Haki's 1993 Mazda Series 6 RX-7

 

Story and Photos: Ben Winstone

 

The FD model RX-7 was one of the most unique sports cars of the 1990s, released in 1992, it featured advanced exterior design, which still looks as good today, as it did when it was first released, in fact the model ran for 10 years without a major exterior update. In Australia, it is more common to see one of these RX-7's at one of the many car shows that have arisen onto the scene nowadays rather than at the drag strip. Reasons for this being their reasonably expensive purchase price when compared with older RX models and the fact that they are much more of a sports car than previous rotary models and are more at home on a set of twisty roads or circuit.

 

While there are a couple of exceptions, with a number of quick series 6 RX-7's in Brisbane and Sydney; in Melbourne there hasn't really been one standout example of this model at the strip for quite some time. However recently this situation has changed with the arrival of this fierce example of a series 6 RX-7 which looks like it has been pulled straight off a Japanese highway...

 

Well that's because it has!

 

Being the owner of a car-import business helps when you are looking for your next car, and having contacts in Japan certainly makes it a lot easier when the time comes to find something different.

Haki is the proud owner of this silver bullet and after owning several GT-R's and a 12-second Lancer Evo, he was after something different and this is when he stumbled upon this RX-7.

 

The car has been imported from Japan and was previously owned by a customer of the Japanese rotary workshop RE-Amemiya. Now if you have seen the numerous Japanese performance car videos available you will know that the Japanese tend to go just a little bit crazy when modifying their cars, and the previous owner was no exception. After getting RE-Amemiya to carry out a single-turbocharger conversion and perform a number of other mods to the car the previous owner decided he wanted to upgrade to a 20B turbo powered Series 7 RX-7, and this meant that this silver series 6 had to go.

 

The car was then purchased by Haki's brother in Japan and was put into a container and sent to Australia. Once the car arrived, Haki naturally took it for a test drive, or should that be test flight? Little did he know however, that the car was running way too lean and ended up detonating and chipping an apex seal, denting a rotor and scratching the rotor housing.

Being based in Melbourne's northern suburbs, Haki decided to take the car to Maztech of Melbourne, located in Thornbury to get the motor rebuilt.

 

Apparently in Japan, the car had run a 10-second pass on semi-comp tyres and using different fuel. After describing the cars history to the guys at Maztech, they had their doubts, however once the motor was pulled down and they saw the extend porting that had been carried out they were extremely impressed, Anthony from Maztech described the porting as "micro-millimetre perfect" and was a great example of the high standards that the Japanese use when building cars.

 

The RX-7 uses the twin-rotor 13B motor, which has been extend ported and now uses 3mm apex seals along with series 5 RX-7 13B turbo rotors. The standard sequential twin turbos have been thrown in the bin and in their place sits a Garrett T04 B turbocharger with a T66 front compressor housing along with a HKS 50mm external wastegate which is used to control boost, which at the moment is 12psi. The wastegate features a "screamer pipe" which means that gases from the wastegate are vented straight into the air, rather than passing through the rest of the exhaust, this creates a great sound once the car comes on boost and its the upper limits of the rev-range and is also great for scaring unsuspecting pedestrians. Compressed air from the turbo flows through a large front-mounted Blitz intercooler before heading into a GReddy plenum chamber. With the increased power of the engine came the need for additional fuel and two 12A Turbo injectors have been used as secondary injectors to try and quench the thirst of the motor. These are controlled by a HKS F-CON Series 5 Piggy Back computer, which Haki says "will soon be replaced with a Microtech MTX12 unit". A four-inch Jasma Stainless Steel dump pipe takes care of the waste gases from the turbo, providing great flow and really allowing the car to emit a fantastic ported rotary sound.

 

When the car was strapped onto the Maztech dyno, this combination of parts and modifications allowed the car to reel off an impressive 290kw (388hp) at the rear wheels on 12 pounds of boost.

Naturally the standard drivetrain would have trouble trying to process this sort of power, so a twin-plate OS Giken clutch has been fitted to the 5-speed RX-7 gearbox which now uses OS Giken gears to increase durability. The standard Mazda LSD rear end is also retained.

 

Suspension-wise, the car differs from most Japanese imports and instead of using the 'normal' A'pexi, HKS or Tein components, the car utilises a all-German setup consisting of Ohlins shocks and Eibach springs all round and sits a fair bit closer to the pavement. Haki says that the car has been setup more for circuit use, rather than the drag strip as it is quite stiff and certainly isn't the most ideal choice for Melbourne's pot-holed and damaged roads. Nevertheless, it provides the RX-7 with superior handling, and creates very little bodyroll, allowing corners to be taken with a lot more speed and confidence.

 

Seeing as the car is now primarily used for drag duties, the standard series 6 calipers are retained and slotted front rotors have been added. Combined with the reasonably light weight of the car, the brakes have no trouble pulling the car up after a high-speed run.

The car rolls on 17-inch 'Stern' wheels which are 7-inches wide at the front and 9-inches wide at the rear and really complement the car, as well as giving it that tough 'street-racer' look, and as you can see in the pics, even with sticky 255 Dunlop Le Mans fitted, it certainly has no trouble smoking them up :)

 

One of the most distinguishable features about the car is its awesome RE-Amemiya headlight conversion kit, which replaces the standard pop-up headlights. Watching the car drive down the street of our photo location, you can't help but notice how distinctive and tough it looks with the RE-Amemiya front bar and headlights fitted, there's no doubt about it that the car means business. A vented RE-Amemiya bonnet also helps to extract under-bonnet heat. The GT-style rear wing (with carbon fibre end plates) fitted on the rear hatch gives the car a much more aggressive stance from the rear end.

 

Lower yourself into the car, and one of the first things you notice is the alloy half cage which was fitted when the car was in Japan. The dash also features white-faced Mazdaspeed gauges including a 320km/h speedo, the usual boost, oil pressure and water temperature gauges and a digital air/fuel ratio readout. A MOMO steering wheel and matching gear-knob complete the interior. The battery has also been relocated into the hatch area. Haki insists that this car is built for speed, so only a small CD system is fitted.

 

In terms of this cars performance, Haki has run a best time of 11.8 seconds @ 121mph at Calder Park during December 2002. This was without the extra 12A injectors hooked up as well as Haki having to shift gear at only 7000rpm and back off at the top end of the track due to a fuel pressure problem, he comments "the car was beginning to splutter and run out of fuel as it neared the finish and you can't hear it ping with the exhaust and such so I had to back off so I didn't hurt it..."

The time was run on normal street tyres as well, as Haki believes that to race with slicks and use C-16 for example is obviously "not a true indication of what the car will run on the street". He prefers to run it in the same spec as how it is driven on the street and assures us that "there will be a lot more to come once the car is fully sorted". Once the car has run a few more times and  improved the time slips then Haki will place it on the market.

 

Haki and the guys at Maztech believe that it is the fastest street series 6 in Melbourne and it still has a fair bit left in it, so keep an eye out for it at the Calder Park Off-Street meets.

 

For the moment however, the car is one of the most unique RX-7's on Melbourne roads and has a genuine Japanese style to it which is definitely unique in today's current flood of imports out on the roads. Unlike them, this car has a genuine Japanese history behind it and certainly has the 'go' to match the 'show...

 

Model: 1993 Mazda Series 6 RX-7

Engine: 13B Twin Rotor Turbocharged

Engine Modifications: Extend porting with 3mm apex seals, Series 5 rotors, GReddy plenum chamber, single turbocharger conversion using Garrett T04 B turbocharger with a T66 front compressor housing, front-mounted Blitz intercooler, extra two 12A Turbo injectors, HKS 50mm external wastegate with screamer pipe, 4-inch Jasma Stainless-Steel exhaust from the turbo back, HKS F-CON Series 5 Piggy Back Computer (to be upgraded to Microtech MTX12).

Driveline: Standard 5-speed gearbox with OS Giken gears, twin-plate OS Giken clutch, standard Mazda LSD differential.

Suspension & Brakes: Ohlins shocks with Eibach springs all round, standard calipers with slotted front rotors.

Performance: 290kw (388hp) @ wheels (12psi, pump petrol with no extra injectors attached) 11.8 @ 121mph (street trim, shift limit at 7000rpm, backing off at top end due to fuel pressure problems).

Wheels & Tyres: Stern 17x7 inch (f), 17x9 inch (r), Dunlop Le Mans tyres.