Mazda RX-7 (FD3S) 92-02 Review
Most people know two things about Mazda's 3rd generation RX-7 - 1) They are one of Japan's most beautiful cars 2) They've got funny engines that are prone to going bang. Point two is often over hyped and having previously owned one, am reasonably qualified to comment.
For me the shape of the RX-7 is superb - the double bubble roof and doors are two of my favourite features with the single side windows giving it that jet fighter look. I often marvelled at the rear panels - seemingly one smoothed piece of metal from the front of the roof all the way around the rear back and sides.
Sold officially in the UK from 1992 - 1995, there are a number of differences to the Japanese import RX-7s, available 1992-2002, rocking up on our shores. Built to compete with the likes of Porsche's 968, the 3rd generation RX-7 (FD3S) gained a much sleeker body than the previous RX-7 (FC3S). Weight was a key issue in the development of the car and Mazda's compact rotary (Wankel) engine helped deliver the goods. The 13B-REW two rotor engine was coupled with a sequential twin turbo system delivering phenomenal performance in a compact package to place the engine behind the front suspension. Developing 237bhp in UK spec, Japanese imports have anywhere between 255bhp and 280bhp - if standard which is a rare thing.
Opening the door via the concealed door handle the door swings open - a keen eye will spot the plastic hinge used for weight saving - and you're greeted with a low slung seat and a dash that wraps around the driver. A large tachometer dominates the centre of the dial arrangement with the speedo to the right and oil pressure, water temperature and petrol on the right. The hand brake and gearstick are mounted high up on the transmission tunnel helping that feeling of being low down with everything to hand.
There are many different variants. As mentioned there's the UK / Japanese choice with the UK spec providing a sun roof, leather, 2 seats only and less power than the imports. There is a whole host of Japanese models - type x, type s, touring x, touring s, type r1, type r2, type rz, type rs, type rb, type rb Bathurst, type rb Bathurst x, type rsr, type r, rb-s, spirit r-a, spirit r-b, spirit r-c. Specification variations include leather, carbon seats, 2+2 seat layout, twin oil coolers and much more besides. In 1996 the ECU was changed from an 8 bit to 16 bit model, the rear gained much more attractive round rear lights increased to 265 bhp. In late 98/99 RX-7 received a mild face lift with a revised front end and rear spoiler. The turbo was also upgraded and boost pressure increased to increase the bhp on type r type rs type rz to 280 bhp. The final incarnation the RX-7 took was the run out model - the sought after Spirit R of which 1500 were produced.
Fire up an RX-7 with a non-standard exhaust and you'll know about it. Once up to temperature the fun begins - foot down and the needle pulls around the tacho at an alarming rate. At 4500rpm the second turbo kicks in FULL BOOST and away you go until the beeper sounds to tell you to change up. The gearing makes for fabulous pub talk - 70mph in second unless you've a shorter final drive. That may sound a little longer than most cars but you're rarely out of the power with the first turbo keeping things on the boil lower down the rev range. I love the fact the RX-7 is so visceral - it pops, it bangs dumping bags of fuel into it's hot exhaust system as you lift off to change gear.
Day to day the RX-7 was great to live with - always an event - but you do have to be aware of a few things. They are thirsty - i got around 17mpg from mine with heavily tuned examples dropping further. If you don't give them regular exercise the engines can suffer from carbon build up - it's no great chore going for a good drive every now and then! Flooding - the engines can flood if you start it cold and turn it off soon afterwards. Servicing - the engine uses a bit of oil in the mix to lubricate the rotor tips so this will need topping up as well as 3,000 mile changes. Even with all this it's still well worth it, it's a high performance machine and needs a little care, attention and a bit of cash!
High petrol costs, frequent servicing and possible rebuilds have all helped push prices down with prices starting from £3,000 but certainly keep your eyes open to potential big bills. With a range of tuned vehicles also available it can also be cost effective to buy one with the modifications already made - a single turbo conversion can quickly end up at nearly £5,000.
So this engine then... The Wankel rotary engine used in the RX-7 benefits from being small in size but achieving a high output from it's two 654cc rotors. The rotary engine, while intimidating to the uninitiated, is in fact considerably simpler that a piston engine - valving is achieved by ports cut into the walls of the rotor housing, the rotor is geared directly to the output shaft, there is no need for connecting rods, a conventional crankshaft and so on. This makes the rotary engine very light.The rotor tips wear and are the most common reason for engine failure. The tips last around 60,000 miles in standard tune but can last longer, or indeed shorter depending on the life they've led. These days RX-7 engines are rebuilt using the more modern RX-8 rotor tips, as well as a range of high performance rotor tips being available if you've the wallet. Rebuilds of the 13B engine start at around £2500 - undoubtedly a large sum of money but compare this with the cost of rebuilding say a Skyline's RB26DETT engine - both have similar performance. Bills can grow while the engine is open - you may begin to think "I'll have it ported" which leads on to aftermarket ECUs.
As mentioned there are no valves - simply a port. To increase the duration much as you would with after market cams to gain power, the port just needs to be enlarged. Of course this is an art with engine builders having their own templates and variations from street porting, extended porting, bridge porting and peripheral porting. A bonus not having to pay out for a set of cams every time, and if you've the balls or the skill a chance to get something for nothing. Rebuilds are carried out by a handful of specialists such as RX Motors but a growing number of UK RX-7 owners are biting the bullet and rebuilding their engines themselves. It's well worth joining a club such as the Mazda Rotary Club if you're thinking of purchasing one of these awesome cars. I'd certainly have another given the opportunity.
