Thinking of getting a custom exhaust on my 07 sedan. What are the pro's and con's of Stainless and anodized?

It seems pointless to pay upwards of a grand for an exhaust when I can buy the components and have tubing bent for a total of 5 or 6 hundred. I can't see mandrel bending making much difference on our cars. I looked under the car and It doesnt look like the bends on a new system will be much more the 30 degrees.

Last question> why don't alot of the aftermarket kits for the 2gen sedan come with flex tubing in the system?

 

Exhuasts actually do not come anodized. I think what you are referring to is aluminized steel which is not the same thing. The pros of stainless is that it is more corrosion resistant and gives you that nice shine for the pieces that can be seen. Since it is so much more corrosion resistant it is often times made of a thinner gage metal and is therefore often times lighter than in identical setup made from the aluminized steel. The only major con for stainless is its higher price. Also I do not know if this is what you meant, but if you are buying standalone components and running your own piping I would not mix the two materials. They do not blend very well metalurgically when you weld them and the thermal expansion coeffients are different so you may have cracking issues. Speaking of expansion, that is another con of stainless. The higher level of expansion creates some issues with cracking too, but most of the manufacturers take that into account when designing them so there usually is not a problem with that. I have heard of it happening on rare occasions though.

As for the flex tubing, most aftermarket systems do not come with them for two reasons. One is cost from extra materials and construction time. The second is because aftermarket systems focus primarily on maximizing performance. Flex tubing creates a larger pressure drop because they do not have inside walls that are as smooth as straight pipes (this is also why mandrel bending is better). OEMs use them to isolate vibrates from the rest of the car and to compensate for thermal expansion. They put some flexibility into the system so that the pipes can be pushed and pulled around for better alignment.

 

Thanks for your input and yes i was asking about aluminized steel. the exhaust on this car looks like it could be opened up a bit. I have not decided if I will have flex pipes put in yet or not. I am sure mandrel would make a small diff. but at half the price I dont think I will be finding out. Anybody with 2nd gen's want to add their 2 cents on which is better, H or X pipes for our cars? I am leaning towards x right now.