C5 - Upgrades and General Performance
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Since purchasing my 1998 Corvette in August, I have had a few interesting experiences I
thought I should share with other C5 owners. As a long time Corvette enthusiast, auto
racer, and mechanical engineer, I find that I crave performance parts, whether I drive
fast or not. I think the gene that makes us crave these types of automobiles is also
responsible for the desires we have to enhance their performance. My attempts at this thus
far follow.
The first step in enhancing the performance of my C5 came in the form of the air-box. A
duct-forming shroud covers the factory air cleaner, and I immediately removed it. I
have heard this was added to reduce intake-air noise, but I personally feel it was put in
to keep water from entering the filter. There in lies my first warning; don't open the
hood in the rain if you remove this shroud, or water will pour into your air filter. Of
course once you remove the shroud, there is no where to attach the straps that hold the
filter in place. My solution was to use extra long zip-ties to wrap around the entire air
box assembly. I also added a factory sized K&N filter, but I am not convinced as of
yet that this was a good idea. I truly believed in the excellent reputation of
K&N, but this particular filter has significantly less filter area than the factory
paper element. Where the factory paper stretches the entire surface of the filter, the
K&N stops short at the top and bottom. Maybe someone will flow-bench the two, and give
us a comparison!
Next step: Exhaust! I chose the B&B Fabrication exhaust set-up due largely in part to
magazine recommendations, as well as the fact that the LS-1 is the first Corvette to have
a 180-degree flow muffler. B&B seems to have had a great deal of experience with these
type mufflers, and I therefore thought it worth giving them a try. I purchased my system
directly from B&B, and my opinion of the company is varied. Their customer
service is great, and all of my questions were expertly answered. However, shipping time
was poor, as it took two weeks to receive my exhaust. This would not have been so bad had
I not taken the factory system off the day after my order was placed. B&B made up for
this slight irritation with quality! The entire exhaust system is beautiful. Every piece
is polished, and the bends and welds are far superior in appearance than that of the last
Borla system I tried (on a 91' ZR-1). GM did us a favor by making the factory system easy
to remove, and B&B did a great job of making their system simple to install. I have
the good fortune of having a lift in my shop, but it could easily be done with a floor
jack and a set of sockets in well under an hour! Once installed, I fired up my black 98',
and was impressed by the exhaust tone. The car definitely has a more noticeable sound, but
is far from loud. My wife did not even notice the difference, which is a good thing!
Driving the car is no less pleasant now than before, and I enjoy the knowledge that my car
now sounds as fast as it looks!
Next item of business is purely cosmetic. I have grown to love the look of the C5, but I
personally feel it is missing something. I chose to help out the "tail" of my
car by installing a rear spoiler. I chose the one from Mid-America, although there are
several other companies offering an identical model. Installation was pretty simple,
although their templates for drilling the 5 required holes were not accurate, and I had to
re-drill several times to get the holes lined up. Once painted and installed, however, I
was happy with the results. The spoiler looks great and helps finish the rear of the car.
The design allows the rear hatch to open unimpeded, and in my opinion, really adds a lot
to the car. I know a lot of you are thinking I just ruined the aerodynamics of a car that
GM spent all of those hours in the wind tunnel for. I say "Oh-well." My car
makes so much wind noise around the passenger side window already, that I am willing to
give up a little slipstream for appearance. Also, I don't drive 160mph every day!
As an engineer, I usually like to scientifically analyze modifications I make on my cars.
However, as my Vericom and G-Analyst were both stolen last year, I have given up such
testing. I don't trust a stopwatch, and the nearest ¼ mile dragstrip is two hours away
(and closed for winter). I did take the car to Charlotte Motor Speedway a few days ago for
some track testing though. Although it rained the entire day, I am happy to say the C5 is
a very balanced car! I was not able to run the car all out due to the water, but the car
pulls strongly at all speeds. The car is stable at 130mph in rain, and is very
predictable, even in rain. The car does not have the power of my last Vette, the ZR-1, but
it is fast nonetheless. The car feels much more solid than the older models, but it still
likes to be driven with the rear tires out a little in the turns (oversteer). I don't like
the F1 tires much on the street, but I am happy to report that they perform exceptionally
in the rain a speed.
Overall, the C5 is a fun car to drive fast, even in the rain. I doubt I will be able to
get the C5 back on track any time soon. I drive a Z28 in SCCA World Challenge, and that is
where I release most of my "speed" adrenaline. I would love to here from anyone
with similar experiences with their cars, and am happy to answer any questions about the
products listed above. CLICK HERE FOR APRIL '98 UPDATE!
-David Farmer
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