When
GM introduced the C4 back (seems like an eternity), in 1984
they forever changed the industry benchmark for high performance
automobiles. In 1984 the C4 was declared by the media as being the most
technically advanced automobile on the planet.
The 1984 C4's rock hard
suspension and GM's infamous cross-fire injection gave way the
following
year to a more refined and streetable version of the C4. A radical
redesign of a car within the first year of a new platform
introduction is almost unheard of. GM was forced by its customers
to fix its mistakes and by 1986 most of the production bugs had been
worked out.
The C4 emerged as a true world class performance
machine and forced most of the traditional hot rodders to go back
to school and relearn a new language. That language was until that time
reserved for computer nerds and rocket scientists.
Times have changed and the C4 has taken a back seat. The C5
and
C6 like all new toy's get the most attention. Well, C4 owners take
heart because a properly set up L98 or LT1 will stand head to head with
the new kids on the block.
The L98 and LT1 were designed as street machines. The C4 power curve
is right where you need it. The power is emphasized in the lower rpm
ranges
(1500 - 3500 rpm) hey folks this is where you live on the street.
I don't care what Porche owners or anyone may tell you,
the fun factor of a high performance street machine is directly
proportional to low end neck snapping torque.
In stock form the L98 puts out an amazing 350 lbs of torque that comes
in
under the 4400 rpm. Net horsepower was rated at around 250, that's net
horsepower, if the auto industry was still using the gross horsepower
rating system, like it did in the old days,
the L98 would be rated at
around 300 horses. Thats nothing to sneeze at
.
The first time we got a
chance to actually do some serious work on a C4
was back in 1986. Until that time we followed the time honored formula
for hot rodders:
- Slap on a set of long tube headers and a 2 1/2"
dual exhaust system with a
x-over pipe
- Install an Edelbrook hi-rise intake manifold with a Holley carb
- Port the heads
- Slap in a 3/4 cam
-Modify the timing curve by
messing with the weights in the distributor
-Install 4:10 gears and hold on.
There were no computers to mess with on C3's, no fuel curves, no
sensors
no exotic fuel injection parameters. What you saw is what you got. A
gas guzzling, bad tempered, bad ass machine that was hard to handle at
high speed,
tended to overheat and would not idle. It was a straight line rocket
sled from Hell.
In short a thing of beauty for a hot rodder.
The C3 had to be babied
and
tended to on an almost daily basis. The plugs had to be inspected,
cleaned or changed out after a few weeks of semi normal driving. If you
couldn't afford to install stainless steel brake cylinders, bleeding
the brake system was a daily event.
Yes we have come a long way baby.
In 1986 a customer brought in his spanking new C4, he told us he wanted
more power. We knew then that it was no longer
business as usual.
At the time we were lucky enough to have a very good friend
who was a head mechanic at a local Chevy dealership. He had just
completed a six month GM sponsored course that was dedicated to the new
C4.
We convinced him to moonlight with us and at the same time pass down
the new Holy Grail of GM C4 performance knowledge.
What we found was that you could meld old school hot rodding tricks
with
the new rocket science. The C4 in stock form was a revelation, it
delivered incredible performance and at the same time was actually a
real car. By that I mean it could be driven on a daily basis in all
kinds of weather. It didn't break down,or overheat. It stopped and
handled unlike anything that Chevy had ever mass produced.
A spanking new out of the
box C4 was an impressive package for the mid
80's. Remember high performance was just emerging from the dark ages of
tight emission and cost controls.
The American auto industry had just come to the realization that in
order to survive it had to offer something that was previously unheard
of, "Quality".
GM actually performed quality control testing on the new C4. This the
first time
a major US auto manufacturer did not use its customers to quality test
its vehicles.
A new C4 could do the quarter mile in about 14.2
seconds, 0 to 60 came
in at around 6.3 seconds. Those were respectable numbers in 1986. Of
course respectable
is not what new C4 owners wanted. They had just paid top dollar for an
American icon
and were not enthusiastic about to getting dusted by four cylinder
Porsche's.
The Solution
Like its
predecessors the C4 will
respond to the traditional hot rodding formula:
Intake + Exhaust + Ignition + Gears = More Power
The difference with this new computerized marvel is that after the mods
are
completed the car can still be used as a daily or long distance driver.
You won't even have to listen to your wife complain about how you
ruined your car.
With some planning and coordination the C4 will easily slip into the
mid thirteen second 1/4 mile bracket. Computers are a wonderful thing,
when high performance
modifications are planned around sensor operating parameters the end
result will be a very
civilized and reliable touring machine. A machine that will deliver the
same rocket sled acceleration
of former Vettes while at the same time delivering a very street able
ride while getting 25+ MPG.
If you are the proud
owner of a C4 who is just a little tired about
constantly
being told that a C5 or C6 is the only way to go, listen up.
Upgrading the performance level of a C4 is pretty easy, with a little
patience your
car will keep up with and in most cases dust off unwary C5's. The
majority of C5 owners are yuppie types that really never do much to
their cars other then put gas in them. I hope I didn't piss off anybody
with that last remark. Hey if you are a C5 owner and you are reading
this, you
don't fit into the, "I only put gas in my car" category and have
probably ordered
our ,(shameless plug) Corvette
Performance
Modification Manual
Seriously, if you
want to
increase your overall driving experience with a C4 or C5 for that
matter
take a look at our manual. It will guide you through all modifications
to the major systems in your vehicle.
It will also help you to make some sound decisions on the road to more
horsepower
while saving you money and the aggravation associated with mismatching
performance parts.