RO­TOR REVO­LU­TION

When Donn An­der­son first tested an RX-7 some 35 years ago, he was so im­pressed he bought one

New Zealand Classic Car - - Front Page -

DONN AN­DER­SON ON MAZDA’S GROUND-BREAK­ING RX-7

From day one, the orig­i­nal Mazda RX-7 was a sales sen­sa­tion. Cars chang­ing hands for pre­mium above-list prices were noth­ing un­usual in New Zealand in the late ’70s, yet al­most un­known in North Amer­ica — un­til the ar­rival of Mazda’s unique ro­tary-en­gined RX-7.

Here was a hand­some sports car with Euro­pean-like styling, a re­mark­able silky-smooth mo­tor and su­perb build qual­ity for less than the price of a Porsche 924 or Dat­sun 280Z. It went on sale in the US for un­der $7000 and Mazda could not cope with de­mand, de­spite im­port­ing 4000 a month. Near-new ex­am­ples in the US fetched $3000 over the rec­om­mended re­tail, and much more in New Zealand.

While the car had real ap­peal in mar­kets like Europe, Australia and New Zealand, it was the US that ce­mented the suc­cess of the model.

Of the 474,565 first-gen­er­a­tion RX-7S made be­tween 1978 and 1985, no fewer than 377,878 went to the States.

The Lo­cal Mar­ket

Be­fore the large-scale ar­rival of Ja­panese used cars, there were never enough RX-7S to sat­isfy our mar­ket. First ex­am­ples ar­riv­ing here in 1979 re­tailed at $18,000 but re­al­ized more than $25,000 on the used mar­ket, even af­ter a year or two. By 1981 the New Zealand new price had climbed to $26,000, $33,425 in 1983 and $40,000 in 1984. When the last ones landed in early 1986 they had sky­rock­eted to more than $48,000. They were fol­lowed by the sec­ond gen­er­a­tion, newly-bod­ied P747 cars — the price hav­ing risen to $71,500 by the time they ar­rived on our shores.

With the in­flux of ex-over­seas used ver­sions, orig­i­nal first­gen­er­a­tion mod­els be­came much more af­ford­able, and al­ways seem­ingly des­tined to be­come a fu­ture clas­sic. And surely, that time is now.

Ro­tary Power

Re­plac­ing the RX-3, the first RX-7 car­ried sev­eral des­ig­na­tions, in­clud­ing X605, SA22C and FB, with early plan­ning in place by 1974. The project was lucky to get off the ground, since the some­times fickle and thirsty ro­tary had been widely blamed for Mazda woes in Amer­ica.

In the early ’70s half of all Maz­das were pow­ered by ro­tary en­gines, but the first oil cri­sis dev­as­tated sales, forc­ing a re­think. NSU had an­nounced ro­tary en­gine pro­duc­tion in Novem­ber 1959, and Toyo Ko­gyo (Mazda) signed a con­tract in July 1961 to de­velop and make its own ver­sion of the rev­o­lu­tion­ary power unit, with the two-door Cosmo Sport twin-ro­tor launch­ing in 1967. Yet this am­bi­tious swing to ro­tary power al­most pushed Mazda into bank­ruptcy.

The RX-7 marked a turn­ing point for the ro­tary, a time of ac­cep­tance. As the snappy new sports car swung into pro­duc­tion, Mazda could lean on the ex­pe­ri­ence of 16 years of ro­tary en­gine devel­op­ment, and the man­u­fac­ture of more than a mil­lion of this rad­i­cal power plant.

En­ter Taka­haru ‘Koby’ Kobayakawa, a tal­ented en­gi­neer who was vice pres­i­dent of Mazda re­search and devel­op­ment in North Amer­ica. He had joined the com­pany in 1963 as a mem­ber of the orig­i­nal ro­tary en­gine devel­op­ment team.

In 1980, when I met Koby at Mazda’s Hiroshima head­quar­ters, he was manager of in­ter­na­tional public re­la­tions, and would go on to be­come the RX-7 pro­gramme manager for the third-gen­er­a­tion model in the lat­ter stages of the ’80s. Un­like ‘gen one’ this was, in­deed, a su­per­car with its 198kw, two-ro­tor en­gine with twin tur­bos and a stonk­ing 253kph (157mph) top speed. It was dif­fi­cult not to be im­pressed and warmed by Koby, whose ca­reer with Mazda in­cluded over­see­ing the brand’s his­toric win with the ro­tary-pow­ered 787B in the 1991 Le Mans 24 hour race.

A Real En­thu­si­ast

Koby was clearly a real en­thu­si­ast (his fa­ther owned an MG K3 Mag­nette), a man who ap­pre­ci­ated a good sports car should al­ways cre­ate an in­ti­mate re­la­tion­ship be­tween car and driver. He reck­oned the ro­tary en­gine was in­trin­sic to any RX-7, since it dis­tin­guished Mazda from all oth­ers. In ad­di­tion to be­ing the top-sell­ing ro­tary car of all time, the RX-7 be­came the world’s best-sell­ing sports car, only to lose the ti­tle to yet an­other Mazda — the MX-5 — 10 years later.

Rewind to the ’70s and ap­plaud the sim­plic­ity and bal­ance of the orig­i­nal RX-7. From in­cep­tion, the car’s de­sign­ers in­sisted on re­tractable head­lights and a sin­gle-piece wrap­around rear win­dow as part of the smooth, func­tional body, but be­cause of cost and weight considerations the pro­duc­tion car came with a three-piece win­dow. While most Ja­panese cars of the era suf­fered from gar­ish over-adorn­ment, the RX-7 emerged with a shape that is just as ap­peal­ing to­day as it was 36 years ago.

The com­pact ro­tary en­gine weighed only 142kg and al­lowed the Mazda to have a low bon­net line, with a drag co­ef­fi­cient of 0.36 and a 195kph top speed. Min­i­mal styling changes on the 1981 Se­ries 2, which ran from 1981 to 1983, in­cluded a new ure­thane-cov­ered front bumper / air dam that fur­ther low­ered the drag to 0.34, equiv­a­lent to a gain of 3.7kw. Disc brakes re­placed rear drums, and a ther­mally more ef­fi­cient en­gine pro­duced 85kw (114bhp), up from 77kw (103bhp) in the orig­i­nal RX-7. Im­prove­ments to the facelifted RX-7 ro­tary in­cluded larger, sec­ondary in­take ports, a re­vised po­si­tion for two of the four spark plugs, mod­i­fied com­bus­tion cham­bers ma­chined into the ro­tors, bet­ter seal­ing be­tween the ro­tors, and a new ex­haust sys­tem with less back pres­sure. The sec­ond-gen­er­a­tion FC P747 (1986-1988) boasted a com­pletely new shape, while the third-gen­er­a­tion twin-turbo FD that ran un­til 2002 was a more so­phis­ti­cated beast, although it mea­sured no more than the 4285mm of the orig­i­nal Se­ries 1. While the car’s evo­lu­tion saw im­prove­ments and greater re­fine­ment, none of the sub­se­quent-model RX-7S could em­u­late the phe­nom­e­nal eight-year sales suc­cess of the orig­i­nal.

The Kiwi Ro­tary Con­nec­tion

dur­ing the rally while still pick­ing up speed. In place of the stan­dard 12A ro­tary, Rod fit­ted a 13B pe­riph­eral-port in­take and ex­haust two-ro­tary en­gine, with car­bu­ra­tion pro­vided by a 51mm We­ber. Keep­ing it sim­ple and us­ing as many stan­dard Mazda parts as pos­si­ble, Millen cam­paigned the 4WD RX-7 for three sea­sons.

Ex­ter­nally the rally car looked lit­tle dif­fer­ent from stan­dard RX-7S, but it ran 14-inch-di­am­e­ter Panas­port wheels in place of the stan­dard 13-inch al­loys. Weis­mann’s trans­mis­sion re­search and devel­op­ment com­pany made the power take-off unit that adapted to the rear end of the trans­mis­sion. The Mazda’s dif­fer­en­tial was also mod­i­fied, and front-wheel-drive sus­pen­sion and driv­e­train parts from the Mazda 626 were cleanly mated to the front of the RX-7. This com­mon use of stan­dard parts by Rod im­pressed Mazda.

The live rear axle with trail­ing links and Watts link­age was some­times con­sid­ered the weak­est fea­ture in the pro­duc­tion RX-7 (and was re­placed on the 1986 sec­ond-gen­er­a­tion car with a fully in­de­pen­dent set-up), but Millen strength­ened the axle, added To­kico gas dampers and a limited-slip dif­fer­en­tial. The stan­dard unas­sisted, low geared, re­cir­cu­lat­ing-ball steer­ing was never a de­sign high point, so it was not sur­pris­ing Rod swapped this for a rack-and-pin­ion sys­tem. When the 4WD con­ver­sion was com­pleted, only 45kg had been added to the weight of the car and, with around 225kw (302bhp) un­der the bon­net, the Mazda was an im­pres­sive per­former. How­ever, Kobayakawa dis­missed the idea of a 4WD RX-7 ever go­ing into pro­duc­tion, be­cause he thought it had no place in a tra­di­tional sports car.

On Test

When I first tested an RX-7 on lo­cal roads in 1979, the ro­tary en­gine’s flex­i­bil­ity and re­spon­sive­ness im­pressed, as did its re­mark­able smooth­ness, although there was a ten­dency for back­fir­ing on a trail­ing throt­tle, and a lack of con­ven­tional en­gine brak­ing. Bot­tom-end power was limited even though the en­gine was re­mark­ably vi­bra­tion free, with an ab­sence of flat spots in the power de­liv­ery. Low-speed torque would be im­proved on facelifted mod­els, yet still peaked higher up the rev range and was clearly not bril­liant. The car was in­clined to hunt on over-run, and could be jerky in city and ur­ban run­ning due to the fly­wheel ef­fect of the en­gine.

Back in 1979 the pop­ping on a trail­ing throt­tle dur­ing the warm-up pe­riod was due to the high level of lead in our petrol, and was noth­ing to worry about, ac­cord­ing to Mazda. But that ro­tary en­gine was in­deed a rev­e­la­tion the way it spun like a top, with the warn­ing buzzer sound­ing each time the power unit ex­ceeded 6700rpm.

Even to­day any­one im­pressed by fine en­gi­neer­ing can­not help but ad­mire the un­der-bon­net scene. The en­gine com­part­ment is im­mac­u­lately laid out, with easy ac­cess to dis­trib­u­tor, car­bu­ret­tor and spark plugs. There’s even a small mo­tor to set the throt­tle at the cor­rect open­ing when the car is fired up. The en­gine is lo­cated well back in the com­part­ment be­hind the front wheels, con­tribut­ing to the near ideal weight dis­tri­bu­tion.

Oil con­sump­tion could be high, and the mo­tor was sen­si­tive to spark plugs which some­times oiled up. And, of course, the of­ten sav­agely high fuel con­sump­tion was the re­sult of the com­bus­tion cham­ber sweep­ing past the spark plugs, mak­ing it dif­fi­cult to en­sure com­plete com­bus­tion be­fore the ex­pand­ing gases de­parted the ex­haust port. Dur­ing my ru­ral test run, the RX-7 av­er­aged 10.2 litres/100km (27.7mpg) but work the car hard and driv­ers could be look­ing at 15.6l/100km (18.1mpg) and worse.

How­ever, there was al­ways some­thing spe­cial about this car, and when a low mileage, mint con­di­tion ex­am­ple be­came avail­able in 1980 I leaped at the op­por­tu­nity to own what was a driver’s de­light. It proved to­tally re­li­able and fuss-free dur­ing my ten­ure, and I was sorry to even­tu­ally sell it.

Ja­panese Clas­sic

Per­haps the most de­sir­able of the first-gen­er­a­tion RX-7S are the cleaner-look­ing Se­ries 2 and 3 mod­els with their re­vised bumpers, smoother rear end with ti­dier tail lights and num­ber plate po­si­tion­ing, bet­ter brakes and up­graded in­te­ri­ors. The gear lever was also repo­si­tioned closer to the driver and weight of the steer­ing eased, but power as­sis­tance was still un­avail­able. A new sound sys­tem fed through four speak­ers in­stead of two, the win­dows were now elec­tri­cally op­er­ated, and seat­ing was im­proved.

The last of the first-gen­er­a­tion cars boasted fur­ther im­prove­ments to the en­gine, with re­shap­ing of the apex seals to im­prove gas seal, im­proved breath­ing with a larger sec­ondary in­let port and re­designed com­bus­tion re­cesses in the ro­tor flanks, and repo­si­tion­ing of the lead­ing spark plug. But all RX-7S are noted for their good per­for­mance, fine han­dling and gen­er­ous equip­ment lev­els.

At the 1978 press launch of the RX-7, Mazda pres­i­dent, Yoshiki Ya­masaki, said — “The his­tory of the sports car mar­ket is a study in frus­tra­tion and com­pro­mise.” Hap­pily, nei­ther of th­ese fac­tors ap­plied to the RX-7.

Kenichi Ya­mamoto, the man re­garded as the fa­ther of the Mazda ro­tary, per­se­vered with the en­gine orig­i­nally de­vised by Felix Wankel, while the Ger­mans ex­pe­ri­enced re­li­a­bil­ity is­sues with the NSU Ro80. When he later be­came Mazda’s pres­i­dent, Ya­mamoto looked back on the Wankel as an en­gine that cap­ti­vated en­gi­neers world­wide. Although Mazda ex­pe­ri­enced its fair share of dif­fi­cul­ties and hard­ships as­so­ci­ated with the devel­op­ment of what was a rev­o­lu­tion­ary in­ven­tion, im­por­tantly, what Mazda did was to make the ro­tary en­gine work — and, of course, it also in­stalled it into a de­sir­able and time­less car.

Book Shelf

Amanda Mclaren and her hus­band Stephen Don­nell left New Zealand last year to take up am­bas­sado­rial roles at the com­pany that bears the name of her late fa­ther. Stephen was back in Novem­ber briefly, and left me a copy of Mclaren—the Wins by David Tre­mayne. It’s a large cof­fee-ta­ble book that starts with win num­ber one (Bruce at River­side on Oc­to­ber 10, 1964) and goes through to Lewis Hamil­ton’s victory at Shang­hai on April 17, 2011. That was win No. 636 ac­cord­ing to the book — ex­cept that it’s not. Johnny Har­vey’s many vic­to­ries in Bob Jane’s spe­cial Repco-pow­ered M6B en route to win­ning the 1971 and 1972 Aus­tralian Sports Car Cham­pi­onships are over­looked, but the tome oth­er­wise pro­vides a su­perb ref­er­ence, and a graphic re­minder of what the or­ga­ni­za­tion started by a Kiwi half a cen­tury ago has achieved.

Clas­sic dash­board de­sign was a hit with West­ern buy­ers, as was the car’s in­te­rior and ex­te­rior treat­ment

Cut­away of the ro­tary en­gine in the first-gen­er­a­tion Mazda RX-7 Rod Millen, seen here in the ’70s, was a driv­ing force in the RX-7’S mo­tor-sport suc­cesses Kiwi Rod Millen’s unique four-wheel-drive RX-7 was a rally suc­cess, but Mazda dis­counted the idea of

The first-gen­er­a­tion RX-7 with its clean, un­clut­tered lines and open­ing glass rear win­dow

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