Contemporary review/driving impressions originally published in AutoWeek March 11, 1985
The big room is quiet on a Saturday afternoon as the December sun slants in through the skylights and the ceiling-high frosted glass windows and our voices and footsteps echo off 50-year-old whitewashed brick walls of what used to be the shop of a Chevrolet dealership. Almost at random are the three dimensional spiderwebs of space frames and sports cars in various states of incompletion, each on its own pair of sawhorses, each bearing a strip of masking tape on the foremost tube on which is lettered the customer’s name. The city is Hagerstown, Md., the old shop is the new factory for Rotus Ltd., and the man in charge is Christopher Custer.
Custer is building, he explains, a modern version of the Lotus 7, Colin Chapman’s back-to-basics roadster, introduced in 1957 and changed only minimally over the years. Chapman’s Seven has refused to go away. Despite the championships from club racing to Formula One and road cars eons more sophisticated than the Seven, a collection of tubes and aluminum sheeting and fenders with the drag factor of parachutes, sold so well that to keep people from coming around to Hethel asking for them Chapman sold the production rights to Caterham Cars in 1973. And Caterham Cars is still making them.
The Lotus 7 has that certain magic that defines a sports car, the fundamental elements of performance and fun. As someone once said, the sports car is what you have left if you throw away what you don’t want and don’t need. The Seven is elemental, but in all the right elements and it hits the sports car enthusiast in the psychological solar plexus. Custer, a Lotus 7 owner himself, knew that. It was not, however, perfect. Which Custer also knew.
“The concept is fine,” explains Custer. “But if you’re willing to drive a Lotus 7 you’ve got to be your own mechanic or know one, and you’ve got to put up with an awful lot of ‘working on’ instead of driving.”
So, in a loft garage with working space for two cars, Custer set out to build a better Lotus. Using the basic Lotus 7 dimensions, Chassis No. 1 was built incorporating changes that would eliminate a lot of the weaknesses inherent in the Lotus design without eliminating the good stuff.
As it turned out, Chassis No. 1 was never built into a whole automobile and the frame now leans against the far wall of the Rotusworks, a sort of steel tube memorial to the company’s origins. What happened was that A. Lee Kaiser, engineer and Lotus 7 owner, joined the fledgling firm. Kaiser, who was now in California with Chrysler working on a Laser project, evaluated the frame and added his own improvements. And that, apart from running changes to enhance the basic package, is the Rotus frame of today.
Of course, it was not quite that simple. Although Custer and Kaiser knew the Lotus 7, Custer queried more than 100 Lotus 7 owners about what it was that they liked about the Lotus 7, what they would change about it, and what specific problems they had encountered with the English sportster. Based on the results of their survey, changes were made to the Lotus concept. Lack of foot room was addressed by increasing the foot well. A lack of luggage room, for anyone crazy enough to tour in a Seven, was eliminated by a basic form of research. Custer measured nine popular suitcases and assured that the luggage well was large enough to accommodate the dimensions of each. A fuel tank behind the rear axle and a frame tube away from intruding disaster in the Lotus was moved in the Rotus to a vertically oriented tank straddling the driveshaft, affording the protection of the spare tire and the luggage space (and luggage, if any).
Less obvious but at least as important for the structural changes to strengthen the frame. The rollbar on the Rotus (1½-inch seamless steel tubing, 0.125-inch wall) is the structural center of the car, of which the rear suspension is taken, thus making what was one of the weakest points on the Lotus 7 the strongest on the Rotus. On the Lotus, Custer points out, one of the rear suspension links was taken off the center of an unsupported frame tube, and was frequently the site of frame failure. “We didn’t ever want that to happen.”
“We weld in bushings through the tubes rather than just drilling a hole and putting a piece of tube in it and using it as a crush (as Lotus did),” says Custer, adding that the open hole in the frame invites breakage by designing in a weak point in the frame. Lotus even used this method for its engine mounts. A weld-in tube actually strengthens the frame rather than weakening it.
Is not just a stronger frame. Lotus owners won’t tell you about it, but Lotus Sevens – despite their suspensions being taken from Chapman’s first formula cars – have significant bump steer, steering action as suspension goes through its travel. Kaiser, drawing on a couple of decades of experience that Chapman didn’t have, laid out the Rotus’ suspension in such a way that it has no bump steer.
Kaiser went one step better yet by replacing the Lotus outboard coil over shocks (i.e., the shock absorber cum coil spring from the outer end of the lower suspension arm to the frame outside the body of the car) with a cantilevered front suspension. The upper suspension arm acts as a center fulcrum lever with the wheel at one end and the coil-over shock at the other inside the car behind the grille. It probably has little effect on overall drag figures, considering those sweeping fenders, but it does make the front end much more tidy.
The front suspension design, like that of the Lotus seven, was in fact formula car inspired. “We took a whole pile of formula automobiles,” Custer recalls, “and Lee sat down at his computer and began to figure what the similarities were among some extremely good racing cars. Bunch of Marches, Crossles, handful of Van Diemens.”
Custer notes that Kaiser was very good at getting information from the top builders by visiting the pits in the morning when only the owners and other People Who Know were around and asking a few discrete, well-placed questions. Those bits of information were added to the computer’s calculations and the result was the Rotus front suspension, probably the only road-going cantilevered set up in the world.
With the frame and suspension, Custer still had only the world’s trickest soapbox. Seeking reliability as well as performance, Custer based the running gear and a few odd bits on Toyota mechanicals. (His being a Toyota dealer probably had something to do with it, too). The base engine is the 1800cc “3T” Toyota “hemi head” and the Toyota five-speed is the standard transmission. The driveshaft is a modified Toyota piece and the rear axle comes from a Corolla or Celica, though the four trailing links are custom-made. Lateral location of the rear axle is by Panhard rod.
Radiator, wipers, brakes (disk front, drum rear), and rack-and-pinion steering are all Toyota, as are the front suspension uprights. The steering arm is specially made, however, for better geometry and – thanks to a choice of locating holes – a choice of autocross quick or street quick steering.
Not Toyota is the racer stuff: Tilton break dual master cylinder/hydraulic clutch assembly with balance bar for fore-and-aft brake bias adjustment. The whole assembly is adjustable for placement for-and-aft and the pedals can be adjusted for height relative to each other (the first Rotuses, like the Lotus, have a non-adjustable “bench” seat). Be forewarned, however, that this adjustability is a nut and wrench affair, so it’s a custom fit for the primary driver. Fully adjustable Koni shocks are used front and rear, with the back units modified, with a longer shaft, to reach the mounting point.
The whole car: Sides, hood, cowl, bottom, pedal boxes and transmission tunnel, is skinned over in aluminum of the most primary shapes, as was the Lotus seven, and fenders and nosecone are made of reinforced fiberglass. The Rotus frame weighs 31 pounds more than that of the Lotus, a small price for the strengtheningmod. All told, dry weight for a standard Rotus 7 is under 1250 pounds, no more a problem for even a stock Corolla engine than plastic barbells for a 98-pound weakling.
But Wait, as they say on TV, There’s More. Because it’s a low volume, “custom production” manufacturing process, Rotus can tailor your roadster to your personal desires. Though the frame dimensions and suspension are fixed, the bigger-than-Lotus engine bay will accept any number of interesting engines. How about the 16-valve Corolla four-cylinder? No problem. Custer has the engine on order. Or how about the twin-cam Celica six? It’ll fit. So will the Cadillac 4.1-liter V-8 or the Buick-Olds-Pontiac aluminum V-8 (also in Triumph/Rover guises), though Custer will strengthen the frame first such applications. “Everything from our next demonstrator (on) is a V-8,” says Custer, pointing out frames around the shop. “That one goes to Paris, Texas; this one goes to Rockville, Md.; this one to York, Pa. That car goes to upstate New York.”
Small-block Chevy and Chrysler Hemi partisans will have to look elsewhere, however. Interestingly enough, though, is that the Triumph/Rover V-8 weighs 11 pounds less than the Toyota cast iron T-series four. And Custer has an experiment planned for a Mazda rotary.
For those interested in the ultimate Rotus or an ultralight race car, Custer will make the frame out of 4130 chrome moly and skin it in 0.025 or 0.030 aluminum instead of 0.050. “We can get it down to 1,100 pounds without any problem for the total weight of the car,” claims Custer. “We can peel a couple of hundred pounds off without losing any structural integrity by just using more high-tech metals.” Just bring money.
Of course, customer preference and such things as color, instruments, steering wheel and tires and wheels are easily accommodated, though Custer normally specifies 195/60 or better.
Low production also facilitates running changes. For example, on early Rotuses the rollbar was vertical above the body, but has been changed to a more aesthetic seven-degree rate, matching the windscreen. A gullwing fiberglass top would fit better if the top tubes behind the rollbar were horizontal instead of sloping slightly downward so, with no wait for committee approval, the change was made. Other less dramatic changes, such as standardization of bushings or altered shock mountings, can also be made when a better way is found.
Custer normally fits BFGoodrich Comp T/As to Rotuses, and a test sponsored by BFGoodrich at the Transportation Research Center in Ohio, the Rotus 7 easily achieved 1.0 Gs lateral acceleration on Comp T/A\s. Only one other car at the test, a kit car, managed to break the decimal point barrier after considerable trying.
Pulling 1.0 Gs on the skidpad, says Custer, “is something you can’t do with the Lotus 7. They are so twitchy in the back and that you wind up flat spinning it.”
The performance is more than just test track tricks, however, as we learned when we took 2½-year-old Chassis No. 2., the first Rotus to be completed, out for a short drive and photo session. (Custer was going to send me out into the 40-degree weather on my own – no fool he – until I explained to him that someone had to drive the car for the action photos. The “short drive” is explained by the temperature).
Chassis No. 2, which is used to break in and sort out engines before they are put into customer cars, was equipped with a relatively tame 1800cc Toyota Corolla engine with a mild ¾ Toyota Racing Development cam and twin dual sidedraft Mikuni-Solex PHH-44 carburetors (“too big for this engine,” says Custer). Power is approximately 90 horses.
What we learned is that, first, one gets noticed in a Rotus. Of course, with the top down one gets noticed in anything in December north of the Potomac. Mothers pointed us out to their daughters as the sort of man to avoid. Others merely assumed we were Federal Wind Chill Investigators.
Second one thing one learns in a Rotus is that even 90 HP can give you a thrill. In fact, when a Corvette that appeared destined to be paired with us at a stoplight turned off instead, we were truly disappointed. Name any other Corolla-engined vehicle about which you could say the same. Chassis No. 2 easily spins its tires in the first three gears with little effort, and that with comp T/A’s. It might have done it in fourth, too, but we didn’t have the room to try.
The shifter, however, will take a little getting used to, as it’s cut down from standard length – the transmission is much higher in the Rotus that in a Toyota – and the result is that the pattern is very small. Try shifting a stock length shifter with your hand halfway down the shaft. It’s easy to go, say, from second to fifth until you get the hang of it.
Another skill the Rotus driver must master is getting in and out. No doors and low cut sides is as sporting as bare-handed grizzly wrestling and about his exciting, but it means that one must stand on the seat and then find a way to get both legs under the steering wheel. Double jointed knees would help. Early Rotuses had bench seats, as did the Lotus. With the transmission tunnel and the side of the car, though, the fit is snug and one won’t slide around in the curves. But in response to customer demand for a seat with four-and-aft adjustability, Custer will be fitting Recaro seats, specially modified to fit.
A thorough twisty-bit evaluation was impossible, but we can report that rough pavement didn’t unduly deflect the Rotus from its appointed trajectory and that the Rotus steering response was at least as quick as the driver’s.
It takes more than one good car to make a car company, however, but Rotus is a more than a one prototype wonder. The company has moved from its claustrophobic second-story beginnings to a larger – though suitably traditional – site. Chassis No. 18 is in production (the production figures include a few Lotus frames for Lotus reconstruction) and Custer has orders waiting. Such endeavors are frequently no more durable than the gossamer dream stuff of their creators, a fact not lost on Custer. Custer knows the odds.
“Long run, two years, three years down the street, we want to be doing something on the range of five or six cars per month,” projects Custer. “Right now, one or two is sufficient to keep everything going and keep us developing at a slow rate. I don’t want to get to a point where we have 90 orders and get all frantic about building things and lose the quality and the control we have on it now.
“I’m 55 now and I should have thought about retiring and doing less. Instead I fired up the sucker and discovered a superb way of spending my life’s savings on something I wanted to do. I thought about it and said, well, do you get four or five years down the street and say “Gee, I wish I had,” or do you go out and do it? I decided to do it.” Somehow, we think Colin Chapman would approve.
So where did the name Rotus come from anyway? Chris Custer explained that with Japanese engine in Lotus-inspired vehicle, an Engrish name would be appropriate, exchanging the “L” for an “R.” But concerned about the political correctness of the proposed name, he gently inquired of a Japanese Toyota executive about whether he might me offended by Rotus. To the contrary, the Japanese executive laughed. So, not offensive. Rotus it would be.