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Pfadt tri-y headers

7K views 10 replies 7 participants last post by  LewisDela 
#1 ·
#6 ·
no sir, I'd just get in the way :laughing: Although I should probably have Mike teach me a thing or two. I've picked up a lot of welding theory from this project, but that doesn't do much good without real world practice.

I'm trying to get them to take some better pics of our more recent welds. The pics on the website right now are from some of our pre-production parts when fit-up was less accurate and welds weren't as pretty as they are now. Not to mention that several of the pics are just out of focus...

Is this the FIRST non-adjacent setup offered? Also looks like the primary to secondary merger is much more downstream then I've seen on any other tri-y header ever before. Some cool new ideas here, hope it works out for the best.
By "non-adjacent" are you referring to the cylinder pairing? Ideally you'd pair cylinders that are 360 degrees of crank rotation apart from one another so you have equal timing between exhaust pulses for those two paired cylinders. Unfortunately, with the cross-plane crank in LS motors, you can't achieve that without pairing cylinders from opposite banks.

So the next best thing is to pair cylinders based on the firing order that get you as close to even timing between exhaust pulses as possible. Hence the pairing of 1&5, 3&7, 2&4, 6&8.

With regard to primary length, yes these are the longest primaries I've seen on a production style tri-y. The runner lengths help tune the exhaust pulses for different RPM ranges. Generally speaking, longer tubes equate to lower RPM, but that only holds true for a particular wavelength.

So far I have yet to hear of any alternative header on the market out-performing these, but only time will tell. I also saw that LG had a used set of these headers for sale, so I'm guessing there's going to be some serious chest beating in the near future. :laughing:
 
#8 ·
here are some better pics. And these are standard production parts, not some one-off project to show off welding capability.









 
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