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Could someone who owns, or has at least driven, the GT with the hardtop on please let me know how it affects the chassis stiffness / body rigidity? I'm considering buying the top as an accessory but would like to know what I'm getting before laying out the cash.
 

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Hardtop does not effect any rigidity
well, maybe like 0.1% it’s not welded together, it has no effect with a few bolts lol, if you roll that shit you might have a little more protection because it isn’t a piece of cloth, but what will save you is the roll bar not your hardtop

If you want rigidity you’ll need a real Coupe, or a welded Roll Cage, or a stiffer multipoint roll bar like mine (Blackbird GT3). or a good quality chassis brace for cross rigidity

Or a new car
 

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Discussion Starter #3
Hardtop does not effect any rigidity
well, maybe like 0.1% it’s not welded together, it has no effect with a few bolts lol, if you roll that shit you might have a little more protection because it isn’t a piece of cloth, but what will save you is the roll bar not your hardtop

If you want rigidity you’ll need a real Coupe, or a welded Roll Cage, or a stiffer multipoint roll bar like mine (Blackbird GT3). or a good quality chassis brace for cross rigidity

Or a new car
Do you own the 124GT?
 

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Do you own the 124GT?
no, but that is not relevant to understand how physics works.

I own a CF hardtop from DG motorsport. Quality is bad but rigidity wise it makes zero difference with the OEM Hardtop, actually I think my car is safer because I have a GT3 roll bar not the OEM hoop

Agian, ZERO gain in rigidity because it’s a removable top
 

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I have a regular Lusso and I bought the GT hard top (How to install Abarth GT hardtop on a Fiat 124 Spider).

The top is bolting to the back of the car but on front it uses the same latch as the soft top. So it is as Klikai said, basic physics understanding works; It has no effect on the body rigidness what so ever.

But it multiplies the cool-factor and looks. I have it for winter use and will soon be removing the hard top.
 

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Con mucho dinero, amigo!
 

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no, but that is not relevant to understand how physics works.

I own a CF hardtop from DG motorsport. Quality is bad but rigidity wise it makes zero difference with the OEM Hardtop, actually I think my car is safer because I have a GT3 roll bar not the OEM hoop

Agian, ZERO gain in rigidity because it’s a removable top
Well, from owning two other convertible sports cars it makes a difference when the roof is installed. So it's surprising if the DG did not. There should absolutely be some gain as you are attaching a rigid structure. With the 124 it may simply be that it cannot 'feel' this difference like higher end cars which would make sense.
 

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Well, from owning two other convertible sports cars it makes a difference when the roof is installed. So it's surprising if the DG did not. There should absolutely be some gain as you are attaching a rigid structure. With the 124 it may simply be that it cannot 'feel' this difference like higher end cars which would make sense.
Em no, you connect them with a clamp and a few small bolts
The structure is not weld on nor itself has the capability to add rigidity
Also its a few layers of fiberglass and CFRP so it flexs easy plus small bolts that holds on to the hinges, so again it add zero rigidity, it adds some protection, but not from rollover, maybe a flying object
What you said also made absolutely no sense at all about feeling it.
High-end cars, the F-type Coupe is 80% stiffer than their convertible, and you can feel how it performs differently on track.
You can feel the difference with rigidity with the braces at the correct place
It really doesn't matter how high or low end the car is, the car is a car.
 

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I believe the hard top could bring some frame rigidity it it was bolted properly to the window frame. In this case the top should also be sturdier in structure support. But hard top is using the same mechanism as soft top thus it is engineering wise not attached from the window frame, just latched.
 

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Em no, you connect them with a clamp and a few small bolts
The structure is not weld on nor itself has the capability to add rigidity
Also its a few layers of fiberglass and CFRP so it flexs easy plus small bolts that holds on to the hinges, so again it add zero rigidity, it adds some protection, but not from rollover, maybe a flying object
What you said also made absolutely no sense at all about feeling it.
High-end cars, the F-type Coupe is 80% stiffer than their convertible, and you can feel how it performs differently on track.
You can feel the difference with rigidity with the braces at the correct place
It really doesn't matter how high or low end the car is, the car is a car.
Em, yes. You connect a rigid structure to a flexing frame. The Miata / Spider frame is known to flex a lot. And folks can certainly ‘feel’ and report on a difference by simply changing the door bushings. And note the large number of braces available for the Miata/Fiata - they make a difference. A rigid roof like that offered on the GT should make a difference. Have you driven a GT with and without the hard top?

Feeling differences should make sense. If you can’t feel differences in a tight or lose car that’s too bad. I certainly can. And so can many others.

Yes there is a difference in feel between a high end car and a low end car. In my garage I take out my 2019 Vette and can certainly feel a lb of tire pressure difference. In my 2020 Abarth, no. In my friends McLaren he can also feel a lb of tire pressure difference but not in my Abrath. I can only assume you haven’t driven higher end cars.
 

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Em, yes. You connect a rigid structure to a flexing frame. The Miata / Spider frame is known to flex a lot. And folks can certainly ‘feel’ and report on a difference by simply changing the door bushings. And note the large number of braces available for the Miata/Fiata - they make a difference. A rigid roof like that offered on the GT should make a difference. Have you driven a GT with and without the hard top?

Feeling differences should make sense. If you can’t feel differences in a tight or lose car that’s too bad. I certainly can. And so can many others.

Yes there is a difference in feel between a high end car and a low end car. In my garage I take out my 2019 Vette and can certainly feel a lb of tire pressure difference. In my 2020 Abarth, no. In my friends McLaren he can also feel a lb of tire pressure difference but not in my Abrath. I can only assume you haven’t driven higher end cars.
?????
I have no clue what are you talking about. Of course, you are going to feel the tire pressure regardless of the car???? You don't feel it in the abarth??
I myself had a 2015 C7 Z51, it was nowhere as fun as this thing on the track. When I talked about the F-type, I drove both the convertible and the coupon around the track.
The Miata is known to flex, so as the whole corvette series. The Vette has a very low rigidity if you actually see the tensile chart, lower than the miata.

What you said make no sense if you did a little bit of googling you'll know that's not how physics works with the top adding rigidity. It's almost like saying the C7 Targa top makes the body
stronger. What a joke
 

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?????
I have no clue what are you talking about. Of course, you are going to feel the tire pressure regardless of the car???? You don't feel it in the abarth??
I myself had a 2015 C7 Z51, it was nowhere as fun as this thing on the track. When I talked about the F-type, I drove both the convertible and the coupon around the track.
The Miata is known to flex, so as the whole corvette series. The Vette has a very low rigidity if you actually see the tensile chart, lower than the miata.

What you said make no sense if you did a little bit of googling you'll know that's not how physics works with the top adding rigidity. It's almost like saying the C7 Targa top makes the body
stronger. What a joke
Umm what I posted is pretty clear. You started to go sideways about feel and no difference in high end and low end cars. Which is simply wrong. The point about feeling subtle tire pressure changes is to simply illustrate that, yes, higher end cars absolutely feel small differences that low end cars wouldn't or don't. The point with the door bushing is to highlight that even a small part like this can make the 124 more rigid.

This is a discussion about the GT roof and whether it helps make the 124 more rigid. Do you have one of these roofs? Apparently not. But the solid roof structure should make a difference because of the... physics... by adding a more rigid structure. It may be subtle. But saying there's zero gain without any first hand knowledge is pretty weak. And yes the physics are totally there for the roof - pretty basic mechanical engineering stuff actually.
 
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