How to Get More Horsepower on Chevrolet Carsby Contributing Writer
The Chevrolet car is a very simple and inexpensive motor to build and to add horsepower to. As a consequence, this motor is found in applications from hot rods and sports cars to boats and trucks. No matter what application your Chevrolet car motor is in, a few simple steps can get you more better performance and higher horsepower.
Under The Hood:
- How to Get More Horsepower on a Chevrolet S-10
- How to Get Big Horsepower Out of a Chevy Big Block
- How to Get the Most Horsepower Out of a 454 Chevy Engine
- How to Get More Horsepower for the 1994 GMC 5.7 Liter TBI
- How to Get More Horsepower Out of My Chevy 350 Small Block
- How to Get More Horsepower for the 2007 Chevy Silverado
Getting more horsepower from a Chevrolet S-10
Install high-performance spark plugs by uncapping their wires and turning them in a counterclockwise direction, then replacing the plug with a new one and turning it clockwise into the empty plug hole. The need to gap the tip of the plug is only relevant if the plug is an older-style, single-node type. Multifire plugs, with multiple nodes on the tips, cannot be easily gapped. Heat ranges vary, but the S-10 with a 4.3 V6 calls for a heat range of 4, and going to a class 5 plug will boost horsepower.
Increase the width of the ignition wires by replacing them with 8 mm types (the wires pull off with minimal tugging). The wider wire will cause less resistance for the energy being sent to the plugs, and replacing the worn-out plug wires with a new version will increase performance. Stock width for the later S-10 models was 7 mm, and earlier versions could have 6 mm wires. Wires also can be purchased in a variety of colors.
Add an air snorkel with an open element filter by removing the air box and intake hose and mounting the snorkel into the same area. The air box has two screws holding it in, and the hose will come with it, but be sure to disconnect the MAF sensor on the air hose, if so equipped. The open element will allow more air into the intake and allow the engine to "breathe" easier. More, colder air will deliver more horsepower because the oxygen molecules are closer together than with warm air. The engine can gulp as much as it requires without straining or "bogging down" like it would with an air box.
Clean the intake and intake manifold with a can of spray carburetor cleaner. Most types of cleaner are made for both fuel-injected and carburetor-style fuel delivery systems, so the only real difference is packaging. Spray a liberal amount of cleaner onto and into the intake manifold with the air hose removed and the engine off. Let it sit for a few minutes, then spray it down again. Once the cleaner has dried, crank the motor and give short bursts of cleaner to the intake while tugging on the throttle cable to keep the RPM's up. The cleaner will stall the motor, so giving a little gas will keep it alive for the cleaning. Shut the motor off and allow the intake to dry.
Items you will need
High-performance spark plugs
8mm ignition wires
Snorkel air intake
Upgrade your camshaft, rods and pistons to aftermarket items specifically for generating higher power levels and better performance than the stock models. Specially designed and plated pistons and rods can increase performance and power. This will require taking the motor completely apart and a mechanic or automotive professional should do it.
Install a performance chip. Performance chips work with the powertrain control module on your engine to optimize the fuel-mixture and flow for additional power.
Replace the intake manifold with that advertises increased horsepower and performance. Improved airflow through an aftermarket intake manifold will allow the engine to generate more power.
Upgrade your exhaust with aftermarket components.Typically these will be larger than the stock equipment and allow exhaust gases to exit your vehicle more quickly. Expediated exhaust flow allows your engine to burn fuel more efficiently and more quickly, creating more horsepower.
Install a turbocharger, supercharger or nitrous on your engine. These all provide extra speed, torque and horsepower. Turbochargers work by using exhaust gases to generate extra power. Superchargers use a pulley system that uses power from the engine and nitrous is a gas that burns to provide boosts of power.
Determine the power output desired. The factory high performance GM engine components are capable of supporting well over 500 horsepower, and the early LS6 Chevelle engine was rated at 450 horsepower. Factory crankshafts, connecting rods and pistons can support more than that when properly machined and prepared.
Machine the engine block and internal rotating assembly for correct clearances for high output usage. Careful detail needs to be given to block alignments and specifications as well as the clearances of bearing surfaces for the rods and crank, camshaft and the piston-to-cylinder wall clearance. Clearances that are too tight must be avoided.
Consult---as an alternative---with a reputable engine builder/machinist who is familiar with the 454 BBC. A machinist can provide ready-to-assemble short blocks built to predetermined specifications and with a piston designed to achieve the desired compression ratio. Note that higher compression ratios produce more torque and horsepower but require high octane fuels.
Select a cylinder head with airflow characteristics that support high horsepower output. Not all factory production heads are suited to high horsepower production; however, there are several choices available from aftermarket vendors. Generally speaking, a head with 290 to 320 cc intake port volumes will allow high RPM airflow and maximum horsepower outputs in a 454-cubic inch engine. "Smaller," street-oriented heads will produce lower RPM torque at the expense of high RPM power.
Choose a camshaft that is designed for the intended RPM range the engine will be most typically used in. For a street-driven engine that sees only occasional full-throttle runs to 6,500 RPM, select a camshaft that is designed for an RPM range that is lower and broader. Race applications, such as drag racing, however, have operating ranges of perhaps 5,000 to 7,500 RPMs only. While they may generate more horsepower, the application is very concentrated. This cam design will not work well on a street/strip engine.
Select the intake and carburetor system. A dual-plane manifold that generates more low-end torque works well on the street (or in a tow truck) but will not flow enough air at high RPM to permit larger heads and cams to work well. A single-plane (open "plenum") manifold design and carburetor that flows 850 CFM or greater will produce more horsepower.
Items you will need
Heavy-duty rotating assembly
Aftermarket cylinder heads and induction system
Aftermarket camshaft and valve train
Fill up your vehicle with high octane fuel rated above 90 octane. Higher octane fuel burns more completely during combustion, resulting in higher power output. Higher octane fuel also typically increases the fuel economy of a vehicle because of its better combustion properties.
Add fuel injector or carburetor cleaner to your vehicle's gas tank every 3,000 miles. This should be done on a nearly empty tank that should then be immediately filled to full to mix the cleaner into the gasoline. This ensures that the car receives adequate fuel at high engine speeds, increasing the amount of power each cylinder produces.
Install a cold air intake on your vehicle's air intake manifold. This keeps air from becoming restricted on the way to the engine and keeps it cooler. Colder air is more conducive to burning than warmer air and gives a slight increase in horsepower.
Replace the stock exhaust system with an aftermarket, 3-inch cat back exhaust kit from the exhaust manifold to the tailpipes. This allows exhaust to move out of the manifold quickly. The higher the air movement ratio in an engine, the more horsepower output there is.
Install a performance camshaft to increase airflow and exhaust movement during combustion. Camshafts determine how far the valves open and let air in and out of the cylinders. Performance-rated camshafts will typically increase horsepower output by between 10 to 30 horsepower, depending on the camshaft purchased.
Port the cylinder heads. This allows exhaust to escape the cylinders faster by removing metal from the engine where the exhaust manifold meets the cylinder heads. Exhaust gases can then move in a direct path to the exhaust manifold rather than having to bend around a corner to escape the cylinder.
Tune the vehicle’s computer. A tune is an adjustment of a car's computer, making it optimally programmed for horsepower. This should only be done by an expert using advanced automotive computer programming software. You can remove the computer in your vehicle and send it to a tuning company by mail and get it back a few weeks later with a performance tune.
Items you will need
Fuel injector/carburetor cleaner
Cold air intake
Aftermarket exhaust kit
Modify your air intake. This can be done in a variety of ways, from simply installing a K & N air filter to installing a complete cold-air-intake system. A cold-air-intake system, also offered by K&N, will gain the most horsepower, but is the most expensive. The more cool air your motor can take in, the more horsepower it can generate, so choose the intake modifications you make based on what horsepower gains you desire.
Modify your exhaust. Once you have increased air intake, you must give the engine a place for that air to go. Exhaust options include a dual exhaust, headers and increases in pipe diameter up to 3 inches. Headers are scientifically designed exhaust manifolds that produce the proper back pressure for your motor, while allowing it to "exhale" more efficiently. More expensive headers do a better job of increasing horsepower, and are of higher quality. A dual exhaust is considered the most efficient for horsepower gain, but for aesthetic reasons, sometimes a single exhaust system can be designed to provide adequate horsepower gain without detracting from the appearance of a hot rod.
Change your camshafts and valve train. From cams with more lift and duration, to roller rocker arms and hydraulic lifters, increasing horsepower through valve train modifications is relatively inexpensive. However, some camshafts decrease the drivability of your Chevy 350 as a street vehicle. Typically, anything above what is known as an RV cam is too radical for street use, and considered a racing cam. Roller rockers and hydraulic lifters increase horsepower by decreasing resistance in the valve train. These modifications require a minimum amount of engine disassembly, and can enhance performance significantly.
Purchase new cylinder heads, or have yours ported and polished. There are several different companies offering different cylinder head configurations to enhance performance and horsepower. These improve fuel and airflow through bigger valves and specifically designed intake and exhaust ports. Often, these heads are aluminum instead of cast iron, and so reduce engine weight as well. A machine shop can rebuild your heads, and polish the ports as well. This may not produce as much horsepower gain as new heads, but it is generally less expensive.
Have your motor rebuilt and blueprinted. Blueprinting a motor involves math calculations to make sure that the crank, camshafts, pistons and cylinders all meet exact specifications. A rebuilt motor or one from a factory that you purchased is allowed a certain amount of error in these areas. If it is not exact, it still is shipped, and considered to meet factory specifications. A blueprinted motor has a smaller margin for error. Exact specifications are demanded, and thus the motor runs better and produces more horsepower. At this point, the motor could be bored out for more volume, and the crankshaft can be changed. These steps will result in significant horsepower gain.
Replace the stock air intake system with one designed to provide better horsepower. It does this by filtering dirt out of the air that flows through your engine, allowing the air to flow better. An engine that has more air moving through it runs at a cooler temperature and is therefore more efficient. Improving air filtration can give you up to 10-percent more horsepower.
Change the standard exhaust that the truck came with. An exhaust with a high-flow muffler will give you more horsepower by letting the air out of the engine quicker. Increasing the diameter of the exhaust pipe will also improve airflow.
Change the spark plugs to make the engine perform better. Badly sparking plugs can severely reduce the horsepower that you get from your engine. Check the owner's manual to confirm the recommended sparking distance, and check the plugs regularly to ensure that they are in good condition.