Project: 1957 Porsche 356A Cabriolet (replica) general
performance upgrades and custom dyno tune. (Custom built Porsche replica with
Subaru 2.0L turbo engine)
Products:
- Blouch 18G turbo Samco blow off valve
- Deatchwerks 750cc injectors
- Walbro 255lph fuel pump
- Perrin equal length turbo manifold - wrapped
- Perrin up pipe - wrapped
- Oakos/Speed Industry modified downpipe - wrapped
- Speed Industry/Magnaflow custom fabricated stainless exhaust
- STI Intercooler
- STI oil pan and pickup
- Flexalite intercooler fan
- Cobb Accessport
- Speed industry EBCS kit
- Redline full synthetic gear oil and engine oil
- NGK Iridium spark plugs (one step cooler than stock)
- Throttle body coolant bypass
Price: Don't ask :)
Claimed power increase: Dyno verified 100+ RWHP
Impressions: This has by far been Speed Industry's most interesting project to
date. The customer came in looking for more power, but also very importantly -
better driveability. After a more in depth conversation, it turns out that the
customer also did not want his Porsche to sound like a Subaru. I suggested the
Perrin equal length turbo manifold because it completely gets rid of the
trademark Subaru-rumble. Subarus sound good, but this car needed to sound more
Porsche-like. After careful thought, the upgrade pieces were decided upon. This
project did have a budget, but no short cuts were taken. All the components
were chosen based on quality, performance and fitment with price being a
secondary, albeit important consideration. The car was base lined on my Mustang
dyno at approximately 150whp prior to any modifications. The baseline pull
needed to be aborted due to leaning out and knocking (more on the root cause
later) After modifications the car put down over 250whp - needless to say that
in a car weighing less than 2000 lbs, this is a significant amount of power.
Ready to be made as fast as it looks.
Dyno baseline test.... < 150whp?.... lean and knocking.... hmmm what
could be wrong?
I decided to start with the fuel pump. I was shocked to see that the sock
on the fuel pump was about 75% blocked/clogged up with foreign material. The
material appeared to be mostly metal chips with some carpet fiber and silicone
sealant.
Let's take a look into the fuel cell... WOW! A combination of aluminum
slivers and chips, tons of carpet fiber and clumps of black RTV sealant was
everywhere. I had no choice but to drain and clean the gas tank.
Brand new high performance (255lph) Walbro fuel pump and clean new sock
ready to go into a nice cleaned out fuel tank.
A nice pile of go-fast goodies.
The existing K&N filter deserved a good cleaning with warm soapy water
and a re-oiling with K&N filter oil.
Verified compression. All four cylinders were at 160 Psig +/- 0.5 Psig. A
proper health assessment is necessary prior to increasing performance.
Perrin equal length header and up-pipe. This is one of the highest quality
and best performing pieces available for any Subaru power plant.
In order to install a Perrin equal length header on a 2.0L Subaru engine,
an STI
oil pan must be gasketed. Instead a proprietary sealer called Fujibond is
used.
Both surfaces must be absolutely clean and a liberal amount of Fujibond
must be used in order to create a proper seal.
Stock up pipe on the left vs. Perrin on the right. This vehicle is a
classic and emissions-exempt, so the cat-less up pipe is a great way to make
significant performance gains.
Thermal management was of supreme importance on this project due to the mid
engine configuration and radiator and intercooler positions. I used heat wrap
on all the exhaust components, and sprayed all of it with flame retardant
spray. Pictured in the photo above is an Oakos downpipe, which was perfect for
this project due to the space limitations imposed by the tube frame chassis.
Normally I use 3" bell mouth downpipes on Subaru powerplants, but in this case
the bell mouth would have interfered with the frame of the car. The bracket on
this pipe was later cut off.
Stock turbo vs. the Blouch 18G. When this project was initiated, the
customer had future plans of upgrading the short block to a 2.5L, so I spec'd
out the 18G because it will perform well on the 2.0L and will be efficient on
the 2.5L as well.
A beautifully polished turbine inlet. It's all in the details....
The new Blouch turbo sitting in its nest. A stainless braided oil feed is
necessary in this application.
I fabricated a custom exhaust system for this project. This was not an easy
task. I chose all stainless so that all the exposed pieces would always remain
looking good. There were very little design attributes discussed with the
customer. He allowed me to take some liberties in the final design... I crossed
my fingers and hoped he would be pleased.
Speed Industry exhaust system vs. original. I think the photo speaks for
itself.
played with all the angles until it looked right from all directions.
Again... it's in the details.
I brought the customer in to specify tip angles... once you cut it... it's
final. I did the final trimming on the car... very carefully...
Tuning the ECU
(Engine Control Unit) consists of data logging crucial parameters,
adjusting ignition timing advance and fuel mapping. The changes to the maps are
quantified by power and torque gains as measured on the dyno and the AFR (Air
to Fuel Ratio) as measured by my laboratory grade Lamda-Pro wideband system.
Once all of the calibration edits have been tested, the final ROM file is
flashed into the ECU. For this project I chose to use the Cobb Accessport so
that the customer may switch maps at a later time, and also read any engine
trouble codes and also monitor engine parameters on the color screen of this
unit. When not in use, the Accessport is tucked away in the glove box. Cobb
ProTuner software was used to tune this vehicle. (As Michigan's only Cobb
ProTuner presently known as AccessTuner, Speed Industry has extensive
experience in tuning Subaru power plants). The power increase on
this project vehicle was 100 wheel horsepower over the baseline as measured on
my loading Mustang Chassis Dynamometer. Let me tell you, when I test drove this
car...it was very impressive.
