Exhaust question: What's the function of an X-pipe??

Just as titled. I am thinking to put an exhaust on my Q45. I am probably going to muffler shop and have them make one for me, gutting everything out except the cats.

I am trying to make 2 exhaust outlets from each side, not a single one like the stock form. I have seen some V8 putting X-pipes but I have no idea whats the function of it. Do I need an X-pipe to make the flow smoother or just 2 seperate pipes coming from each cat will be fine? 

If I need an X-pipe where can I find them, does any of the muffler shop will be able to make one??

Thanks guys

Quoted from jcSCOOPS.com
"[b]X pipe = used in most dual exhaust systems, smoothing out the pressure and improving performance. Located between the catalytic converter and the muffl[/b]"

Here's a good link with a nicely made custom "crossover junction" from Dr. Gas

[img]http://drgas.com/store/files/master/product_images/TXJ.gif[/img]

[url]http://www.drgas.com/store/product.php?productid=2&cat=14&page=1[/url]

Nice, thanks a lot Pagong!!!

But dang $169.95 for a piece of x-pipe?? they sounds steep......

There's alot more in that site....check out thier site.
Good Luck.

X-pipes also help to create a venturi effect. As each bank of cylinders fire in scuccessive order the exhaust pulse's as they cross through the X create a vacumn thuse creating additional exhaust scavenging. They help to create more power and torque as well as quite a exhaust system down.

[url]http://magnaflow.com/02product/02xypipes.asp[/url]

Here's a good thread from NICO that talks about why you should use the X pipe.
[url]http://forums.nicoclub.com/zerothread/172085[/url]

And, from that same thread, a link for the Magnaflow X pipe for ~$80.
[url]http://www.autoanything.com/exhausts-mufflers/69A2672A0A0.aspx[/url]

thanks! I was also wondering about using an X pipe

Or go to [url=http://www.summitracing.com]www.summitracing.com[/url] they have alot of selection for universal X pipe kits.

you'll probably want to gut out your pre-cats actually... well, they're not even pre-cats, they're real cats. The ones that are attached to the exhaust manifolds. In most all cases, they are all clogged up by now, and do nothing but hinder the car's breathing.