if u wanna save the most money u can ud buy 1, rather than having the possibility of something breaking because u didnt get one, then end up shellin out more $$$.

 

Ah, that makes sense. Thanks.

 

Yes, it's necessary. As much so as motor mounts, and suspension bushings. Without those flexible sections hard parts that can't flex, break. The first thing to go would be a weld in the exhaust somewhere. All the torque and vibration of the engine has to go somewhere, and the flex section helps absorb it.

 

Heres the question, would all these manufacturers really have spent butt loads of money in R&D, and still deemed it a good idea to include the flex section, if it wasnt needed? My best guess is its needed, than again im a newb. Hope it helps..

 

Its not needed and i will prove it. First off all of our hangers are RUBBER!!! and if you want rev your engine up now i bet your exhuast moves and it has a flex. THe rubber hangers will let the exhuast move enough to not break anything.

 

you make it sound like ppl who make these exhaust systems are rocket scientists, theyre anything but, the avg joe could make an exhaust for MUCH MUCH less the cost. might not be all pretty and bling, but itll function the same. basically the key to exh is, less bends the better.

 

The hangers are rubber, yes, but you have a solid mass, the engine, with a long straight tube running several feet along the bottom of the car with no way to flex independently of the engine. The longer and thinner an object is, the more prone to stress it is. Those rubber bushing are there to absord vibration and eliminate exhaust rattles, not compensate for the flexing of the exhaust. Trust me, I've tried to pry my downpipe back just an inch working against the rubber bushings to get a 2.5" O2 housing to fit, and I had a bitch of a time moving it the slightest amount. They're fairly solid.
If you want to try it then by all means go ahead, but I've seen 2 downpipes crack at the exhaust housing flange, and neither one had a flex section. :dunno:

 

I completely agree with colonelfox. All the vibrations and torqe would eventually break something. You want to have a little play in the exhaust system in case the engine turns or twists a little. A flex pipe will achieve that.

 

Rocket Scientists? No. Although, im SURE they spent more than the price of one exhaust to design it. Do you honestly think they just grabbed some pipe, bent it, and welded it together with just some random flex section that isnt really needed that most likely raised the cost of the product for the hell of it?

 

I would say just spend the extra money for the flex section. Would you rather it have a little give there or force the WHOLE exhaust system to move with the motor on the rubber hangers?

 

It sure as hell isn't difficult to build your own exhaust. I made mine for quite a bit less than the cheapest full turboback exhaust you can find. I don't see how much R&D can be put into something so simple. And to reinforce what everybody else has been saying, yes, a flex section is necessary.

 

well most of them just took the stock exhaust as a guide, and just recreated it in a larger diameter piping trying to use less bends, so really they didnt spend alotta money on researching and testing exhausts.

 

Nah, there's not a lot or "research" needed anymore. It's been done to death, and there's not much room for improvement with DSM's. The original designers though, like Mitsu with the stock (geared more toward drivability than performance obviously, but engineers did design it nonetheless), Buscher, Thermal, etc did put some time and effort into it.