5.4L ppl ?......Mike??.....
#1
01-15-2001, 11:42 PM
Join Date: Jan 2001
Location: The Ocean State
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5.4L ppl ?......Mike??.....
I want to get a lil more power out of this thing(my truck) and am going to have the exhaust done soon and want to know if I should get a Large single exhaust ( 3") with NO cat and 1 MUFF.....OR
Get Dual exhaust with NO cats and 2 muffs???
Does the 5.4L like a lot of backpressure in a TRUCK situation or would it perform better with a restrictionLESS exhaust?
Any Free Mods?.......and what about a chip?
Thanks all,
JON
FWIW,I bought the truck with a HACK exhaust system.I does not have the factory Y-pipe or the Cat on it
------------------
1999 F350 SD XLT 5.4L Black!
See my TRUCK!!
Get Dual exhaust with NO cats and 2 muffs???
Does the 5.4L like a lot of backpressure in a TRUCK situation or would it perform better with a restrictionLESS exhaust?
Any Free Mods?.......and what about a chip?
Thanks all,
JON
FWIW,I bought the truck with a HACK exhaust system.I does not have the factory Y-pipe or the Cat on it
------------------
1999 F350 SD XLT 5.4L Black!
See my TRUCK!!
#2
01-16-2001, 01:17 PM
Former Sponsor
Hi Jon,
Good questions!
First, it's not a matter of "backpressure" that is affecting the torque, or that the engine needs a certain amount of backpressure, it's what happens to the actual velocity of the spent exhaust stream traveling through the system when you open it up, and the resultant changes in the actual pressure waves, their pulse and phasing, that affects all of this, not backpressure per se.
It's very common for people to express this by saying things like "the engine needs a certain amount of backpressure, or you lose low-end torque". That is not technically correct, nor am I really qualified to explain it properly, in all honesty. It all gets down to what happens to the actual velocity, or the speed at which the spent exhaust gases travel through the system, which affects the actual pressure waves.
For example, let's say you put a set of "true duals" on it, in a 2.5 or 3 inch size. Sure, you'll gain horsepower at heavier throttle openings at higher rpms, easily! But what will also happen is you will lose some torque in the lower rpm ranges, particularly on part-throttle, and *that* kills driveability in these heavy trucks. In a lighter car, like a Mustang or a GM Camaro for example they weight a lot less, a lot of people put higher numerical gears in the rear end (3.73's, 4.10's, etc.), and so they can much more easily tolerate those kinds of exhaust system changes than these heavy trucks with stock gearing can.
There are a couple of ways to go here....if you want true duals, then you re-do the entire system, and you'll want to use nothing larger than 2.25" for the pipe diameter, any larger and you'll kill low-end torque too much. Since teh Y-pipe has already been altered, that's what I would do most likely.
Or, if you want to go with a single system, which is how most aftermarket cat-back systems are designed these days for these newer trucks, then you go with a 3" single system, like Gibson, etc.
It also depends on just what the vehicle is going to be used for. Are you going to be towing? If so, then you need to concentrate on low-end torque, using a system such as Gibson's Swept-side model, that was designed with towing in mind. You don't have to tow to get the benefits of that system, either.
If you're not going to do any towing, then you might want to opt for a true-dual setup, though it can be a bit expensive.
Also, running without the catalytic converters is illegal in every state, that is *Federal* law and hence supercedes individual state policy (I mention that only for those who live in states that have dropped their emissions inspections and thus think that there are no emissions laws, that isn't the case, everyone has to abide by the Federal laws on this). Also, they do not rob you of any appreciable amount of power these days like they used to. Most cats today do not produce more than 2.0-2.5 lbs. backpressure, whereas with older vehicles (say roughly pre-1988 or so) the cats *did* produce a lot of backpressure, in the area of 5-7 lbs. The automakers have done a lot of work to improve flow rates, backpressure, etc., so that has changed from what it used to be, and cats are no longer a source of significant restriction in most systems today.
If it were me, I would want to first make sure everything is operating properly, that the O2 sensors were put back where they belong, etc. Since there are no cats on the vehicle now, I would install aftermarket high-flo cats, so as not to pollute the atmosphere any worse, and so you can pass any smog check. Since the system on it now is a "HACK" setup as you say, I'd do it over from front to back. For me, that would be a pair of high-flo cats, and a true-dual setup on it, since the Y-pipe has already been altered, and I would use 2.25" diameter tubing front to back. That should produce acceptable torque down low, a great tone, and nice power when you stand on it.
As far as "free" mods, well, there is a tech article on how to open up the factory airbox a bit here on F-150 online, but I'm not in favor of doing that, as replacing the factory airbox is expensive, cutting holes in it only gets you maybe 2-3 more hp, and excellent aftermarket completely airbox elimination kits are available that will get better power gains. That's just my opinion, you may feel differently of course.
With regards to the Superchip, sure, that's available, and will work very well to not only improve power, but to also clean up the overall shift characteristics in the autoamtic transmission. It does require the use of premium gasoline.
If you would like, you might want to just give us a call and let's go over all the various aspects of this vehicle, what has been done to it, how you're using it, what you really want to get out of it, your budget, etc., and we'll be happy to give you some suggestions based on all of that, for you to give some thought.
------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer
Good questions!
First, it's not a matter of "backpressure" that is affecting the torque, or that the engine needs a certain amount of backpressure, it's what happens to the actual velocity of the spent exhaust stream traveling through the system when you open it up, and the resultant changes in the actual pressure waves, their pulse and phasing, that affects all of this, not backpressure per se.
It's very common for people to express this by saying things like "the engine needs a certain amount of backpressure, or you lose low-end torque". That is not technically correct, nor am I really qualified to explain it properly, in all honesty. It all gets down to what happens to the actual velocity, or the speed at which the spent exhaust gases travel through the system, which affects the actual pressure waves.
For example, let's say you put a set of "true duals" on it, in a 2.5 or 3 inch size. Sure, you'll gain horsepower at heavier throttle openings at higher rpms, easily! But what will also happen is you will lose some torque in the lower rpm ranges, particularly on part-throttle, and *that* kills driveability in these heavy trucks. In a lighter car, like a Mustang or a GM Camaro for example they weight a lot less, a lot of people put higher numerical gears in the rear end (3.73's, 4.10's, etc.), and so they can much more easily tolerate those kinds of exhaust system changes than these heavy trucks with stock gearing can.
There are a couple of ways to go here....if you want true duals, then you re-do the entire system, and you'll want to use nothing larger than 2.25" for the pipe diameter, any larger and you'll kill low-end torque too much. Since teh Y-pipe has already been altered, that's what I would do most likely.
Or, if you want to go with a single system, which is how most aftermarket cat-back systems are designed these days for these newer trucks, then you go with a 3" single system, like Gibson, etc.
It also depends on just what the vehicle is going to be used for. Are you going to be towing? If so, then you need to concentrate on low-end torque, using a system such as Gibson's Swept-side model, that was designed with towing in mind. You don't have to tow to get the benefits of that system, either.
If you're not going to do any towing, then you might want to opt for a true-dual setup, though it can be a bit expensive.
Also, running without the catalytic converters is illegal in every state, that is *Federal* law and hence supercedes individual state policy (I mention that only for those who live in states that have dropped their emissions inspections and thus think that there are no emissions laws, that isn't the case, everyone has to abide by the Federal laws on this). Also, they do not rob you of any appreciable amount of power these days like they used to. Most cats today do not produce more than 2.0-2.5 lbs. backpressure, whereas with older vehicles (say roughly pre-1988 or so) the cats *did* produce a lot of backpressure, in the area of 5-7 lbs. The automakers have done a lot of work to improve flow rates, backpressure, etc., so that has changed from what it used to be, and cats are no longer a source of significant restriction in most systems today.
If it were me, I would want to first make sure everything is operating properly, that the O2 sensors were put back where they belong, etc. Since there are no cats on the vehicle now, I would install aftermarket high-flo cats, so as not to pollute the atmosphere any worse, and so you can pass any smog check. Since the system on it now is a "HACK" setup as you say, I'd do it over from front to back. For me, that would be a pair of high-flo cats, and a true-dual setup on it, since the Y-pipe has already been altered, and I would use 2.25" diameter tubing front to back. That should produce acceptable torque down low, a great tone, and nice power when you stand on it.
As far as "free" mods, well, there is a tech article on how to open up the factory airbox a bit here on F-150 online, but I'm not in favor of doing that, as replacing the factory airbox is expensive, cutting holes in it only gets you maybe 2-3 more hp, and excellent aftermarket completely airbox elimination kits are available that will get better power gains. That's just my opinion, you may feel differently of course.
With regards to the Superchip, sure, that's available, and will work very well to not only improve power, but to also clean up the overall shift characteristics in the autoamtic transmission. It does require the use of premium gasoline.
If you would like, you might want to just give us a call and let's go over all the various aspects of this vehicle, what has been done to it, how you're using it, what you really want to get out of it, your budget, etc., and we'll be happy to give you some suggestions based on all of that, for you to give some thought.
------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer
#3
01-16-2001, 04:48 PM
Join Date: Jan 2001
Location: The Ocean State
Posts: 50
Likes: 0
Received 0 Likes
on
0 Posts
Mike,
Thank you for the info
I will be getting a Flowmaster Y-pipe and a single 3" exhaust into a single muff(not sure what kind yet).
As far as the Cat goes.....I will think about it.
I will be towing around my Mustang to race tracks all over the damn place
Thanks again,
Jon
------------------
1999 F350 SD XLT 5.4L Black!
See my TRUCK!!
Thank you for the info
I will be getting a Flowmaster Y-pipe and a single 3" exhaust into a single muff(not sure what kind yet).
As far as the Cat goes.....I will think about it.
I will be towing around my Mustang to race tracks all over the damn place
Thanks again,
Jon
------------------
1999 F350 SD XLT 5.4L Black!
See my TRUCK!!
#4
01-16-2001, 05:24 PM
Former Sponsor
Hi Jon,
I'm glad to hear that Flowmaster has a Y-pipe that will bolt on for you, excellent!
You'll of course want to make sure to have the O2 sensors put back where they belong, and you shouldn't have any problems.
So then it's just a mnatter of deciding which muffler to put on it. There are a number of good choices, my choice in that case would probably be the Dynomax (used to be made by Walker, before Walker was bought out by Dynomax) Ultra-Flow models, now that they are available in aluminum as well as the stainless steel they were always available in.
Best of luck whatever you decide!
------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer
I'm glad to hear that Flowmaster has a Y-pipe that will bolt on for you, excellent!
You'll of course want to make sure to have the O2 sensors put back where they belong, and you shouldn't have any problems.
So then it's just a mnatter of deciding which muffler to put on it. There are a number of good choices, my choice in that case would probably be the Dynomax (used to be made by Walker, before Walker was bought out by Dynomax) Ultra-Flow models, now that they are available in aluminum as well as the stainless steel they were always available in.
Best of luck whatever you decide!
------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer