MAZDA RX-7 SERIES 6-8

EARLY RX-7S WERE LAUDED FOR THEIR VALUE AND AFFORDABILITY THAT DISAPPEARED WITH THE PRICEY SERIES 6

When Mazda’s RX-7 started its journey in 1978, no one could predict the pace at which the friendly little coupe would evolve. Seven years later it had become the Porsche inspired Series 4 and from 1992 the Series 6 with dual sequential turbochargers dragged it into supercardom.

Unlike previous RX-7s, the S6 was a dedicated two-seater with weight saving strategies to deliver a car that had 176kW but was 80kg lighter than Series 5 counterparts. Four-speed automatic transmission was available in some markets, but Australian cars were all five-speed manuals.

New price of an S6 in Australia was $72,000 – 31 per cent more than the Series Five Turbo. Taxation took a fair chunk of the increase, but Mazda had itself to blame too for slumping sales, due to its decision to offer just one version instead of the range of RX-7s available in other countries. Series 6 sales declined from 108 during 1992 to just 59 in 1995, by which time the price had climbed to $80,000.

Value for money was not an issue. Included in the asking price of Australian cars was air-conditioning, a tilt and slide sunroof, leather seat trim, cruise control, central locking, driver’s airbag and an alarm system. The sound system was by Bose and incorporated a radio/cassette system, CD player and Acoustic Wave technology that saw the minuscule boot half-filled with sound equipment.

Performance testing by local magazines had the S6 running 0-100km/h in 6.9 seconds and the standing

400 metres in a whisker over 15 seconds. Top speed was 252km/h and the car became an immediate must-have for several teams with ambitions in the Series Production racing arena.

Wins at Bathurst in the 1992-94 12 Hour races confirmed the car’s pace and durability, but in the face of sophisticated competition from Porsche’s 911 RSCS and the BMW M3-R, Mazda Australia devised its own `GT Production’ special’ with performance and handling improvements. Only 35 RX-7 SPs were built, with 29 additional kilowatts of power due to improved intake ducting and a larger turbo intercooler.

Local sales ended in 1997 but RX7s remained popular with Japanese enthusiasts and remained in production until 2002.

These Series 8 cars were built only for the Japanese Domestic market, however as used cars they have since been exported in significant numbers and appear regularly on Australian sales sites.

Strong demand and limited supply have helped Series 6-7 RX-7s reverse value downturns and rapidly improve retained values. Pre-1997 cars bring close to new car price, while Series 8 imports in excellent condition reach and sometimes exceed $100,000.

Expert inspection by a rotary specialist is essential to your finances and the car’s longevity. While some pops and whistles generated by the twin turbo engine may well be `they-all-do-that’ normal, an expert will quickly identify anything with the potential to cause expensive trouble.

BODY & CHASSIS

Rust is rarely an issue with local RX-7s of this age, so the major concerns are poorly repaired accident damage and abuse. Look underneath for damage to the vulnerable front spoiler and cracks to the bulbous rear bumper. While you’re down there, check the wheels for `kerbing’ because genuine replacements can cost $3000 each!. Also take a look at the fuel tank for impact damage. The special aluminium bonnet fitted to SP versions is no longer available but one in fibreglass was offered at $1320 and a rear spoiler for $660. Japanesedelivered cars may have suffered at the hands of uncaring owners, so check a few cars before committing.

ENGINE & TRANSMISSION

A comprehensive service history and use of appropriate oils and coolant is vital to the longevity of highperformance rotary engines. Debate exists regarding correct oils for these cars, but the real issue is the frequency. Mazda recommends oil and filter changes every 5000kms. But few will travel that far in a year, so make sure they are serviced at least annually. Turbochargers rarely last more than 100,000 kays and other engine components up to 150,000. Any exhaust smoke signifies a problem with rotor seals or the turbos. Repairs could cost $10,000+. An oily smell may come from lubricant leaking onto the exhaust pipes, while hesitation under acceleration is often due to vacuum hose leakage. Check for coolant leaking from the radiator filler neck.

SUSPENSION & BRAKES

Service items like shock absorbers and brake pads wear according to the way a car is driven while age consumes items made primarily from rubber. Local suspension specialists do stock most of what you need but seem shy about quoting prices. We did see a pair of KYB (decent brand) shock absorbers at $400 and sets of four competition-spec coil-overs at less than $2000. Some RX7s of these types run quite exaggerated negative camber at the rear, so check that tyres aren’t showing wear to their inner edges. Brakes in good condition are adequate but Mazda did elect to fit cross-drilled rotors to later cars to improve cooling and these are available after-market. Cars that don’t get used often can suffer seized calipers, leading to uneven brake effort because one wheel isn’t contributing at all.

INTERIOR & ELECTRICS

All of these interiors are 20+ years old and some can reach 30 so deterioration is an issue. Look at the dash for cracks, crumbling switches and column controls. Make sure that the sunroof, windows and concealed headlamps operate correctly. While the lights are exposed, examine them for stone damage. A carbonfibre dash, complete with instruments, was advertised in 2022 by a British supplier but one of these would cost around $6500 landed here. Batteries can fail prematurely due to excessive underbonnet heat but there really is nowhere else to mount the battery.