Intake & filters / BUYING GUIDE
Universal cone air filters: choosing a 3, 3.5 or 4-inch connection
“Universal” describes connection options, not a promise that a filter bolts straight onto every car. The right starting point is the outside diameter of the intake pipe where the filter will clamp on.
Our red and black cone filters have a 4-inch main inlet and include 3.5-inch and 3-inch reducer rings. Measure the pipe at the connection and check space for the whole filter before ordering.
Which measurement do I need?
Measure the outside diameter of the intake pipe at the point where the filter will attach. Do not use the pipe’s inside diameter or the circumference around it. Measure across the circular opening, ideally with suitable measuring tools, and check that the connection is round and has enough straight section for a secure clamp.
| Nominal connection | Metric equivalent | Connection option |
|---|---|---|
| 4 inches | 101.6 mm | Main filter inlet |
| 3.5 inches | 88.9 mm | Included reducer ring |
| 3 inches | 76.2 mm | Included reducer ring |
These are nominal sizing options. Confirm that your pipe and the filter connection form a proper fit; tightening a clamp is not a way to compensate for a mismatched size.
What comes with the TTRP filter?
- One cone air filter in your selected red or black colour.
- One 3.5-inch reducer ring.
- One 3-inch reducer ring.
- One adjustable metal hose clamp.
The set does not include vehicle-specific intake pipework, support brackets or fittings. Check the product page for the current price and contents.
Check more than the connection diameter
- Allow space for the filter body. Check clearance around the entire installed filter, not just at the inlet.
- Check nearby components. Account for heat sources, moving parts and engine movement. A filter should not rub against another component or be left unsupported.
- Consider the intake system. Identify any sensors, breather connections and factory mounting points. Removing a factory airbox may involve more than replacing the filter itself.
- Confirm the installation plan. Ask a competent fitter to check the layout if adapters, extra pipework or a bracket will be needed.
Will a cone filter increase power?
A cone filter alone does not establish a horsepower gain. Results depend on the complete intake layout, engine and operating conditions. Choose this product for a compatible installation, not on the assumption that it guarantees more power or a particular sound.
Can the filter be cleaned?
The TTRP listings describe the element as washable and reusable. Obtain the appropriate cleaning instructions before servicing it. Do not assume another filter brand’s cleaning chemicals, oiling method or drying procedure apply to this element.
Red or black: what should I choose?
Choose the appearance you prefer once the fit has been confirmed. Both website listings describe the same nominal 4-inch inlet and supplied reducer sizes. Colour does not establish a difference in vehicle compatibility.
Sources & product references
Technical guidance checked against the references below. Vehicle fitment still requires an exact part check.