A fastback hardtop often adds a certain je ne sais quoi to a roadster, whether it's a Honda S2000, a Mazda Miata or even a Porsche Boxster,
How do you feel about adding a fastback hardtop to a drop-top sports car? Does it offer a worthwhile aerodynamic improvement, or does it defeat the whole purpose of getting a roadster?
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Driven5
UltraDork
8/19/21 12:25 p.m.
It defeats the purpose of a roadster, but makes for a great sports car.
How about the Zeintec hardtop for the early Boxster? I shot this back in '07.
there were some cool Fiat 850 spyder fastback hardtops in the early 70s
Sigh. If they had put that NB coupe in the OP into production, it would probably be the most desirable car that Mazda has ever made. For me anyway. It's just beautiful, like a smaller FD.
Anyway- a lot of people like small lightweight cars, but don't like convertibles. They're not great for motorsports, have poor aerodynamics, are noisy, and are only fun to drive with the top down a few months a year in most places where people actually live.
Aerodynamically and structurally a way better deal.
j_tso
Reader
8/19/21 1:35 p.m.
ShinnyGroove (Forum Supporter) said:
Anyway- a lot of people like small lightweight cars, but don't like convertibles. They're not great for motorsports, have poor aerodynamics, are noisy, and are only fun to drive with the top down a few months a year in most places where people actually live.
And if you don't have a garage the top has to stay up when parked which soon becomes a raggedy top.
ShinnyGroove (Forum Supporter) said:
Sigh. If they had put that NB coupe in the OP into production, it would probably be the most desirable car that Mazda has ever made. For me anyway. It's just beautiful, like a smaller FD.
They did just not in the US.
https://www.motortrend.com/vehicle-genres/mazda-mx-5-miata-coupe-production-jdm-photos/
They are very rare and japan only but they do exist.
Right? And Mazda had to put out the dang ND RF instead of an actual coupe.
msterbeau said:
Aerodynamically and structurally a way better deal.
Maybe not? Aero wise a full windshield pushes a lot more air than a speedster type convertible with a cut down windshield or driver only windshield.
Now granted you only see those on race cars often with a tonneau cover over the passenger side.
I'm willing to bet such an arrangement push's at least 30% less air.
NOHOME
MegaDork
8/19/21 3:56 p.m.
Because the discontinuity of the lines in a convertible offends the primordial eye.
Brett_Murphy (Agent of Chaos) said:
Right? And Mazda had to put out the dang ND RF instead of an actual coupe.
We offer an RF coupe conversion kit.
All of my Miatas have permanently installed hardtops, my ND will be an RF and there's a good reason my MG is a GT instead of a ragtop. But there's a difference between a fastback hardtop and a coupe version of a roadster. The former tends to be awkward from a load space standpoint and is mostly for aero.
Didn't somebody make an NA/NB fastback with a drawer slide out? I remember reading about something like that years ago but I could have also dreamed it.
In reply to frenchyd :
I'd like to see a comparison, in the wind tunnel, between the same car with a full windshield and well-shaped roofline and a SCCA prod car kind of aero screen and exposed roll cage. What you gain in lower frontal area may be lost in a higher CD from the cage, driver and other random bits exposed to the air stream.
Personally I feel better inside a full car with a roof. Also, if we're taking about street cars, then the contest is easy because you probably still have a full windshield and the structural deficit doesn't get fixed by a cage.
Aesthetically, I also prefer a fixed roof over a convertible but that's a personal choice and dependent on the specific car.
Tubes are really messy, aerodynamically speaking. I know my Seven picked up a lot of drag when the (fairly small) windshield was installed but even with the small frontal area it was draggy compared to a Miata.
msterbeau said:
In reply to frenchyd :
I'd like to see a comparison, in the wind tunnel, between the same car with a full windshield and well-shaped roofline and a SCCA prod car kind of aero screen and exposed roll cage. What you gain in lower frontal area may be lost in a higher CD from the cage, driver and other random bits exposed to the air stream.
Personally I feel better inside a full car with a roof. Also, if we're taking about street cars, then the contest is easy because you probably still have a full windshield and the structural deficit doesn't get fixed by a cage.
Aesthetically, I also prefer a fixed roof over a convertible but that's a personal choice and dependent on the specific car.
Look at a 1955 Jaguar DType. With only 250 horsepower it was doing over 170 mph at LeMans. Then there are Indy cars as well as F1 with great big drag inducing open wheels.
I understand your preference to have a roof over your head. Not only a real safety item, but a psychological one as well. Most will agree with you.
wspohn
SuperDork
8/19/21 8:39 p.m.
A Belgian garage, Coune, did a conversion on some MGBs that looked pretty good though I don't recall if it was removable.
My Solstice coupe has a fixed rear section and a removable top. A private builder has made removable hard tops in that pattern for the convertible versions.
In reply to frenchyd :
F1 and Indy cars have open wheels because the rules say they have to. They'd be a lot faster if they were enclosed.
If we're going back to the D type era (roughly speaking), let's talk about the Cobra Daytona Coupe. Created specifically because it had superior aero to the roadster, because the coupe 250 GTO was running away from the open topped Cobra.
jmc14
HalfDork
8/19/21 9:30 p.m.
I really enjoy driving my Cheetah Roadster tribute. Nothing like the open air driving experience for me. But, I want a fast back hardtop version as well. I've been working slowly on it. I've built another frame. And, have the Roadster body that I'm modifying. LS engine, Tremec TKX 5speed, and C4 vette suspension. A friend photoshopped a top on my Roadster body for me. Still working out door ideas. The Cheetah had gull wing doors. I'll probably go that route.
In reply to Keith Tanner :
I did say great big drag inducing wheels. And the reason I mentioned the D type is if you look at my Black Jack you should understand.
Tom1200
SuperDork
8/19/21 10:55 p.m.
In reply to ShinnyGroove (Forum Supporter) :
I like them to.