Rules for NOT having exhaust issues:
#1: FLEX section as pictured above (not the SHIT picture, the other) installed between the down pipe and anything aft. As mentioned, the engine WILL move around, even with solid mounts it vibrates more than you might think. Your exhaust will fail without it.. maybe not in 24 hours.. but it WILL fail.. do not hang the exhaust from ANYTHING solid in front of your flex section.
#2: Flexible hangers in several places all the way back to the tailpipe. preferably used 2 at a time, on opposite sides of the exhaust where you use them.. might be a bit of overkill, but pit time to fix exhaust SUCKS.
#3 Quality U-bolt clamps or welding joints ONLY, plenty of overlap for either method. Well crimped pipes using QUALITY u-clamps will trump poor welds every time... (ugly welds are not always poor welds... lol) NO other method of joining pipe sections is acceptable.
#4 Safety back up. Like Spud said.. Wire Rope, or chain is fine... we don't use it, we don't use OEM hangers, and we are redundant, I think there were six hangers on about 8 feet of exhaust... 4 could have failed and the exhaust would have been fine... none failed. $2 spent on overkill is better than 15 minutes and 10 missed laps...
#5 JB weld, or ANYTHING out of a tube or roll is garbage for exhaust... period dot, the end.
Price? a good quality glass pak at a parts supply, about $20-30 10 foot of pipe, about $15-18, hangers $2 each, Clamps less than $2 Our whole exhaust on the Ohio entry was under $40 (welded) and had ZERO issues with 24 hours at Nelson. We buy where the shops buy.. KOI, so find out where your local Midas Muffler shop buys their pipe and go there, acting like you are a shop owner if you aren't.
Owner: Stanford Motorsports (sounds better than it is!)
Lamest Day entry: Team EAU RUDE silver/red NON-CHEATING Sentra SE-R #40 (Crew Chief, Large Fat Bald Guy with white Mutton Chop sideburns)
Other nonsense: Solo Director, Cincy SCCA, Board of Directors, Cincy SCCA