[TORCHD 02 TA]

Originally Posted by titter

He didn't gain that just from a merge, he gained that from the merge, and I-pipe together. Having a 4" I-pipe greatly increases exhaust flow, and will allow maximum power for a Y-pipe. Someone posted the correct math before, but I will explain it a little more.

You have to think about two 3" pipes merging into each other. The combined area of two 3" pipes from your Y-pipe would be 14.13 square inches. If you have a 3" I-pipe, you have an area of 7.065 square inches. Which now means you are dumping a combined 3" Y-pipe into 7 square inches, or basically halving the output. If you were to merge into a 4" I-pipe, the 4" I-pipe has a area of 12.56 square inches. The 4" pipe has 43% more area than the 3" pipe. It also almost matches the output of two 3" pipes, which will greatly increase exhaust flow. Also just for reference, a 3.5" I-pipe would only have an area of 9.6163 square inches. The 4" pipe still has 23% more area.

If you want to check the math, Area of a Circle, A = Pi * r * r. In this case, we are dealing with diameter, so you would first convert diameter to radius ... d / 2 = r.

where can you get a 4" I pipe from?