High velocity header collectors, are they worth it?

SSDiv6 · 08-03-2010, 10:59 AM

Because there is an array of differences between engine designs and components used, especially camshaft designs, establishing the correct header size for any engine can be complicated and many times considered a mystery.

As others have said, headers that work in the dyno may not work at the track. For many years, the old belief was the larger the header, the more power the engine will make. (The old “Bigger the Better” Theory) The reality is many are running engines with headers that are too big in size for its application.

I have examined data from both dyno and track date were a Comp Eliminator engine gained a lot of power by switching from a 2-Step header to a 3-step design with smaller primaries and merged collectors. Very interesting to see how the change affected both the BSFC and EGT also eliminating a reversion issue that the engine was experiencing.

In the early days and prior to the advent of computers when we had to use a slide rule, paper and pencil, I recommended the use the guide lines as shown in the book titled; “Scientific Design of Exhaust & Intake Systems (Engineering and Performance) by Philip H. Smith and John C. Morrison. Another good book is Practical Gas Flow by John Dalton.

To have an idea on what it takes to design the proper header for your car, the elements and factors to be considered, just go to the Burns Stainless or Kromer Kraft Headers website and look at the “Race/Engine Specification Forms” and you will have an understanding of all the parameters they take in consideration when designing a header.

In fact, Calvin Elston asks potential customers to fill the form from Burns Stainless and when they get the results, he will discuss the recommendations and add his input based on his prior experiences.

Mark at Performance Welding Headers has a lot of knowledge and experience he gained throughout the years while working at Ak Miller Turbo. Ak Miller was the pioneer of race and street turbocharging and much of today’s turbo technology started at Ak’s shop. Much of the power of turbocharged engines is dependent on proper exhaust design. I believe this is one of the many reasons why his headers work so well and because he has taken the time to read and study many of the published SAE treatises and publications on exhaust science.

This is not taking away from other great header builders such as Stahl and Gebbler.

If you are serious about the performance of your car and have the budget, stay away from other brands that just bend tubes to build headers to fit a specific chassis and do not take in consideration how the will perform.

08-03-2010, 10:59 AM	#21
SSDiv6 VIP Member Join Date: Feb 2003 Location: Glendale, Arizona Posts: 3,039 Likes: 712 Liked 1,556 Times in 578 Posts	Re: High velocity header collectors, are they worth it? Because there is an array of differences between engine designs and components used, especially camshaft designs, establishing the correct header size for any engine can be complicated and many times considered a mystery. As others have said, headers that work in the dyno may not work at the track. For many years, the old belief was the larger the header, the more power the engine will make. (The old “Bigger the Better” Theory) The reality is many are running engines with headers that are too big in size for its application. I have examined data from both dyno and track date were a Comp Eliminator engine gained a lot of power by switching from a 2-Step header to a 3-step design with smaller primaries and merged collectors. Very interesting to see how the change affected both the BSFC and EGT also eliminating a reversion issue that the engine was experiencing. In the early days and prior to the advent of computers when we had to use a slide rule, paper and pencil, I recommended the use the guide lines as shown in the book titled; “Scientific Design of Exhaust & Intake Systems (Engineering and Performance) by Philip H. Smith and John C. Morrison. Another good book is Practical Gas Flow by John Dalton. To have an idea on what it takes to design the proper header for your car, the elements and factors to be considered, just go to the Burns Stainless or Kromer Kraft Headers website and look at the “Race/Engine Specification Forms” and you will have an understanding of all the parameters they take in consideration when designing a header. In fact, Calvin Elston asks potential customers to fill the form from Burns Stainless and when they get the results, he will discuss the recommendations and add his input based on his prior experiences. Mark at Performance Welding Headers has a lot of knowledge and experience he gained throughout the years while working at Ak Miller Turbo. Ak Miller was the pioneer of race and street turbocharging and much of today’s turbo technology started at Ak’s shop. Much of the power of turbocharged engines is dependent on proper exhaust design. I believe this is one of the many reasons why his headers work so well and because he has taken the time to read and study many of the published SAE treatises and publications on exhaust science. This is not taking away from other great header builders such as Stahl and Gebbler. If you are serious about the performance of your car and have the budget, stay away from other brands that just bend tubes to build headers to fit a specific chassis and do not take in consideration how the will perform.