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Discussion Starter · #2 ·

Block and Basics
Displacement: 350 cubic inches, 5733 cubic centimeters, 5.7 liters
Block Material: Cast Iron
Main Bearings: 2-Bolt Centers and Ends (The Corvette LT1/LT4 had 4-bolt mains)
Stroke: 3.48"
Bore: 4.00"
Compression Ratio: 10.4:1
Combustion Chambers: 54 cubic centimeters
Factory Redline Rating: 5700 Rotations Per Minute

Bottom End
Piston Material: (10159437) Eutectic Aluminum/Silicon Alloy
Connecting Rod Material: (10108688) Powdered Metal
Crankshaft Material: (12556307) Cast Iron

Top End and Valvetrain
Cylinder Heads: (10168448) Cast Aluminum, 2 valves per cylinder/16 valves total, ~212 CFM flow (Impala SS and Caprice heads were made of cast iron*)
Valve Diameter: (intake- 10241743, exhaust- 12550909) 1.94 intake, 1.50 exhaust
Valve Overlap: 41*
Valvesprings: (10206040) 85 lbs, seated
Camshaft Specs (12551705): 205/207 duration @ 50*, .447/.459" lift, 117 Lobe Seperation Angle
Rocker Arms: (10089648) 1.5:1 Stamped Steel
Timing Chain: (10128485) Powdered metal butt link

Intake and Fuel Delivery
Fuel Delivery: Electronic Fuel Injection, sequential port
Injector Size: (17124248) 3.0gps, 22lbs/hr speed density (1992-1993), 24lbs/hr mass airflow (1994-1997)
Throttle Body: 48 millimeter twin butterfly
Intake Manifold: (12552137) Aluminum

Factory Power Ratings
92-96 LT1 Corvette: 300bhp, 330lb-ft
1996 LT4 Corvette: 330bhp, 340lb-ft
1992 LT5 Corvette: 375bhp, 370lb-ft
93-95 LT5 Corvette: 405bhp, 385lb-ft
93-95 LT1 F-Body: 275bhp, 325lb-ft
96-97 LT1 F-Body: 285bhp, 325lb-ft
96-97 WS6/SS: 305bhp, 335lb-ft
93-97 Firehawks: 315bhp, 340lb-ft

Factory LTX Camshaft Specifications**:
1992 Y-body: 205/207 0.451/0.450 lift 117 LSA
1993-1995 Y-body, F-body: 202/207 0.450/0.460 lift 116 LSA
1994-1996 B-bodies (including L99 4.3L): 191/196 0.418/0.430 lift 111 LSA
1996 Y-body, 1996-1997 F-body: 200/207 0.447/0.459 lift 117 LSA
1996 Y-body, F-body LT4: 203/210 0.476/0.479 lift 115 LSA

* Cast iron heads are known to flow better, but are also more prone to heat-soak than aluminum heads.
** Thanks to [email protected] for these specs

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Discussion Starter · #3 ·

Intake Components
Moroso, K&N, SLP, IRS, Hypertech(Air Foil), etc.
Cold Air Intake(CAI) - $150 to $300 - Replaces the stock Air Box and Filter with larger filter(K&N Usually) and better flowing intake tract that connects to the MAF Sensor.
Mass Air Flow Sensor Ends(MAF Ends) - $50 to ? - Replaces stock MAF ends and Maf screen with a ported set of MAF Ends that still utilize the original MAF Sensor.
1LE Elbow - Approx $70 - Replaces the stock unit with a smoother unit that does away with the silencer(the donkey dong on the bottom of the stock elbow).
Air Foil/Air Charger - $30 to $60 - Bolts to the front of the Stock Throttle Body to smoothen out the airflow going into the intake.
Throttle Body (aka a "TB") - Starting around $320 for a 52MM or 58MM BBK which is the most often purchased TB, or you can port them yourself free of charge if you have a dremel at your disposal.

Exhaust Components
Hooker, Mac, BBK, SLP, Borla, Flowmaster, FLP, Edlebrock, Magnaflow, Custom (Kooks)
Catback Exhaust - $250 to Custom - A performance exhaust system that starts after the catalytic converter and generally includes all pipes, the mufller, and tips.
Headers - $300 to Custom - Shorties include Hooker, Mac, Edlebrock, BBK, etc. and Longtubes include Hooker, FLP, etc. and custom setups from Kooks and other manufacturers.
Y-Pipes - $250 to Custom - Y-Pipes are generally included in Shorty Header systems but not always and are rarely included in Longtube Header systems. Y-Pipes are shaped like a "Y" and connect both header collectors to the I-Pipe which connects to the Muffler System.
Cutout/Electric Cut-Out - $30/$200 - Exhaust dump best placed infront of the cats or as far down the I-Pipe as possible if you wish to stay emmisions legal.[/SIZE]


Sub-Frame Connectors (aka "SFCs") - $All Ranges - Tube'd or Box'd versions that connect the front section of the car's frame to the rear section of the car's frame providing a more stable, tighter, and properly handling ride.
Sway Bar Kits - $350 to ? - Keeps the car from "rolling" in the turns.
Lower Control Arms (aka "LCAs") - $95 to Custom - Connects the axle to the rear subframe. Aftermarket LCA's replace the stock stamped steel. LCA's with more solid/rigid units that are generaly bought to greatly enhance straight line performance. Generally used to eliminate wheel-hop as well.
Panhard Rod (aka a "PHR") - $100 to Custom - Used to align the rear end once the car has been lowered or heavily modified suspension wise. Greatly increases the cornering stability and helps keep the back end of the car centered under hard cornering situations.
Torque Arm - $150 to $600 and up - One end connects to the rear end of the transmission and the other connects to the Rear End housing. Helps keep the car "planted" without robbing the car of Tq and HP.

Rear Gears
GM, Motive, Richmond, Moser, Strange, etc.

3.23:1, 3.42:1, 3.73:1, 4.10:1 - $179 to $300 - You can greatly increase a vehicles acceleration while only slightly reducing top speed by changing the gear ratio from a taller gear (3.23:1) to a shorter gear (3.73:1).

160 Degree Thermostat - $20 - A thermostat which opens at a lower temperature allowing the car to run cooler, usually used in conjunction with a Hypertech Power Programmer or a Fan Switch that allows you to turn the fans on earler as well.
Underdrive Pullies(Crank and Alternator) - $60 to $100 - These pullies are resized and replace the stock pullies allowing the motor to free up some lost HP that was formerly used to turn the accessories. The pullies free up HP by turning the accessories slower requiring less effort from the motor.
MSD Ignition Box(MSD6A or MSD6AL) - $150 to $250 - Provides a stronger and more accurately timed spark to more efficiently burn mixed gases in the combustion chamber.
Maunal Fan Switch - Free to $75- Used to manualy turn the radiator fans on and off when needed. TO do so for free, all you need is an automotive relay, switch, and some wire....10bucks at radioshack
Short Throw Shifters For M6 Cars (B&M, Hurst) - $160+ - Installed to provide a shorter and more accurate shift.
Hypertech Power Programmer - ~$330+ - Used to lower fan activation temperatures, rev limiters, fuel curve, gear ratio's, change in tire size, etc.
Tunercat/LT1edit - An alternative to hypertech that will allow you to manualy adjust a larger variety of settings within the PCM.
Weight Loss - FREE!!! - Any thing that you can do without on the car and are willing to yank out. Weight is the ultimate name of the game and you will see the most gains from weight loss..weight is 90% of racing.

The most often asked question is "what are the first mods I should do to increase my car's performance?". Basically, all a car wants/needs to make more power is air. Increase the amount of air going into and out of the motor and you will increase the power output. Best way to do this is to increase the volume of air going into the motor while also maintaining a high air velocity. The first few mods installed on the car should be purchased to accomplish this. First and foremost, the most productive component you can install to get the most power from your stock car is the CAI. From there, most people move on to installing the Catback exhaust. Dont buy a complete longtube exhaust system with custom piping, no cats, and cutout expecting to see maximum gains when you havent touched the intake system yet. You always want to try and balance out the intake and exhaust system so that you have an equally balanced motor, otherwise you are leaving power out on the table. First few power mods should be a complete intake system and complete exhaust system(CAI, MAF Ends, Airfoil or TB, Header, Y-pipe, Catback or Cutout). Once you have accomplished this, then you have a good solid base from which to build a stout, internally modified motor. Basically, being able to get the air into and outta the motor as fast as possible will create the most power. If you plan on roadracing, the best thing you can do to increase the performance of your car is to add a nice suspension setup for it. Just like in the quartermile, large amounts of power in a car without suspension is useless, but even moreso on a roadcourse. Putting the power to the ground is just as important as making power. Generally speaking, to increase straight line performance, LCA's are most effective while PHR's, Sway Bars, and SFC's are most effective in eliminating body roll and flexing. Spring and Shock kits are most effective in eliminating bounce, weight transfer, body roll, dive in braking, etc.

Special thanks to [email protected] for this writeup

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Discussion Starter · #4 ·

Compression ratio is a term that all of us are familiar with, but very few of us really understand. Whether we are milling down stock heads, swapping for some aftermarket ones, changing the stroke, the pistons or just simply using a thinner head gasket, changes to you engine combo have a profound affect your compression ratio and, consequently, on overall performance and drivability. With that in mind, I developed and easy to use formula to calculate compression ratio.

Compression ratio is defined as "the volume of the cylinder at BDC (bottom dead center) divided by the volume of the cylinder at TDC (top dead center).

CR = (Vbdc/Vtdc)

Without getting into too much detail, we can expand this to the following equation:

CR = [{(B/2)^2 * S*Pi}+Vcc+Vp+{(B/2)^2*Pi*(DH+TG)}]


CR= Compression Ratio
B = Cylinder bore (Stock LT1 = 4.00in)
S = Stroke (Stock LT1 = 3.48in)
Vcc= Combustion Chamber Volume (Stock LT1 = 58cc = 3.539 in3)
Vp= Piston Volume (Stock LT1 = 4.5cc = 0.274606 in3)
DH = Deck Height (Stock LT1 = 0.015 in)
TG = Head Gasket Crush Thickness (Stock LT1 = 0.05 in)
Pi = 3.1415

As long as all other variables remain constant, you can change a single variable (for example larger/smaller combustion chamber size) to determine your new Compression Ratio.

*Convert Cubic Cenimeters (ccs) to Cubic Inches (in^3) using the following formula

in^3 = (CCs/16.387064)

Big thanks to [email protected] for submitting this formula

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993 Posts
Discussion Starter · #5 ·

! - using this before an acronym means removal of that item from the vehicle (example: !EGR)
1/4 - Quarter Mile (drag racing)
1LE - Suspension Handling Package Option
2WD - Two Wheel Drive
4L60E - actual part name for the Automatic 4-speed transmission
4WD - Four Wheel Drive
700R4 - older generation 4-speed GM automatic transmission
A3 - 3-speed automatic transmission
A4 - 4-speed automatic transmission
A/F - Air Fuel Ratio
AIR - Air Injection Recirculation (part of emissions system.)
APHR - Adjustable Panhard Rod (Suspension)
AFR - Air Flow Research (Vendor)
ASP - Automotive Specialties Performance (Vendor)
ASR - Camaro version of traction control
ATF - Automatic Transmission Fluid
ATI - Supercharger Company (Vendor)
AWD - All Wheel Drive
B4C - Police Package Option
BBC - Big Block Chevy engine
BBDC - Before Bottom Dead Center
BDC - Bottom Dead Center
BHP - Brake Horsepower
BOV - Blow Off Valve (turbo related)
B/O - Bolt-On Modifications
BSM - Body Side Moulding - door ding guards on your doors.
BTDC - Before Top Dead Center
BTW - By The Way
C4 - Fourth Generation Corvette (1992-1996)
CAGS - Computer Assisted Gear Selection (the "skip-shift" on M6 cars.)
CATS - Catalytic Converters (emissions/exhaust system)
CAI - Cold Air Induction
CI - Cubic Inches (engine displacement)
CKP - Crankshaft Position (sensor)
CMP - Camshaft Position (sensor)
CONV/'vert - Convertible
CR - Compression Ratio
DEG - Degrees (timing or temperature)
DRL - Daytime Running Lights
DR's - Drag Radial Tires
DSL - Driveshaft Safety Loop
DTC - Diagnostic Trouble Code
ECM - Engine Control Module
ECL - Exhaust Lobe Center Line (camshaft)
ECT - Engine Coolant Temperature (sensor)
EGR - Exhaust Gas Recirculation (emissions system)
EGT - Exhaust Gas Temperature
E/T - Elapsed Time (drag racing time measurement)
FAST - Fuel Air Spark Technology (Vendor)
FBODY - GM chassis designation for Camaro/Firebird
FI - Forced Induction (turbos, superchargers)
FIPK - Fuel Injection Performance Kit (See K&N)
FMIC - Front Mounted Intercooler (turbo)
FMS - Futral Motorsports (Vendor)
FMU - Fuel Management Unit
FPR - Fuel Pressure Regulator
FPSS - Fuel Pressure Safety Switch
FRA - "Free Ram Air" modification
FRC - Fuel Rail Covers
FLP - Finish Line Performance (Vendor)
FTRA - Fast Toys Ram Air (product)
FWD - Front Wheel Drive
FWIW - For What Its Worth
GMMG - Vendor known for producing modified GM backed F-bodies
H/C - Heads and Camshaft
HO2S - Heated Oxygen Sensor
HP - Horsepower
HPE - Horsepower Engineering (Vendor)
HPP3 - Hypertech Power Programmer 3 (product)
IAC - Idle Air Control (solenoid)
IAT - Intake Air Temperature (sensor)
IC - Ignition Control Circuit
ICL - Intake Lobe Center Line (camshaft)
IGN - Ignition
IMHO - In My Humble Opinion
IRS - Independent Rear Suspension
K&N - Brand name of air filter
KR - Knock Retard (tuning)
LCA - Lower Control Arm (suspension)
LGM - Lou Gigliotti Motorsports (Vendor)
LM - Loud Mouth (exhaust system by SLP)
LMAO - Laughing My Ass Off
LOL - Laughing Out Loud
LPE - Lingenfelter Performance Engineering (Vendor)
LT1 - Generation 2 GM smallblock V8 engine (introduced 1992)
LT4 - Generation 2 GM smallblock V8 engine (introduced 1996)
LT5 - GM/Lotus/Mercury Marine joint collaboration project, DOHC 5.7L V8 engine found in the Corvette ZR-1 (introduced 1990)
LSA - Lobe Seperation Angle (camshaft)
LSS - Lou's Short Stick (shifter handle)
LT - Long Tube Headers
LTFT - Long Term Fuel Trim (tuning)
LTRIM - Long Term Fuel Trim (tuning)
M6 - 6-speed transmission
MAF - Mass Air Flow sensor (measures amount of air entering intake)
MAP - Manifold Absolute Pressure (sensor)
MAFT - Mass Air Flow Translator (product)
MN6 - Option code for factory 6-speed transimission.
MTI - Motorsport Technologies, Inc. (Vendor)
N/A - Naturally Aspirated (all-motor)
N20 - Nitrous Oxide
NBM - Navy Blue Metallic (color)
NOS - Nitrous Oxide Systems (brand name)
NWS - Not Work Safe (do not click link if you are at work, unsuitable material inside)
O2 - Oxygen Sensor
ORY - Off Road Y-pipe
ORP - Off Road Pipe
PCM - Powertrain Control Module (your vehicles engine/tranny computer)
PCV - Positive Crankcase Ventilation (emissions system)
PE - Power Enrichment (tuning)
PHR - Panhard Rod (suspension)
PITA - Pain In The Ass
POS - Piece Of ****
P/P - Ported And Polished
QTEC - Quick Time Electric Cutout (product)
QTP - Quick Time Performance (Vendor)
ROFLMAO - Rolling On Floor Laughing My Ass Off
RPM - Revolutions Per Minute (engine speed)
RWD - Rear Wheel Drive
RWHP - Rear Wheel Horsepower
RWTQ - Rear Wheel Torque
SAE - Society of Automotive Engineers
SBC - Small Block Chevy engine
SC - Super Charger
SES - Service Engine Soon lamp (on dash)
SFC - Subframe Connectors
SLP - Street Legal Performance (Vendor)
SOM - Sunset Orange Metallic (color)
SOTP - Seat Of The Pants
SS - Super Sport
SSRA - Super Sucker Ram Air
STB - Strut Tower Brace
STFT - Short Term Fuel Trim (tuning)
STRIM - Short Term Fuel Trim (tuning)
T56 - actual part name for the M6 transmission
TA - Trans Am
TB - Throttle Body
TBODY - Throttle Body
TBRAKE - Transmission Brake
TEA - Total Engine Airflow (Vendor)
TC - Torque Converter
TCS - Firebird version of traction control
TDC - Top Dead Center
TFP - Transmission Fluid Pressure (switch/valve)
TH350 - Turbo Hydromatic 3-speed automatic transmission
TH400 - Heavy Duty Turbo Hydromatic 3-speed automatic transmission
TNT - Texas Nitrous Technologies (Vendor)
TP - Throttle Position
TPiS - Tuned Port Induction Specialties (Vendor)
TPS - Throttle Postion Sensor
TQ - Torque
TR - Thunder Racing (Vendor)
TSP - Texas Speed & Performance (Vendor)
TT - Twin Turbo
TT2 - Torque Thrust 2 (type of wheels by American Racing)
TTOP - T-Top roof
TTT - "To The Top"
UCA - Upper Control Arm (front suspension)
VATS - Vehicle Anti-Theft System (the coded chip in your ignition key)
VERT - Convertible
VSS - Vehicle Speed Sensor
WB O2 - Wide Band Oxygen Sensor
WOT - Wide Open Throttle
WS6 - Firebird Performance "Ram Air" Package (RPO code)
WTB - Want To Buy
WTF - What The ****?
WTT - Want To Trade
WU8 - Camaro Performance SS Package (RPO code)
Y2Y - Exhaust Upgrade Option Code for SS Camaro (Dual-Dual system)
YBODY - GM chassis designation for Corvette
Z28 - Camaro equipped with V8 engine (RPO code)
ZR1 - Corvette with LT5 motor, GM and Lotus joint project in the early 90s

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How Too- Free mods (LT1)

(admin note: Free Mod FAQ originally written by Mean Green and posted to

Free Mods

De-screening the MAF sensor.


Start by removing the MAF from the car and finding a clean area to work. There?s many ways to remove the screen, but probably the safest way is to use a Torx head socket and unbolt the 2 metal halves from the actual sensor. This will prevent you from accidentally damaging the wires. Set the sensor aside where it won?t get damaged.
Some people have had some negative effects from removing the MAF screen, so I would suggest trying not to damage it while removing it. There is a small snap ring that can be removed with a pick or small screwdriver, and the screen will come out, in one piece. I?d do this just incase you need to reinstall it.

If you don?t care about the screen. Grab a screwdriver and go wild.

Throttle body bypass.

Start by removing the intake elbow so you can easily see the underside of the throttle body. Locate the hose that leads from the radiator to the drivers side of the TB. Have plenty of rags ready and loosen the clamp. Some coolant will drain out, it?s not much, but try to keep it from spilling on the Opti. Next, find the hose that leads from the TB to the steam pipe. (it?s the other hose on the bottom of the TB). Remove the hose from the TB and from the steam pipe. Now take the first hose and connect it directly to the steam pipe. Clamp it down and you?re finished. Some people use caps to cover the ports on the TB, but it?s not necessary.

Intake silencer delete

This one requires a bit of creativity, but it?s pretty straight forward. Start by removing the intake elbow. You?re probably going to need to cut the clamp off the silencer, then remove it. Now you just need to find something to plug the whole with. I?ve heard some shampoo bottle caps and deodorant caps work or you can trace the shape on to some wood or aluminum and cut it out. Then simply insert the cap into the hole and use a new hose clamp to clamp it down. When inserting the cap, try to position it so it is flush with the surface on the inside of the elbow.

50 Cent Skip shift eliminator.
Another one that?s not pretty but it will work. Go to Radio Shack and buy a 2200 Ohm ? Watt resistor. Disconnect the wire harness on the CAGS solenoid and insert one end of the resistor into each of the 2 ports on the harness (wire side, not the solenoid side) tape up the harness and resistor so water can?t get to it. Then tape up the solenoid connector for the same reason. Ziptie the wire harness somewhere out of the way so it doesn?t fall out and drag on the ground.
This will disable the Skip shift solenoid, however the light on the dash will still light up when it?s trying to activate.

Gutting the catalytic converter?

This isn?t technically free, but it?s usually cheap. WARNING?.you will fail visual inspection during emissions testing and most people fail the smog test without a cat. The easiest thing to do is find a muffler shop and ask if they will cut out the CAT and weld in a straight pipe. It is illegal for them to do this, but most places don?t really care. Try to avoid the chain muffler shops, use an independently owned shop. They?re more likely to say yes. It cost me $20 to have my first one done. On my second car, I bought the owner lunch ($4.00 at Taco Bell) and he did it for me.
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