The Curse of the Mid-engined Roadster
by , 02-27-2011 at 08:04 PM (3793 Views)
A couple of days ago, I printed out some design worksheets. I took the stated 95" wheelbase of this project, drew in some circles that matched the diameter of the stock WRX wheel and tire package, and printed three per sheet. Suddenly, 95" seemed like a really long wheelbase. If you assume that the engine sticks out in front of the rear wheels by a bit, suddenly things start getting difficult. Let's look at why.
The 95” wheel base of the new car is almost identical to that of the second generation Toyota MR2, at 94.5”. Here's an MR2.
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Works pretty well. Rather bland styling, but mass appeal is how Toyota came to dominate the market. There’s nothing wrong with the proportions here. The curve of the windshield, roof, and rear buttress works just fine. The front and rear decks work well together, with the front hood longer than the rear deck. The design flows and nothing looks tacked on.
But wait. The Factory Five car is slated to be a roadster. Let’s lose the top!
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Oops. Look at that massive rear deck. You could land an aircraft on there! The proportions are all wrong. OK, so I helped a little bit by getting rid of that rear spoiler, but we're playing by my rules here. It could be worse. I was actually surprised at how well this works - then I realized that it was because the windshield tilts so far back onto the cockpit. Still, the rear mid-engined design necessitates a long rear deck, which is minimized by a coupe body style. Look what happens to that same car when we move the doors back almost against the rear wheels, the way they are in a front-engined car.
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Forgetting the ugliness that comes from me spending two minutes on the chop, that looks much better if not slightly bland. The curse of the mid-engined roadster then is that the engine forces the cockpit forward, which elongates the rear deck, which is the reverse of classically beautiful designs like the D-type, the E-type, and other front-engined roadsters.
A pretty and proportional roadster is going to be a challenge. Don't kid yourself that this is just a Toyota-is-bland problem.
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Yep, the very pretty R8 suddenly looks hump-backed and stretched once the top is off.
The Lotus 2-eleven works because there is no windshield to describe the front of the passenger compartment. You can’t have a rear deck if you don’t have a front deck. And the wheelbase is five inches shorter, which minimizes everything, making misproportions smaller in scale.
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If we have to retain a windshield, I think a targa design might be in order. But those have their issues too...
I am getting completely excited for the competition to start on Tuesday. I can't wait to have all the rules, dimensions, and specifications laid out so I can wrestle with them. It's going to be a challenge!




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