Thread: 3" Catless Downpipe

Ever wonder what goes into a quality downpipe?

3" catless downpipe prototype is all buttoned up and on the car. Here are a few photos of it going together last night. All thats left is to tack on the hanger when they come off the CNC.









Complete 304 stainless construction, 1/2" 304 flanges, concentric reducer, interlock and lined flex....best part is it bolts up with no modification!

Quick video:
https://www.youtube.com/watch?v=xHx6yw-vz3A

Overall I am very happy with the results. Only things I am going to change on the production pieces are the flanges and the flex. The flanges will still be 304, but I am going to step down to a 3/8 thick piece. For the flex, I am going to use smooth walled bellows like these ones we use on our tubo cars...



I will be taking orders real soon!

Price thoughts?

My ZZP DP yanks the catback all crooked.

Looks great though man!

Im shooting for 225.00 plus shipping. It *MIGHT* come in a little cheaper, but I dont know yet.

Originally Posted by 92builtbird

Seems like there's never an agreement on how much power these are worth. Being that I need headers bad, I'll probably just hold off until you're done with those.

Fair enough sir!

Real long tunes would be the **** it's part of the problem on why these ls4 on n/a can't make the power they should. I looking at dyno from the 5.3 trucks longtubes vs shorties there picking up almost 15 to 20 whp over shorties.

I'm a noob to fwd exhaust possibilities, but is it remotely possible to have equal length headers on a fwd 3800? If so I bet they would make these cars sound so much better.