Im pulling my hair out and I know this is simple please help!!!

[Rage91GT]

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..

 

[wythors]

1. Improved exhaust scavenging and, theoretically, more power. In my experience, this really only applies to an engine that has had fairly extensive modifications. For a mostly stock 5.0, shorty headers are more than adequate.

2. Side by side tests that I have seen in magazines show very little, if any, gain to be had with equal length vs. unequal shorties. Any benefit is more than offset by the hassles involved in getting to the spark plugs and burned plug wires.

3. Depends on where you live. California requires four cats. Most other states are satisfied with two. My LX passes DEQ with extensive mods and a two cat pipe cleaner than when it was new.

4. Every mid pipe that I have seen has provisions for the O2 sensors and the air injection tube.

5. Off-road = no catalytic converters. Street legal = with cats.

6. Dunno. See #4

7. Sound. They just sound "different". Some people say an X sounds "raspy" and an H sounds deeper. My experience is that they sound different, but not enough to make a difference to me. I'd just pick the least expensive.

As far as recommendations, it is all very subjective. Personally, I'm partial to FRPP shorty headers, either in stainless or coated. Top quality stuff. A good friend just got a set of BBK coated long tubes. I was very impressed with the fit and finish. I'll probably get a set for my Saleen when I do the blower. Mid pipe, like I said, take your pick. I have a Bassani catted X on my LX and it is fine. For the cat-back, you're on your own. You need to decide what sound you like. I have a car with SLP Loudmouths on it, one with Powerflo's and another with 3-chamber Flowmasters. They all sound different. Get on Youtube and start searching.

 

[Mustang5L5]

Keep it simple for now. Just buy a cat-back exhaust setup of your choosing and bolt that on and enjoy. There's no rule that you need to change headers, h-pipe and cat-back at the same time. So start with the cat-back, see how you like it, then at a later date change the H-pipe.

If you are near stock, stock headers are fine. You can use shorty headers (i recommend ford racing) and these can be changed out in the future too.

If you have money to burn now though, changing all 3 would be easy, but you can do one at a time as well

 

[ID89GT]

If you buy an aftermarket catted h pipe or x pipe, do you have to run the smog pump? I see in the pictures they all have the tube to hook up the smog to so just wondering if you could just cap that off or is it needed

 

[Mustang5L5]

Yes, you need it.

 

[ID89GT]

Lame, is there any catted mid pipes that don't require a smog pump?

 

[90mustang50]

1. Benefits of shorty headers: In my opinion, they seem to sound more throaty, and also, you have a lot easier access to the spark plugs with shorty headers.
2. Equal length only add about 10 hp, give or take a few, depending on your setup.
3. Many people, have no cats, and as long as you don't live in a state where they will check your car annually or whatever, you should be fine.
4. I'm not sure what different types they make, I imagine you could find pretty much anything. But if you just get a set of shorty headers and a good cat-back exhaust system, it will do wonders. And by the way, the smog pump isn't all that hard to delete. And you will also gain a little bit of power from deleting the weight and the pump itself off of the belt.
5-7. Some times you have will have to weld the sensors into the pipe. I believe the difference between x and h pipes is one helps you more with torque and the other with hp. X I believe is torque. As for what kind you want, it depends on the sound you're looking for, and the setup you have. You want a lot of flow. I would say Mac exhaust systems or Flowmasters. I personally have a full Mac exhaust, and I am VERY VERY pleased with it.

 

[wythors]

1. Benefits of shorty headers: In my opinion, they seem to sound more throaty, and also, you have a lot easier access to the spark plugs with shorty headers.
2. Equal length only add about 10 hp, give or take a few, depending on your setup.
3. Many people, have no cats, and as long as you don't live in a state where they will check your car annually or whatever, you should be fine.
4. I'm not sure what different types they make, I imagine you could find pretty much anything. But if you just get a set of shorty headers and a good cat-back exhaust system, it will do wonders. And by the way, the smog pump isn't all that hard to delete. And you will also gain a little bit of power from deleting the weight and the pump itself off of the belt.
5-7. Some times you have will have to weld the sensors into the pipe. I believe the difference between x and h pipes is one helps you more with torque and the other with hp. X I believe is torque. As for what kind you want, it depends on the sound you're looking for, and the setup you have. You want a lot of flow. I would say Mac exhaust systems or Flowmasters. I personally have a full Mac exhaust, and I am VERY VERY pleased with it.

Much of this is balderdash.

 

[Mustang5L5]

Much of this is balderdash.

Have to agree

 

[Chrome_Rust]

Have to agree

+1

 

[mob]

Most of the questions have been answered but I can add a few things. I would recommend shorty headers for your setup. Longtubes are unnecessary for your application and are going to be nothing but a hassle. If you stick with the shorties your stock mid pipe will bolt right up to them allowing you to buy one piece at a time. Or, you can do it the other way around, buy a mid pipe for shorty headers so they will bolt up to the stock headers and then you can by the aftermarket shorties later on.

The EGR and smog are different systems. The exhaust system on these cars do not have any pipes that go to the egr valve, it is all internal through the heads and intake manifolds.

Difference between H and X pipe is honestly sound and that's about it, go on youtube and see which you prefer. If you are in a state that does emission testing I would stick with a street legal mid pipe and keep the smog. If you do not have to worry about emissions, going with an offroad pipe and ditching the smog stuff is the way to go.

Leave the EGR alone, it has nothing to do with the headers or mid pipe on these cars.

 

[C6AE]

One of the great things about these cars is the choices you can make in this area. I've had so many different exhaust configurations, I doubt I can remember them all. Right now it's FR coated shorties, Bassani catted X, and Flow Paths (love the sound...) When I need to pass vehicle inspection (they don't love the sound...), the Dyno Max Ultra's go back on. Ball and socket makes it an easy swap. Like others have said, do one part at a time.

 

[Sharad]

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..

There is a lot of misinformation and general squabbling in here. I don't want to get involved with that, so I'll just cut to the chase.

With a stock 5.0, you don't need super crazy race exhaust. A good off-road x-pipe and a nice cat-back system will work great and sound awesome. (headers probably wouldn't give you 2 horsepower at your power level) This setup wouldn't be a restriction until you are making nearly double the factory horsepower.

I went 12.91 @ 103 in my '89 LX with a stock 302 using an off-road mid-pipe and MAC Pro Dumps. I strapped a blower to the same stock 302 and same exhaust system, and ran 11.36 @ 122. (stock headers)

If I were you, I'd add the exhaust I listed in my second paragraph there and bypass/eliminate the smog system. Simple and effective!

If you have any more specific questions, feel free to drop me a PM and I can offer up suggestions. I'll give you my cell # if you'd rather just discuss it over the phone.

Here are some links to the articles I wrote with the two passes I just mentioned:

1989 Ford Mustang LX - Fox Buildup

1989 Mustang LX Upgraded - 5.0 Mustang & Super Fords Magazine

 

[reldla1996]

I think Wythors is pretty much spot on. Long tube headers will generally net you a few more hp, but the closer you are to stock, the smaller the difference is. All the tests I've seen show the equal and non-equal length shorties virtually equal, and the non-equal are so much easier to live with. I've had both X pipes and H pipes, and the X pipes are supposed to make slightly more power, while the H pipes make slightly more torque, but the difference is so slight that you really should pick them on sound. The H pipes tend to be louder, and more throaty, while the X pipes have a higher pitch (frequency) to them while being quieter.

 

[wythors]

Nice. The magazine writer advocates violating federal law.

 

[mob]

lol what does being a magazine writer make him a cop? I'm only a retail sales person so its cool for me to advocate it?

 

[wythors]

lol what does being a magazine writer make him a cop? I'm only a retail sales person so its cool for me to advocate it?

I just find it humorous. The magazines always tiptoe around the emissions equipment issue because they know that it's against the law for a business to advise a customer to remove emissions equipment. His other employer (UPR) clearly states "off road use only" on their mid-pipes, because they also know that it is against federal law to offer them as direct replacement. Yet he says to rip it all off and you're good to go.

If you are a counterman in the auto industry, you need to be careful what you do or sell regarding emissions parts. Several years back I was running some Midas stores. A guy came in and wanted me to remove his cats for him. I refused. He pushed. I still refused. He showed me his EPA identification, said I did the right thing, left my shop and went down the street to an independent shop. They did it for him and he wrote them a $50,000 citation. Do what you want to your own car, but if you're in the industry, you can screw yourself or your employer if you don't play by the rules.

 

[kpack5982]

Just a recommendation: If you do decide to go headers, whether shorties or long tube, look into the ones that have one flange that bolts to the head versus individual flanges for each exhaust tube. Individual flanges don't always line up as well and can be a pain getting all the bolts in.

 

[90lxcoupe]

1. Benefits of shorty headers: In my opinion, they seem to sound more throaty, and also, you have a lot easier access to the spark plugs with shorty headers.
2. Equal length only add about 10 hp, give or take a few, depending on your setup.
3. Many people, have no cats, and as long as you don't live in a state where they will check your car annually or whatever, you should be fine.
4. I'm not sure what different types they make, I imagine you could find pretty much anything. But if you just get a set of shorty headers and a good cat-back exhaust system, it will do wonders. And by the way, the smog pump isn't all that hard to delete. And you will also gain a little bit of power from deleting the weight and the pump itself off of the belt.
5-7. Some times you have will have to weld the sensors into the pipe. I believe the difference between x and h pipes is one helps you more with torque and the other with hp. X I believe is torque. As for what kind you want, it depends on the sound you're looking for, and the setup you have. You want a lot of flow. I would say Mac exhaust systems or Flowmasters. I personally have a full Mac exhaust, and I am VERY VERY pleased with it.

Dont listen to a word of these shennanigans.

Just a recommendation: If you do decide to go headers, whether shorties or long tube, look into the ones that have one flange that bolts to the head versus individual flanges for each exhaust tube. Individual flanges don't always line up as well and can be a pain getting all the bolts in.

Header studs could eliminate this problem. Or if you dont wanna spend 60 on the kit just get some socket head set screws and grade 5 or 8 nuts and you will be mint.