How to Get More Power in Vehicles

by Contributing Writer; Updated June 12, 2017

The Vehicles engine is one of the classic big block engines produced by American car manufacturers during the period of time known as the muscle car era. Car performance enthusiasts use engines such as these to power hot rods and street racing cars; because of this, many Vehicles owners are seeking a way to pump more horsepower out of these already powerful engines. Though these engines are already made with performance in mind, there are many upgrades you can use to get more power out of them.

Under The Hood:

 How to Get More Power in My Toyota Motorhome


Remove as much weight as possible from the rear of the motorhome to reduce the amount that the small engine has to haul. This will have the largest impact on speed and economy. All of the water tanks should be emptied before travel, both fresh water and black water tanks. On a normal motorhome, this is usually not a concern, but here it can mean the difference of a few hundred pounds. Interior appliances that are not used can be removed, such as the refrigerator, stove and cabinetry. Chairs and tables that are not needed can go, too. With the rear as light as possible, the Toyota can gain maximum speed and save gasoline with higher mileage. Some mid-80s models are known for being the heaviest of the bunch, with the four cylinder engines standard. These were also the most lavish of the series. Many extraneous items can be removed and actually increase comfort.

Replace the spark plugs with units with a higher hear range rating. Remove the old plug with a long socket by turning it counterclockwise, then replace it with the new plug in a clockwise direction. Most manufacturers will pre-gap the plugs, but experts will at least double check it with a gap tool. The higher heat value of the plug gives more power to the cylinder ignition, and will be around a five rating. Stock Toyota plugs for most engines rate about three.

Replace the ignition wires with 8mm models by pulling each plug wire and replacing it individually. The wider core plus better insulation means that there is less resistance for the energy to go from the coil to the plug. This results in more power. They can even be purchased in a variety of colors. Do not pull all wires and replace them en masse; this can cause misfiring if they are not replaced in exactly the same position.

Replace the stock Toyota air box with an open element air cleaner. Take the old air box off by turning the mount bolts counterclockwise, then removing the hose clamp and hoses connecting the box to the intake. The open element air filter kits install easier on older models, but they are relatively easy to install regardless. Position the new air cleaner and connect it to the hoses with clamps. Most open element cleaners will have one or two mount arms that can be secured with bolts turned clockwise. This lowers air restrictions and allows more power because the engine doesn't have to fight the air box opening for oxygen.

Items you will need

  • Socket set

  • Spark plugs (higher heat range)

  • 8mm ignition wires

  • Open element air filter

  • Gap tool

 How to Get More Power out of a John Deere Gator

Put nonmethanol power additives in the fuel. This will boost the performance of your Gator by increasing the combustion efficiency of your fuel. Add engine cleaners to your fuel, which remove debris and sludge that slow your engine with friction.

Use high octane fuel -- 87 octane or higher is recommended. If your Gator runs on diesel, use white, rather than red. As with many other vehicles, the higher the octane content, the less buildup the Gator gets throughout the engine. The John Deere factory conducts equipment tests with aviation fuel. A clean engine means a more powerful engine.

Change the spark plugs. Replace them with high performance spark plugs if your Gator has a gas-powered engine. The firing capacity of a spark plug can greatly enhance or detract from the torque your Gator can exert.

Replace fuel filters and fuel lines on your Gator regularly. A clogged fuel line or filter can greatly inhibit your Gator's ability to get the right mixture of fuel and air into the carburetor, as can a crack in the fuel line that sucks in air.

Recalibrate the governor set-screw on the linkage attached to the carburetor -- if your Gator does not have electronic fuel injection. With the set-screw you can determine the Gator's top-end speed. Back the set-screw out a little and you will notice the additional power.

Items you will need

  • Spark plug socket set

  • Fuel filter

  • Premium fuel

 How to Get Power Out of a 305 Chevy

Bolt-on Upgrades

Replace the exhaust manifold. The stock exhaust manifold of the 305 engine restricts air flow from the engine increasing back pressure. Back pressure is the the result of something obstructing the flow of air causing air to build up behind the obstruction and increasing pressure. This back pressure results in exhaust gases contaminating the fresh fuel air mixture in the combustion chamber reducing horsepower. Headers or other aftermarket exhaust manifolds designed for the Chevy 305 increase the flow of exhaust gases which decreases back pressure and increases the power of the engine.

Replace the intake manifold and carburetor. Aftermarket intake manifolds designed for the Chevy 305 increase and smooth out the flow of air and fuel to the engine. A larger carburetor for the Chevy 305 also increases the flow air into the engine. The reduction in air resistance and turbulence ensures the efficient delivery of the fuel/air charge to the cylinders and better horse power.

Add cold air induction. Standard induction systems with paper air filters again restrict the flow of air to the engine. Cold air induction systems reduce resistance and temperature of the air provided to the engine increasing horse power. An effective system will produce a cold air intake for the Chevy 305 that improves the flow of cool air to the engine. Its filters reduce the dust and other particles that create wear on the engine parts.

Replace the computer chip. Newer cars with computer controlled electronic ignition systems see a horsepower increase with special aftermarket computer chips. These chip are designed to alter the performance profile of the car in favor of additional horsepower. Some computer chips for different Chevy cars with the 305 cubic inch engine offer gains of up to 75 horsepower.

Rebuilding the Engine to Increase Horsepower.

Bore and hone the cylinders. Rebuilding an engine to increase horsepower is a major undertaking. It requires the removal of the engine from the vehicle and stripping it down to the core. Boring and honing each cylinder and replacing the pistons and rings increases the displacement of the engine and restores lost compression from worn rings and age. An automotive machine shop with a cylinder boring machine is required.

Replace the camshaft. Depending on the requirements of the owner, aftermarket camshafts can increase power and the lower end or the upper end of the engine's RPM range.

Port and polish the heads. In the same way as an aftermarket intake manifold , porting and polishing each valve seat increases the flow of air into and out of the engine by eliminating restrictions. It also provides a smoother and better fitting seat for each valve, preventing leaks when the valve is closed.

 How to Get More Power Out of a Sportster 1200

Replace the stock air intake system. The factory-equipped air intake system is restrictive, allowing a smaller amount of air into the carburetor. While this lowers emissions, power is also reduced. Removing the stock air filter and intake and replacing it with a free-flowing high-performance intake and air filter will allow an increased amount of air into the carburetor for stronger combustion and more power.

Replace the stock exhaust system. The exhaust system, like the air intake, is also designed to reduce emissions, both gaseous and audible, through the use of smaller-diameter exhaust pipes and baffles. Installing a free-flowing performance exhaust system, which includes an increasing diameter along the length of the exhaust pipes, and less-restrictive or removable baffles will improve the flow of exhaust gases, increasing power.

Rejet the carburetor. As supplied from the factory, the carburetor on your Sportster 1200 uses a series of nozzles, or jets, to meter a specific amount of fuel into the air pulled in from the intake system to create the air/fuel mixture required to power the motor. This mixture is set leaner, meaning there is more air than fuel in the mixture, to reduce emissions. Unfortunately, this lean condition also robs the motor of power. Replacing the carburetor's jets with larger jets will add more fuel into the air/fuel mixture, making it richer and increasing the power of the combustion. This step is mandatory after replacing the air intake and exhaust systems to compensate for the additional amount of air traveling through the motor.

Replace the stock drive (front) pulley. A Sportster 1200 is equipped with a 29-tooth drive pulley that pulls the drive belt to turn the rear wheel's driven pulley. This allows for decent acceleration while providing more comfort while riding at highway speeds above 55 mph. Replacing the drive pulley with a 27-tooth pulley from an 883 Sportster will dramatically increase acceleration, but it will make the engine work harder and reduce comfort while at highway speed.

 How to Get More Power Out of a Harley Road King

Intake and Exhaust Systems

Lowering the resistance in the intake and exhaust systems is one of the least-invasive procedures you can perform to gain immediate horsepower and torque increases. Low-restriction filters, intake components and exhausts are available through Harley, as well as performance aftermarket companies such as S&S and K&N. These modifications will allow an increase in the volume of the exhaust note, and while they are generally street-legal, the decibel level of your exhaust note may not be in all areas. Check for relevant laws in your area before making these modifications.

Internal Modifications

Increasing the displacement of the engine by boring out the existing cylinders or installing larger cylinders and pistons will give you a significant power boost. Kits are available through Screamin' Eagle, S&S and other performance part manufacturers. Performance cams are often part of the kits, but more radical cams are certainly available. Your 2014 Road King comes equipped with slightly hotter cams than previous years, so swapping the cams should not be high on the list of priorities as far as how much bang you can expect for your buck. Since valve-to-piston clearance becomes an issue with the more radical cams, unless you are experienced in engine building, consult with a professional for guidance through the cam selection process.

Electronic Control Module

Performance ECMs give a moderate boost to performance and are available with a range of capabilities, from simple ones with a fixed power curve and rev-limiter, to fully programmable modules. The best ones can be patched into a laptop or PC and, using the proprietary software, dialed in to the last tiny detail. Screamin' Eagle and the Dynojet Power Commander are two of the more popular ECM brands.

Other Considerations

The more traditional methods of increasing performance, such as porting, polishing and the use of performance headers will help to coax a modest amount of power from your engine. Performance electrical components are easy to install with non-invasive procedures. High-output coils, spark plugs and spark plug wires help to increase flame-front propagation and more complete combustion of the charges as they come through the combustion chamber, leading to a minor performance increase with a small increase in mileage.

 How Do I Get More Power out of a Chevy 454?

Improve the fuel and air intake system. The more fuel and air you are able to get into your Chevy big block engine, the more power it will be able to produce. By replacing your stock carburetors and air filters with high-performance parts, you will be able to greatly increase its power.

Replace the stock exhaust system with a high-flow system. By changing the stock headers and mufflers attached to your 454 with high-flow parts, you will be able to increase the speed that air flows out of your engine and the power it creates.

Replace the stock timing parts with ones tuned for racing. By changing the stock spark plug wires, distributor cap, and camshaft with racing-tuned parts you will give the engine more aggressive timing and enable it to produce much more power than it did before.

Bolt on a supercharger. A supercharger will use your engine's power to compress the air before it enters the combustion chamber. The compression allows much more air to enter the chamber, which leads to much bigger explosions at combustion, which will in turn translate to huge power gains.

 How to Get More Power From My Civic Hatch 1.5L

Power Modifications for a 1.5-Liter Civic

Replace the stock air box on your Civic with a cold air intake system. This is the best performance modification you can make for the money. Installation is as simple as pulling out the old air box and replacing it with the new cold air intake. The end result is a filter that is lower in the engine compartment, which allows it to suck up cooler, more dense air for combustion. This increases engine power and responsiveness.

Remove the stock crankshaft pulley and install an underdrive crank pulley, which will be smaller and lighter than the stock pulley. The underdrive crankshaft pulley serves two purposes. First, the smaller crankshaft pulley will slow the spin of the accessories' pulleys --- such as those of the air conditioning compressor and the alternator. This will reduce the power used by those accessories, increasing horsepower. Second, decreasing the crankshaft pulley's mass lowers the amount of energy required to get the pulley to spin, causing another gain in horsepower for your Civic.

Take out the stock exhaust system and replace it with an aftermarket system. An exhaust system consists of headers, a catalytic converter and an exhaust pipe. Swapping out these parts on your Civic's exhaust will allow the exhaust gas to flow more freely from the engine, providing an increase in power output. Additionally, most aftermarket exhausts weigh less than stock exhausts. While this does not increase power, it will enhance the effect of the existing power by reducing your Civic's weight.

Items you will need

  • Cold air intake

  • Underdrive crankshaft pulley

  • Exhaust system

 How to Get More Power Out of a 92 4.3 S10

Start with a production Chevrolet 4.3-liter block and install four-bolt 350 main caps on the center journals. All 4.3-liters left the factory with two-bolt mains, but the center V-8 four-bolt caps will interchange with those on the V-6. Retrofit procedures are identical; install the caps, drill and tap the block for the additional bolts, secure all the mains with chrome-moly studs and have the block line bored to align the journals. GM performance did offer a Bow Tie race block cast for use with four-bolt mains and set up for dry sump oiling, but they were tremendously expensive when new and practically impossible to find now.

Select a rotating assembly. You've got two routes to go with here; you can either go with an off-the-shelf, steel, split-pin crankshaft and steel I-beam rods with 10.5-to-1 V-8 pistons, or a fully custom setup that will maintain your true even-fire firing order. The first approach is less expensive because while it does require an expensive V-6 crank, the rest of the parts are less costly 350 pieces. The 350 piston does use a slightly different wristpin offset, but it's useable in a 4.3-liter. The second approach, using custom parts to maintain your stock firing order, is far more expensive, but you'll end up with a smoother running and higher revving engine.

Bolt on a set of true Vortec cylinder heads, casting numbers 772, 113 or 140. Vortec heads will far outflow your stock heads right out of the box, but now is a good time to do some porting work for an extra 40 to 50 naturally aspirated horsepower. Use chrome-moly head studs and a gasket with an integrated sealing ring.

Choose your induction system. You've got three options for the intake: Use a ported 1996-later intake manifold if you want to keep the fuel injection; rework the bolt holes on the intake and heads to make the stock manifold fit; or chuck it all and buy an aftermarket carbureted manifold and carburetor. The first approach is fine if you've got the money, the second works if you're broke and don't mind making a few compromises and the third is probably the best all-around option if you want the engine to run.

Top off your motor with a set of equal-length headers sporting 1 7/8-inch primaries and 3-inch collectors, adjustable roller rocker arms and a 750 double-pump carburetor. A cam with about 238 degrees intake and 248 degrees exhaust at 0.050-inch lift, 0.520- and 0.540-inch valve and a 113-degree lobe separation angle should deliver between 340 and 350 horsepower with the carbureted setup -- a bit more with a multipoint fuel injected setup. While that's not bad, you may be thinking that this sounds like a lot of work for 350 horsepower. And you'd be right. That's why the last step is to...

Install a 200-horsepower plate nitrous system. Up to this point, you've built a fine anvil to contain the wrath of some sort of power adder. Turbochargers and superchargers are both fine options but require lower compression pistons, an intercooler and aftermarket fuel injection unless you want to go with a fuel-sucking and power-wasting Roots-type supercharger. A plate nitrous system and carburetor will easily deliver 500-plus reliable horsepower; more if you upgrade the system with propane injection instead of gasoline fuel enrichment. Propane runs about 110 octane, will act as a powerful intercooler in the intake and will absorb some of the combustion heat to enhance engine reliability. Add in propane injection and you could easily be looking at 550 to 600 horsepower from a stock-block V-6.

 How to Get More Power Out of a V6 Engine

Open the hood of your vehicle.

Remove the negative battery cable from the battery by loosening the nut with a wrench and pulling the cable from the battery post.

Locate the ECU of the vehicle. Most ECUs are mounted on the firewall. They have a large wiring harness connected to them. If you are unable to locate the ECU, find a wiring harness and trace it until you can determine the location of the ECU.

Unplug the stock wiring harness from the ECU by pressing the release tabs on each side of the harness and pulling it toward you.

Plug the male end of the performance module into the ECU.

Plug the stock wiring harness into the opposite side of the performance module.

Reconnect the battery cable and tighten the nut with a wrench. Lower the hood.

Items you will need

  • Wrench set

About the Author

This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. To submit your questions or ideas, or to simply learn more about It Still Runs, contact us.