Choosing the Right Exhaust
Let’s face it; most stock exhaust systems are heavy, restrictive, and worst of all, quiet. You certainly don’t want to put that brand new crate engine in your car and hook it up to a stock exhaust do you? This article will cover a few of the many ways we can fix those particular issues.
It makes sense to start at the front and work our way back, right? In that case, headers it is! Nearly all stock manifolds are cast iron, and have casting remnants remaining in the exhaust pathway. This causes turbulence and restriction. Most of the nearly 800 different headers Speedway Motors offers are a tubular steel design, ensuring maximum flow with minimal interruption. Some are long, some are short, and some are center dump style. It all depends on your application, as well as your preference. Most stock applications below 350ci can be best served by a 1.5” header, where a higher power application will inevitably need a larger tube.
The quick and easy way to choose what diameter pipe you will need from the headers to the mufflers is to go back to the old rule of thumb, that for every 100 horsepower, 1” of total pipe diameter is needed across the system. For example, a 500 horsepower engine needs a 2.5" dual exhaust. This, of course, is a rough estimate, and there are several complex mathematical formulas to help you discover the “perfect” size of pipe to use. There are also several online calculators you can utilize, like this one. Simply input the horsepower figures, the number of exhaust pipes, and hit “Calculate.” The calculator will do the math for you and tell you the minimum recommended pipe diameter for your application. Then you can Click Here to shop and add the system you want to your cart.
Your choice of mufflers is as much about performance as sound. Do you want a low growl, or do you want to wake up the neighbors on Sunday? There are multiple options available to you. Click Here to take a listen to some of Flowmaster’s offerings. You can click on the chart and expand it to see what model applies to your specific needs. We also stock Dynatech, Moroso, Dougs, and our own in-house Speedway brand.