they add weight, especially their because its on the roof. I also kept hearing that sunroofs somehow make the roof less ridged. Sounded like BS to me so I figure I ask here.

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