Im pulling my hair out and I know this is simple please help!!!
10-03-2011, 09:08 PM
#1
Thread Starter
Join Date: Sep 2011
Location: Virginia
Posts: 13
Im pulling my hair out and I know this is simple please help!!!
I am really having a time here with an exhaust question I just can't seem to figure out.. I know this is going to sound really dumb considering every Fox body mustang in the world has an exhaust system except for mine lol. I have a 91 Gt that is All Stock.. It does still have the Smog Stuff and from what I have read it is really not worth trying to delete it so here is my question's
1. What is the benefits of long tube verses Short tube headers?
2. If you go with short tube should you do equal length pipes? or just run standard shorty's
3. Do you really need 4 cat converters? I know there is the legal emissions issue but what if you have a way around that or do they make a set that is not so restrictive..
4. Now I am wanting to do from headers to tail pipes but I assume If I am going to keep my smog stuff I need to buy a kit that incorporates all three connections into it as in the EGR sensors and the Smog tube.. Do all headers come with these connections?
5. What is the difference between an off road kit and a street legal kit.
6. I notice when I look at pictures of headers and H pipes I really don't see the holes I need for the EGR valves why is that?
7. What is the difference between X pipe and H pipe..
If you have any suggestions on products please list them out.. I have no clue what I am doing when It comes to this I just would like to have an idea of what I am doing so when I go to the muffler shop to get everything installed or even purchase it I don't look like a total retard. Please don't use abbreviation I am no good with them lol. And detailed answers with great descriptions are wonderful.. Thanks very much.. Sorry to be a pain but I am really not sure where else to turn to get a good answer from other mustang guys..
1. What is the benefits of long tube verses Short tube headers?
2. If you go with short tube should you do equal length pipes? or just run standard shorty's
3. Do you really need 4 cat converters? I know there is the legal emissions issue but what if you have a way around that or do they make a set that is not so restrictive..
4. Now I am wanting to do from headers to tail pipes but I assume If I am going to keep my smog stuff I need to buy a kit that incorporates all three connections into it as in the EGR sensors and the Smog tube.. Do all headers come with these connections?
5. What is the difference between an off road kit and a street legal kit.
6. I notice when I look at pictures of headers and H pipes I really don't see the holes I need for the EGR valves why is that?
7. What is the difference between X pipe and H pipe..
If you have any suggestions on products please list them out.. I have no clue what I am doing when It comes to this I just would like to have an idea of what I am doing so when I go to the muffler shop to get everything installed or even purchase it I don't look like a total retard. Please don't use abbreviation I am no good with them lol. And detailed answers with great descriptions are wonderful.. Thanks very much.. Sorry to be a pain but I am really not sure where else to turn to get a good answer from other mustang guys..
10-03-2011, 10:27 PM
#2
6th Gear Member
Join Date: Nov 2006
Location: Spfld, MA
Posts: 9,240
1.) Long tubes will give you a bit more sustained power throughout the RPM band, but its worth noting that long tubes are illegal in all 50 states for street applications.
2.) Equal length pipes sometimes give issues with motor mounts and/or steering shafts, the unequals don't.
3.) Federal law inducted in 1973 mandates that all cat's installed on the vehicle at time of production must remain, with a $10,000 penalty for each cat removed. Fox's came stock with 4 cats.
4.) Check the fine print on the parts you buy. Most aftermarket stuff that is labeled "smog legal" will come with the holes you need, but if not, any competent exhaust shop can weld in some bungs for your needs.
5.) Offroad means no cats, at all. Street legal usually comes with 2 high flow cats(Usually reserved for people in california, or anyone needing to pass a tailpipe smog test)
6.) See #4
7.) Exactly as it would seem. X pipe has a X shaped crossover, whereas an H pipe is shaped like an H. They produce different sounds. H is more throaty and typical of your average stang, X pipes are a bit raspier(my personal preference).
2.) Equal length pipes sometimes give issues with motor mounts and/or steering shafts, the unequals don't.
3.) Federal law inducted in 1973 mandates that all cat's installed on the vehicle at time of production must remain, with a $10,000 penalty for each cat removed. Fox's came stock with 4 cats.
4.) Check the fine print on the parts you buy. Most aftermarket stuff that is labeled "smog legal" will come with the holes you need, but if not, any competent exhaust shop can weld in some bungs for your needs.
5.) Offroad means no cats, at all. Street legal usually comes with 2 high flow cats(Usually reserved for people in california, or anyone needing to pass a tailpipe smog test)
6.) See #4
7.) Exactly as it would seem. X pipe has a X shaped crossover, whereas an H pipe is shaped like an H. They produce different sounds. H is more throaty and typical of your average stang, X pipes are a bit raspier(my personal preference).
10-03-2011, 10:38 PM
#3
Join Date: Jul 2011
Location: TX
Posts: 24
Hey Rage91GT - here are some thoughts on some of your questions-->
1. What is the benefits of long tube verses Short tube headers?
A general rule of thumb I learned over the years is that if you plan to modify the engine with larger power adders like heads/cam/intake or even super charger, long-tubes are the way to go. But if you're just adding smaller mods like flow masters, cold-air intake, etc, short headers will do well. The specs of this aren't quite so clear cut and it can become science in measuring dyno numbers but this method has worked for me and several other mustang enthusiasts I've known over the years.
3. Do you really need 4 cat converters? I know there is the legal emissions issue but what if you have a way around that or do they make a set that is not so restrictive..
I've only seen/used catted x-pipes that have 2 cats, not 4. The legal emissions issue is tough to get around if your state/county enforce testing. I recommend just installing the cats and being done with it. It's not really worth trying to get around it b/c you'll be in the same boat the next year. And, cats don't really hurt performance too much.
4. Now I am wanting to do from headers to tail pipes but I assume If I am going to keep my smog stuff I need to buy a kit that incorporates all three connections into it as in the EGR sensors and the Smog tube.. Do all headers come with these connections?
If you're keeping all smog-related components, you don't need anything special. For example, if you buy BBK short headers with a matching catted long x-pipe, everything should just bolt up with no problems. The only mod necessary is the smog tube running down from the engine compartment that connects to the x-pipe. Usually, a heavy-duty hose and some clamps are included. Just cut the tube off the current exhaust and attach using the hose & clamps. Should have no exhaust leak problems.
5. What is the difference between an off road kit and a street legal kit.
Off-road = no catalytic converters, Street legal = catalytic converters
7. What is the difference between X pipe and H pipe..
I can't really explain the exact science of it but overall, x-pipes are known to have higher flow because of the "crossover" X design, which produces a little more horsepower. And, they're a little more expensive too but probably worth it in the long run. I think x-pipes actually produce a slightly different sound than the h-pipe, which isn't a primary reason to buy.
I'm guessing your Mustang is a fairly regular ride that you just want to give some pep and have a nice sounding exhaust. For this, a suggestion is to just go with something like matching BBK short headers & catted x-pipe along with some 2 chamber Flowmaster mufflers, finished off with 2.5 inch pipes. Do not go with "Dumps" that cut off underneath the car to get a louder sound...bad idea unless you're pushing some serious horsepower and the setup actually calls for the omission of full exhaust pipes.
If any of my thoughts above could be better explained, others feel free to jump in and add some comments. Hope this stuff helps you get started on your project!
1. What is the benefits of long tube verses Short tube headers?
A general rule of thumb I learned over the years is that if you plan to modify the engine with larger power adders like heads/cam/intake or even super charger, long-tubes are the way to go. But if you're just adding smaller mods like flow masters, cold-air intake, etc, short headers will do well. The specs of this aren't quite so clear cut and it can become science in measuring dyno numbers but this method has worked for me and several other mustang enthusiasts I've known over the years.
3. Do you really need 4 cat converters? I know there is the legal emissions issue but what if you have a way around that or do they make a set that is not so restrictive..
I've only seen/used catted x-pipes that have 2 cats, not 4. The legal emissions issue is tough to get around if your state/county enforce testing. I recommend just installing the cats and being done with it. It's not really worth trying to get around it b/c you'll be in the same boat the next year. And, cats don't really hurt performance too much.
4. Now I am wanting to do from headers to tail pipes but I assume If I am going to keep my smog stuff I need to buy a kit that incorporates all three connections into it as in the EGR sensors and the Smog tube.. Do all headers come with these connections?
If you're keeping all smog-related components, you don't need anything special. For example, if you buy BBK short headers with a matching catted long x-pipe, everything should just bolt up with no problems. The only mod necessary is the smog tube running down from the engine compartment that connects to the x-pipe. Usually, a heavy-duty hose and some clamps are included. Just cut the tube off the current exhaust and attach using the hose & clamps. Should have no exhaust leak problems.
5. What is the difference between an off road kit and a street legal kit.
Off-road = no catalytic converters, Street legal = catalytic converters
7. What is the difference between X pipe and H pipe..
I can't really explain the exact science of it but overall, x-pipes are known to have higher flow because of the "crossover" X design, which produces a little more horsepower. And, they're a little more expensive too but probably worth it in the long run. I think x-pipes actually produce a slightly different sound than the h-pipe, which isn't a primary reason to buy.
I'm guessing your Mustang is a fairly regular ride that you just want to give some pep and have a nice sounding exhaust. For this, a suggestion is to just go with something like matching BBK short headers & catted x-pipe along with some 2 chamber Flowmaster mufflers, finished off with 2.5 inch pipes. Do not go with "Dumps" that cut off underneath the car to get a louder sound...bad idea unless you're pushing some serious horsepower and the setup actually calls for the omission of full exhaust pipes.
If any of my thoughts above could be better explained, others feel free to jump in and add some comments. Hope this stuff helps you get started on your project!
10-03-2011, 10:49 PM
#4
4th Gear Member
Join Date: Aug 2008
Location: Seattle, WA
Posts: 1,233
As for #3, I think the fine for removing them is mostly aimed at exhaust shops who remove them. I don't think the law is really enforced in the sense that if you are caught without a cat, they will charge you $10,000. I think they can't really prove that you removed the cat, but if a muffler shop removed them then it's in the records.
I might be mistaken but this is how I saw it.
However, by removing the catalytic converters, even if you're not fined, you may fail to pass your state's emissions test/inspection (if you have one) and they'd require you to get it fixed.
I might be mistaken but this is how I saw it.
However, by removing the catalytic converters, even if you're not fined, you may fail to pass your state's emissions test/inspection (if you have one) and they'd require you to get it fixed.
10-04-2011, 04:41 PM
#5
4th Gear Member
Join Date: Jan 2008
Location: Louisville, Ky.
Posts: 1,326
Flowmaster sound good, but don't flow very good. Magnaflow has a much higher CFM rating.
I bought an off-road H-pipe and put a set of high flow converters in it cheaper than buying one already made. They flow great, just makes it a little quieter under hard acceleration.
I bought an off-road H-pipe and put a set of high flow converters in it cheaper than buying one already made. They flow great, just makes it a little quieter under hard acceleration.
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