Header Change Dragster
 

Hello All
Thinking of swapping headers, but want to know if I am wasting my time and more important my money. Motor 584 bbc 1000hp Here is what I run now, dynatech chrome 2 1/4 to 2 3/8 to a 4 1/2 collector, looking at some performance welding headers, 2 1/4 to 2 3/8 with a 4 1/2 merge collector 3 1/2 throat size. Here is some visual aid of what I have and the ones I am looking at. Have any of you swapped before or any other thoughts ? thanks


http://i203.photobucket.com/albums/a...b/100_0416.jpg

http://i203.photobucket.com/albums/a...terheader2.jpg

I seen a couple changed out. Engine sounds more responsive in the shop, but only runs a couple hundreds faster at the track. I think the overall increase is minimal. And they don't look near as good.lol.

I AGREE , PARKER ,,ON A LIGHT CAR LIKE A DRAGSTER MAKING 1000 HP ALREADY , A HEADER CHANGE IS GOING TO MAKE VERY LITTLE NOTICABLE DIFFERENCE FOR THE AMOUNT OF MONEY THEY COST , THE TOP ONES ARE BEAUTIFUL AND LOOK WELL BUILT, IF WERE MINE i I WOULD STICK WITH THEM , BUT THAT JUST ME :D PAUL

thanks for the replies guys, the bottoms will not look like that when I get them (just a mock up photo I posted) they will have a SS look. What gains are we speaking of, 2-4 and 1-1.5 mph ? or less ?

I've read on drr some picked up a tenth some picked up 5 just my luck i'd buy a set and slow down lol

The bottom set look more "flowing" in their curves Ie not nearly as tight,as to what advantage who knows?

Heck yeah run it, but here are more details for you
 

The merge collector if properly sized to the engines horsepower will net gains in horsepower and torque depending on how well the primaries are suited again for the horsepower of the engine. The throat of 3.5" is big for 1000 hp, a 3.25" is closer to appropriate for your engine. I have used Chris Hill at SPD in california. They advertise in your national dragster. Chris has helped me design headers and provided me with working collectors that he and I design based on the engines horsepower and peek RPM. Over a set of dyno headers that look like your existing headers we gained 45 Horsepower on my own engine last year with a merge collector and a step design that had the steps in the correct locations for the engine or at least it sure liked them. Always run a merge collector over a standard 4 to 1 vanilla piece. The entry angles ideally can be 12 degrees but this makes the collector very long and not fit under some cars. They more abrupt the 4 pipes come into the merge cone, the less gain you can expect with the new collector. On your existing collector, the pipes are at 0 degrees. The 12 degree one will have a 12 degree bend in each primary on the collector to point at the throat which makes a nice gradual transition to the throat. The lower photo the degree appears to be between 15 and 25 degrees. The 15 and less desirable 24 degree ones have more abrupt transitions and this hurts the horsepower measurably. In conclusion, Run the merge collector but if you are willing to order one you will benefit more if it is designed for your engine and has the more gentle 12 degree transition in the primaries of the collector.
Food for thought.........
I would have sang in earlier but got burned out on header questions a while back and did not notice who authored the question, Sorry Dave
Bruce

Bruce is really up on headers, so David if you buy a set and run 5 hundredths faster or better I'll get a set. I really have been curious, just not curious enough to spend 1500.00 dollars to try it.

You guys may enjoy inputting your engine specs and seeing what the calculated header dimensions are for your engines at HEADERDESIGN.COM. This site is helpful for comparing how each variable change effects the ideal header design dimensions. There are other places, I am sure, but this one seems to parallel the conclusions that Chris Hill does at S.P.D. that supplies my collectors. Try changing the horsepower amounts to see how it effects the primary ID dimension and the collector ID. You have to sign in to use it, but it is free and useful info if you are trying to find the best header for your car from a mass producer. One supplier may make there one size fits all design that actually fits you best. But you have to know what you are looking for and not just purchase what a so called credible header producer has on the shelf that fits your chassis. No two engines will have the identical pipe needs so knowing what your target is will allow you to compare what is available that fits you needs best , or suffer with a nice looking set that perform poorly due to improper sizing.
Bruce

I don't know about the headers but that is one clean dragster....anyone that hasn't already should check out his pics found in the link in his sig....bad ass and excellent workmanship.

Hey, you know my answer on this one. Smida's just got their new Fab Shop Headers this week. I will tell you what he sees between the same header you have and the new headers.
http://static.racingjunk.com/63/ui/4...h-Swingarm.jpg

http://static.racingjunk.com/63/ui/5...1456134732.jpg