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.

Re: High velocity header collectors, are they worth it?
 

gmonde,

Did you have the extentions on when you put the step headers on ?
Also, how long were they ? Thanks, for your input .....

Re: High velocity header collectors, are they worth it?
 

We run Mark's Merged collectors on all our stockers! On our low torque/HP cars they make a very nice improvement(.03 to 04) in our 60 ft times. If we could afford them we would have his headers on our cars...just not in our current budget. We run a production Hooker or TTI header....13/4 on small block mopar and 17/8 on big block ...usually buy different used one's from swap meet to try. These collectors were best money we have spent on our cars in terms of improvement per $$.

Re: High velocity header collectors, are they worth it?
 

Dave, go to Larry Meaux's site www.maxracesoftware.com and get his PipeMax software. While you're at it, get on the list for his ET software. The PipeMax software is some of the best header software there is, it has some pretty good dyno simulation software built in, and it is affordable. The software comes with tech support and a membership to his tech support forum.

Re: High velocity header collectors, are they worth it?
 

when first done i just had a short collector(cone) car sounded very responsive but didnt seam to have torque (60 foot wasnt there) removed the short cone and installed a longer tapered 10 " cone that opened to three inch and used the short cone removed and installed on the end coned back to 2 5/8 ,,,the car had its best 60' at the divisional in july,with not the best air conditions
but that is my combo,,i do a lot of asking of racers what they are running and there are so many different senarios for the same cubic inch ,,,gmonde

Re: High velocity header collectors, are they worth it?
 

Thanks ; Alan, gmonde & GTX JOHN for the input ... Looks like I will have to some more reading & testing ....