I-pipe modification!!!?
Thread Starter
Staging Lane
Joined: Sep 2005
Posts: 53
Likes: 0
From: west alexander, pa
X-pipe modification!!!? Got a question that seems feasable. 
I'm thinking about going with a true duals setup with headers to cats to x-pipe to bullet-mufflers. But I just had a brainstorm.
The idea is getting the X-pipe and cutting it in the middle and welding a catalytic converter/bullet-muffler in place and making it longer...I would probably do the catalytic converter instead of the bullet muffler because it would be cheaper and then use the bullet mufflers further on down the line but if I could place both of them back to back and have it fit, of course I would do that to eliminate any further restriction...or should I just stick with the original x-pipe setup? I know I sound confused and lost on this but I'm just trying to brainstorm here...I know I'm asking for it but, any insight would be appreciated (be gentle). Would there be any problems with air flow in doing this?
Does that sound reasonable enough or am I just chasing a "pipe" dream, so to speak?...no pun intended. Anybody thought about doing/done the same thing? Let me know if there is a better way to go about doing this. Maybe an I-pipe would be better...just have to use 90`pipe to connect to the headers. Thanks...
Griff
2000 5.7L formula, stock lid(removed baffles, raised up 1.5inches for better airflow), k&n air filter, smooth bellows, tb bypas, 160`stat, spiral max(yeah I know, but I notice a difference with it in there and so does everybody behind me
)
I'm thinking about going with a true duals setup with headers to cats to x-pipe to bullet-mufflers. But I just had a brainstorm.
The idea is getting the X-pipe and cutting it in the middle and welding a catalytic converter/bullet-muffler in place and making it longer...I would probably do the catalytic converter instead of the bullet muffler because it would be cheaper and then use the bullet mufflers further on down the line but if I could place both of them back to back and have it fit, of course I would do that to eliminate any further restriction...or should I just stick with the original x-pipe setup? I know I sound confused and lost on this but I'm just trying to brainstorm here...I know I'm asking for it but, any insight would be appreciated (be gentle). Would there be any problems with air flow in doing this?
Does that sound reasonable enough or am I just chasing a "pipe" dream, so to speak?...no pun intended. Anybody thought about doing/done the same thing? Let me know if there is a better way to go about doing this. Maybe an I-pipe would be better...just have to use 90`pipe to connect to the headers. Thanks...
Griff
2000 5.7L formula, stock lid(removed baffles, raised up 1.5inches for better airflow), k&n air filter, smooth bellows, tb bypas, 160`stat, spiral max(yeah I know, but I notice a difference with it in there and so does everybody behind me
) Last edited by griff71177; Oct 31, 2005 at 06:29 AM.
TECH Addict
Joined: Jun 2005
Posts: 2,660
Likes: 14
From: England
Confused - YES fraid so.
There are lots of after market cat backs which use a single muffler then split into a Y and dual out let.
Remember there are double the amount of exhaust gases from 8 cylinders as oppossed to 4.
The stock CATS only have to deal with 4 cylinders each. If you move the cat to the I pipe it will have to deal with 8 cylinders. They are already restrictive with 4 so moving it would be far worse.
You need to make sure every thing can flow well enough for the BHP level you are at or desire for future mods.
Long tube headers into high flow cats are a sensible bet. You can then do a Y pipe and cat back. 3" Y and high flowing cat.
Or from the CATS you could do an X Pipe into 2.5" duals. The duals should sound a little different. But on a bolt on Fbody there will be no difference in BHP. The duals flow better so at 500bhp they will exceed the 3" Y setup, but on a bolt on car you will likely sacrifice a little low end torque with the duals.
There are lots of after market cat backs which use a single muffler then split into a Y and dual out let.
Remember there are double the amount of exhaust gases from 8 cylinders as oppossed to 4.
The stock CATS only have to deal with 4 cylinders each. If you move the cat to the I pipe it will have to deal with 8 cylinders. They are already restrictive with 4 so moving it would be far worse.
You need to make sure every thing can flow well enough for the BHP level you are at or desire for future mods.
Long tube headers into high flow cats are a sensible bet. You can then do a Y pipe and cat back. 3" Y and high flowing cat.
Or from the CATS you could do an X Pipe into 2.5" duals. The duals should sound a little different. But on a bolt on Fbody there will be no difference in BHP. The duals flow better so at 500bhp they will exceed the 3" Y setup, but on a bolt on car you will likely sacrifice a little low end torque with the duals.
TECH Addict
Joined: Jun 2005
Posts: 2,660
Likes: 14
From: England
Originally Posted by griff71177
Say if I were to use a bigger cat...I know they make them 3, 4, and 5 inches round. Well I guess I'm just trying to do too much. But thanks for the advice
Random Technology make some excerlent metal matrix CATS, the 3" in/outlet ones flow around 580cfm.
use this as a guide 2.2cfm per 1hp.
So if your engine is producing 350bhp (stock) you would need 350 x 2.2 = 770cfm. Many CATS only flow around 200-300cfm. So even the metal matrix ones will still restrict gas flow. By putting one CAT per bank the flow rate is halfed, so each CAT only has to deal with 385cfm, on a stock engine. Well within the bounds of many high flow after market CATS.
The same principle applies for mufflers. If you are having only ONE muffler then it must flow at a sufficent rate not to inpeed gas flow.
Powerstick mufflers flow very well and are very compact. Search for Classic Chambered Mufflers in Google.
They would work well in either a custom dual setup or a custom Y setup.
However if you want to make an easier job of it, just get yourself a decent cat back like Stainless Works chambered exhaust or a GMMG.
