NOS Basics and Layout

The basic nitrous oxide injection system, or a NOS kit, is pretty straight forward and easy to grasp. It consists of a nitrous oxide tank, some tubing, a nitrous solenoid, a fuel solenoid and toggle switch, throttle position microswitch, jets, a nitrous fogger, a relay, nylon pipe, and a distribution block.

The nitrous tank is used to store Nitrous Oxide in a liquid form. The tank is actually a pressurized canister as Nitrous Oxide must be compressed to remain liquid at room temperature. Remember N₂O reaches boiling point (i.e., it becomes gaseous) at -127° F and more Nitrous Oxide can be stored when it is in a liquid form. Approximately 850 psi of pressure is required to keep Nitrous Oxide liquid at room temperature and at sea level but the nitrous tank must be pressure tested and certified to withstand 1,800 psi. If the certification on your NOS tank is older than five years, your nitrous dealer will not refill it and you will have to have the tank pressure tested and recertified. The tank is mounted in the car's trunk and has a siphon tube that is connected to the release valve and extends to the bottom of the tank. The tank must be mounted at a 15° angle to ensure that the maximum amount of Nitrous Oxide can be released from the tank.

High pressure nylon or Teflon inner-lined braided-steel pipe is used to carry the Nitrous Oxide to the engine where it is regulated by the NOS solenoid. The solenoid is an electrically controlled valve which uses a strong electromagnetic field to open a small plunger the blocks the flow of the liquid Nitrous Oxide. A second solenoid is used to supply extra fuel so that the air/fuel mixture remains constant. Both solenoids are controlled by electric switches that activate the electromagnetic field. The NOS system should have at least two switches — a microswitch that is fitted to the accelerator linkage and is only activated at full throttle; and a spring-loaded momentary switch that is activated by the driver. The microswitch on the accelerator linkage ensures that the nitrous system can only be activated at full throttle. Activating the system during part throttle or during a gear change can have very catastrophic consequences. As an added precaution, the oil pressure switch can also be used to ensure that the system can only be activated when the engine is running and there is oil pressure. Starting an engine with NOS in the combustion chamber can also be very catastrophic.

Some more high pressure nylon or Teflon inner-lined braided-steel pipe is used carry the nitrous and fuel (which are still separate at this stage) to the intake manifold where it is released into the engine via two small jets that are located in a special nitrous injector. The jets must be correctly calibrated to release the correct amount of fuel for a given amount of nitrous. In addition, the pressure on the fuel supply side must be adequate and at a constant level to ensure that the air/fuel mixture is correct at all times. This may require the fitting of an electric fuel pump and a fuel regulator.

The quantity of the nitrous flow depends on the size of the jet fitted. A jet is basically a screw with a whole through it. It's used as a restriction tool depending on the size of the link up orifice. Applying a bigger jet is the easiest way to squeeze a bit more power out of your current system. The fuel supply comes from a similar jetting system.

There you have it — the basics behind NOS systems and NOS kits. In our next section we'll look in more detail at NOS installation ...

An Introduction to Nitrous Oxide (N2O) Injection

Anyone for some NOS?

Nitrous Oxide (N₂O), or NOS as it is commonly referred to, is a quick and easy performance boost for any motor vehicle, regardless of whether it's a car, a bike, a boat or a plane. In technical terms, Nitrous Oxide is a chemical compound that consists of two Nitrogen atoms and one Oxygen atom. However, Nitrous Oxide does not occur naturally as a chemical compound but has to manufactured by applying heat and a catalyst to nitrogen and oxygen compunds. Nitrous Oxide was first discovered by the British chemist, Joseph Priestly, in 1772 but it wasn't until 1942 that Nitors Oxide was first injected inon an internal combustion engine to boost the power output from the engine. Nitrous Oxide is not combustible and is in liquid form when under pressure. When it is released into the combustion chamber the pressure is removed and the Nitrous Oxide becomes gaseous, releasing extra Oxygen that allows your engine to burn more fuel during the combustion process. At the same time, the chemical process of changing from a liquid into a gas absorbs lots of the heat from inside the combustion chamber, reducing the chances of detonation and pre-ignition. NOS thus provides an instant but relatively safe performance boost.

The major advantage of NOS is that it is relatively cheap when compared to all the other forms of car modification and the amount of work involved to install a full nitrous system is far less than that of installing high performance cam shafts, turbochargers or superchargers. The only drawback is that you must refill your Nitrous Oxide tank. Nitrous Oxide is stored in a pressurized tank to keep it in a liquid state. Unfortunately, Nitrous Oxide refills are not as freely unavailable as gasoline and must be purchased from an authorized dealer. The relative low cost of installing a NOS system makes it an ideal power boost project for anyone who can read and understand a little simple physics. As with anything in life, if you don't do it right, you're going to get problems. There is also more to installing NOS than just bolting a NOS tank to your trunk and connecting a long tube to your engine. The bottle has to be mounted at a 15° angle to ensure that the last of the gas is used and none is wasted. The plumbing is also very intricate and can be very tricky to a first time NOS installer.

None the less, in this custom-car.us NOS guide, we will explain the physics of nitrous oxide injection and show you how to install a NOS kit and how to test and tune NOS.

There are three different types of nitrous oxide systems that you can implement:

• The Dry System, which is the NOS system in which no fuel is sent to the intake charge outside the vehicle's normal means.
• The Wet System, which is the NOS system in which fuel and nitrous oxide are supplied through a fogger and then sprayed through the throttle body.
• The Direct Port System, which is a Wet System in which each engine cylinder has its own fogger.

We'll cover all of these over the next few pages. Now let us start with some NOS basics ...

WARNING: NOS causes an extreme increase in fuel combustion; therefore, any problem in your engine can turn out to be 10 times worse with nitrous installed!

2011 Volvo Sport Sedan C70 Luxurious Convertible Model

2011 Volvo Sport Sedan C70 Luxurious Convertible Model

First seen in the U.S. at the South Florida International Auto Show, the 2011 Volvo C70 receives a bold new look and a number of interior enhancements. With its new front appearance, the 2011 Volvo Sport Sedan C70 Luxurious Convertible Model reveals traces of the S60 Concept Car that was unveiled in early 2009. The 2011 Volvo Sport Sedan C70 Luxurious Convertible Model now relates more closely to the design language of the larger cars in the Volvo model range.

2011 Volvo Sport Sedan C70 is a convertible model, manufactured since 1997. This model is in its second generation. First generation model was offered with soft top convertibles and second generation models are installed with retractable hardtop. Second generation model was launched in 2006 and this model is based on Volvo P1 platform. New generation Volvo C70 is installed with advanced accessories like LED tail lamp, sleeker headlamps and many other accessories. 2011 Volvo C70 is a luxurious convertible model which offers smooth and comfortable drive experience. This new model is likely to face some tough competition from other convertible models like Infinity G37, Volkswagen Eos, Lexus IS 250 C and BMW 3 series.

2011 Volvo Sport Sedan C70 Luxurious Convertible Model

Volvo C70 2011 will be sold at a price of 39,950 USD – 50 USD cheaper than the price of old, but with the additional standard equipment for 4000 USD, which was once optional. Like 5 speed automatic transmission, SIRIUS satellite radio, a layer of luxurious leather upholstery, LED taillights high-tech, complete airbags only from the front but also on the side of the vehicle.

2011 Volvo Sport Sedan C70 Luxurious Convertible Model’s cabin is very slim and houses little gaps between console and dash. Stereo, navigation and Bluetooth are offered with straight forward access with button interface. This model’s interior can also be decorated with wood trim on center stack and standard aluminum material. Optional stereo system presents good sound quality to its occupants. 2011 Volvo Sport Sedan C70 Luxurious Convertible Model’s seats are designed to offer comfortable seating position to its occupants. Rear cabin is very expansive and relatively comfortable for an average individual. Cargo compartment of this vehicle is also bit spacious and can easily accommodate small luggage.

The 2011 Volvo Sport Sedan C70 Luxurious Convertible Model is a four-passenger luxury convertible with a retractable hardtop, and it's available in only one trim level, the T5. It comes with 17-inch alloy wheels, a power-retractable hardtop, front and rear foglights and heated outside mirrors. Standard interior features include leather upholstery, eight-way power front seats (with driver memory), automatic dual-zone climate control, full power accessories, cruise control, Bluetooth and an eight-speaker CD/MP3 audio system with auxiliary audio/USB jacks and satellite and HD radio.

2011 Volvo Sport Sedan C70 Luxurious Convertible Model

The front-wheel-drive 2011 Volvo Sport Sedan C70 Luxurious Convertible Model is powered by a turbocharged 2.5-liter inline five-cylinder engine rated at 227 horsepower and 236 pound-feet of torque. A five-speed automatic with manual-shift control is mandatory. This powertrain is EPA-rated at 19 mpg city/28 mpg highway and 22 mpg combined.

2011 Volvo Sport Sedan C70 Luxurious Convertible Model

The C70 comes standard with antilock disc brakes with brake assist, stability control, front-seat side airbags, side curtain airbags for front passengers, roll bars that deploy in the case of a roll-over accident and whiplash-reducing front head restraints. In crash tests, the Insurance Institute for Highway Safety awarded the C70 its highest rating of "Good" for frontal-offset and side impact protection.

But the 2011 Volvo Sport Sedan C70 Luxurious Convertible Model is about more than safety and an innovative roof. In the U.S., the 2011 C70 is offered with a powerful 227 horsepower turbocharged five-cylinder engine that's mated to a standard five-speed automatic transmission with driver selectable Geartronic shifting. Power is seamlessly distributed to the front wheels with Volvo's standard Dynamic Stability and Traction Control (DSTC) system.

Cylinder Head Porting

Now that we've got a good understanding of air-flow, we can move on to cylinder head porting. If you haven't yet read our article on the basics of cylinder head porting and air-flow, I'd suggest you do so now as it provides the foundation for understanding what we want to achieve with the actual cylinder head porting.

PREPARING THE CYLINDER HEAD

Before we can get started, we need to strip down the cylinder head; remove the camshafts and camshaft pedestals, then remove the valves, valve springs and valve stem seals. You should also remove all manifold studs. With everything stripped, you need to inspect the cylinder head for cracks. It's no good porting a cracked cylinder head, though a cracked cylinder head may still be good for experimenting on, so don't throw it away! The most likely areas where cracks will appear are between adjacent valve seats, and around the valve seats, especially around the exhaust valve seats. You may need to some emery cloth to remove any carbon deposits to do a thorough check.

If you don't see any cracks, have the cylinder head thoroughly cleaned in a chemical bath. You can dip a cast iron cylinder head in a hot caustic solution but don't dip an aluminum cylinder head in it! Caustic solution will react with the aluminum and give off an explosive gas! For an aluminum cylinder head you should use Trichloroethane. If you don't have access to a chemical bath, you can use engine cleaner and a stiff brush to get oil and gasket pieces off. Once the cylinder head is clean and dry, use a sand blaster or a wire brush to clean off any stubborn carbon deposits. Once that's done, do another thorough check for cracks.

If you don't see any cracks, have the valve seats replaced and the valve guides removed by a reputable engineering shop. Replacing the valve seats are not crucial as long as they're in a good condition. However, you must have the valve guides removed.

WARNING: Take care when working with a grinder. Adhere to the following safety precautions when porting cylinder heads and using a grinder in general:

• Wear eye protection when working with a grinder; goggles are advisable but a full face visor would be better.
• Wear a dust mask or a respirator; inhaling metal filings is harmful.