G1 Prelude Body & Chassis Design History

From G1 Prelude

The 1st generation Honda Prelude started development in early 1977 and was inspired by the newly established "Benz" mindset within the Honda R&D department. A simple question was asked amongst the design group, what made a Mercedes Benz desirable and cool? What did Western buyers want in a sports car? How does a car be cool, sexy and intelligent? These questions were used heavily to help develop the cars styling and unique characteristics. The Prelude was conceived to fill a hole in Honda's growing lineup for a sporty, upscaled 2+2-seater that Honda was severely lacking, since production ended of the 145 Coupe five years prior.

After the Prelude's release in late 1978, it unfortunately did not perform well domestically in Japan. This caused an image problem for Honda. The Prelude was advertised exclusively alongside the launch of Honda Verno dealerships and interested buyers were just not taking it seriously. Sale numbers showed that both young and older generations were not buying into the sporty nature the Prelude promised on its "Benz" ideology. Major interior revisions and model options throughout its four-year tenure showed it struggled to fit into a sporty niche market and was the not the mid-ship sports car Honda promised. This was also an interesting time for Honda as the car grew quite popular in the US and European markets, where the competition was much harsher. Oversea sales slowly grew with the 20–35-year age groups who wanted a small upscale car, but with Honda reliability and cheaper cost. Only 30% of the cars volume sales were domestic, while 70% were exported to overseas markets.

"This is not a sports car for performance or handling. This is a rare moment for a car to offer sophistication, comfort and looks at an affordable price with Honda values." Honda R&D

Later nicknamed the "Kawagoe Benz", the 1st generation Prelude was a very unique Honda created by its designers and not by the customer, bringing forth a radical new viewpoint for Honda R&D and its marketing teams in the early 80s. The immense luxury value found in the Prelude was extremely rare for Honda and it proved they were serious about an adult sports coupe that had European styling but kept with Honda's simplicity and rugged ergonomics. Its electric sunroof was innovative and exciting at the time, making the Prelude the first Japanese car to have a production sunroof standard. To this day it stands as the most radical Prelude in the five generations it helped launch and still holds it's worth today. It proved that Honda could build a high-quality sports 2+2-coupe with classy "Benz" sophistication, but in the end, the consumer spoke and breathed a change back into Hondas designers for the 2nd generation Prelude mid-ship sports car.

Quoted straight from Car Styling Quarterly Magazine #26, Spring 1979. This is a superb article about the SN body style and how it came to be.

This is a direct translation from the original Japanese text, strong grammar errors exist in this article.

"Honda Prelude" - Opening to Honda's Symphony No. 3 by Jack K. Yamaguchi

HONDA's new specialty coupe is a creation of the tight group of probably the youngest and most brilliant designers and engineers in the Japanese motor industry, headed by "Le Cap, Director Hiroshi Kizawa, 45 years old, of Honda Research and Development Company, wholly owned subsidiary of Honda Motor Company. Kizawa is responsible for the successful Civic and Accord ranges, thus richly deserves the title CAP or head in French. C for Civic, A for Accord and P for Prelude.

Honda's four wheeled production can chronologically be classified into one ear and three successful generations. The genesis era covers the S-series 2-seat sports car, a jewel like but fragile devise powered by the exquisite twin cam roller crank inline four, which was technically interesting, but commercially a near disaster. The first generation car is the 1300, again an unusual design betraying the flamboyant character of the founder Soichiro Honda. The second generation products, Civics and Accords, established Honda firmly in the four wheeled world. Each of these era and generations are heralded or accompanied by diminutive light class vehicles. Of interest are such oddities as the type AK truck powered by a DOHC roller bearing inline four mounted midships under the truck bed, the furious N360 micro car and the suave Life.

Each transition from an era to a generation, from a generation to another marked distinct changes in product concept, philosophy, design and engineering, some of which were electrifying. The transition from the second generation, as represented by the Accord, to the third whose first product is the Prelude, seems relatively gradual and free of jolt, and perhaps excitement. Superficially, the Prelude may be regarded as a logical development of the Accord, thus belongs to the second generation. Nothing can be further from the truth than this interpretation.

In vehicle dynamics, no doubt the most important feature of any car, the Prelude is outstanding. It outshines any and all Honda production cars to date, and is equal if not better than the best Europe offered FWD configuration. One may still want more performance form the 1750 cc CVCC charged stratification engine inherited from the latest Accord, but he finds very little to fault in the car's superb road manner. At a closer examination, one will see readily that it is not an assortment of existing components, and Honda has gone through considerable retooling programs to produce the Prelude which as it's own unique full monocoque body and suspension.

Then why the Prelude as it looks outwardly? How Honda reached this seemingly classical 3-box coupe shape? The subject is indeed full of intriguing questions and some candid and a few masked answers.

Honda is now a force to reckon with in Japan and in the world. Its annual production is reaching three quarters of a million 4-wheelers, in addition to myriads of motor bikes. On the other hand, it's domestic marketing capability is not without problems, inherent in the rapid growth period of the production side. In the system, Honda cannot aim is products to buyers in the single life-cycle type, otherwise it will soon hit the saturation wall. The corporate planners will naturally want a product or two that appeal to the different life-cycle clientele, people who live outside of the Civic-Accord cycle. Most desirable is a car with "self-selling" ingredients, or more specifically cars with sporting and personal appeal. Fuse into this corporate demand Honda's unfinished job. Honda built some ambitious sports cars and sporting coupes, the S500, 600 and 800, the 1300, which were not accepted for one reason or another in their times. strong desire to resurrect their sporting spirit has never left the minds of the RD designers and engineers.

Here one must be careful. Do not consider the Prelude a Franz Liszt's symphonic poem which ends with a pessimistic connotation (my intial mistake, I must confess) The Prelude is not an indepdent and single shot project. It is literally the first movement to the Honda's Symphony No.3. It's four key notes, body construction, suspension design, power-unit (CVCC may soon undergo extensive modification for improved output) and more significantly chassis dimensions will soon appear in the ensuing movements of the symphony. And the Prelud's virtues will not be confirmed in a "true sports car" from Honda. Immediate beneficiaries will be in those in the segment Europeans call "C" Sector....

Hiroshi Kizawa, Center Shinya Iwakura

"Our new battle to pave the way to a different life-cycle segment wasn't an easy one," recall Shinya Iwakura, chief designer at the R&D. "We had to research, grope and find the only strategy by which we would be sure of victory, as advocated by the great admiral Yamamoto." Sportscars and sporty cars are now in full bloom all over the world. Honda's designers initially came up with the image proposals of sleek and contemporary sports wares, and they put these images in clay. It was toward the end of the early design development stage when the final shape of a notchback coupe with a strong teutonic influence appeared. During the Prelude development, Honda men visited the grand landscape of America, where they examined cars in motion. Their conclusion was, "However sporting it may be, a car still has to meet the demand of the changed world. It cannot sacrifice comfort and convenience for sheer performance. It cannot be a stark and crude device, or a thinly disguised sedan." A new sporty car could relatively be easily developed using existing components. In fact, such a car was built from the Accord. But Kizawa's team wouldn't have it over their dead bodies.

The new car had to be sexy. But they wouldn't want superficial and flippant sex appeal. it should look good but it should also show it's Honda discipline. 'Le Cap' describes the fact and heart of the Prelude, "Sexy and intellectual. "No one in his group denies a Mercedes 450SLC influence in the Prelude. Iwakura admits, "A Mercedes would is the only one that permissible in the sector we are aiming at."

The well mannered coupe was initially conceived a 2-seater, which explains a rear seat that looks impressive but good only for a couple of pigmies. Honda who has done such outstanding packaging jobs as the Civic and the Accord, must have thrown out it's text book, and concentrated in improving dynamic quality and visual appeal in the Prelude. Iwakura and his designers wanted to keep the overall height under 1300mm. Their irresistible force finally moved the immovable object that was Kizawa. And they managed to put a 50 litre fuel tank under the floor as well.

Halfway through the design development, Iwakura and company were still spending agonizing days and nights, unable to realize the visual quality they had worked so hard to achieve. It was found in the missing link to the old S-Sports car - friendship with wind and air, thus the adoption of the electric sunroof in a wholesale scale across the board. The interior is not exemplary in space utilization, in certain directions it is limited, to the say the least. "Minor trade-off in view of the car's dynamic quality and refreshing appeal. It is an acceptable package even for the most discriminating," asserts Iwakura.

Honda has a very practical approach to the aerodynamics. Kizawa is fully aware of drag improvement with a fastback shape with extending roofline. But coefficients aren't everything. The prelude drag coefficient is CD 0.45 and lift CL 0.32, which are within the norm of the day. The design teams efforts were directed at practical aerodynamics, like reduction of wind noises, addition of the air-flow lip on the trailing edge of the hood to direct onrushing water off the windshield.

One of the most controversial features of the Prelude design is undoubtedly it's "Concentrated target" instrument, a concentric multi-story speedo/rev counter/warning lamp cluster rather like cyclos. The basic concept of this unique instrumentation is to emphasize the speedometer, which is the most used and relied upon information source. It is given the largest space, best location, most prominent color contrast and illumination in the panel. Kizawa contends, apart from what he likes and dislikes, that the multi-story layout is better for quicker recognition and digestion of information than scanning instruments on the same plane. His men have done their preparatory works well, in and out of Honda. A reviewed rating by System Technology Inc., in Hawthorn, California, was extremely good. On the other hand, they did not claim this is the ultimate in the automotive instrumentation, but rather like it interpreted as a significant and ambitious step to that direction. One thing is certain. the prelude as a car is more personal and individualistic than the suave and likable Accord. A touch of love or hate wouldn't hurt it's character.

History is a fascinating repeater. Yesterday's advanced concept is suddenly a stereotype of today. Take the fashionable hatchback/fastback configuration. Suddenly a classical 3-box coupe looks fresh. "It will stay fresh into the 80's, as long as it succeeds to say classical and avoid being antiquated," concludes Iwakura.

Early Sketch Studies - In search of the "Shape"

As usual for Honda, the designers approached their new sports coupe project with an open mind and free imagination. They considered three different body type, fastback, semi-notch and notchback designs.

1. 2.

These renderings show very fast fastback ideas. From the onset, low overall height and wedge lower body were among top priority items, even if they might make the beltline look higher.


Modified fastback idea proposal.


This sketch, reminsiscent of Lancia's Beta HPE sports estate, progress to 1/1 clay stage. Extending the roofline with an upturned "lip" could help smoothen airflow and reduce drag, as well as improving the rear seat head room, yet the Honda men did not opt for this practical consideration.


Semi-notchback coupe proposal, which thick B pillar and panoramic rear glass section. This also moved up to the 1/1 clay stage.

6. 7.

Winning image sketch which depicted a notchback coupe with an ordinary trunk. Sunroof was already considered at this stage. Clean and pleasant design ala Accord Hatchback, but lacks visual persuasion.

8. 9.

Final Sketch. Thick Teutonic influence was showing up. Rear end details were yet to be finalized, but upright taillamp clusters were decided on in rebellion to the universal "Horizonal Justice."

Competition in Clay

1. 2. 2.

Full size clay of the fastback design. The design team characterizes this model "Gust and Pride." Pride in the established Honda design identity inherited from the Civic and the Accord? A well used approach, yet a charming HPE-like appeal. Pity guts didn't push it through.

4. 5. 6.

"Semi-notch" model in clay. Character lines that run from the thick B-pillar to fore and aft have been tried on Mazda's Cosmo coupe, with mixed success. Once a radical technique now looking dated. Front end is also bland.


Strongest competitor in full size clay. Triple shallow grooves on the lower body link the bumpers.


Rear end now carrying final taillamp shape.


Alternative single opening front end, as compared with the triple opening proposal in the sketch (separate and upright grille to the headlamps). This is more Honda.

10. 11. 12.

Final Clay 1/1 Model. Described "Vivid and Dignity." Front end shows the domestic E-series upright grille with split textures.

13. 14. 15.

Full size mockup taken from the final clay. The triple lower body grooves replaced by a single bold one.

Interior Design Development


Early idea sketch of the controversial cyclops instrument panel. Three dimensional "tower" houses all information sources and control switch gears, including the radio tuner/selector dials.


Compromise plan with four separate auxiliary gauges placed conventionally on either side of the cyclops speedo/rev counter. Radio is also moved to a more normal location.


Radio is no on the side of the instrument nacelle.


Interim design proposal stressing the width of the instrument panel.


Early mockup model. Visual aids and controls are pulled as close as possible to the operator, and the deeply recessed instrument panel is emphasized. By why "Civic GL" on the panel?!


Second stage development model. Direction of refinement was: Polish off the rough edges of the original instrument cluster, change the vent/air conditioning outlet shape from circular to rectangular to match the main instrument panel, and adopt a sportier four spoke steering wheel instead of the original 2-spoke version.

7 8

Final interior model. Instrument cluster is now in matte black, contrasting the color keyed facia and nacelle to stress width and remove some of the design heaviness associated with the second stage model. Steering wheel shape is also cleaned up, soon to lose the central divider in the pad.


Early image sketch pursuing sporting image


Straight out of the Star Wars X-wing fighter?


Close to the production seat pattern

The SN Honda Prelude was manufactured only in the Sayama Automobile Plant, in the Saitama prefix of Japan adjacent to Kawagoe City. It was nicknamed by workers and locals as the "Kawagoe Benz" due to it's similar looks towards the Mercedes Benz 450SLC.

Below are some rare and unique factory pictures showing members of the production team during assembly of the the SN Prelude. All photo rights belong to Kouichi Kikushima, 菊島幸一 and Honda Motor.