Quote:
Originally Posted by SS_Firehawk
Doing some basic math, granted I'm no mathematician, the 3" is 15% larger than the 2.75". To go a little deeper, I wanted to find the area of the inner diameter of the pipe to get a more accurate measurement. so I took the known radius, divided by 2, subtracted the thickness of the wall, squared it, then multiplied by pi. For reference, the Tanabe Medallion wall thickness is .047" and the Motordyne wall thickness is .062".
Results:
3" = 6.49sq in.
2.75" = 5.54sq in
With it converging to a 2.75in mid pipe, I'm a bit worried about it. I'm sure the long tubes are helping compensate for the smaller piping, but I have my reservations that this will be enough. I saw a chart on line but it seems to overestimate the pipe size necessary. What is known is that at about 550whp, 2.5" dual exhausts starts hitting a wall. Combined area for a dual 2.5" is 8.86sq in. My hypothesis... I need a different exhaust  |
Your hypothesis is correct.
Power can be boiled down to airflow. Airflow can be (roughly) estimated by using square inches of orifice area just like you've done here.
A single 3" is sufficient for most N/A builds where your peak power output is around 350-400hp at most.
You could do a single 4" most likely, or a 4.5" but routing a pipe that fat will be annoying under a Z.
A true dual setup running at least 2.5" will serve you best, or a single of at least 3.5-4". (If you can make it work, I'd love to see a big honking 4"+ single on a Z, and hear what it sounds like)