1-800-551-4754 Tech Tips
Manual Transmissions Explained
Whether you are dealing with sprocket teeth on a bike or gear teeth on a transmission gear, the simple formula for calculating a gear ratio is: Ratio = Driven ÷ Drive. So if the drive gear has 10 teeth and the driven gear 20 teeth, the ratio equals 2....
Performance Exhaust Systems: Pipe End Forming
Depending on the specific application, each end of a pipe may be unmodified, featuring the same diameter as the rest of the pipe. Or, one or both ends may feature a smaller or larger diameter in order to provide a slip-together mating to a pipe or muffler. Find...
How to Build Racing Engines: Carburetors Guide
Despite the widespread acceptance of electronic fuel injection and recent advances in tuning ease, carburetors remain the primary fueling device for most racing applications from Saturday night drag racers to top-level Sprint Cup racing. While electronic fuel injection offers desirable advantages in applications that have a wide operating range with...
How to Tune Your Engine at Wide Open Throttle
This step in the tuning process is the fun part: wide-open throttle. Many tuners jump straight to this part too early. It’s easy to understand why. WOT is F-U-N when the engine makes a lot of power, and there is usually some degree of glory associated with making a lot of...
Cylinder Heads Performance Guide for Pontiac V-8 Engines
In its simplest terms, an internal combustion engine is nothing more than an air pump. The more air that’s drawn into a cylinder as the intake valve opens and closes, the more intense the combustion event is when the appropriate amount of fuel is added, and that translates into greater...
LS Engine Swaps: Transmission and Clutch Guide
Adaptability is the name of the game for a Gen III/IV LS engine. No matter the kind of vehicle you have in mind, an LS and your favorite transmission can swap into it. Or you can start a few steps earlier and build the engine before swapping it into a...
How to Find the Right Engine Tuning Formula
Now that we have covered how information travels between the engine and PCM, it’s time to start processing. Internal combustion gasoline engines only operate within a specific window. Things have to happen in the right order with the right amounts of each input for the desired result. Much like baking...
Manual Transmission Performance Upgrades
Automatic transmissions obviously shift for you, and as a result, there are no missed shifts with an automatic. If you use an automatic transmission coupled to a torque converter, you will in most cases see more horsepower loss at the rear wheels compared to a manual transmission. There are, however,...
Manual Transmission Assembly Tips and Techniques
The transmissions outlined in this book were chosen because of their popularity as well as their capacity to be rebuilt with common shop tools. Although you may want to rebuild a transmission not outlined in this book, you must realize that the cost of certain specialty tools required for a...
Automotive Welding: Tube Steel Projects Step-by-Step
A hollow tube is not as strong as a solid cylinder of the same diameter, but it is stronger than a solid cylinder of the same weight. This is why tube steel is used to build race car frames, roll structures, and high-stress parts such as sway bars and suspension...
Automotive Welding: Sheetmetal Guide
Sheetmetal is at the heart of automotive metalworking. From the most basic flat-sided race car to the most exacting restoration, if you’re working with cars you’ll soon be working with sheetmetal. Some of the exercises already discussed in this book have involved cutting and bending basic flat sheetmetal. In this...
Turbocharger Maintenance and Rebuilding Guide
Maintenance For the most part, the turbocharger is a very durable device that despite its precision internal tolerances and incredible operating speeds (turbine shaft speed can be in excess of 120,000 rpm) is very capable of a long life. However, just like the engine itself, this presumes that certain care...
How to Build Your Engine for a Turbocharger
A common question among enthusiasts is whether a given engine is capable of being turbocharged. The answer to this question varies depending upon several considerations. First of all, is the engine sound and in good shape mechanically? What is the expected use of the engine and what is your horsepower...
Anatomy of a Turbocharger: What's Inside and How it Works
Performance enthusiasts typically have a desire to know and understand everything they can about the modifications they make to their engine, and with good reason. The deeper the understanding, the better the application of the component and or system. Besides, everyone likes to bench race once and awhile. Everyone knows...
Fuel System Math in Racing Engine Design
To calculate and service the requirements of your engine’s fuel system, you need a basic understanding of brake specific fuel consumption (BSFC), fuel flow requirements, injector sizing, jet area calculations, pump sizing, and other factors that affect how your engine burns fuel and how to optimize your fuel system. You’ll...
Cylinder Head Math for Engine Performance
Cylinder heads involve a lot more than just rocker arm ratios and valve spring installed heights. In this post, I discuss formulas for converting combustion chamber volumes, exhaust to intake ratios, valve curtain area, port crosssectional area, and various other factors that affect the performance potential of any cylinder head....
Basic Engine Math and Science to Design High-Performance Engines
You can’t do engine math without numbers. The numbers we use are measured with precision tools or, in some cases, they are assigned values for the purpose of brainstorming proposed modifications and theoretical results. Measurements are taken in what we all recognize as U.S. Customary units of measure such as...
The Five Golden Rules of Porting Cylinder Heads
Follow the five rules discussed here, and you are sure to avoid making a power breaking move. The success of any engine as a high-output unit entirely depends upon successful combinations of flow, velocity, and mixture motion (swirl or tumble). A port for a naturally aspirated, 410-ci small-block-Chevy race...
Optimizing Cylinder Head Airflow to Create More Power
Fig. 1.2 This is my power box. So called because it contains all the elements you need to address to build a high-performance engine. If all these facets are optimized and we add high RPM to the concoction, the result is high output. Find more tips like this in...
Performance Exhaust Systems: Mufflers
by Mike Mavrigian The purpose of a muffler is to aid in managing the engine’s exhaust sound level, and to “tune” exhaust tone. While some view the use of mufflers as simply a necessary evil, in terms of controlling engine exhaust noise level, mufflers provide an additional engine tuning...
Performance Exhaust Systems: Header Styles
by Mike Mavrigian Apart from fully custom-designed setups, common header styles include full-length (often called long-tube), shorty (often called block-hugger), lakester, and tri-Y. Long-tube headers are usually designed with (in the case of an 8-cylinder engine) four primary tubes that merge into a single collector. Long-tube headers are generally...
Performance Exhaust Systems: Pipe Shape
There’s no rule that says a pipe must be round. Specialty dies are available that allow an oval profile to be created. Why would you want an oval pipe? This shape is favored primarily when you have clearance issues. While an oval pipe can be made with the same...
Honda K-Series Engine Swaps: AN Plumbing
Almost any K-series engine swap exposes you to specialty fluid components, such as steel-braided hose and anodized-aluminum fittings, and they might lead you to the home improvement warehouse’s plumbing aisle in search of enlightenment. At first, it all seems simple: Like plumbing underneath a bathroom sink, your car’s fuel, cooling,...
Jeep 4.0 Engines: Piston Pins
All 4.0 inline-6 Jeep engines use pressed piston pins. The amount of interference fit between the pin and the rod is .0006 to .0021 inch. An arbor press is used to disassemble and reassemble pressed-pin rod/pistons. Heating the small end of the rod can also aid in assembly. These...
