Re-issue a few updated versions of the Z600, one as an affordable, high-performance, fuel-efficient sports car capable of seating 2, another as an affordable, high-performance, fuel efficient compact car that can seat 4, and another as a minitruck that seats 3.
What powerplant? All of them will use the 140 HP 2.2 i-CTDi diesel, tuned to run on petrol diesel, B100, and any mix in-between. It will be mid mounted as low as possible behind the passenger area, rear wheel driven, and air-cooled.
All cars will share the same transmissions.
All of them will share the same chassis. A wheelbase around 100-110 inches or so.
Where the cars are different is the body. All of them will have a similar theme in appearance or looks, with some modifications between them. Think of the differences between the Corvair sedan, Corvair Monza, and Corvair Rampside.
All car bodies will share the following: rounded LeMans style front end with covered lenses(think Jaguar E-Type, Porsche 550 Spyder, ect.), Honda Insight rims and tires, shaved door handles, aerodynamic driver/passenger mirrors, rear wheel skirts, full smooth underbelly, small gaps to allow engine cooling via air(think GM Precept, so minimal drag penalty is created), rear boattail where appropriate(depends on which of 3 car styles), roll cage, driver and front passenger both approxamately in the center of the vehicle, fiberglass body wherever appropriate, a frame built to withstand being loaded to 3,500 pounds.
The trunk in all cars will be in the front. Sort of like Porsches and similar cars.
The sports car will only need to seat 2 people, and given what it is, it will be lower in ride height than the other cars. Ground clearance will be about 3 inches, total height from ground to roof around 45 inches. Keep it down low. Since it only needs to seat 2 people, the rear can be tapered back to perfection to minimize drag. Target weight around 1,800 pounds, target drag coefficient around .18, and target frontal area around 16 square feet. This would yield a sports car that did around 0-60 mph in 6.5 seconds, and appropriately geared, could top 170 mph. Fuel economy would be somewhere around 80-90 mpg US, judging by the figures achieved with the diesel Accord.
The compact car will be built like the sports car. Same exact front end and design, up until the passenger area starts. The passenger area will be slightly taller, and the car will be shaped more like GM's Precept. The front section will seat two adults, rear section seat 2 adults. The rear area will be hatch, with a partial boat-tail. Ground clearance around 6 inches, roof height around 54 inches. Target weight around 2,400 pounds, target drag coefficient under .20, target frontal area under 19 square feet. 0-60 mph would be about 8.5 seconds, top speed ~150 with proper gearing, and around 70-80 mpg.
The pickup truck will be like the compact car, only with no rear seats, and a straight cutoff right after the passenger compartment with the bed being above the engine. Target weight around 2,000 pounds, target drag coefficient under .35(Offer an attachable aeroshell as an option to reduce that to under .20), same frontal area as compact. This would give 0-60 around 7 seconds, top speed around 125(with aeroshell unattached), and around 55-60 mpg(with aeroshell unattached). The truck bed itself will be steel, while the rest of the vehicle body would be fiberglass. It would be the only sports car/pickup crossover around, and it would fill both roles very nicely. So a farmer might have a tool to use around the farm on the weekdays, fuel it up with biodiesel he makes himself, and then take it to the track on the weekends and kick ***.
Since all of these vehicles would be built on the same sporty platform, manufacturing costs are greatly reduced. I could see such a vehicle being made and sold at a profit around $13-15k. It would basically be an updated, multi-platform Honda Insight with a diesel engine instead of the pricey hybrid drive.
Yup, but "platform" engineering doesn't go far enough. Just try to buy a pickup truck with anything better than a 3.73 axle. Optional axles now go higher to 4.11 and such!
Providing optional FE axles is such a trivial design exercise that all auto manufacturers should be mandated by the government to do it. Even better, they should mandate the easy FE options such as Atkinson cycle cams, electric fans, LRR tires and wheel spats.
Capitalism: The cream rises. Socialism: The scum rises.
I would want enough inherent stability in the design to make a dedicated roll cage unnecessary (also, I don't plan on going 170 mph- see below). Of course, you still need roll-over protection in case of an accident where "tripping" occurs- current standards are adequate for that.
A roll cage is preferred because it is a cheap/simple way to add both safety and structural rigidity.
My entire idea is to keep things relatively simple.
Driver and pass. can be almost anywhere in the vehicle- I have a '60 VW Microbus, of course driver and pass. sit on top of front wheels- it works.
But there is a preference for being in the center of the car if high performance driving is being done.
Frame should be built to intended purpose moreso than arbitrary number- a 2-seat sports car does not need 3500 lb cargo capacity (people <600lb and cargo <4-600 lbs), neither does 4-seater (1200 lb people + 1000 lb cargo?) it would almost be impossible to load it that heavily, so why put in so much structure?
Why put that much structure? Because one of the platforms, the pickup, would be able to make use of it. The others would make use of the stronger brakes, increased transmission/differential strength, and increased chassis rigidity. For all three vehicles, you get better performance, but the 'truck' would have a practical application for it as well when hauling things.
Structure that is not needed = extra weight and extra cost.
True. But the cost penalty wouldn't be dramatic and the weight increase a little over 100 pounds. The additional materials cost might actually be less than the extra engineering costs and machine tools costs needed to eliminate or add this weight to the other platforms as needed.
I have a number of rear-engine cars. I know first hand that if you have an oversize item (i.e. lawnmower, bicycle, roll of carpet, 2x4, lamp, etc.) to move and you can't close the trunk lid, on a front-trunked car you are kind of screwed and you have to go find another way to move the item whereas on a rear-trunked car you simply leave the lid up or bungee it down as far as it will go.
Fair enough. But this isn't meant to haul large items around(except for the pickup), and the same can be said for most cars.
Another is the chassis dynamic of having a very light front end (unloaded) to heavy front end (loaded to capacity) on the end with the steering wheels- the behavior of the vehicle changes quite a lot between those extremes whereas when the load variability is on the rear, non-steering wheels the effect on handling is not as extreme.
Again true. But this isn't meant to be a do-everything vehicle like today's SUVs and oversized pickups. It is meant to have two main purposes: commuting, and racing. Except for the pickup idea, which would actually be quite practical provided one doesn't need to haul a family around in it.
With the mid-engine design, you don't need a grill or airflow to the front of the car, things which add lots of drag. This makes obtaining an ultra-low Cd feasible.
What the hell are you going to do with 170 mph?
Care to take a guess?
Why not have everybody sit low for no frontal area penalty compared to the sports version?
For added passenger room for the 'sedan', and greater ground clearance for the pickup.
You outlined almost a Tempo-sized package, although w/better Cd and far-out performance predictions.
Might seem a bit far out. But if you run the numbers, you're looking at about 75 kW at the wheels needed for 170 mph for a car with a .18 Cd, 16 square foot frontal area, 1800 pound weight, and tires with a .006 Cr. A car with same frontal area and weight and a .4 Cd would be lucky to hit 125 mph with that amount of power at the wheels.
Aero drag makes a big difference at those speeds!
Again, no need for 150 mph capability, it'll never get used. Same with the fast 0-60.
Sure seems to sell quite well though. It would definately garner sales if a vehicle of such performance was sold for so cheap that got such unreal fuel economy.
Again due to VW experience (Squareback): You have your vehicle totally loaded and then suffer an engine problem. Instead of simply popping the hood, you have to unload all your junk at the side of the road to gain access to the engine compartment. Lemme tell ya, that sucks.
That's the idea behind using a low-maintenance diesel. The goal is to make a car that isn't generally going to have engine problems so that this is no longer a concern. Diesels can hum along with very little maintenance for 300,000-500,000 miles.
The Ranger plant in St. Paul is closing down. Evidently nobody buys small economical trucks in this country;
People don't buy them because they aren't availalble.
The Ranger and S10 in the 1990s ballooned into overweight hunks of pork. The people that bought small trucks no longer had any available to purchase, as those models no longer delivered them that. They took their cash and kept it.
There are a lot of people that would love a small, economical pickup. But the auto companies won't make them. They would rather sell more profitable vehicles.
even the imports are much bigger now than they used to be.
Adding all sorts of useless crap that the small pickup truck buyer doesn't want or need allows the company to inflate the cost of the vehicle and rake in more profit.
The VW Rabbit pickup and the Rampage were kind of neat but never really took off.
They took off, but their market was small relative to the size of other markets, and dedicated. Once trucks like those were no longer sold, the buyers in this market had nowhere to go.
The Rangers aren't wanted, for instance, precisely because they have become oversized, overweight trucks. The small truck market does not want a full size truck. Had the Ranger been kept small as it was in the 80s, it would probably still be selling as it has. But industry would rather have the small truck market buying larger and more profitable vehicles.
We are seeing two things at work:
a) Market manipulation
b) Price discrimination
It's no surprise what the end result is. The small truck market simply quit buying trucks after what they wanted wasn't available anymore.
Would it sell? Maybe if we had $7 gas.
That's where the performance aspect comes in. You need to lure buyers with outstanding fuel efficiency and high performance in the same package for cheap if such a vehicle is to sell today in markets other than the small truck market.
But the auto industry wouldn't do that anyway. It would take away from sales of other larger, more-profitable vehicles. But it's still a nice idea to ponder.
Structure beyond what is needed is extra cost and weight. There's no getting around that!
Unless it takes more money to modify or eliminate part of that structure than to simply keep it the same for all three platforms and use the exact same machine tools. It's a balancing act.
Ex. Beetles would NOT perform better if they had Microbus pans, brakes, etc.! Miatas would not be lightweight with 626 mechanicals and chassis bits!
Yet Triumph Spitfires fitted with TR6 brakes, GT6 engine, TR6 differential, TR6/GT6 chassis pieces perform much better than their stock counterparts in acceleration, braking, and handling. Depends on the car.
Like I said, it's not a deal-killer, people own Fieros and Corvairs and such, but it DOES definitely decrease the ultimate utility of the vehicle, I know this for a fact!
I'm not denying that the utility of the vehicle is decreased, but I am saying that the utility such vehicles have often goes unused. Some people will use it, some won't.
But like you said, it's no deal killer.
Based on past and present production vehicles I would tend to agree, but then on the other hand I would think that a front engine compartment with carefully managed air-flow through it could be just as efficient as a mid or rear engine layout if not moreso due to the ease of tapping into high and low pressure areas for airflow that doesn't require mechanical assistance.
But then you have new difficulties in keeping frontal area down, with said front engine design. But it could be workable, just not the easiest solution.
Just challenging the status quo a bit- again, why should rear seat passengers require more headroom (taller greenhouse) if they are provided enough legroom and are seated at the same height as the front passengers?
The wheelbase may not be long enough to accomodate increased legroom. Increase then wheelbase, and the handling characteristics are changed.
It keeps shrinking! I thought it had <20 sq.ft. frontal area.
Depends on the hypothetical model. The sportscar was < 16 sq. ft.
I don't know how it will hit a 1800 lb target weight with all that heavy-duty stuff in there!
Not quite that difficult if all the fluff in the interiors that new cars have now days is left out. Such a car would basically not have the womb-like interiors cars now days have.
What's interesting is that cars today have gotten much heavier than the cars of the 60s and 70s, and that weight isn't all because of safety devices, either. Cars have all sorts of crap now days that often goes unused. Interiors of cars are often loaded with hundreds of pounds of sound deadener and other dead weight to reduce road noise caused by poor suspension geometry, tire selection, and other factors, and to make the car feel more 'heavy' when it is cornering in effort to lure people into thinking they are buying quality. Then this extra weight is used as an excuse to inflate the price of the vehicle.
I know of two cops that got into an accident. The dashboard of their Ford Crown Victoria fell and crushed their legs. That's quite a large bit of useless weight to lug around.
Addressing this interior weight could easily shave 400+ pounds off of most of today's cars, and racers often shave off 200-300 pounds of this crap from 90s model cars.
Do you want to be going 170 mph on LRR tires?
So long as they're rated for it.
Maybe at Bonneville, maybe at the drags, but everywhere else you race, you're expected to corner!
A properly sized wheelbase, low center of gravity(eg. mid engine), and sufficiently rigid suspension could provide adequate cornering capability on LRR tires, perhaps even comparable to an Audi TT or other such car.
I know of electric car conversions that use LRR tires, and still manage ~.85 G on a skidpad. That's comparable to many $40,000 sports cars.
Ah- the fabled "sealed hood". Yet for some reason we keep needing to get in there to piddle around...
Depends on the car. Most Hondas and Toyotas could operate just fine if everything were sealed to that extent. GM, Ford, no way in hell.
Consider that I'm under the assumption that Honda's diesel possesses consistent reliability compared with their other products, and if not that. If that assumption turns out incorrect, then yes, the sealed hood is a very bad idea.
It's true that for example the Ranger has gotten heavier- around 400 lbs more between '85 and '06 for the reg. cab 2.3 m/t. Likely much of that 400 lbs on the '06 is bigger and heavier wheels, tires, and brakes, a/c, pwr steering, pwr brakes, heavier frame, bigger cab (yes!), even thicker glass! and lots more sound insulation than the '85 had standard. That is discouraging, but EPA ratings only show a 1 mpg loss hwy and 2 mpg loss city while horsepower is up from 86 to 143! Well, all these people that would love an economical pickup aren't stepping up to the plate- if that was the case, Ranger sales would be better and the foreign models wouldn't have grown so much bigger either.
The EPA estimates are notoriously inaccurate. When I get the chance, I'll try to find the data from consumer reports on what people are really getting with each model. Newer car models are often getting less than their older counterparts by the users as a general trend, even if the newer models often have better EPA estimates.
But economical doesn't just mean low fuel usage. It also means low maintenance. That power steering, power windows, power brakes and all that other crap adds to maintenance costs. Unlike the older models that were easily repaired, newer models usually require the service of a mechanic when even the slightest problem arises.
P.S. Matt: I looked at the first page of your N600 rebuild thread and it mentioned converting to EFI- I bet there is a motorcycle system out there that could be adapted without too much re-engineering.
That would be awesome if you had that information available.