The kit we used is the Stage-2 Boost Cooler (PN 20010),
which is recommended for all centrifugal superchargers.
We also added the optional SafeInjection (PN 30010) with
a blow-off valve upgrade (PN 30030), which includes a
solenoid to open the blow-off valve to release boost and
protect the engine if the flow of Boost Juice should be
too low.
Snow Performance Boost Cooler
Snow Performance
www.snowperformance.de
Boost is
your friend, but detonation is your worst enemy.
Unfortunately, the two often go hand-in-hand in
forced-induction engines, and it's a fine line between
fine-tuning to get those last few numbers out of the engine
and crossing over into potentially disastrous territory.
Intercooling goes a long way toward helping
the situation, but oftentimes packaging can be a concern on
street cars. Such was the case with our '04 Z06 Corvette
test subject. The ProCharger kit for this car actually uses
two intercoolers behind the vents in the front fascia, but
because of space and airflow limitations on the stock Vette,
they were roughly the size of a heater core. Water/methanol
injection, essentially a chemical intercooler, is supposedly
more effective than standard air-to-air intercoolers at less
than 20 psi of boost, so we spoke with Matt Snow of Snow
Performance
to put together a water/methanol injection kit to see what
we could safely squeeze out of the Z06.
We used a piece of 4-inch-od exhaust pipe and two hex
nuts to fabricate the adapter for the Boost Cooler
nozzles. In any installation, be careful to keep the
nozzles several inches away from the mass air meter.
The now double-intercooled Vette laid down an impressive
639.5 hp at 6,364 rpm and 553.8 lb-ft of torque at 5,388
rpm with 91-octane and a safe air/fuel ratio.
With
91-octane in the tank, even 14 degrees of timing was causing
the knock retard sensor to dial back the advance. Using HP
Tuning software and a few test pulls on the dyno, Robert
Barth from Strictly Performance in Van Nuys, California, was
able to get the Vette into the 12.25-12.50 air/fuel ratio
range, and at the aforementioned 14 degrees of timing, we
saw 585.6 hp at 5,906 rpm with 540.3 lb-ft of torque at
5,430 rpm on Westech's chassis dyno with 10 psi of boost.
This is
the ideal air/fuel ratio to begin with when installing the
Boost Cooler, and with patient tuning of the ECU and the
Boost Cooler kicking in around 3 psi (~3,500 rpm), we were
able to dial in an impressive 24 degrees of timing with the
knock retard occasionally dialing back about 1 degree. With
a little more dyno time, we would have most likely remedied
this as well. Best of all, the car picked up more than 50 hp
to the wheels and the air/fuel ratio stayed well within the
safe 12.00-12.25 range for most of the dyno pull.
--Christopher Campbell