What happens when exhaust back pressure exceeds 10 kPa?
The Deutz study on a Euro I engine, Figure 2, showed a BSFC penalty of about 1.8% per 10 kPa back pressure increase when back pressure exceeded the back pressure limit for this engine [224]. Work in the 1970s found that fuel consumption for turbocharged engines increased by 1.5% for every 10 kPa increase in exhaust back pressure [1320].
How to calculate exhaust pipe size and diameter?
Easy Way To Estimate: Your intake system needs to flow 1.5 CFM per engine horsepower, and your exhaust system needs to flow 2.2 CFM per engine horsepower. Good Way To Estimate: Take engine RPM x engine displacement, then divide by two.
How can an after market muffler improve engine efficiency?
Bottom Line:Adding an after-market performance muffler or exhaust system will improve engine efficiency from 2-10%. Improvements in efficiency can be used to either increase horsepower or improve fuel economy.
Where does the gas go when it comes out of the tailpipe?
Along the way, the gases travel through the catalytic converter, where any remaining fuel is converted to water to reduce emissions. Finally, the gases exit through the tailpipe. When everything’s working properly, this exhaust is colorless. But if something is amiss, you’ll see a cloud of smoke coming out of the back of your car.
How does a smaller exhaust pipe improve engine efficiency?
This reduces the energy required to clear the cylinder of exhaust and re-accelerate the gas residing in the exhaust pipe already, thus reducing the energy wasted pushing out exhaust and improving the efficiency of the engine. Further, smaller exhaust pipes means the mass of gas held within is less.
Easy Way To Estimate: Your intake system needs to flow 1.5 CFM per engine horsepower, and your exhaust system needs to flow 2.2 CFM per engine horsepower. Good Way To Estimate: Take engine RPM x engine displacement, then divide by two.
The Deutz study on a Euro I engine, Figure 2, showed a BSFC penalty of about 1.8% per 10 kPa back pressure increase when back pressure exceeded the back pressure limit for this engine [224]. Work in the 1970s found that fuel consumption for turbocharged engines increased by 1.5% for every 10 kPa increase in exhaust back pressure [1320].
Can a performance muffler improve gas mileage?
1. Exhaust systems and performance mufflers don’t add power – they improve efficiency. Almost every new vehicle comes with a restrictive factory exhaust system. The reason? Restrictive exhausts are both quiet to the ears and inexpensive to build.