Exhaust - will it pass tech?

There are a lot of cars that come standard with flex pipe, our MR2 has it coming off the exhaust head just before the first clamp. There is nothing  wrong with flex pipe. Major concerns are placement of the exhaust pipe, is it close to something that might likely catch on fire. Exhaust pipe is part of safety once it passes the exhaust manifold, so you can spend as much money as you like to fix it right so it will pass tech. Personally if your working on a POS exhaust system that cold drop at any moment, Pull a Part is a good resource.

# 3.26: Exhaust System: A professional-quality exhaust system is required. Exhaust outlets and tubing must be designed, routed, and maintained to avoid heating the fuel tank(s) and/or fuel-system components. FUEL HEATING IS EXTREMELY DANGEROUS AND MUST BE AVOIDED AT ALL TIMES!

          o 3.26.1: Exhaust system may not dump ahead of the driver, and must not allow undue levels of exhaust to reach the driver's compartment.
          o 3.26.2: All teams must maintain their exhaust in good condition, without leaks, throughout the event.
          o 3.26.3: Exhaust system must include at least two professional-quality flexible exhaust hangers (ie, not baling wire or plumber's tape) aft of the collector. All exhaust joints must be properly slip-jointed, properly bolted or welded, and must not leak.

There is nothing in the rules about JB weld, it's not used in professionally  made exhaust systems that I know of. If you use it, it may not pass tech and you would be scrambling to fix it right.
This is one thing you want to do right. You have too much other stuff to worry about, once you get to the track.
Good Luck

FYI, all exhausts should have flex pipe.  The engine is going to move and rock in the engine bay, without some compliance in the exhaust, you will break it - ask me how I know. 

BTW - this is shit:

This is what you want to use:

We had our exhaust loose, breaking a hanger, after a massive hit from behind at the start of the race. This set in motion a stop to fix it, then another stop to fix it again, then another black flag to fix it after we had already fixed it but they didn't know that (WTF?), then the whole thing coming off and cutting down a tire and another stop to change the tire and rip it off after the cat.

My point is to think about what might survive a pretty good whack from behind (or front if you're the guilty party).

1 piece would be quite awesome, I will need to investigate this.

Yeah my $80 figure included 2 hangers that we bolted through the floorboards, worked like a charm.  I think the exhaust will last longer than the car!

I thought we'd have no problems with the factory tubing off the manifold coming down to a u-clamp to a glasspack, u-clamped to a 90degree bend, welded to ~20" of straight pipe out the passenger side. All held up by the factory hanger up front and a rubber hanger on the straight pipe.

The frontmost u-clamp failed 4 laps into the race. We blew ~1hour trying to fix it, and the fix lasted 1 lap. After that we just pulled the glasspack and everything else.

2 "tech" black flags and 90 minutes of racing time blown because I was too lazy to get back under there and weld the glasspack.

Weld it, but make sure it's on flexible hanger(s).

I raced for years with clamped exhausts without issues. Do it up tight enough and the pipes will crimp enough to stay together even if the clamp fails...if that's an issue, stainless clamps are cheap enough. More hangars is likely a good solution. Mine are attached so that any individual joint failure will still keep the pipes under the car without dragging. Sparks sure attract the black flag!

Spud, that's an excellent idea, thank you.  I think we're still going to need a friendly mechanic to weld our exhaust system together.  Time's getting kinda tight.

Bump for clarification. 

Red flags for burning cars lead to quite a bit of sitting still at CMP this fall.  As did the lineup to get onto the track each morning and after the curse.

Our exhaust problem was that we didnt have a trunk in the week leading up to the race.  Even at speed enough exhaust got carried forward into the car that we were getting dizzy.  I'm sure the giant wing had nothing to do with it.  We took it as an opportunity to put the trunk back on and add a spoiler.