Can you gain hp and tq w/duals?
Senior Member
Joined: Aug 2004
Posts: 2,824
Likes: 0
From: North Huntingdon,Pa.
?
Exhaust Science Demystified
I ran duals for awhile. Lost a lot of torque and pushed my HP power band so far up the RPM scale that it was useless. David Vizard's article set me straight. I now run a DI/SO Dynomax Super Turbo which flows 671 cfm.
I ran duals for awhile. Lost a lot of torque and pushed my HP power band so far up the RPM scale that it was useless. David Vizard's article set me straight. I now run a DI/SO Dynomax Super Turbo which flows 671 cfm.
1-tubing size?
2-muffler type?
3-x-pipe?
4-mandrell bent?
i did mine right and my tq went up
Member
Joined: Mar 2001
Posts: 60
Likes: 0
From: Columbia, SC.
Happy 4th of July.
Dear “openclasspro11”, “2001screw4x4”, “jbrew”
You’re so full of sh*t, it’s really hard to know where to begin … and this reply isn’t for you, but for the more impressionable forum members who might actually buy into your crap.
My performance exhaust expertise is reserved for my Mustang, (CAR) = [(Ncy - 1)(Dp²)] + Dtp², many thanks to David Vizard and Dave Carpenter. It became evident early on, that our pickups, Lightnings aside, were more susceptible (valve overlap) to the common aftermarket performance muffler add-on marketing ploys.
In our slow flow systems, 2.25” pipes have too much surface area in a dual setup to be efficient. You must have spent a fortune in dyno runs to achieve slightly elevated stock performance with 2.25 duals. How do I know? Any “so called” performance gain would have been better with a single 3” pipe (7” area, 9.42” surface resistance) in place of the 2.25” pipes (8” area, 14.12” surface resistance) on a stock pickup.
But that’s not the really the truth is it? You’re just bs’n the forum so that no one will know how totally punked you were by the exhaust mechanic who oversold you his SS pipes at $10 a ft after convincing you to put in hi-flow clay (ceramic) cats while he sold your metallic cats right out from under you.
Why is it that dual and worst, SI/DO, “aficionados”, insist on propagating their errors on the rest of us. X-H pipe AFTER the cats? What were you thinking? Do your homework Fool.
Ps: BigDaddy64, you’re just shilling for these “dually” punks right? How are those glass packs working for ya? Turned your pickup into a 3-ton paperweight yet? Been fun, gotta go.
You’re so full of sh*t, it’s really hard to know where to begin … and this reply isn’t for you, but for the more impressionable forum members who might actually buy into your crap.
My performance exhaust expertise is reserved for my Mustang, (CAR) = [(Ncy - 1)(Dp²)] + Dtp², many thanks to David Vizard and Dave Carpenter. It became evident early on, that our pickups, Lightnings aside, were more susceptible (valve overlap) to the common aftermarket performance muffler add-on marketing ploys.
In our slow flow systems, 2.25” pipes have too much surface area in a dual setup to be efficient. You must have spent a fortune in dyno runs to achieve slightly elevated stock performance with 2.25 duals. How do I know? Any “so called” performance gain would have been better with a single 3” pipe (7” area, 9.42” surface resistance) in place of the 2.25” pipes (8” area, 14.12” surface resistance) on a stock pickup.
But that’s not the really the truth is it? You’re just bs’n the forum so that no one will know how totally punked you were by the exhaust mechanic who oversold you his SS pipes at $10 a ft after convincing you to put in hi-flow clay (ceramic) cats while he sold your metallic cats right out from under you.
Why is it that dual and worst, SI/DO, “aficionados”, insist on propagating their errors on the rest of us. X-H pipe AFTER the cats? What were you thinking? Do your homework Fool.
Ps: BigDaddy64, you’re just shilling for these “dually” punks right? How are those glass packs working for ya? Turned your pickup into a 3-ton paperweight yet? Been fun, gotta go.
Thread Starter
|
Senior Member
Joined: Mar 2008
Posts: 113
Likes: 0
I haven't done anything yet...all speculation, I wanna get an exhaust put on by the end of the summer. If I lose 5 tq because of 2.25 duals and bullets, then so be it, I guarantee I will love the look and the sound.
I think maybe that setup on a almost stock truck may cause some torque loss...but on a truck beefed up with performance mods, I think it will help. The loss couldn't be too substantial, it's only exhaust.
I see where you anger comes from, so many people spread false information on this forum; but they are unaware. You obviously had duals on your stang at some point too.
Oh and as for the cats, i'm keeping those they sell very well. I will see what my local exhaust guy says about everything, he's not the type to screw someone over for money, especially a long time customer.
If someone has dyno-proven results, and seem legit I will take the risk, but I hear and see new things everyday. You may be right, you may be wrong...can't trust anyone these days. I will post after I talk to the guy at my muffler shop.
I think maybe that setup on a almost stock truck may cause some torque loss...but on a truck beefed up with performance mods, I think it will help. The loss couldn't be too substantial, it's only exhaust.
I see where you anger comes from, so many people spread false information on this forum; but they are unaware. You obviously had duals on your stang at some point too.
Oh and as for the cats, i'm keeping those they sell very well. I will see what my local exhaust guy says about everything, he's not the type to screw someone over for money, especially a long time customer.
If someone has dyno-proven results, and seem legit I will take the risk, but I hear and see new things everyday. You may be right, you may be wrong...can't trust anyone these days. I will post after I talk to the guy at my muffler shop.
Suspended
Joined: Nov 2004
Posts: 17,079
Likes: 0
This might be good. I didn't notice any loss of torque from my set-up. 2.5" tubing true duals, cats in tact, with a H-Pipe and Dynomax Bullets. I also just noticed something in your speel above ...
What are you talking about? Of course the mid pipe is behind the cats ... What about the S197s Mustangs? Do they benefit from muffler swaps or muffler deletes?
Why is it that dual and worst, SI/DO, “aficionados”, insist on propagating their errors on the rest of us. X-H pipe AFTER the cats? What were you thinking? Do your homework Fool.
Last edited by ThumperMX113; Jul 1, 2008 at 10:25 PM.
Senior Member
Joined: Oct 2007
Posts: 560
Likes: 0
From: Londonderry, NH
What is it with these threads lately? More and more I'm seeing new members come in here and shat all over members who have been here fore a while, tried different things, gotten experience, and passed that on with many praises from people who have benefitted, myself included. (Stang I see you were a member in '01, where've you been for 7 years? You still have the 98 4.2L? If so, or not...
you'll need to clarify with us...first, do you have experience with the 6000 pound 5.4L 3v 04+ F150s? And not the Civic you tested on the dyno...
Second, in your own thread about exhaust specs from another site, obviously 2 1/2 flows more cfms than 2 1/4, so what are you going on about a single 3" over dual 2 1/4s? You trying to tell all us F150 owners we should now strip off our systems and run 3" straight back? I would think you'll get more of your cfms out of dual 2 1/4s. As far as $10/foot on ss, you mentioned in another of your threads mandrel does in fact give up a few more hp, and fyi, ss does flow better and have less friction loss due to abnormalities in the tubing than aluminized...
you'll need to clarify with us...first, do you have experience with the 6000 pound 5.4L 3v 04+ F150s? And not the Civic you tested on the dyno...
Second, in your own thread about exhaust specs from another site, obviously 2 1/2 flows more cfms than 2 1/4, so what are you going on about a single 3" over dual 2 1/4s? You trying to tell all us F150 owners we should now strip off our systems and run 3" straight back? I would think you'll get more of your cfms out of dual 2 1/4s. As far as $10/foot on ss, you mentioned in another of your threads mandrel does in fact give up a few more hp, and fyi, ss does flow better and have less friction loss due to abnormalities in the tubing than aluminized...
Last edited by ryan42680; Jul 2, 2008 at 12:24 AM.
Senior Member
Joined: Aug 2004
Posts: 2,824
Likes: 0
From: North Huntingdon,Pa.
?
sorry-been swamped with my buisiness do the hot spell and in midst of moving into bigger home,yes, if done CORRECTLY you will gain,i ran 2.25" ss mandrell bent pipe ,x pipe as close to original y location as possible,and magnaflow 4x9 mufflers-let me say this -my van which i did this on weighs ~8500 lbs-if 4 one second i lost hp and tq-especially tq,the 3" oem single would have been on in a heartbeat-it's bs to say you will lose hp and tq with true duals,i tow alot and my tq increased substanially-i make 328 lbs rear wheel tq at 2000 rpms and it stays in the 300's to 4300 rpms where it starts to drop-i speak from experience and will not steer another memeber wrong
2-the ss tubing i didn't pay for let alone the labor-i traded work for it-i guess you'll be telling me next that ss tubing isn't as good as carbon steel or aluminum tubing for heat retention and scavenging
3-like i said if i didn't feel the increase let alone see it on a dyno-your so called 3" siso mother of all exhausts would have been back on in a heartbeat-money my friend isn't an issue with me,having the best performing version os a product is-i for one don't have to post the before and after same day dyno's of the exhaust-cuz you will just believe in your mind you are right--on a parting note-i guess you'd say the 4" siso exhaust i put on my 89 20th anniversarry ta didn't do an ounce of good to allow it to run 111.0@121 on the original gatorbacks-the ball is in your court slick
Senior Member
Joined: Aug 2004
Posts: 2,824
Likes: 0
From: North Huntingdon,Pa.
stang2-as far as your exhaust expertise not someone elses-please explain to us about the static regain method of imploding the exhaust tubing-oh wait a minute-contact ure sources on this one mr know it all
Technical Article Contributor
Joined: Oct 2005
Posts: 25,641
Likes: 19
From: MI
Dear “openclasspro11”, “2001screw4x4”, “jbrew”
You’re so full of sh*t, it’s really hard to know where to begin … and this reply isn’t for you, but for the more impressionable forum members who might actually buy into your crap.
My performance exhaust expertise is reserved for my Mustang, (CAR) = [(Ncy - 1)(Dp²)] + Dtp², many thanks to David Vizard and Dave Carpenter. It became evident early on, that our pickups, Lightnings aside, were more susceptible (valve overlap) to the common aftermarket performance muffler add-on marketing ploys.
In our slow flow systems, 2.25” pipes have too much surface area in a dual setup to be efficient. You must have spent a fortune in dyno runs to achieve slightly elevated stock performance with 2.25 duals. How do I know? Any “so called” performance gain would have been better with a single 3” pipe (7” area, 9.42” surface resistance) in place of the 2.25” pipes (8” area, 14.12” surface resistance) on a stock pickup.
But that’s not the really the truth is it? You’re just bs’n the forum so that no one will know how totally punked you were by the exhaust mechanic who oversold you his SS pipes at $10 a ft after convincing you to put in hi-flow clay (ceramic) cats while he sold your metallic cats right out from under you.
Why is it that dual and worst, SI/DO, “aficionados”, insist on propagating their errors on the rest of us. X-H pipe AFTER the cats? What were you thinking? Do your homework Fool.
You’re so full of sh*t, it’s really hard to know where to begin … and this reply isn’t for you, but for the more impressionable forum members who might actually buy into your crap.
My performance exhaust expertise is reserved for my Mustang, (CAR) = [(Ncy - 1)(Dp²)] + Dtp², many thanks to David Vizard and Dave Carpenter. It became evident early on, that our pickups, Lightnings aside, were more susceptible (valve overlap) to the common aftermarket performance muffler add-on marketing ploys.
In our slow flow systems, 2.25” pipes have too much surface area in a dual setup to be efficient. You must have spent a fortune in dyno runs to achieve slightly elevated stock performance with 2.25 duals. How do I know? Any “so called” performance gain would have been better with a single 3” pipe (7” area, 9.42” surface resistance) in place of the 2.25” pipes (8” area, 14.12” surface resistance) on a stock pickup.
But that’s not the really the truth is it? You’re just bs’n the forum so that no one will know how totally punked you were by the exhaust mechanic who oversold you his SS pipes at $10 a ft after convincing you to put in hi-flow clay (ceramic) cats while he sold your metallic cats right out from under you.
Why is it that dual and worst, SI/DO, “aficionados”, insist on propagating their errors on the rest of us. X-H pipe AFTER the cats? What were you thinking? Do your homework Fool.
Stank2- You a Freakin Fruit Loop or something ? What's this "Dear jbrew" sh^t ?
Alright, I'll give yuh a shot - Do this . Post me up the Very Best exhaust system that WILL net a Stock 4.6L/5.4L the most Torque and Horsepower.
In case you forgot already - that's for a- Stock Engine
Here's your chance to shine Glory Boy, lets see it... Oh, and try to do it without contradicting yourself so much. That just makes you look like more of an a$$
BTW - David Vizard and Dave Carpenter ? WTF - Can you explain WHY your thanking people that aren't even members of this site ? -- WHY? - Is there something wrong with you, seriously ?
Last edited by jbrew; Jul 2, 2008 at 03:13 AM.
Senior Member
Joined: Aug 2004
Posts: 2,824
Likes: 0
From: North Huntingdon,Pa.
also note-i drive my van in the 1,500-3,500 rpm area of the operating range-pretty much -i'm babying it-takin advantage of all of the low end grunt i have now-you should see the look on friend's faces after i let them drive my van with my mx race trailer hooked up- especially the fellow ford owners -comments on low end tq come frequently-nice post j brew
Senior Member
Joined: Oct 2005
Posts: 3,579
Likes: 1
From: Wilmington DE
Well,,I for one must of put the worst possible combo on my truck.
The first thing I ever did to my truck,( back when it was completely stock) was put a true dual system on with Flowmaster 40s( witch every one say they suck!)lol
I never felt a loss in power or torque. It sounded great and looked good and that's what I was going for.
It's an exhaust system for shi*s sake. What are we talking here 5 or 7 HP MAYBE?
Phil
The first thing I ever did to my truck,( back when it was completely stock) was put a true dual system on with Flowmaster 40s( witch every one say they suck!)lol
I never felt a loss in power or torque. It sounded great and looked good and that's what I was going for.
It's an exhaust system for shi*s sake. What are we talking here 5 or 7 HP MAYBE?
Phil