BRZ comes last in EVO group test

[Subaruwrxfan]

Originally Posted by Lighting Red

Certain aspects of what defines the BRZ's character, such as steering rack speed, more than likely will not change. On that level I agree with you.

Where I completely disagree with you is with your assertion that the character of the car (in this case meaning the overriding character traits of the BRZ) as defined by the BRZ's low weight and low Cg will not be altered. Even though you did not define the overall character as such, I think we can both agree those two attributes truly define the car, and all the other sub-traits fall from there.

Besides adding a nice panaramic view of the environment, convertible tops (hard or soft) do two things to a cars: add complexity, and add weight relatively high on the car. Convertible top cars also suffer from reduced rigidity, especially when compared to solid roofed counterparts. To overcome this, convertibles require additional material added to the frame in the form of structural members in order to gain back some measure of lost rigidity. Without belaboring the point, all these factors contribute towards undermining the two major attributes that make the BRZ a, well... a BRZ.

I have a feeling I am not saying anything new to you, or most other members on the BRZ side of the house (the kids on the FR-S side might be a different story ). Basically even if Subaru designed this car from the get-go to also support a convertible top variant, unless they extensively employ exotic materials throughout the top's construction, I do not see how the driving experience and performance of the base car will not be negatively affected. Then again... I suspect people who buy convertibles generally do not car all that much about the performance.

Lol I'm well aware of what goes in to constructing a convertible version of a car. What I'm saying is that Subaru engineered this car from the beginning with a convertible version in mind (there are many articles with quotes from the engineers saying this).

Because they are planning to make one, this car already has extreme rigidity and I think it will require very few modifications to the frame of the car, if any at all. It's hardly complex, custom shops do it all the time. Hack the roof off and put a soft top on it instead, add some motors for the roof, and place a little more bracing in the car (if needed). I actually think this car could be BETTER as a convertible. If they did engineer it with that extra rigidity like the engineers have claimed, then there will be minimal weight added to the frame, plus you are losing lots of weight up top (because of the lack of a roof!)

I think the convertible version could be lighter than the hardtop (look at the miata), have better handling and even less body roll (if that's even possible, lol) because of all the weight of the car being lower.

Your last comment about people who buy convertibles don't care about performance made me laugh, as you're insulting every single Miata and S2000 owner out there, among other cars. The only thing more glorious than carving up back roads is carving them up in the open air while being able to hear your exhaust twice as good as you could with the windows down in a hardtop. Viva la convertible!

[dsgerbc]

If the body is already that strong so that a convertible would not require 1-2 hundred pounds of reinforcement - why there's no moon/sunroof option?
I think the chances of a convertible gt86 weighing less then coupe are very slim; most likely it will be fatter and less rigid.

[Subaruwrxfan]

Originally Posted by dsgerbc

If the body is already that strong so that a convertible would not require 1-2 hundred pounds of reinforcement - why there's no moon/sunroof option?
I think the chances of a convertible gt86 weighing less then coupe are very slim; most likely it will be fatter and less rigid.

There's no moonroof because adding glass to the roof would have made the handling worse and the car heavier. Having no roof and a lighter fabric top stowed in the trunk can only help the car's handling, as long as they did engineer the car to be as rigid as they say it is.

[Spaceywilly]

Originally Posted by Subaruwrxfan

Having no roof and a lighter fabric top stowed in the trunk can only help the car's handling, as long as they did engineer the car to be as rigid as they say it is.

The 370z roadster is 200lbs heavier than the coupe in the same trim. For cars that are designed to have a hard top (as opposed to being designed as a convertible and then having the top stuck on) there is no weight penalty for having a roof, and the added rigidity of the hard top will always be better for handling. Even on the Miata and S2000, which were both designed to be convertibles like you say the BRZ/FRS was, people add the hard top to stiffen the chassis. Unless there's a carbon fibre monocoque they have been keeping secret from us, cutting the roof off the car is not going to help the handling.

[JohnnyR]

Originally Posted by sysfailur

Lemme sum this up... auto transmission and prius tire fail. I am not worried a bit. I'll be throwing on some proper wheels/tires as soon as the car arrives. Let's not forget the possibility of adding extra power with an intake/exhaust and tune.

I wouldn't expect car dynamic changing gains from an I/E/T. It's a high strung, high-comp, NA engine.

Originally Posted by Subaruwrxfan

There's no moonroof because adding glass to the roof would have made the handling worse and the car heavier. Having no roof and a lighter fabric top stowed in the trunk can only help the car's handling, as long as they did engineer the car to be as rigid as they say it is.

It will lose rigidity regardless going to the convertible top. The vast majority of cars do this, even cars designed as a droptop from the start. The 86's profile isn't so sleek to not impact it as much as other cars.

[dsgerbc]

Originally Posted by Subaruwrxfan

There's no moonroof because adding glass to the roof would have made the handling worse and the car heavier. Having no roof and a lighter fabric top stowed in the trunk can only help the car's handling, as long as they did engineer the car to be as rigid as they say it is.

Er, what? Make it plastic. It's not the weight, it's the fact that it compromises chassis rigidity. Same reason there's no sunroof in 5door STI.

And reports of convertible only surfaced few months ago. Before that there was nothing about it, sometimes mixed with 'no way'. It makes zero sense to design a light weight-coupe with all the extra rigidity in the 'base' and the top doing nothing (so that the hypothetical convertible could be lighter) and not selling it as a convertible from the get-go.

[Spaceywilly]

Originally Posted by dsgerbc

Er, what? Make it plastic. It's not the weight, it's the fact that it compromises chassis rigidity. Same reason there's no sunroof in 5door STI.

And reports of convertible only surfaced few months ago. Before that there was nothing about it, sometimes mixed with 'no way'. It makes zero sense to design a light weight-coupe with all the extra rigidity in the 'base' and the top doing nothing (so that the hypothetical convertible could be lighter) and not selling it as a convertible from the get-go.

It also would reduce headroom, which is already on the low end

[Subaruwrxfan]

I'm not saying they loaded the hardtop up with extra rigidity, I said they engineered the car with a convertible version in mind. That means I expect there to be very little needed to regain the small amount of rigidity that is lost when the roof is gone. And having no roof swinging above you when you dive into a corner, the car will handle better. If it does gain any weight, I think the weight they would save with the lighter fabric roof could cancel it out. Worst case scenario, the convertible top will add 100 lbs. to the car. In that case, a manual convertible would be barely heavier than an automatic hardtop.

[JohnnyR]

How do you know it's a "small amount" of rigidity would be lost? Taking the roof off of a car, especially something with a higher roof line like this usually dictates a significant loss. Can you say we're wrong, sure. But our stance has a far greater chance of being correct.

[Spaceywilly]

Originally Posted by Subaruwrxfan

And having no roof swinging above you when you dive into a corner, the car will handle better.

4/20 was last week

[Subaruwrxfan]

So you think that having a huge piece of metal at the absolute highest point of a car helps it's body roll and turn-in? And I'm the high one?

As for rigidity, you could be right, the whole frame of the car may turn to jello when you remove the roof, but I really don't think that a car this light has a super thick roof that is the absolute crux of the car's rigidity. Yes, it's possible that the convertible would be slightly less rigid than the coupe, but I don't think the difference would even be noticeable to a weekend racer unless Subaru botches the job.

[Dimman]

Originally Posted by Subaruwrxfan

So you think that having a huge piece of metal at the absolute highest point of a car helps it's body roll and turn-in? And I'm the high one?

As for rigidity, you could be right, the whole frame of the car may turn to jello when you remove the roof, but I really don't think that a car this light has a super thick roof that is the absolute crux of the car's rigidity. Yes, it's possible that the convertible would be slightly less rigid than the coupe, but I don't think the difference would even be noticeable to a weekend racer unless Subaru botches the job.

It's more the unified shape than the thickness or amount of material that gives it the rigidity.

[Subaruwrxfan]

Originally Posted by Dimman

It's more the unified shape than the thickness or amount of material that gives it the rigidity.

Yeah, I can see what you mean. I just think the car would be better without a roof. Look at all the hardcore weekend track cars, the Ariel Atom, KTM X-Bow, or the Caterhams for example, all topless. If a roof was so fundamental to good rigidity, these cars would have them.

[OrbitalEllipses]

Originally Posted by Subaruwrxfan

Yeah, I can see what you mean. I just think the car would be better without a roof. Look at all the hardcore weekend track cars, the Ariel Atom, KTM X-Bow, or the Caterhams for example, all topless. If a roof was so fundamental to good rigidity, these cars would have them.

Aluminum spaceframes vs. unibody...not the fairest of comparisons.