Our development program has centered on our own 2004
SRT-4.
During
the past year, this car has seen dozens of dragstrip
passes, countless dyno runs in our development lab, as
well as
over 12,000
miles of
daily
street use.
Rather than mimic what other companies were doing
,
we decided to take a novel approach.
Our head engineer and resident Doctor of
Turbology, Bill Hahn Jr, charted a unique course that
would attack the most deficient areas first
.
Bill has been tuning Turbo Neons for longer than anyone,
and has developed a keen sense of what works...and more
importantly, what doesn't.
Phase One:
Stock Turbo, Fuel System Upgrades
With our car in stock Stage 0 form, we installed our
innovative new PortFueler system, our Fuel Mapper, a
boost controller, and a modified wastegate actuator.
Results were good, with 280
whp and low
13-second dragstrip performance.
Power had been greatly improved, but the stock
turbo proved to be hard to control at high RPM...the
typical boost dropoff
was evident.
Bill decided that the stock turbo was simply a
waste of further development time.
Phase
Two: Upgraded Super 16G Turbo, but Stock Airbox,
Catalytic Converter, and Exhaust System
Next, he really deviated from the standard approach.
Rather than replace downpipe, exhaust system, and
airbox, he went straight for the turbo.
With our Super 16G upgrade, he charged to over
300 WHP and 350 ft/lbs of wheel torque on the dyno, and
deep into the 12's, with a 12.65 @ 111 MPH pass on
slicks. The
PortFueler system previously installed was re-tuned for
the new turbo.
The best part? He did this on STOCK exhaust, catalytic
converter, downpipe, intercooler and airbox!
Bill was right...he theorized that these stock
parts were capable of much more airflow than the stock
turbo could ever provide, and the numbers he achieved
proved it. There
simply was no need to replace the downpipe, cat, airbox,
or exhaust until the turbocharger itself was replaced.
Phase
Three: Upgraded Exhaust and Air Intake
Case closed!
Next, Bill decided to take the gloves off. The more
conventional parts now went on...he installed a Thermal
R&D race downpipe and 3" stainless exhaust, our trick
Intercooler Upgrade, and our innovative new CoolRam
Intake.
An
upgraded clutch was also in this recipe, since the stock
unit was starting to fade.
Dyno tuning and recalibration of PortFueler for the new airflow
improvements netted 350 HP and 400 ft/lbs of torque
at the wheels.
At the track, the
slicks stayed home...drag radials went back
on, and we were rewarded with a 12.31 @ 116
MPH. Stock fuel
pump, no return line or external regulator!
Phase
Four: Super 20G Turbo Upgrade
Satisfied that the
Super 16G was at full potential, the Super 20G went
on. A larger set of injectors were fitted to the
PortFueler, and an intank fuel pump upgrade was
installed. After remapping the PortFueler to
accomodate the injector and turbocharger changes, we
were rewarded with 425 WHP. A couple of trips to
the track netted the BIG prize..back to back 11
second passes on street tires! A best of 11.86 @
122 MPH proved that you don't have to extensively
modify your SRT-4 to go 11's on street tires!
This amazing performance was achieved with full
factory equipment...weight reduction was limited to
removal of spare tire and jack.
Why
replace parts that work fine?
What is most notable about the car is what has NOT
been replaced: even at
nearly 500HP, the fuel delivery
system is still stock
save for a drop in pump upgrade, as is the fuel
regulator...no
return line or external regulator is
required.
The stock
'Stage 0' ECU and injectors also remain.
On the street, the car still runs perfectly, with
no driveability or Check Engine light issues...EVER.
Used for daily commuting, its stock injectors and ECU
humming along perfectly, it achieves outstanding fuel
mileage to boot. It's consistent and predictable
in every way, whether fired up on a 20 degree winter
morning, or idling in stop-and-go traffic
in 95 degree heat.
