I was inspired by the C5 exhaust mod to make this post. No expert on exhaust system here, but in my reading about all the upgrades, many have mentioned that the crossover in the stock system is so small that it is more or less meaningless to exhaust flow.

For those who arent neccessarily looking to upgrade to long tube headers, X-pipe, etc, would there be any benefit to opening up the crossover to the full diameter of the pipe? I would propose doing this in one of two ways:

1) cut a hole in the side of the exhaust pipe to give access to the crossover, then cut to open the crossover fully. Then patch the hole. Repeat on the other side if you cant cut out both from one side.

2) cut in a new crossover, either in place of or in addition to the factory one.

Would either of these provide any meaningful effect, either to sound quality or to power output? It seems to me that either of these could be done relatively cheaply (especially compared to buying a new X-pipe) at any exhaust shop.

 

Seems like a lot of work when you can buy a true X Pipe for a decent price.

 

Sounds like alot of work even you have your own welder, cutter, grinder, etc. I picked up a Corsa X pipe for a couple hundred bucks, no muss, no fuss and it got rid of the popping on decel too. But, hey if you like to tinker I say go for it and post pics.

 

If you are going to do that,,cut the H cross pipe then you can open both sides up with 1 cut, Slip a 2 1/2" connector over and clamp it or weld it!! Still a lot of work for little results. I got a Corsa X,,barely used for $150 !!

 

Bought an x off of the auction site for about 30 bucks, cut the factory H pipe section out and welded in the x. Easy and cheap. If you're going to the trouble of the mod on the H pipe get the x pipe on there. It sounds better too....

 

Probably the easiest cheapest way to go

 

I know someone that cut the halves apart using a hacksaw. He cut the "H" in half and with a torch he was able to blast out the little holes to full size. Then he welded the two pipes back together on the "h"

It's a pointless move since the location of the h is so far away from the manifold collectors. The point is to equalize flow from side to side. There is a point where too far back doesn't really help.

 

And the true X-pipe will be designed to give maximum benefit.

 

I wouldn't think that it would be worth the brain damage to do.

 

The 97 and 98 H pipe was actually a decent scavaging system even with the half dollar sized crossover.. But in 99 a line change in manufacturing cause the opening to be downsized to the size of a dime. The Cross over X pipes that are offered today are a better design but that application in manufacturing was outside of the cost budget for the exhaust system... If you have the money the X pipes are the better way to go, but if you dont have the money, any one who has a plasma cutter can cut the h pipe in half and burn out the opening in each pipe in les than ten minutes.. then reweld the crossover.. its simple and effective.. if you have to pay someone a hundred dollars to do this , you might want to consider buying an Xpipe...if someone will do this for free.. you may want to consider it.. it will do the job...

 

I have a Magnaflow X-pipe on my 2002 Z06 ( installed 2 years ago).

IMO- the car sounded much more aggressive (better) with the oem H-Pipe. Actually- bodacious.

Had to install a Corsa Extreme Cat-Back to regain the right sound balance.

Just another view from someone who's had both.

 

Nate, the problem with the stock H pipe is that it makes the engine run alittle rough, and because the exhaust gases are trapped as the exhaust valve opens... in other words, you want those exhaust gases to be Pulled out of the cylinders even though the exhaust stroke does the work, the savaging helps to get those exhaust gases out quicker than the cylinder push by itself.. the engine runs alittle rougher, but for this same reason, some people want a cam just for the rough loping idle..The stock H pipe causes uneven scavenging, therefore, the engine does not run as smooth and this uneven savaging cause a loss of HP.
When I see some people ask " How does this cam sound" rather than how much power and torque does this cam make. Its not a performance mod... its a profiling mod.