by leaftye, Corvette Forum Member
Many C5's came with AC Delco Freedom batteries that had a
tendency to have it's case crack open near the battery posts.
The leaking battery acid would drip down the side of the
battery, down the funnel-like battery support, straight down
onto the PCM and the wiring loom. It can also get onto the A/C
lines. I believe they are the vacuum lines that control the
movement of the interior vents, and usually the system will
default to blowing out the defroster vent. Sometimes car
crippling damage would occur, sometimes not. It worst it would
mean replacing the battery, the PCM, the wiring harness,
grinding the rust off the frame to repaint it, changing the A/C
lines and possibly swapping out another computer as well. This
mostly happened on early C5’s because later C5’s used a gel-type
battery that cannot leak, but I believe the problem resurfaced
on ’04 or ’05 models again.
Check this out on any car you look at. Use a 8 mm monkey wrench,
preferably a ratcheting closed-end version, to removed the
battery cables. You also remove a holding block on the front
side of the battery. You will need a long extension to reach it.
The battery basically lifts right out. Also remove the black
plastic battery tray. Look beneath the tray for rust or white
powder. Signs of both are evidence of battery acid damage. It
would probably be best to move to the next Vette unless you
don't mind possibly tackling this repair in the future. It's
possible that the car will throw codes for no apparent reason.
No matter what Vette you buy, just make sure you replace the
battery with a gel-type battery, like the Optima Redtop, sold at
CostCo for $100.
Grounding Problems aka CRAZY electrical gremlins!
Bill Curlee has a great thread on the problems that corroded
ground connections can create, and how to clean out the grounds.
The most problematic ground connections are behind the
headlights on both sides. Check out Bill’s thread for detailed
Here’s where all the grounds are:
Water leaks have several ways of getting in the car, and none of
them AFAIK are very difficult to fix. Proper adjustments and
maintenance will prevent most leaks.
Bill Curlee’s thread abouting locating & cleaning the udders,
and sealing the door hinges.
Here’s a few TSB’s from the CorvetteActionCenter.com:
1997-1998: Service Bulletin: Waterleak Above Door Glass (Reseal
1997-2002: Service Bulletin: General Waterleak Guide
1997: Service Bulletin: Water Drips into Rear Compartment After
Hatch/Glass Has Been Opened
Corvette seats are delicate.
Sliding hard across the bolster can break it, causing it to flap
The leather is cheap, and there's little protection for it. It
will wear out and form cracks, which is normal…for cheap
The wire springs in the seat bottom, and the bars in the
bolsters can also wear thru the foam and leather, but that can
be fixed by placing layer of burlap between the springs and the
Check the black plastic surround on the bottom of the seat to
make sure it fits snugly against the leather, and isn't cracked.
Older style plastic surrounds had a tendency to separate from
the seat, but could be pushed back in. The newer style plastic
surrounds can be used as a direct replacement, but one of the
plastic studs may need to be ground off, or a hole will need to
get punched into the leather.
The seats tend to rock back and forth by about a 1/4" during
acceleration and braking. It can be fixed, but GM will not fix
it. Some lucky owners can get the dealer to replace the frame
under warranty. The seat backs swinging forward under braking is
normal, and not considered a problem.
Here are a couple fixes:
Corvettemechanic.com --- must be a member
Rocking Seat Fix
Get the sport seats. The sport seats have a hole under the
headrest. Some people put racing harness belts thru those loops.
The seat frames and foam in both seats are interchangeable.
Harness belt holes can be installed using Ford harness cutouts.
Ask the dealership for them, they should know what it is without
a part #. The foam in a standard seat will need to be cut, and
sewing will have to be done, but it’s an easy job.
Headlight bezel plugs
There are 1-1/2" plugs that are located on the headlight bezels
that would fall off on the older Vette's. The new style plugs,
have a twist-lock to prevent them from falling out, but also
requires new bezels. Only the new bezels & plugs are available
now, and they are compatible with older C5’s.
The gears in the headlight motor are plastic, and wear out over
time. Ice, heavy Euro or projector headlights and twilight
sentinal will cause the gears to wear out quickly. Fortunately a
few years ago, Rodney started selling replacement brass gears,
check out his
website. Corvette America and probably a few other vendors
now sell their own copy of his brass gears. Here’s a
thread that shows how to replace the gears.
If you buy a coupe with a removable roof, you can expect wind
noise and some creaking. The wind noise will never totally go
away, but if there's creaking, you can eliminate that by thinly
applying dielectric silicone grease to the weather-stripping. It
also prevents cracking, so do this to all weather-stripping, on
During cold weather the rubber hood stops can also rub and
rattle against the hood. Adjust and lubricate the rubber stops
so when you pull the corner of the hood up, it doesn’t pull up,
but the hood still closes.
The valvetrain makes a significant amount of noise at idle. It
may sound like sewing machine. Converting the valve rockers to
true shaft-mounted adjustable roller rockers with may help
eliminate the valvetrain noise if adjusted properly. Installing
a big cam and stiffer valve springs will make the noise louder.
On manual transmission cars (M6 or M12), the transmission sounds
like it is rattling when leaving the line. It is normal. It is
the clutch throwout bearing rattling around. Sometimes you'll
hear a horrible rattle if you shut off the engine. If you press
the clutch pedal in while shutting off the car, you won't hear
The front brake rotors warp easily under heavy braking…or at
least that’s what uneducated drivers think. I tend to believe
I verified this by lightly grinding my rotors with steel wool.
Garnet paper is recommended, but I haven’t tried it.
If you insist the problem is warping, don’t turn the rotors
since thinner rotors warp more easily. Resurfacing the rotors is
only a temporary fix, one that is less effective each time your
resurface the rotors due to the reduced thermal capacity of the
rotors. Rotors are available for $25 at Napa and RockAuto.
Scraped front ends and rocker panels
Checking for scrapes is an easy way to tell if the car was
treated well. It's almost impossible not to scrape the front
end, but there are two metal crash bar loops that should prevent
the bumper from scraping. The bumper itself should not have
scrape marks on it. Check the underside of the tip of the
bumper, and the bottom corners of the bumper. If the crash bar
gets scraped enough, eventually it will wear down to the point
where it needs to get replaced. It costs about $220 for the
crash bar, nut-serts, bolts and insulators, and can be replaced
in a couple of hours, just be sure to hook the hoses and
electric connector back to the A.I.R. pump.
Here’s a list of ALL the parts you’ll need to replace the impact
bar and the side air deflectors:
10188023---001---Insulator (goes to bottom of radiator)
10278679---001---Insulator (goes to bottom of radiator)
10400765---001---Plate (the actual impact bar, unpainted)
10419312---001---Panel (air deflector)
10419313---001---Panel (air deflector)
Not all of these parts need to get replaced, and there will be a
few leftovers, but it will get the job done.
The rocker panels tend to get scraped on lifts and big speed
A & A Corvettes invented two products to prevent damage from
both kinds of scraping. They have wheels that attach to the
crash bar, allowing the car to roll on driveways instead of
wearing down the crash bar. It will still scrape the spoiler,
but the spoiler is a cheap wear item that takes only 2 minutes
to replace without a lift or jack. They also make two aluminum
strips that attached the frame next to the rocker panels, and
they take the scrapes themselves instead of the rockers panels.
Neither of the devices are visible unless looking under the car,
and they are discreet enough to possibly be missed anyway. If
you see these devices installed, you can be pretty sure the
owner took good care of the car. Without this extra protection,
you can expect to replace the crash bar and repair the rockers
several times over the life of the car. WARNING: It won’t stop
all scraping damage, just reduce the possibility of it
happening, and reduce the damage when it does happen. Low
hanging headers will probably still scrape.
Hood seal weather-strip
The sides and back of the hood compartment have weather-strip
installed from the factory. The front is left open. Many owners
install weather-strip along this front edge. You may not even
notice it since it looks identical to rest of the
weather-stripping. This extra weather-strip helps keep the
engine compartment clean, and may also help the air intake
system work better. This is another sign that the owner took
good care of the car. The engine compartment stays pretty clean,
but this the "extra step".
There are two kinds of climate controls. One is manual with
knobs, and the other is a dual-zone electronic system. The
dual-zone system did cost more, but is not as reliable as the
manual system. A leaking battery can affect both systems. A
strong system is when the vents cannot be switched.
Over time, and especially in humid climates, the system can
cause condensation to leak onto the passenger side carpet. There
are three udders under the driver’s side cowl. There are slits
on the bottom, much like real udders. Vigorously squeeze and
massage the udders until the debris has fallen out. Stop
If the vent settings cannot be changed, the vacuum line is
probably loose, clogged or broken.
Squeaky steering wheel
When you turn the steering wheel, you may hear a squeak. It's
just the plastic surfaces rubbing against each other. A shot of
lubricant fixes this.
Squeaky/chirping/grinding wheel bearings
Drive slowly, better yet, coast along at low speeds with the
windows open in a quiet location. Listen for a squeak from the
wheels. Try turning in different directions. If you hear the
rear wheels squeaking, you may have a worn wheel bearing. A
replacement bearing costs $600 list, but you can usually find it
for $400-450. I've heard that AutoZone has a better replacement
for $126 by a company named Timken. The part is easy to replace
if you can separate the ball joints. I had to buy a special
Kent-Moore tool to do mine. This problem may persist safely for
a few months, but eventually will become annoying. It seems to
be a common problem, and more so for the rear wheel bearing.
I've never heard of it happening twice to the same car, so if
you fix it once, you're probably good for life. Several racers
replace their wheel bearing every year.
A broken emergency drum clip may cause a false diagnosis. Be
careful when removing & replacing the rear rotors.
Many late 2000 thru 2001 Vette's burn a lot of oil when the
engine is kept constantly over 4,000 rpm's. This is caused by
ring flutter, which allows extra oil to seep past the oil
control rings, but doesn't seem to cause any extra wear to the
engine. Chevrolet has rebuilt and replaced engines for owners
that complained about excessive oil consumption. Their policy is
that while the engine isn't normally operated like that outside
of racing, it is the owner's prerogative to drive around in
second gear all the time if they want to. It is covered under
The PCV system also has a tendency to suck oil back into the
intake at high rpm's. It doesn't seem to cause any problems,
other than a slight mess inside the intake manifold. The newer
style PCV system can be installed, but this requires removing
all the components in the top of the engine valley. Usually only
racer's bother with the hassle. Several generations of PCV
systems have had the problem, and at this time, December 2004,
the PCV system still sucks oil into the intake.
The oil-sucking problem will cause carbon buildup in the
cylinders. The dealership sells GM Top End Cleaner, and Napa
sells SeaFoam. The Top End Cleaner is not available in some smog
states like California. Run a tube from the bottle into the hole
for the PCV system behind the throttle body on the passenger
side. Start the car, then start slowly sucking the solution into
the engine. Don’t go too fast or the engine could lockup. As
soon as the solution is gone, stop the motor for >4 hours, but
preferably 12 hours. Be aware that when the engine is restarted,
there will be a LOT of smoke!
The oil-sucking can be prevented by installing a catch can. AMW
and Greddy make catch cans, but a homebuilt catch can may be
built using a Campbell-Hausfield air tool oil separator from
most tool stores, including AutoZone. The AMW and Greddy cans
are ~$100, but look great. The CH can is $15-25 for all the
parts, and you can see how much oil is in it.
Overheating & burning smells
Even though the engine can heat up to 220, even 240 degrees
Fahrenheit, this is normal. The radiator will keep the engine
cool enough unless the radiator is blocked. Reprogramming the
PCM can allow the fans to turn on earlier. If the fans also cool
an aftermarket oil cooler, make sure the oil occasionally gets
to 220 degrees to allow condensation and fuel to evaporate away.
Fan settings and oil thermostats are two different ways to do
It's not uncommon for plastic bags to get sucked up under the
front bumper, and cover the radiator, thus causing the car to
truly overheat. If this happens, take a quick peek under the
bumper, and remove anything under there. Sometimes bags get
stuck to the exhaust pipes too, causing quite a stench as they
Locked steering column
All C5’s, particularly manual transmission C5’s, and early C6
steering columns have a tendency to lock and stay locked.
Usually it can be unlocked once, but just once. Some owners
claim that vigorously shaking the steering wheel can unlock the
steering wheel. Dealer's are able to disable the locking
mechanism with a modified locking plate. Currently this is the
only real method to disable the locking mechanism. Basically the
wheel will still try to lock, but there will be nothing for it
to lock to. It’s like a door dead bolt with a slot cut into the
door jamb. There is a $100 kit that disables the steering column
lock, and can be installed easily, but enough car vibrations can
cause the lock to fall into the locking plate, even while
GM has a part (#88952428 or 88952428) that has a harness wiring
jumper and different lock plate. Not sure what the difference in
the kits are.
After reading a few posts, manual transmission C5’s & C6’s are
still in danger, even if the lock is disabled. The lock can
vibrate out over time and get trapped in the locking plate. Auto
transmission cars that have undergone the recall and new auto’s
will not have the locking plate at all, so they are safe. More
information about COMPLETELY disabling the steering column lock
will be forthcoming from other’s on the forum, and by my own
personal project. Until then, here are a few links about the
Corvette Forum - Column Lock Harness K Installation
Corvettemechanic - A4 non locking column plate --- must be a
Corvette Forum - Column-lock again even with CLB!
Corvette Forum - Has anyone ELSE beat column lock?
Faulty gas gauge
If you have bad gas (phew!), the fuel sender can be affected by
the high sulfur content in the fuel, and cause the gauge to read
empty. They car will still operate normally, and the gas gauge
will work again if you use better gas, and will usually start
again when you restart the car. It's just better to use good
gas. Some people have had luck with running fuel filter cleaners
thru the gas tank. New fuel senders sometimes fixes this
thread has a LOT of ideas about what could be causing the
problems, how to avoid problems, and how to fix it. It also
points out how the late C5 fuel tanks and crossover tube is
Noisy fuel pump
There are two fuel tanks, and two fuel pumps. One fuel pump
continually pumps gas from the passenger side tank into the
driver side tank, and is quiet. The main fuel pump is directly
behind the drivers seat, and can be annoying loud, especially on
early C5’s. It's normal, and not a sign of a failing fuel pump.
Chevrolet does have a bulletin out instructing how to better
insulate against the sound of the fuel pump. This is merely an
annoyance. A newer, quieter pump can also be installed.
Extremely high oil pressure reading
The oil pressure sensor can fail, but it is still okay to drive.
Turn the car off, but with the key in the “on” position and
check the oil pressure gauge. It should read “0”. If the oil
pressure sensor is bad, it will show a positive reading. The oil
pressure sender is located behind the intake manifold, and will
require moving the intake manifold. The sender costs about $40
and part # 12573107 or 12562230.
In cold weather you may hear the suspension creak when you go
over speed bumps. To fix this, clean (optional) and lubricate
the sway bar bushings. The adjustable metal sway bar end links
on Hotchkis and T1 bars can also create loud clicking sounds.
Most adjustable end links are quiet initially, but wear out and
get noisy over time. Greasing and protecting the end links from
dirt may prevent wear.
The shifter in manually shifted Corvette's takes a strong arm to
get it into gear. You really have to make sure that the shifter
is fully in 1st and Reverse, or it will pop out of gear when you
let the clutch out. This is not the fault of the car, but rather
the fault of the driver.
Manual transmissions -- Replacing the transmission fluid often
helps shifting. Early transmissions have paper blocker ring that
require Dexron III compatible (usually organic) fluid because
some synthetics will destroy the paper blocker rings and
subsequently the transmission. Later transmissions, and all
rebuilt transmissions, have Kevlar/carbon fiber parts that allow
the use of synthetic fluids. I believe the 98-00 transmissions
have the paper blocker rings. The safe transmission fluids seem
to be: GM Synchromesh PN #12345349, Honda ATF-Z1, Royal Purple
Synchromax, Amsoil ATF, O’Reilly Dexron III ATF. The following
transmission fluids may be unsafe for early transmissions:
Redline D4 ATF, Mobil 1 ATF, Royal Purple Max ATF.
LS1.com - Ending the speculation: Blocker rings, who's had them
LS1Tech.com - Ending the speculation: Blocker rings, who's had
Mobil 1 Synthetic ATF for a M6?
If it is especially tough to shift into 2nd or 4th gear, it's
possible that the synchro's are worn out or the forks are bent.
Do NOT force it into gear. Abuse creates and aggravates this
problem. You can still drive, even quite well, without synchro's....or
a clutch for that matter if you know how to rev match.
Some aftermarket shifters make it easier to make sure you're
fully in gear, and prevent gear grinding, but they also vibrate,
and require more effort to shift. The stock shifter has a tuned
weight damper that changes the vibrations to a non-audible
frequency. The shaking doesn’t annoy some people, and there are
The differential can leak from the side covers. The problem has
to do with the design. The lip on the casing is not wide enough
to create a proper seal with the cover. Resealing the covers can
be successful, but many dealers do not use the correct sealant.
Inside/outside tire spinning
If one tire spins while turning, adjust the friction modifier
ratio. Aftermarket gear fluid from Royal Purple, Amsoil and
Redline do not require additional friction modifier. GM’s
friction modifier is PN #12377916. Too much friction modifier
and the inside tire will spin/skip/hop. Too little friction
modifier and the outside tire will spin/skip/hop. -- Thanks
Tire hop during hard acceleration in cold weather is common,
even if the same tires don’t hop in warmer weather. Tire rubber
when viewed thru a microscope looks like a web. Normally parts
of this web grabs onto objects on the ground and stretch until
either the car moves forward, or the web breaks, resulting in
tire spin. I believe in cold weather, the web is too stiff for
either of these events to occur, so the tires hop. To find out
Racing & High Performance Tire: Using Tires to Tune for Grip and
Balance. I haven’t read it, but if you do, please let me
know if my guess is correct. I found a couple stories on Google
about people curing wheel hop with stiffer bushings and/or (jounce)
The visors may rattle when they are put up, but if you flip them
down, the rattle goes away. Squeezing the mirror lid down seems
to take care of it. Try glueing a piece of felt or velcro
between the mirror and lid to see if that fixes it. Caravaggio
also makes replacement leather visors, but they go for $400.
The stereo is Bose, and to go along with the historically crappy
build quality of Bose products, Bose has graced the Corvette
with Bose emblems on the door speaker covers that rattle when
you play music with bass. A Bose system doesn't exist that puts
out good bass, but the system still manages to rattle the
emblems when playing Country, Hip Hop, or Techno at moderate
volumes. Check this problem by having a passenger and yourself
putting a finger on the emblems with music playing. Glue the
emblems down to fix it.
If the roof isn't tightened down enough, it will rattle. There
are some adjustment screws in the roof to make this adjustment.
During cold weather, the belt can chirp. Goodyear Gatorback
belts from AutoZone don’t chirp.
During cold weather, the hatch may pop up slowly, or not at all.
Spray the latches with silicone grease until they come up
properly. If the struts do not hold up the hatch, try lubing the
1997: Service Bulletin: Hatch Will Not Pop Up When Activated in
The needle bearings in the OEM rockers have been known to fail.
Usually the problem is noticed with extra valvetrain noise and
needle bearings stuck to a magnetic oil plug. Nasty Performance
will rebuild OEM rockers with Harland Sharp bearings. This seems
to be one of the better solutions since the stock rocker is very
good at high rpms. Most aftermarket rockers are nose heavy and
require grinding the heads and valve covers to fit. Currently
Harland Sharp rockers are having problems with c-clip retainers
falling off and causing problems on the way. I’ll be following
this issue since I have a set of HS rockers on my shelf waiting
for this issue to be resolved. Here are some links:
LS1Tech - EMERGENCY!! ROCKERS! Help ASAP!
LS1Tech - Harland Sharp Rocker Failure
LS1Tech - Install or not install HS rockers?
Active Stability Control
This allows you to keep some control of the car even when you do
really stupid stunts. It doesn't bend the laws of physics, but
will keep the car pointed where you are steering; you may still
slide off the road, but at least the car will be pointed in the
direction you were steering! One of the sensors is located
around the passenger seat, and needs to be considered when
installing a racing bucket. If you move that sensor, Active
Stability will not know how to balance the car, and can be very
dangerous. Active Stability came out around '99.
The C5 was the first car to use hydroformed frame rails.
Hydroformed rails are quickly becoming a common platform for new
cars, but not many shops are prepared to lift these vehicles.
The C5 requires an adapter for regular jacks and lifts to fit
the jacking points. Make your own adapters with a hockey puck
(or two) with a 1 1/2" eye bolt screwed thru the center. Stick
the eye bolt thru the slit in the jacking point, turn 90
degrees, place jack under adapter and jack away....if you can
get the jack under the car. You may have to use ramps. The C5 is
so low that most people make their own wooden ramps....rhino
ramps are too steep.
There are basically two different kinds of key fobs, and they
are not compatible with each other.
97-00, but 00 does not have the Passive Lock feature
The OEM platinum plugs, along with other plugs have had problems
with the pucks falling off. I have a picture of missing pucks in
thread outlines some of the problems with using platinum,
and a recommendation for using silver tipped plugs. Basically,
of all spark plug tips, platinum is the worst conductor, copper
is good, iridium is even better and silver is the best. Don’t
take my word for it, do a little research, starting with this
review. As for longevity, platinum, iridium and silver do
have an advantage over copper, but plugs foul up after ~10K
negating any difference corrosion would cause, and no plug will
run well after 100K miles.
To make the spark plugs easier to change, get the Snap-On
double-swivel sparkplug tool and remove the coil packs. Here’s
all you need to know about sparkplug changes:
These problems, and many others, are addressed at the
http://www.corvetteactioncenter.com/ in the Tech Center ->
While these problems do sound numerous and severe, just remember
that JD Power considers this a very reliable car. If you buy a
Corvette, consider yourself fortunate that there are many
resources available to help you locate and correct problems.
Secrets of the C5
little yellow “helper light” on the bottom of the
rear-view mirror that illuminates the shifter area.
● That you can put your key in the driver’s door and
turn it twice towards the front to unlock the
passenger door and a third time to pop the trunk.
● That you can pop the trunk and also pop the gas
cap cover by pulling on metal lines hidden in the
● The little slotted cover on the dash behind the
steering wheel is where the inside air temperature
sensor is located.
● All of the option codes are in the glove box.
● Tire inflation recommended pressures are on the
● The thing that looks like a little LED near the
DIC buttons is a light sensor.
● The thing that looks like a little LED near the
defroster vent is a UV sensor for determining A/C
usage to compensate for the heating effect of the
● The build sheet is in the front re-bar.
● If you leave your turn signal on, in about 1
minute it will start to ding (loud enough to hear
over the stereo) to let you know you have old timers
● You can reset the oil life by pumping the gas
pedal 3 times (but not with the engine running).
● Hold down the reset button while on one of the
trip odometers and it changes that reading to the
miles you’ve traveled since last starting the
● Hold down the Active Handling button for 5 sec. to
engage “Competitive Driving” on cars equipped with
active handling (2000 and previous years must be
● If you pull the seatbelts all the way out while
you’re buckled in, they ratchet back in to hold you
tighter into the seat. (then move the seat
forward to make it extra snug -- Leafty)
● Simply remove fuse #2 under the hood and your DRLs
will be out permanently. Only thing affected is that
when you unlock at night using the key fob your
front turn signal lights and back up lights will not
flash. Your front turn signals will operate
● The side-view mirrors can twist both forward and
backward, decreasing the chance of damage if struck.
● There is a release opening with a flap to let air
out of the car when the hatch is closed. It is
located just above the driver side rear compartment
behind the carpet and on the side of the car. Not
that it really works well.
● Also you can ground your amp to a screw/bolt that
holds the rear middle compartment to the frame.
● If you have a 6-speed car you can pop the trunk
when the car is running by lifting the e-brake.
● There is a spot on the driver side just out of the
middle compartment under the carpet for the lug nut
key. You should have a compartment on the drivers &
passenger’s side (in the trunk) and a center
compartment. On the left (drivers) side of the
center compartment, on the left side where the
center cover fits, there is an ‘indent’ that holds
the wheel lock key.
● If you turn on the headlights, then go to parking
light position, the lamps remain up but the
headlights are not left on.
● If you have the passive entry feature: If you lock
the keys in the car, wait a few minutes and then
shake the car. That will unlock the car.
● HUD has a shift light for the manuals.
● You can easily shift the M6 trans up or down
without the clutch if you match revs. (Not great for
● You can eject the cd from the in-dash player
without turning on any power. Don’t even need key in
● The cruise will disengage if you purposely make
sharp side to side turns while cruising at say 60-80
● When the engine is shut off, you can get the
odometer reading by turning on the parking lights.
● You can program setting #3 (both memory buttons at
once) in the seat memory to run the seat back and
steering wheel forward for getting in/out of the car
with the engine running.
● If you hate DRLs you can pull the e-brake ONE
click and they go off.
First you need to know how your car is doing. A trip to the dyno
can give you quick answers.
Tuning software can diagnose and tune your car. LS1Tech and
HPTuners are two popular tuning packages. At some point in the
future, both packages will be able to do scanning with
incorporated wideband sensor support. At this time, December
2004, only HPTuners can do both.
Cold air intakes:
Vararam, Halltech, Blackwing, zip-tie
LS6, LS2, LSX, Wiend, sheetmetal
B&B, Borla, Z06 Ti, Corsa
Long tube headers:
LG, Kooks, TPIS, Stainless Works,
Breathless, Jet-Hot, GHL, QTP
ATI (go to A&A), Vortech, Magnacharger
Stroke & bore
Head & cam packages:
TEA, AFR, TSP, Patriot, Cartek
Kumho Ecsta MX, Nitto Extreme RII
Aerodynamics, gearing and top speed
convertible and coupe (it's really a targa) come
with run-flat tires, with 17" wheels in the front,
and 18" in the rear, with tire pressure sensors. The
Z06 comes with non run-flat tire, but has a tire
repair kit. Switching from run-flat tires to regular
tires typically allows the C5 to ride softer,
accelerate faster, and corner harder, but if you use
the tire repair kit (goo) on wheels with the
unobtainium tire pressure sensors, you'll destroy
the sensors. No C5 has a spare tire. The best way to
improve the handling of any car is usually thru the
The hardtops and Z06 have shorter rear windows, are less
aerodynamic, noisier, and weigh less than the standard C5 couple
like mine. Even though the Z06 has more hp than standard C5’s,
they have a lower top speed than manual Z51 C5 coupes. This is
due to both aerodynamics and gearing. All C5’s top out at
redline in 5th gear, so a taller 5th gear, or much shorter 6th
gear, or taller redline is required to go faster. All else being
equal, a Z51 coupe will still go faster than a Z06. Above 190
mph, air builds up under the front of the car. This can be
solved with a vented hood like the ACP C5-R or MCM hoods.
You can achieve substantial weight reduction with the following
modifications, while still having a car that's very comfortable
to drive. Most of these modifications will directly increase
(and decrease in a few cases) the safety of the car, while
safety is indirectly improved due to the better handling and
limits of a lighter car. Fighter pilots say "speed is life".
Acceleration, deceleration, and lateral acceleration are all
forms of acceleration, and lighter cars accelerate better in
each of these ways because the tires have less mass to
control....thus a lighter car is a safer car. Lighter cars have
better moments of inertia which allows them to turn in more
easily and roll less. Lighter cars are also easier on the tires
All the stage
weight estimates are typically wild butt
guesses, but it makes it easy to see what is possible. The
weight listings in the separate weight posting is MUCH more
Stage I: Streetable weight reduction mods
Non-popup headlights (~40 lbs)
Braking rotors with an aluminum hat, or titanium rotors
(unproven on street cars) (~20-30 lbs)
Carbon fiber hood (~12 lbs)
Z06 (thinner) windshield and side windows (~5.7 lbs)
Non runflat tires (~20 lbs)
Slicks (~30 lbs)
Z06 wheels (~4 lbs est.)
Corsa titanium exhaust (~35 lbs)
Long tube headers (~20 lbs)
Halltech aluminum alternator & bracket (10 lbs)
Carbon fiber driveshaft (~2 lbs)
Newer torque tube
Less options [HUD, elec AC, Active Stability,
seat/mirror/steering wheel memory, cd changer] (~50 lbs)
Less gasoline & wiper fluid (No wiper fluid=9lbs, 6 lbs for
every gallon of gas in that 18 gallon tank....~81 lbs for
Remove cargo net
Remove targa top (~20 lbs)
Remove C5 "appearance mods" - exhaust plates, doorsill covers,
Remove fuel rail covers
Replace stock crank pulley with aluminum aftermarket pulley
Replace steel dampener with aluminum dampener
Replace stock targa top with lexan piece (coupes)
Replace water pump with electric water pump
Replace battery with smaller battery
Replace non-stressed fasteners with aluminum or titanium
Replace leaf springs with coil over shocks with titanium springs
Replace steel shifter with aluminum shifter and delrin or
titanium shift knob
Remove all loose change, CD's, golf clubs, misc. items, from
center console, hatch area, and glove box
Empty your pockets of extra change, PDA's, cell phones, keys,
lead plates, or whatever other junk you lug around
Go on a diet =p
Stage II: Hardcore semi-streetable weight reduction mods
Aluminum flywheel (~10 lbs)
Lighter clutch like Exedy or Quartermaster (~10 lbs)
Racing buckets (40-50 lbs)
Remove tire repair kit (Z06)
Off-road x-pipe (10 lbs)
Remove floor mats
Remove fog lights
Replace stock hood, fenders, doors, roof, hatch and bumpers with
aftermarket carbon fiber pieces
Stage III: Track only weight reduction mods
Racing steering wheel & delete both airbags (~30 lbs, but get a
4-6 point harness)
Use unpadded aluminum or carbon fiber steering wheel
Run open headers
Remove column locking hardware
Remove interior – passenger seat, carpets, speaker panels, head
liner, dash, center console, glove box, door panels, sun visors,
rear view mirror, insulation, etc.
Remove A/C Compressor
Remove A/C controls and ducting
Remove AIR pump system
Remove factory radio, speakers, and/or CD changer, and
Remove HUD projector
Remove windshield wiper fluid reservoir and pump
Remove windshield wipers and motors
Remove stock cat back
Remove power steering pump
Remove front sway bar (drag only)
Remove ABS, TC, AH hardware and sensors (drag only)
Remove fender wells
Remove headlight assembly, turn signals, taillights and
Remove/shave side mirrors
Remove torque tunnel cover
Remove seat belts
Remove parking brake
Remove side windows and motors
Remove power locks and power windows
Remove side impact beams
Replace stock front and rear glass with polycarbonate “glass”
Rebuild motor with Al or Ti connecting rods, Ti valve spring
retainers and pushrods
Port the heads
Remove all flashing from the engine, then polish
Replace valve covers with magnesium or carbon fiber parts
Strip entire car, acid wash chassis, put car back together.
Reducing unsprung weight
—not all is streetable
Replace stock wheels with forged 1-piece wheels
Use 3-piece wheels by Jongbloed, Kodiak, CCW, BBS
Skinny front wheels (drag only)
Use Ti fasteners on 3-piece wheels (~1 lbs per wheel)
Use lighter non-runflat tires, or even Hoosier nylon corded
Use lighter calipers
Replace stock rotors with 2-piece, unvented or titanium rotors
Replace wheels studs with titanium studs
Replace lug nuts with aluminum or titanium lug nuts
Remove tire pressure sensors
Use rubber valve stem without a cap
Balance the wheels without tires or balancing weights, and then
Great literature for hardcore techies
Helm’s Service Manual
--- this should come with every
Key Design Developments of the 1997 Chevrolet Corvette (SAE
GM eSI Techline Service Manual
Nuts, Bolts and Fasteners and Plumbing Handbook, Carroll
Drive to Win, Carroll Smith: The Essential Guide to Race
Engineer to Win: The Essential Guide to Racing Car Materials
Technology or How to Build Winners Which Don’t Break,
Tune to Win, Carroll Smith
Fiberglass & Composite Materials: An Enthusiast’s Guide to
High Performance Non-Metallic Materials for Automotive Racing
and Marine Use
How to Make Your Car Handle, Fred Puhn
Race Car Vehicle Dynamics (SAE R146)
Racing & High Performance Tire: Using Tires to Tune for Grip
and Balance (SAE R351)