Rosta's TM

Original - because this '85 TM is one of the first generation to wear the 'Magna' badge.
Sleeper - because pulling up next to this car, you may get a very nasty surprise.
There ain't no grandma behind the wheel, and the Astron under the bonnet is
far from asthmatic.
The first thing that would give it away is the bonnet scoop - subtle, but
a warning nonetheless. The next would be the sneezing of the Bosch blow-off
valve as the old Magna rips past you. The last things you will see are the
rear lights as they fade into the horizon, and the slowly fading clouds of
tyre smoke - torn from the Magna's front wheels.
Rosta Pesina's 'Original Sleeper' is one hell of a Magna. Despite clearly
having drag strip intentions, the car is still a daily driver - keep your eyes
peeled if you live in the Bendgo or Mildura areas.
It all started when Rosta's brother got his licence and a Mitsubishi Starion
Turbo. Finally, Rosta had an excuse to talk his dad into putting a turbo in
the Magna. The rest is history.
As you will soon see, this car has been through a lot of development changes.
It began mildly - with an upgraded exhaust system and cam. This saw the car's
performance lifted considerably - enough to keep up with the V6's. The head
was then ported and a beefier cam was added. Around about this time Rosta had
a run in with a VB Commodore (4.2L V8 - two originals going head to head!).
In Rosta's own words, he was "blown away". As many of you would know, it's things like that, that cause great wads of cash to be invested into a car.
The stock auto transmission bit the dust so Rosta took the opportunity to
replace it with a manual. This was sourced from a TP Magna - known to be a
much stronger box than previous models. Being significantly bigger it was a
headache to fit - but the benefits soon outweighed the hassle. As Rosta got
used to that extra pedal at his feet, he soon realised the manual unleashed
a lot more power from the engine.
The carby was the next item to be upgraded. A 38 Weber saw great improvements
in torque. Yet another cam variant also took power up a notch - "I soon got my revenge on that V8" says Rosta.
An induction system was devised to get air direct to the carby. An insulated
twin system did the trick, but also froze the fuel in the carby on a cold Victorian
night.
The key upgrade - the turbo - came when Rosta got his hands on a complete
Sigma turbo engine. Both the turbo and manifold were grafted onto the Magna's
Astron. A Starion ECU was wired in, along with its fuel injection set-up. Other
fuel modifications (from a TN Magna) were added, along with an oil cooler.
The air flow system was upgraded to suit the changes - which entailed a 2.5" exhaust and Starion air box/filter.
Despite all this work, the car wasn't running too well. The power distribution
was unbalanced and the Astron was pinging like mad (even at cruising speeds).
The answer came with the addition of a Wolf3D Engine Management System and
Magna multi-point injection. To tame the pinging further an intercooler was
added (from a Toyota Supra). It was also at this point that the Starion scoop
was integrated to the bonnet - for both form and function. The scoop creates
a unique look while drawing cool air into the engine bay.
The car was now running 100% better, but still managed to blow a head gasket
while being tuned. After a replacement head was found (and 550cc Bosch injectors
were added) the car was put on a dyno - the result, a healthy 200hp (the car
really was going 100% better!). It still wasn't enough, so the boost was wound
up to 10psi and yet another cam was thrown into the mix.
The timing chain proved to be a constant problem. The stock item did not appreciate
being played with, and broken parts were often the result. A high performance
kit from RPW sorted that out. The oil pump just couldn't keep up with the rest
of the engine - so that too was tossed and a high performance pump was sourced
to do the job properly (here's a tip from Rosta - a high performance pump can
be found for around $170 - a stock replacement from Mitsubishi is closer to
$500).
The Magna has since claimed its fair share of shocked V8 victims - both on
the street and the drag strip. Following a run at Mildura Drag Strip, officials
called Rosta into the commentary box - to find out just what made that little
4-cylinder go so hard.
According to Rosta, the Magna's strip times have been "disappointing" thus far - a best of 15.26 @ 94mph. That was before the rebuild (required after boost was trialed at 15psi - resulting in an engine meltdown). Rosta is confident of a low 14 second pass. He has tested it against a mate's worked VR Calais (which has run a 14.7 second quarter mile) - beating the VR by around 3 car lengths.
With a hefty dose of horsepower running through the front treads, you would
expect torque steer to become an issue.
"Traction is impossible in 1st" says Rosta, "but usually it doesn't spin too much in 2nd..."
Apparently it's a beast in the wet.
"Going flat out you usually feel a bit of a tug to either side, which is pretty simple to control. It does have its moments when the front lifts and tries to jump into the other lane."
The cam has been constantly updated to suit Rosta's increasing hunger for
performance (while still keeping an eye on the wallet - damn those fuel prices!).
Here's a closer look at the characteristics of the cams:
"The tow cam was good in making the car feel like a V8 - turbo lag wasn't noticeable and it had lots of low-down pulling power - and it loved to tear up the tyres!. It was extremely hard to drive in the wet as it would really make the wheels spin on take-off. You nearly needed telepathic abilities to get the throttle right.
The Wade 'Mild' Cam is pretty good all round for taking off and with enough
bottom end torque to make it easier to drive without burning the tyres. It
also gave me more revs to place - revving quite freely up to 6500. The only
consequence is that it likes to drink a bit more fuel.
The Crow 'Hot' Street/Strip Cam should be quite good once I get it tuned better.
It has a bit less bottom end torque than the Mild Cam, but still has a lot
more than a standard Magna. It redlines at 7000 and chews less fuel than the
other two (under normal driving conditions). It makes the power higher in the
rev range."
The following is a list of the development stages of the car (since it was
inherited in stock condition, from Rosta's mum):

Stage 1

• Extractors, 2 " exhaust, 2 free flow mufflers
  
• Mild Crow Cam
  
• Mechanical Lifters
  

• Converted to a 5-speed manual (from a '89 TP Magna)
  
• 28 Weber Carby
  
• Finer Filter
  
• 'Hot' Crow Cam
  
• Slight engine port
  
• Increased compression
  

• Deleted counter balance shafts
  
  
  

• EFI installed + JA
  
• Starion fuel injection and computer
  
• Garret T3 Turbo (8psi boost)
  
• Bosch blow-off valve
  
• Filter change (Finer Filter for Starion)
  
• 2.5" exhaust, 1 resonator, 1 free flow muffler, 3" tip
  
• Oil cooler
  

• TN Magna multi-point fuel injection (stock injectors)
  
• Starion bonnet scoop
  
• Simota ram pod filter
  
• Wolf3D Engine Management (fully programmable)
  
• Air/Fuel meter, oxygen sensor
  
• Toyota Supra intercooler
  

• 550cc injectors
  
• Replacement head (stock, 8.8:1 compression)
  

• Boost increase - 10psi
  
• Crow Cam ('tow grind')
  
• Wider rubber (215/60)
  

• 'Mild' Wade Cam
  
  Boost increase - 11psi
  

• Multi-coil injection system
  
• Wolf3D adapted to suit multi-coil
  

• Upgraded clutch and pressure
  plate
  
• Boost increase - 15psi
  
• High performance oil pump and timing chain kit
  

• Boost backed-off - 11psi
  
• Engine rebuilt and fully balanced - bored out 20thou
  
• Low compression
  
• Hyperuetectic
  pistons
  
• Shot-peened conrods
  
• Heavily ported head
  
• Heavy-duty double valve springs, ULP valves
  
• Lightened and balanced flywheel
  + custom brass button clutch
  
• T3 turbo rebuilt and balanced
  
• 'Hot' Street/Strip Crow Cam