Will I Gain More Horsepower With An Exhaust System?

It is a truth that post-market exhaust systems are less restrictive than factory exhaust systems. Nonetheless, it does not mean that addition of post-market exhaust results in sure-fire more power. 

The question must pop into everybody's mind: Will I gain more horsepower with the exhaust system? Let's elaborate on this.

The system and vehicle can add up as much as 60 horsepower or as little as two horsepower. Below is the rational way of figuring out the expectation. 

  • Don’t emphasize horsepower only. Horsepower = RPM X Lbs-ft of Torque / 5252
  • High torque with high RPMs equals high horsepower.

Horsepower is enumerated by multiplying torque with RPM. It means if the exhaust system adds up to ten lb-ft of torque to 5,000 RPM, a rise of 9.5 hp will be noticed.  This sounds like a solid horsepower gain, an additional ten lb-ft of torque at the rate of 5,000 RPM does not do you any good in casual driving. 

Overall, how many of us run our engines at the rate of 5,000 RPM constantly?

Chuck Exhaust System Manufacturer Estimates out of Windowpane

As horsepower is a prime function of RPM, it is comfy enough to depict hp gains on paper. A diesel truck is a handy example in point as they produce a hell of torque, summing 35 lb-ft of torque at the rate of 3,300 RPM with a gain of 23hp. 

These statistics may seem inspiring on the face value, but an additional 35 lb-ft of torque at the rate of 3,300 RPM is not that beneficial for typical truck owners. It is a good increase but not usable.

The second reason you should not blindly believe in manufacturer estimates is that “Dyno are easy to manipulate.” When any vehicle experiments on a dyno, there can be prominent variations from time to time without any tinkering to the engine. 

The manufacturer deceitfully picks the worst performance before a test and selects the best post-test. They can manage to sell a significant profit. 

In other words, these estimates are generous to the core. Suppose a kit sprinkles up eight hp, and the kit adds 13 hp or vice versa. There are upbeat chances that both perform closely with each other.

The Most You Can Gain is Just 2-5%

If you want to understand how much power you can extract from your car's exhaust system, for example, your engine gets 2-5%. Strong engines (6.0L V8) see a surge of 2%-3%. On the other hand, small engines (1.8L 4-cylinder) see a 3-5% hp surge.

Nevertheless, the exhaust system also has a multiplying effect if combined with add-ons. The exhaust system itself does not add power, but its combination with air intake can notice an inefficiency. 

Furthermore, you may also witness a slight surge in fuel economy. 

Never Underestimate the Power of Intangibles

Not only do after-market exhaust systems add horsepower or improve fuel mileage, but it also gives a sportier note, improved throttle response, and joy driving effects to your vehicle.  The good news is that the inexpensive after-market mufflers serve you even on a shoestring budget.