Quote:
Originally Posted by PMJ
Thank you BigRed. The picture helps, but unfortunately it did not help the person who posted it. Which raises a few more questions I have as I'm trying to design my own solutions.
1. Size of the J-pipe (3" vs. smaller). In this picture they are using a much smaller size (but it didn't fixe the problem). Does the j-pipe need to match the 3" pipes?
I'm hoping his didn't work because he did not use 3" pipes to match his system, and it does not appear he used the Helmholtz chart...he was at 30", but complaining about 1800rpm drone (so i think he needs to shorten the j-pipes. I'm working on my own design, will post when i finish it for comments.
Here is the Helmholtz chart i'm refering to (i just realized the picture may have been on a V6...in which case the pipe is not long enough):
2. Can someone still clarify if the J-pipe needs to have a "J" at the end, or does it simply need to be the right length per the chart above? I'm planning to build a varible lenth pipe that can grow or shrink about 4". Looking to range between 25-29". |
That pic is from was the person I was refering to. Do research on all theJ pipe threads, but I dont think the shape matters from what I recall reading. You want the shape to the same side to side, same length and welded at the same spot also.I'v seen pics of straight and S shapes also.
Mine are in the 28.5-29.5" range and drone is dead in the 1500 rpm on uo range. Also not exact science as someone said if you have say drone at 1800 and you make the pipes that long per the chart, it kills drone +-300-400 rpm, 1800 being the mid point.
For the Pipe size 2.25-2.5" is fine. I used 2.25" as the outlaws are 2.5" dia on the axelback.
I have the Outlaws and they are way louder then American thunder, I tried it all, resonated x pipe, insulation, only worked a little, the pipes did it.Now I also had the stock LS3 resnators which help(axelback setup)Without them Mine is like a 2.5" piped catback.For me it popped to much and overall a bit loud on the freeway, not bad but just over the top, for me anyway, wasnt drone, just good old exhaust sound.Again Mine is louder then yours so you should be o.k. Besides numerous people have full blown systems on their cars and the J pipes did the trick.
I figure give it a try, if not you may want to get a Solo catback.
Hope this helps