Hahn
RaceCraft's development program for the 420A engine began in
early 1998. It started as a response to the inquiries we
received from our 95-99 Diamond Star customers, whose
non-turbo cars are equipped with this engine. They
practically begged us to design this system! Little did
we know at that time that we would be building over 450HP with
this exceptional engine by late 1999.
| Our
first prototype vehicle for 420A Turbosystem testing
was our own 1998 Eclipse RS. This long-term
testbed vehicle was at first used to engineer our
Stage I and II turbosystems. The components used
in these systems were carefully chosen to offer
excellent results while also allowing higher-powered
options to be employed in the future.
While the car underwent long-term evaluation of the
turbosystem's effects, we worked in the background to
create a foundation for the higher-powered future
iterations. |
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During this period, we were
surprised and pleased to learn that the 420A looked promising and
amazingly modern when inspected internally. As it is a truly
new engine (1995 was its introduction), its CAD design and
contemporary design improvements were apparent upon close
inspection. The design concepts we noted in the 420A
suggested strongly that our current and future power and
durability aspirations should meet with success:
A very strong
bedplate four-bolt main lower end design appeared quite capable of
handling much higher than stock HP. This bedplate design
means the engine block actually separates into two sections along
the crankshaft centerline, rather than the more conventional and
much weaker practice of using separate main bearing caps.
This design is typically used only on high output motorcycle or
automotive (Suzuki, Viper, Porsche, Ferrari, etc.) engines.
Direct Crank
Trigger ignition adds accuracy to spark timing. A strong,
knife-edge crankshaft comes standard.
The Lotus-designed
four valve cylinder head not only flowed well stock, it also
exhibited excellent detonation control from modern port / chamber
design and well executed cooling.
Mahle pistons, well known for
their quality, added durability to the package. The more we
analyzed this engine, the better it looked!
In the first year of testing, we
studied the effects of our Stage I and II turbosystems on
completely stock engines. This long term testing was
crucial to determining the safe upgrade limits for these otherwise
stock engines and drivetrains. Over thousands of street
miles through all types of climates, with dozens of drag strip
passes in between, our prototypes were put through their paces.
The stock engines proved quite well suited to the 250 to 275 HP
that our Stage II kit produces.
| After
a year of successful turbosystem and durability
development with the stock engines, the time had come to
explore the next level. With a target of 375-400 HP, new
engines were prepared with forged pistons and billet
connecting rods. One was installed in our Eclipse,
another in the Neon. These units were carefully
assembled, but were intentionally left otherwise
completely stock except for the pistons and rods. We
also upgraded the fuel systems to full programmable units,
while adding a more powerful ignition amplifier.
These changes allowed the turbo and intercooler
that are standard in Stage I and II systems to run higher
boost and produce their maximum airflow of almost 400HP.
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then power was sufficient to land our 2400 lb. Neon squarely
into the 11.7 second /119-mph quarter mile range, while
still maintaining daily driveability. As a matter of
fact, this car has always been driven, not towed, to the
dragstrip! The engine proved quite docile, yet still
very willing, during street use on pump gas at low boost.
The addition of higher-octane fuel and higher boost allows
400HP, all while retaining daily driven dependability.
The performance value of the Neon was stunning: the total
investment, including the purchase of the 1996 car, was
still under $15,000 for a genuine, daily-driveable,
late-model eleven second car which still gets great gas
mileage in daily driving! The performance per dollar
approaches that of a modern sportbike. Needless to
say, the Neon was responsible for a lot of jaw-dropping at
the local dragstrips.
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next step in power, was tested with our Eclipse RS.
In addition to the fuel system and engine internal mods, we added a larger intercooler and converted the
turbo to Super 20G specs. Remapping of the
programmable fuel system we had previously installed allowed us to take advantage of the additional
airflow provided by the larger turbo and front-mounted
intercooler. Here the 420A engine proved itself yet
again: it was now producing 450+HP, enough to propel the
2900 lb. Eclipse to 122 MPH in 11.7 seconds. Yet the
car is compliant and cooperative in street driving, still
wears air conditioning and goes anywhere!
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is important to note that our 375+HP Neon and 450+HP Eclipse
420A engines are still stock in terms of airflow. For
the sake of turbosystem economy and simplicity, as well as
good street manners, we decided to explore the maximum
amount of power available while still blowing through a
stock throttle body, intake manifold, cylinder head, cams
and valves. The outcome is impressive, to say the
least. Although the durability improvement
provided by the piston and rod upgrades is essential to the
use of these engines over 300HP, the pistons and rods do not
help produce more power. The power gains are strictly
achieved through the capabilities of the HRC turbo and fuel
systems. 450+HP is enough for most, and readily
achievable. Yet a brave few will try to imagine what results
could be achieved with the addition of cylinder head /
manifold improvements! |
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For Hahn RaceCraft, the next
step will be to do just that. Our continuing development of
the 420A will now explore what we can achieve when we are not
limiting ourselves to the 450 or so HP airflow of the stock
components. Moving effectively to the next level prompts us
to finally take off the stock manifold and other parts that had
performed so well to date. It's a bittersweet moment, for
while we look forward to the huge power gains enabled by the new
parts, we will miss the outright simplicity, ease and
affordability of the stock parts. No matter. In order
to maintain our position as the authority on these engines under
high output, we will now forge ahead to ever-higher power levels.
The information learned as we cross the 500HP mark will continue
to benefit all of our 420A Turbosystems and engine components.
We plan to persist until we have achieved the 400+HP per liter of
engine displacement we have achieved with some of our other
notable engine programs.
| P.S.:
The transaxle these engines are coupled to is a nice piece
in its own right. Its durability definitely makes
the engine's strong points even more viable. In the
worst case scenario we've been able to come up with, our
98 Eclipse RS has withstood thousands of miles of
turbocharged street use and 11.7 second quarter miles.
It weighs about 2900 lbs. with driver and has a completely
stock transaxle, uses slicks at the track and has had ZERO
transmission issues. I've never missed a gear in it
in over a hundred dragstrip passes. It's a perfect
marriage with the Stage IV clutch we provide. I
drive it hard, and if it holds up to what I dish out, then
it's a durable gearbox! The fact that the
stock components have held up to this brutal power level
for so long is evidence of the durability that you can
expect. |
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Of course, it has been my
intention to push these components to their limits and beyond.
This is the best way for us to understand what you, the buyer,
will ultimately need to know about these cars and their
capabilities when power is increased. If you are considering
drag racing your car as continuously as we have run the RS, we
heartily recommend a limited slip differential, and a training
session from one of our drivers to teach you how to get that Hahn
RaceCraft power to the pavement effectively while
maintaining good drivetrain life. We'll gladly show you what
we've learned about extending drivetrain durability and traction
effectiveness. We believe it's the best way to make your
experience with our equipment even more enjoyable. We have
the information. That's why we drive, and race, what we
sell!
Thanks,
Bill Hahn Jr.
*Some
products listed are legal for sale or use in CA only for
racing vehicles which may never be driven on a public highway.
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205
Beaver
Yorkville, IL 60560
(630)553-6830
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