Induction and Exhaust Guide

[RrCoX22]

There's two main parts that are primarily influential in acquiring maximum horsepower and torque out of an engine. In doing so, you want to:

- Bring in as much air as possible
- While getting the burnt gases out as fast as possible

The quicker this process is done the more power the engine will produce.

So how do we obtain this? Well... this is where the world of modifications come in. Through this guide we will look at what we can do to enhance our engine's performance through induction (incoming flow of air) and exhaust (release of gases) to reach each application's goals.

Each modification will only enhance and compliment the other. For example: If you have a larger intake manifold than stock but are still running stock exhaust manifolds, that intake manifold will not be operating at it's full performance. Nonetheless you would still see an increase in power over stock, but if longtubes were to be added the benefit of a larger intake manifold would be extremely more useful.

Induction

- Air Filter

Very simple concept here, as certain air filters flow more CFM over others. There's a few different types of air filters to purchase as paper, foam, mesh, etc. Again decide which type best suits your application.


- Lids

A lid is a lid is a lid... simply put. They are just that, basically your stock airbox has lots of restriction and unnecessary passageways and reservoirs that collect unwanted air that shouldn't be there. Instead, it should be GOING INTO YOUR ENGINE! These open your incoming surface area and more appropriately direct the intake of air.

There's many manufactures that make lids as they come in all different colors, etc. although they all serve the same purpose and produce approximate same power.

- CAI

Cold Air Induction kits are also available if you don't mind possibly modifying the stock radiator support and baffling. What these do is bring outside air, much colder that engine operating temperature, and normally from underneath the front area of the vehicle up through a funneled plate into the airbox area. Many different kits can accomplish this which will require modification to the airbox area and supporting baffling.

- MAF

This is a fragile and very sensitive part of the induction system. The Mass Air Flow sensor reads the amount of incoming air and calculates to the PCM how much fuel should be dumped through the injectors. There are wires inside the MAF housing that measure air readings to calculate the Air/Fuel ratio, and these wires should never be touched.

The MAF is a debatable subject in it's own. Some people prefer to port out the housing to allow for a larger volume of incoming air. Others will also say this is not necessary as it may cause problems with readings. Please do what you feel is best from your own research and findings. There's also a screen on the front housing section that air must pass through, which is also another debate whether to remove it or not.

Again, the whole MAF is a touchy subject. Many companies provide aftermarket MAF's which are either descreened and/or enlarged in diameter. This part to keep in mind is also essential for tuners, as it's and essential piece to control the timing of the engine. The stock MAF is rated to allow and handle application of 500hp.

- Bellows

This is the accordion like rubber looking tube that connects from your MAF to your Throttle Body. This is just basically a tract that has no purpose other than to direct airflow and the option change out for possibly a different type of bellow.

- Throttle Body

This piece is bolted to your intake manifold which is used mainly to determine the amount of airflow incoming to your engine based on the position of the gas pedal. Once the gas pedal is press the butterfly valve inside the throttle body housing opens to allow for more air to flow in. Within the throttle body there's a couple of sensors to determine throttle position and idling air. Throttle bodies are also commonly modified to be ported or enlarged for increased airflow. Many companies provide larger diameter housings to provide even greater amounts of inlet air.

- Intake Manifold

This is the part that sits on the cylinder heads and directs all of the incoming air into each intake port on the cylinder heads. These pieces can be constructed and cast to be modified to allow for greater flow. The inlet that the throttle body bolts to can also be enlarged for an increased diameter area of incoming air. These pieces are also know to be ported near the runners of cylinder head area.

Exhaust

- Headers

These replace the stock exhaust manifolds, thus freeing up restriction and allowing for the engine to 'breathe' better. One of the main effects that headers bring, otherwise else known as longtubes, is that a scavenging effect is created in assisting the release of gases from the combustion chamber. In a sense each primary is enlarged and elongated into a merge collector. These primaries in a sense create a vacuum effect that pulls the exhaust out easier as each exhaust valve opens and closes in the cylinder head.

Significant gains will be seen when replacing the stock exhaust manifolds and since the catalytic converter is moved this modification is normally consider illegal in most states. Please check with your states/county emissions regulations when installing longtubes.

Your oxygen sensors will need to be reinstalled which are normally near the merge collector at the bottom of the header. Your car will not run properly without these installed.

- Y-Pipe

This is the section between your exhaust manifolds or headers and the catback. A y-pipe gets it's name since it looks exactly like that, a "Y" as it has piping coming from each exhaust manifold into a merge collector (two pipes merge into one) and then onto your catback. This piece will also include your catalytic converter(s) and rear oxygen sensors. Custom y-pipes can be made as well to help flow or maybe needed as longtubes will cause the stock y-pipe to have to be modified.

- ORY

This stands for Off Road Y-Pipe as these particular y-pipes have the catalytic converters remove and are normally only for off road use. The oxygen sensors will need to be removed as normally they are either simulated or have the codes tuned out. Removing the catalytic converters will cause the exhaust to be extremely noisy and normally not 50-state emissions compliant. Once again please check with your states/county emissions laws.

- X-Pipe / H-Pipe

These are different exhaust styles for replacing the y-pipe. Basically just like they're noted, one style looks like a X and the other a H. Normally there's a preference depending on which style to consider but the overall factor is that both are far superior in performance compared to the y-pipe due to increase flow rate. Both of these styles can be used with or without catalytic converters. Once again these are normally illegal depending on your states/county emissions laws.

- Catback

Yes, that's exactly what they are, piping basically from the cat-back out to the rear tips of the exhaust. This is normally piping that starts near the axle of the vehicle and works around the axle, which includes a muffler or some sort and then spits into two pipes that then become the end of the exhaust and out the rear tips. Many different variations are available but ultimately these produce good power to free up restriction in the stock exhaust.

*Note if a catback is normally not used it is considered as a dumped exhaust which normally turns down at the end of the piping on y-pipe/x-pipe/h-pipe. This can also be used to help reduce the weight of a catback but can also be considered illegal depending on your states/county emissions laws.