30 Years of Separation
By Brad Lord | 1 November 2003, NZ Performance Car Magazine
Mazda’s all-new RX-8 is finally in New Zealand, exactly 30 years after the sale of this original RX-3 sedan. We line them both up to see just how far Mazda’s RX has come
Ahhh, the Mazda rotary. Whether you like ’em or you loathe ’em, there’s no mistaking just how big a following these cars have in New Zealand – it’s simply huge! With an all-new RX on the block the rotary is back, and what better way to check out the new car than with perhaps New Zealand’s most original RX-3 along for the ride.
A few days after the local launch of the Mazda RX-8 we were able to get these two cars together, not so much to shoot them off against one another – no, that would just be unfair – but more to see just how far Mazda has come in the 30 years that separate this 1973 Mazda RX-3 Deluxe Sedan and this 2003 Mazda RX-8.
The RX-3 belongs to Anil Patel. He’s an Aucklander with a passion for Mazda rotary vehicles that has seen him own no less than nine examples, from early RXs to later-model turbo hardware, all in not much more than a decade of driving. The RX-3 was a one-owner before Anil snapped it up five years ago, and has only travelled 30,000 miles since it was sold new in Wellington back in the early ’70s. Under the hood is the factory-fitted 10A twin-rotor powerplant, good for around 75kW and backed up with a four-speed gearbox. Out of all the early RXs the 3 is by far my favourite, although at the time they were sold new, it was actually the RX-2 that was the highest-performing production Mazda rotary of the day. It was subsequently marketed by Mazda as just that.
The birth of the RX-8 can be traced back to 1992, when a Mazda North America Operations (MNAO) project code-named 007 was undertaken. In this early stage the drawings showed some of the key features present on the car today, including the reverse-opening rear doors. The proposal, and a full-size model of 007, were shipped to Mazda HQ in Hiroshima, Japan – but the timing couldn’t have been any worse. With the Japanese economy headed straight down the gurgler and Mazda on the brink of grinding production lines to a halt 007 was filed, never to be seen again until some six years later. That year was 1998 and Mazda, after surviving testing times that really hit the new car manufacturing industry hard, was ready to start looking at the possibility of new sports car to perhaps supersede the current RX-7. A new prototype engine named MSP-RE, which featured a side exhaust port configuration, had already been shown at the 1995 Tokyo Motor Show in a prototype named RX-01. But it was in 1999, a year after Mazda decided to pursue the new RX’s design, that the RX-EVOLV prototype was unveiled to the world’s motoring press, and what would soon come to be known as the RX-8 was quickly starting to take shape.
Today, with its pumped front fenders, fattened track and narrow roof-to-sill line, the RX-8 looks like nothing else on the road, and that’s a perfect compliment to it’s unique mechanical underpinnings that date back further than the RX-3’s. Both Mazda Japan and Mazda North America had design input into the car, working with the ’99 RX-EVOLV prototype as a base, but the final look was left to Ikuo Maeda – Mazda’s Chief Designer of the RX-8.
Those with a keener eye will spot many elements drawn from previous RX models (Mazda calls this its own sports car DNA) have been incorporated into the design, and these, combined with fresh thinking from Mazda’s dedicated design department, have really created something quite special. While subtle touches like the chrome-finished rotor symbols mounted front and rear and the rotor-shaped pressing into the bonnet are nice touches, it’s the functional thought that has gone into much of the design that really impresses.
The ingenious way Mazda has compacted a true four-door car into something that wholly represents a two-door coupé was by incorporating a new freestyle door system into the chassis. These are not the so-called ‘suicide’ doors. The freestyle system eliminates some of the dangers conjured up by opening doors into oncoming traffic, by only allowing them to be opened when the front doors already have been. The mechanism is just as good in reverse, because the front door’s latches are fitted to the outside edge of the rear doors, so they will only shut when the rear doors are completely closed. It’s all good-looking stuff!
Just as when Mazda’s first production rotaries came along it’s under the RX-8’s lightweight aluminium bonnet that things have really started to get interesting. Mazda’s latest and greatest rotary engine technology (and recent winner of the International Engine Of The Year Award 2003) can be found under the lid, but set back under the firewall and mounted extra low for true front mid-ship positioning. This gives the car a very low centre of gravity and a near 50/50 weight distribution between the front and rear wheels. The engine itself has taken off where the last of the RX-7s left off, with a twin-rotor 13B, but this time without the aid of two sequentially boosting blowers.
Mazda’s latest and greatest rotary engine technology retains the same basic design as that found in the RX-3’s 10A twin-rotor engine, but with some new advances that make the RX-8’s 13B-MSP engine smoother, more powerful and even better for the environment.
The biggest changes made, however, have come with the complete relocation of the engine’s exhaust ports. After almost 35 years of siting them in a peripheral position, Mazda has moved them to a side position on the same front, intermediate and rear housings as the intake ports.
The reason for the move was simple, and that was to eliminate the intake/ exhaust port timing overlap that was commonplace in previous Mazda rotary engines. Before the Renesis engine, the design meant that exhaust gases were retained and carried over into the next intake cycle. With the new engine design this doesn’t happen, and the result is a far more stable combustion.
On top of this, the new engine now has almost 30 per cent more intake port than the previous engine’s design, and the intake port closing time has been able to be extended for a direct increase in mixture volume, and subsequently more power. Then there are the three intake ports per rotor chamber, a primary, secondary and auxiliary to give a total of six. These ports are controlled via Mazda’s new Sequential Dynamic Air Intake System (S-DAIS), which operates in response to engine speed by controlling the secondary and auxiliary ports and opening/ closing the variable intake valve installed upstream of the secondary port’s shutter valve.
As for the exhaust ports, their area is now twice the size of those peripheral ones in older models, which means the timing of the exhaust port’s opening can be retarded – and without sacrificing exhaust port area at all. The exhaust system runs straight piping with a large stainless steel rear muffler that splits into dual tail pipes, and this straight-through design has helped increase performance via its largely unrestricted flow characteristics.
Along with these main mechanical differences, there’s also been a healthy 11 per cent weight reduction in the actual rotor, meaning the engine spins quicker, developing maximum power at 8200rpm instead of the 6500rpm in the RX-7. The flywheel was also sent to Jenny Craig, and came back 15 to 20 per cent lighter in a bid to reduce inertia even further – and it worked.
With the whole engine both smaller and lighter through design than the RX-7’s 13B-REW, Mazda design engineers were able to position the powerplant a further 60mm back and 40mm downwards than in the RX-7, setting it nicely right behind the centre line of front wheel, and giving the engine its front mid-ship site.
All this adds up to a factory-fettled 177kW at 8200rpm, with the RX-8 delivering its power through a close-ratio six-speed manual gearbox (in high-output model form) before driving through a one-piece carbon fibre prop shaft into a torque-sensing limited slip differential (Super LSD).
In keeping with the nature of the car, Mazda paid special attention to its suspension set-up, utilising lessons it learnt with the superb-handling third generation RX-7. This set-up uses a double wishbone configuration with mono-tube shock absorbers, coil springs and torsion bar stabilisers on the front end, just as in the RX-7, but in fact no single part has been carried over into the RX-8 – it’s an all new design.
The rear end not only boasts new componentry, it’s a completely new set-up altogether and, unlike the last RX-7 and Mazda MX-5 which employed a double wishbone set-up, the RX-8 uses a multi-link (that would be five links per side) with the mono-tube shocks, coil springs and torsion bars.
All of this is combined with a first-rate chassis and an electrically
power-assisted steering rack system that reacts to engine revolutions
to offer superb steering response, and the total has given the RX-8 outstanding
handling and road-holding.
There are also large diameter vented disc brakes front and rear, an ABS
anti-lock brake system and Electronic Brake Force Distribution (EBD).
Dynamic Stability Control (DSC) helps correct unwanted slides, but can be switched off if you want to indulge in a little on-track sideways action. Good-looking 18x8-inch alloys appear every inch of their size tucked close to the car’s pumped arches, and are shod with 225/45 rubber on all fours corners to give the 8 a big footprint on the road for extra grip and safety.
Inside the RX-8 Mazda has put together one of the most well-finished interiors I’ve seen come out of Japan. This particular car was fitted with the optional coloured trim inserts to match the exterior paintwork, but in standard trim the car comes equipped with black leather. For the driver there’s an eight-way electronically controlled seat, leather-bound SRS airbag-equipped steering wheel and matching shift knob. The instrument cluster carries some of the styling found in the earliest Mazda RXs with deep, separate housings for each gauge. In this instance Mazda has gone for a centrally mounted tachometer with inset digital speedometer, and in keeping with true rotary style, a buzzer still indicates your entrance into the engine’s redline. In the RX-8 that’s at 9000rpm, before a soft-cut rev-limiter forces you to pick the next upward gear cog.
When you’re not ringing the bell, there’s a high-end Bose audio system to keep you happy. Like other impressive systems Mazda never fails to factory-fit into its cars, this nine-speaker, six-disc in-dash number leaves no need for any upgrading whatsoever – not that you could with this source unit, with its integrated position in the dashboard.
There’s is no better place than the race track to really put a car like this through its paces. Taupo’s Centennial Park raceway was the venue at which we had a chance to push the car to its adhesion limits in a controlled environment (and without fearing the wrath of the local Five-O).
Although short and twisty, the Taupo track was a real eye-opener after just driving 120-odd km of back road from Rotorua. While I wasn’t overly excited by the car’s standing start 0-100kph sprint, when kept in the high-rpm powerband (that would be with all ports wide open) it was deceptively quick around the track, and a lot of this can be put down to the RX-8’s outstanding balance and poise at pace. With the DSC on, I felt as if I just couldn’t get it wrong, no matter how nasty my lines were… and believe me, most of them were nasty!
Like all the Mazda rotaries of days gone by the RX-8’s Renesis engine loves to rev, and Mazda has been careful to preserve that unique rotary sound when it does. While it’s no brap-brap bridgeport, there’s no mistaking the buzz that’s bumbling under the bonnet is all rotary – something Mazda has fine-tuned through the design of both the intake resonator and the exhaust silencer.
I guess at the end of the day, I’ve got so many good things to say about the RX-8 that those items which tried to knock the shine off the car (yes, I’m looking at you, fuel economy) really don’t bear much thought at all. This car’s all about having fun, and in that respect Mazda has built something very good indeed! Whether or not we ever do see another new Mazda rotary appear on the market (and I really hope Mazda does resurrect the 7) is another question altogether.
Regardless, let’s just hope that 30 years on there are some RX-8s out there which are as good as Anil’s 3 – as the 8 is certainly bound to become a classic.
Website: www.performancecar.co.nz
Tech Spec
| 2003 Mazda RX-8 (high-output model) | |
|---|---|
| Engine | 13B twin-rotor Renesis, multi-sideport, 10.0:1 compression ratio, multi-point electronic injection |
| Driveline | Six-speed manual, one-piece carbon fibre composite prop shaft, Super LSD, traction control system |
| Suspension | Front - Double wishbone with mono-block shock absorbers and torsion bar stabilisers, Rear - Multi-link (five per side) with mono-block shock absorbers and torsion bar stabilisers |
| Steering | Electric power-assisted rack and pinion |
| Brakes | Ventilated disc front and rear (323mm front, 302mm rear), ABS, EBD |
| Wheels/Tyres | 18-inch alloy wheels, 225/45R18 tyres |
| Performance | 177kW (230hp) at 8200rpm, 211Nm at 5500rpm |
| Weight | 1354kg |
| Price As Tested | $61,995 (2003) |
| + Unique design, superb ride and handling, 13B-MSP naturally aspirated engine is a gem | |
| - Prepare to become a real regular at your local petrol station | |
| 1973 Mazda RX-3 Super Delux | |
| Engine | 10A twin-rotor (491cc x 2) |
| Driveline | 4-speed manual |
| Suspension | Coil spring front, leaf spring rear |
| Brakes | Solid disc front, drum rear |
| Wheels/Tyres | 13-inch steel rims with hubcaps, 175R13 tyres |
| Weight | 865kg |
| Performance | 100hp at 7000rpm |
| Price As Tested | $4,120 (1973) |
