Chassis Heeltoe Explains

About Chassis Braces

Chassis bracing may be the most under-rated and misunderstood modifications available to a vehicle. If the chassis accounts for the frame, steering, and suspension pick-up points; then this assembly must be as rigid as practical to perform at its best. Some compliance in the chassis helps dampen noise, vibration, and harshness (NVH), and it is not possible to completely eliminate flex. However, using strategic pick-up points, aftermarket chassis braces can be very effective at enhancing the feel of steering and suspension systems, greatly improving driver confidence and, as a byproduct, speed.


Bracing works by resisting the forces of compression and tension. Keeping two points at a fixed distance apart is the goal. With a rigid mounting between them, two points cannot bend toward each other. Judging a brace by its assembly* or how heavy it is may not be giving credit to the actual function of the part.


Braces are most commonly made out of steel or aluminum. These materials are inexpensive and strong. Aluminum has a lower weight, but fabricating it to be effective does carry a higher cost than a steel part. The most intricate parts of braces are the mounting points. Some manufacturers will, therefore, use steel for the mounting points and aluminum for the joining bar stock, and attach them with bolts. Carbon fiber and titanium are other materials chosen for their lightweight and strength, in the face of their expense.


Braces made out of one piece, or being a welded-up assembly, are assumed to be stronger than those made of multiple pieces. This statement is a risky one because it is taking design and quality out of the picture. A well-designed brace made with quality materials that bolts together would be preferable to a cheap, flexible brace made to be one-piece. It is generally true that brace which is installed as one piece would be more rigid, but unless the brace is then welded to the chassis itself, this point is largely irrelevant if the brace made is of high quality.


In general, bars mounted laterally (side-to-side) are effective at reducing twist in the chassis. Twisting movements cause the center points of the frame to move closer together. By fixing these points, the twist is resisted. Also, subframes and uni-bodies are made to accommodate the installation and mounting of other vehicle systems (exhausts, suspension parts, and drivetrain assembly) and closing these open areas “boxes” them in making the entire chassis stronger in that area. Lateral bracing will be felt more in turns where there is a high load.

Longitudinal braces help resist bending in the chassis as the front and rear traverse bumps in the road. The front and rear work together more than most would assume. By simply going over a bump, the chassis will bend, and in these bending moments, there is a numbness that reduces confidence. It’s not as apparent at road-speeds, but at highway or HPDE speeds, confidence is very important. Also, keeping the chassis flat reduces unwanted changes in wheelbase that can make the vehicle hard to set in turns after high-braking zones.

Heeltoe Explains Intake & Exhaust

Types of Air Filters

The air filter’s primary function is to remove dirt and debris from the induction charge before entering the intake tract, and therefore, the engine. Keeping dirt out of the engine is a primary means of helping it last longer. If unfiltered air can enter the engine oil, dirt can cause premature wear of internal parts. Replacing or cleaning the air filter is an important part of regular vehicle maintenance, outlined in the vehicle owner’s manual.

This article outlines some of the many different kinds of filters. Cotton oiled, dry cotton, and foam filters are the most popular aftermarket performance filter media. Be aware of the different types, and that some that are universal, non-OE style filters that may need adapters to install properly (cone filters).

Panel versus Cone

Most factory air filter elements are flat panels that are sandwiched into a box in the intake tract (airbox). The box fasteners are removed, the box opened, and the filter panel lifted out. The factory filter is a specific shape with a gasket around the outer edge to seal the airbox lid. Aftermarket panel replacements are designed similarly to the factory panel in shape and size to fit the OE application but are made from different materials to change the air-flow characteristics.

Some original equipment and most aftermarket applications use a cone filter. Cone filters go over the end of an intake tube and attach to it with either a clamp or a flange. These open-element cone filters are typically used in place of a factory airbox, doing away with the potentially restrictive plumbing associated with them. Higher performance applications will almost always use an open-element cone filter. Please note that custom mounting may be required if not using these universal cone filters with a complete air intake system upgrade.

Factory Paper

Most factory filters are made of paper material. The factory air filters are not bad for performance and do last reasonably long. These filters cannot generally be cleaned and are replacement only. Some enthusiasts will claim a factory filter is the best for use on road cars, where there is a lot of debris and a long time in between service intervals. Many enthusiasts will replace the factory filter with aftermarket cotton or foam filters to increase the air-flow into the engine. The power gains are reported inconsistently, but it is considered common knowledge that replacing a factory filter with a higher flowing aftermarket one will help increase the power potential of the engine.

Cotton, Oiled

For more airflow, a popular upgrade is using cotton drop-in replacement filters. The cotton element is a more open matrix than the factory paper and lets more air through. With oiled cotton filters, a light-weight oil is applied to the element which provides a “sticky” place for dirt to attach to before it goes into the engine. The oil is effective in trapping dirt and must be cleaned periodically. These are permanent filters that can be cleaned and re-oiled with a kit from the manufacturer. Some owners have condemned the use of oiled filters because excess oil can be drawn through the filter into sensitive mass-air flow reading components, causing the engine to run poorly. Our stance is, be careful not to over-oil when servicing your oiled filter…it is easy to do this and then blame the filter for the problem, when in reality these filters are often very viable performance parts.

Cotton, Dry

Because of the growing stigma against oiled filters, and to reduce maintenance effort and cost, there is a newer style of cotton elements called dry filters. A dry filter replacement which flows more than stock like an oiled does, but without the oil. The matrix is tighter which allows the trapping of dirt, but the cotton still fundamentally flows more than paper. The cleaning is easier without needing to apply oil. Just wash with water, allow to dry, and reinstall.


Used in many racing applications, foam filters are known to flow a lot of air. We’ve heard reports of foam filters being the highest flowing available. These filters can be made with a foam of various porosity, or layers of foam with different density, with the more open elements using oil to help trap dirt. They are softer and more pliable making them useful in a wide variety of applications, such as wrapped over intake velocity stacks. Foam filters can often be cleaned, however foam filters are less durable than the factory paper or cotton filters, and may need replacement sooner if used and cleaned frequently. Many enthusiasts feel the power gains are a good trade-off for less durability compared to cotton filters.