FREKNU - Simon's 1984 Mazda RX-7

 

Story and Photos: Ben Winstone

 

These days, it can seem as though it is getting harder and harder for cars to stand out from amongst each other on the rotary scene, at times it can look as though everyone has tried all the possible combinations of wheels, engines, turbos and colours. While this may be reasonably true for the 'old school' shapes, one model which is beginning to receive this sort of attention as the older Mazda rotaries, is the first generation RX-7. In recent times there have been quite a few examples turn up on to the scene which have really stood out, one of which is 'FREKNU', this unique 1984 Series 3 model.

 

Owner Simon Izlemik has owned quite a few rotors in his time and goes on to say that "I have owned an example of every rotary powered Mazda model from the R100 through to a Series 4 RX-7 Turbo convertible". So when you have owned such a wide variety of cars, the question must be asked, what do you build next?

 

"I wanted it to be different, something that stood out" is what Simon explains when asked about his RX-7. And stand out it certainly does, using a unique and eye-catching wheel, body kit and colour  combination, and best of all it doesn't just look good, it hauls some serious ass as well!

 

Purchased a couple of years ago now, Simon originally had a standard 13B Turbo conversion in the car, which as you would imagine, helped the car to get up and boogie, however it wasn't long before the bug had bitten and the usual ' need for more power' evolved...

 

Enter Vlad Berak, proprietor of Melbourne rotary specialists Rotorworx, located in the north west of Melbourne. Famous for the 10 and 11-second street cars they regularly turn out (including our last feature car, 'DVITRX'), Simon knew that the Rotorworx team would be able to generate a lot more power from the RX-7 whilst still retaining reliability and keeping the car street-able.

 

The import Series 4 13B motor was opened up (which if you recall from the 'DVITRX' article has lower compression rotors which are more friendly for big power and boost) and given the 10-second treatment. This involved adding extra dowels to the motor to help retain strength under extreme applications, as well as increasing the size of the intake ports of the engine, enlarging them to what is known as a 'turbo' extend port. Because Mazda didn't design the motors with 400+ rear-wheel kilowatts in mind, the rotors were also clearanced, which is "a process of machining parts of the rotor to accommodate for movement and extra expansion due to these extreme forces and much higher combustion temperatures that are created with such high power levels" explains Vlad. New Mazda 2mm apex seals were also inserted in the tips of the rotors.

 

With the engine suitably prepared, the decision was made to use a large Garrett T04E turbocharger in place of the smaller factory unit. Using a 66mm front wheel, in place of the standard 58mm one, the turbo is technically known as a T04E/66 turbocharger. A custom exhaust manifold was created to mount the turbo on, and a 45mm PSR external wastegate is used to show excess boost the door.

The turbo currently crams as much as 32psi into the motor, passing through a custom-made large front-mounted intercooler, (which is mounted diagonally on roughly a 30-40 degree angle in the front nose cone) before entering through a custom Rotorworx log-style plenum chamber. While these plenums are described as being "a lot more harsher" in terms of the way the air enters the motor, they do provide a lot more flow, and can be worth as much as 40-50kw.

 

A 3-inch exhaust dumps straight off the turbo and maintains that diameter right through to the rear of the car, with the large exhaust really giving the car a tough lumpy sound, when combined with the extended porting of the motor.

 

A common fitment on 13B Turbo rotaries are the Microtech engine management systems, and 'FREKNU' is no different, using a MTX-8 model to control the ignition and fuelling needs.

Two Bosch 909 fuel pumps along with a Malpassi fuel regulator and a custom made surge tank are used to flow the juice through two 12A Turbo primary injectors and two Bosch 'Indy' 1700cc secondary injectors which are staged to provide a lot more fuel in the higher rev range.

 

So what sort of power is the setup making I hear you ask; Vlad proudly claims that the car is currently "the most powerful T04-equipped street car in Australia, making 417kw (560hp) at the rear wheels on 32psi", ensuring that the car certainly has the 'go to match the show'.

 

While the standard Series 3 drive train was capable of transferring the 85-odd kilowatts the standard 12A motor made to the ground with no problems, with the current setup making four to five times that amount of horsepower, a serious upgrade was in order.

 

The car uses a 5-speed Series 4 RX-7 Turbo gearbox in place of the stronger Supra unit more commonly used, however it has a lunched a number of these and Vlad says that the car "is on its third gearbox, whilst the car has completed about 90 passes, so it is not too bad". A four-puck clutch with heavy-duty pressure plate is used along with a lightened flywheel, and the clutch gives good feel, whilst not being too heavy or harsh to use. The gearbox then uses a 3-inch heavy duty tail-shaft to transmit power to a Hi-Lux diff. These diffs are becoming more widely used now in high-powered Mazda's due to their lighter weight (when compared to a Ford 9-inch) yet still retaining a lot of strength. A 4.3:1 ratio is used in the diff and the centre has been locked.

 

With over 400kw at the wheels, you would expect a suitable brake upgrade, well, this isn't really the case here. With straight-line duties primarily in mind, the standard discs have been retained all round, however Bendix brakes pads have been used for greater stopping power.

 

The car has also received a subtle suspension upgrade, with King Springs being used to lower the car 1.5-inches all round. This gives the RX-7 a nicer stance whilst not being so low that it causes the spoilers to drag when going up driveways and such. It is still pretty much a street setup, and is not the most ideal setup for the strip, in the way that it is a touch firm, and not softly sprung, like many drag cars.

 

Forget about FR Simmons, or something similar, 'FREKNU' rolls on the ever-popular AME wheels which have been seen on everything from WRX's to Commodores, and whilst they are more popular on the curvaceous Series 6 RX-7, they certainly stand out on the early shape here and help give the car the different look that Simon was looking for. 205 Falken tyres are used on the front, whilst 225mm of Pirelli's finest attempt to keep contact with the road on the rear. For the strip, the car uses 26x8.5-inch slicks on a 15-inch wheel.

 

The exterior of the car is probably the most extreme part on the car, with the unique body kit grabbing the most attention. Commodore fans may recognise the front and rear bars, seeing as they are based on those from a VN Group A SS Commodore. The rear wing is also from the VT series Commodore, whilst the side skirts are custom RX-7 items.

The metallic silver paint is complemented by the vinyl flames, which add "something different to the car" according to Simon.

It is certainly a different look and creates a lot of comment from people when they see the car at shows according to Simon, with some people loving it, whilst others need a little more time to get used to it.

 

Inside the interior has received a number of upgrades, with Recaro buckets giving Simon and the lucky passenger more support when the outside scenery starts getting blurry. The extremely popular Auto Meter Monster Tacho takes pride of place on the dashboard, while a Auto Meter boost gauge lets Simon know how hard the turbo is working. A MOMO steering wheel and gearknob have also replaced the standard items, and look a lot better.

Not that you would be able to hear it well, but a stereo upgrade has been carried out including an Alpine CD player, speakers and amp.

 

As for its performance on the drag strip, the car has gradually worked its way lower into the 10-second bracket over the last 12 months. Originally running mid 10s, Vlad and Simon believed that the large wing and body kit was causing too much drag on the car, and therefore preventing it from running its best possible time, so they were removed for a couple of meetings, and Simon ran a 10.40 @ 137mph.

 

Since then however, more boost was wound into the motor, and the car managed to run a 10.24 @ 144mph at the 4, 6 and Rotary Nationals in Adelaide earlier this year. The most important fact about that pass however, was that the car was in complete street trim, the rear wing and bars were on the car, and it had a full interior, complete with sound system and electrics. So therefore throwing the 'less is more' theory out the window. The high mph means that a 9-second pass isn't too far away, however the car has problems 'hooking up' off the line, wheel-spinning quite a lot and having 60-foot times in the 1.6 second region.

 

However, the cars main use is on the street, where it is driven regularly, Vlad comments that "even at 9psi, the car wheelspins in 4th gear, so the large amount of power is pretty useless for the road". On the street the car runs on 17psi instead of the 32psi used at the strip. Vlad goes on to say that "the car is quite pleasant to drive on the street, however the locked diff can be a little harsh at times, but the clutch is pretty easy to operate, due to the top-shelf materials used and isn't too heavy, in fact Simon's wife regularly drives the car as well"

 

At the end of the day, Simon has created a car with head-turning looks, serious 10-second performance, whilst still being suitable for regular street use, however the time has come to move on and the car has been sold. The running gear has been transferred into Simon's next project, an RX-2 coupe so don't be surprised if the car ends up 'freakin you'...

 

Contact:

Rotorworx - 4 Disney Avenue, East Keilor, (03) 9331 7756.

For more information on the packages that Rotorworx offer, from 'mild' to 'wild', visit their website: www.rotorworx.com.au

 

Model: 1984 Mazda Series 3 RX-7

Engine: 13B Twin Rotor Turbocharged

Engine Modifications: Fully prepared Series 4 13BT motor (including dowelling, clearanced rotors, and extend porting), Rotorworx custom inlet plenum chamber, Garrett T04E/66 turbocharger, custom-made front-mounted intercooler, two 12A Turbo injectors (primary) with two 1700cc Indy injectors (secondary), two Bosch 909 fuel pumps, PSR 45mm external wastegate, 3-inch Stainless-Steel exhaust from the turbo back, Microtech MTX-8 engine management system.

Driveline: Rotorworx steel flywheel and heavy-duty clutch package, Mazda Series 4 RX-7 Turbo 5-speed gearbox, heavy-duty 3-inch tailshaft, Toyota Hi-Lux 4.3:1 differential (with locked centre).

Suspension & Brakes: Lowered 1.5 inches with King Springs (front and rear), standard RX-7 disc brakes (front and rear) with Bendix pads.

Performance: 417kw (560hp) @ wheels (32psi), 10.24 @ 144mph.

Wheels & Tyres: AME 17x 7 inch (front and rear), Falken 205/40 (f) and Pirelli 225/45 (r), 26x8.5-inch slicks on a 15-inch wheel for the strip.