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Sirius Sports 7 Road Test

A Lotus Seven replica with the performance to annihilate, well, almost anything!

By Michael Knowling

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At a glance...

  • Impractical
  • Not as thoroughly developed as a mass produced vehicle
  • Not especially cheap
  • Sensational straight-line performance
  • Balanced handling
  • Feels and drives unlike any other car
  • A ready-to-go racecar
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You wanna go fast? Really, really fast? Well forget about STis, HSVs and XR6 Turbos. If you want a newly built vehicle that’ll satisfy even the most demented speed craving, you need a Lotus Seven replica – one like this Sirius Sports 7. If you’re prepared to get your hands dirty during the build-up, you can have a Sports 7 made to your specs from around AUD$40,000.

First things first, the Sports 7 is an uncompromising machine. From its adjustable coil-over suspension to its minimalist interior, it is built for speed. Interior comfort and accommodation barely rate a mention.

The Sports 7 is completely different to any vehicle you’re used to. For a start, you step over the side panel and lower your backside into the seat from standing height. It’s a challenge at first, but an experienced Sports 7 driver will gladly demonstrate how to step in and out without losing any personal dignity...

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The moment you are engulfed in the leather/fabric race seats it’s obvious that you need to adopt a driving position that suits the car - not the other way ‘round. Sure, the seat slides fore-aft and the ex-Nissan Silvia steering column offers adjustable rake, but we were never able to find the ideal driving position. In the case of our test vehicle, clearance between the steering wheel and the driver’s right leg was virtually zero. This often fouled steering access.

Oh, and don’t bother moving your left foot around in search of a foot rest – real driver’s cars don’t have em’!

Our test Sirius Sports 7 – graciously lent by Andrew Constantine, who is associated with Sirius Track and Road Technologies – had been fitted with the optional Nissan SR20DET/5-speed driveline combo. This is the driveline you ask for if you’re slightly insane...

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Fire the turbocharged SR20 engine into life and it idles and behaves like any mass-produced standard vehicle – not surprising, because the engine is essentially standard and it runs ordinary factory engine management.

We can assure you, however, that the straight-line performance is anything but ordinary!

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The Sports 7’s sub-700kg kerb weight means only a tiny throttle opening is needed to breeze past other cars in traffic - you can’t help wonder why everyone else has left their handbrake on... Push the throttle to the floor and take the SR20 to redline revs and the Sports 7 goes off like a firecracker - there’s no other way to put it. Unlike many other turbo cars, the lightweight Sports 7 never bogs down off the line – all you get is raw acceleration. With 10 psi of boost pressure (as tested) the Sports 7 remains controllable and never comes on with a rush that overwhelms the chassis.

With a decent launch, the Sports 7 can blast past 100 km/h in comfortably less than 5 seconds. With two people onboard and a crappy launch (too much wheelspin!) we recorded 5.0 seconds flat... The brick-like drag coefficient isn't helpful at high speed, but the relatively small CdA of the Sports 7 helps offset the situation. Top speed? Well, depending on gearing, we can only guess it has the potential for in excess of 250 km/h.

Consider the vital numbers for a moment.

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As tested, the Sirius Sports 7 weighs just under 700kg. With an imported non-VCT SR20DET equipped with a sports exhaust, K&N pod filter induction, a front-mount intercooler and up to 10 psi of boost, you’re talking an output of around 200kW. That calculates to a power-to-weight ratio of around 3.5kg per kilowatt – better than a Lamborghini Murcielago, which runs high 11-second ETs...

It’s no wonder this thing feels fast!

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Like many Lotus Seven replicas, the Sirius Sports 7 is ideal for the racetrack - in fact, that’s arguably where it’s at its best. With a smooth racing surface and plenty of run-off area, the Sports 7 can make the most of its light weight, near 50:50 weight distribution, low centre of gravity and wide track. We were unable to hit the racetrack, but we can give you our handling impressions after some spirited road driving...

With the spring/damper settings as supplied, the Sports 7 turns into a corner very well. Mid-corner, it feels extremely stable for such a small car - the considerable wheelbase and wide track obviously pay dividends. Chassis attitude can be adjusted through the corner by movement of your right foot – a progressive breakaway power oversteer can be pulled outa the bag whenever you want. Oh and, when you’re used to driving a conventional car, the rearward seating position of the Super 7 means slight oversteer feels like a m-i-l-e of oversteer!

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Our biggest handling gripe is the inconsistent behaviour from the live-axle rear-end. Any irregularities on the road unsettle the rear, which can cause problems if you’ve already set the car up with a balanced mid-corner attitude.

The Sports 7’s suspension design was developed by Adelaide’s Sirius Track and Road Technologies. At the front are TE Ford Cortina hubs working with double wishbones, while the rear employs trailing arms and a Panhard rod to locate the live axle. At both ends are SPAX coil-overs, with adjustable ride-height and damping. The test vehicle proved you can achieve a neutral chassis balance without sacrificing ride quality.

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At the front the Sports 7 employs TE Ford Cortina ventilated front discs and calipers, while the rear uses the drum brakes that came on the end of the Cortina 4.1-litre diff. These provide good stopping power for the sub-700kg Sports 7, but we’re told that Mazda RX-7 brakes are currently being assessed.

Note that the braking system doesn’t include a vacuum booster so you need to stand on the brake pedal harder than usual.

The Sirius Sports 7 can be built with either a Cortina or Escort steering rack but Andrew’s car uses the factory Escort quick-rack arrangement. This gives excellent response and a nice direct feel, but it does get heavy during parking and when pushed through tight corners. No power steering is fitted.

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The body of the Sports 7 is loosely based on the classic Lotus Seven design. The bonnet, front guards and nosecone are moulded in fibreglass while the rear quarters are made from aluminium. The aluminium panels are attached directly to the steel frame, which boasts plenty of triangulation to maximise chassis rigidity. Andrew had his example built with ex-motorcycle front indicators and exterior mirrors (there is no centre rear-view mirror). Completing the package are suitably styled 14-inch alloys wearing 205/60 14 tyres.

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The Sports 7 is built largely for track use, so it comes equipped with a CAMS approved roll-over bar. Note, however, the vehicle is exempted from ADR 69, 72 and 73 crash test standards – as explained by this plaque on the dashboard.

The interior features list is a short one.

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Andrew’s car was equipped with a speedo, tacho, fuel level, oil pressure, water temperature and boost pressure gauges. A sequential shift-light was also built into the dash. Don’t bother looking for a sound system, interior light or any interior air vents – not that air vents are needed...

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The test car also had a Momo wheel and Autotecnica gearknob – the latter unfortunately hit the handbrake lever when changing into second gear. (See pic).

Storage is not a strong point because, well, there isn’t any! There is a small amount of space behind the rear seats where you’ll find the aluminium fuel tank, electric fuel pump and diff. This space was not being put to use in our test car, but we’re told a boot ‘shelf’ is available.

But let’s not focus too much on these everyday practicality issues – the Sirius Sports 7 is all about performance.

When you opt for the turbocharged SR20 powerplant the Sports 7’s straight-line performance is matched only by the world’s top exoticars or thoroughly tuned mass-production performance vehicles. Its acceleration really is breathtaking.

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As mentioned, it’ll cost you around AUD$40,000 to build a SR20DET Sports 7 so long as you’re willing to get involved in the build. On the other hand, if you only want to write out a cheque and pick it up a few months later it’ll cost approximately AUD$60,000. Note, however, these prices depend on your desired specifications and the availability of a driveline.

So far, eight Sports 7s have been completed and there are more in the build. If you’re unsure about committing $40 – 60k for a car without air-con, power steering or any mod-cons, we suggest you take one for a drive...

The Sirius Sports 7 was provided for this test by AutoSpeed reader Andrew Constantine. Many thanks to Andrew for approaching us and offering the car for testing.

CONTACTS

Sirius Track and Road Technologies
+61 8 8283 1970

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