My buddy has a carbed 377 in his thirdgen, it has longtubes on it. He's pretty adept in the fabrication of things, so he made his exhaust out of rectangle tubing, not oval or round. He made reducer/adapters for his three inch collectors to mate to it. Then took it back and dumped it front of the rear axle. On all the bends he had to cut the angle he needed, then weld it together. The tubing is two inches by four inches. Is there any logical reason for this (performance?)? Sounds pretty unique, but to much trouble for me. I'll try to get some pics, or a sound clip on here.


Max

the only logical reason i could think of would be ground clearance.

Square tubing has a lot of transition regions in it as well having greater internal surface area versus a similarly sized round pipe. This in turn hurts flow and can reduce performance significantly. You never want your flow area to have sharp turns or 90° corners. You want constant cross sections with minimal bends. Square tubing does not offer this. If ground clearance is an issue one should look into oval tubing or smaller dual set-ups.

I thought there was somthing about greater surface area slowing down airflow. There arent any 90* bends in it, but it's not a straight shot either. I just thought a dual three inch round pipe setup would work just as good if not better. Tried to tell him that, but he had his mind set on it... and well, you know how that goes.



Max

There is.

The rectangle/square tubing has 90° edges and

Your assumption of a better sized round set-up was a good one. He should have listened to you.