I have a true dual system on my truck and I don't like the drone of the dynomax muffler, so I contacted flowmaster to see if they had a muffler or mufflers that would work better for me. The tech guy told me that you should never put a true dual system on a newer fuel injected vehicle, as the computer won't know whats going on and you will actually lose performance.

I hope this isn't true as mine is already done!

Any thoughts??

 

well the only way i could see it hurting anything is if you removed any of the cats and o2 senors...and a x pipe wouldn't hurt too

 

What kind of system do you have silverfx4? Is it dual after the cats like mine?
Are your 40 flowmasters the delta flow's?

The reason I ask is I'm looking for different muffler's that with less droan inside the cab. I've heard that the flowmasters have little droan.

Thanks

 

I put true dual on my 08 F150 screw 5.4 and the only thing I did when I got home was disconnect the battery for 1/2 hour then started it up let it run for a few min and drove it down the highway....runs great the only thing is the driver side sound good but the driverside sound a little differant and I blame that on how the pipes are bent.....
Iam running magnaflow muffs.

 

I have true dual delta 40's on my truck and there is no drone at all. I'm really thinking about an x-pipe though because it does pop sometimes when I rev really high. It's not overly loud and I wish I had gotten original 40's.

 

Has anyone used the dual in dual out super 40? That would be a little cheaper, but will it sound as good or the same as 2 ?

I drove a truck like mine with 2- 40 deltas and was very impressed with the low interior noise, and it sounds pretty good outside too!

 

I used the single in double out on mine and didn't like it.

The tech did not give you all the correct information (like most techs, undertrained, and act over qualified). I have true duals on my truck and I have no problems at all (even supercharged). The thing you want to keep in mind is keeping the pressures balanced and that is where a x-pipe, h-pipe, or a muffler with a built in x pipe comes into play. I have a magnaflow that has an x-pipe built in and equalizing back pressure. I did not remove the cats and simply cut the y. I stuck with 2.5" piping utilizing manderel bends throughout the whole exhaust. On an NA application I would not worry about this large of piping, but anything less with the supercharger and I was getting a lot of back pressure in the exhaust (measured at wideband 02 bung). IMO, flowmaster doesn't make a muffler that doesn't drone to some degree. Magnaflow has always done the trick for me and sounded the best (IMO). I have tried flowmasters on most of my vehicles (01 Mustang GT, 03 Mustang Cobra, 07 F150) and they all sounded the same and droned down the highway. I switched botht the 03 Cobra and my F150 to Magnaflow and couldn't be happier. Loud when you hit the loud pedal but quiet when normal driving is required.

EDIT:

Another thing, if true dual was bad why would Ford have put the true duals on the mustang?

 

on mine i did 3 inch with a super 40 flowmaster and a 3 1/2 inch tip thats about 14 inchs long ...some might say that the 3 inch pipe is to big but its not manderal bent..so its a hole different story

but mine i only hear the exhaust when i'm hard on it but at highway speed its sound stock inside.

but i was thinking of redoing mine to be just like the roush side exhaust but still look for pics so know how the pipe needs ran

 

mrpositraction, is your magnaflow a di-do? Is it loud in the cab ie.drone? I'm just trying to find a good muffler or mufflers that have little drone & cab noise but have a healthy snarl outside. I wish I knew someone with a magnaflow so I could hear it in person.
Thanks

 

I don't think it is loud inside the cab, but I have always had louder vehicles at highway speeds. It doesn't drone like my flowmaster did on my Mustang GT did, but you do hear it.....not a drone, but you can tell it is a V8

Edit: Yes, dido, the longer version, I wanted quieter.

 

No offense, but we really can't use our supercharged vehicles as a benchmark for N/A sound. My truck became quieter during cruise and louder under boost after adding the Roushcharger - the air flow characteristics changed completely.

My opinion on the subject... if you go three inches all the way back to the muffer you're essentially going to get the same benefits as a true dual system and its going to cost you less. These trucks don't gain a whole lot of power going to true duals, and the airflow difference between a full 3 inch y-pipe into 3 inch intermediary pipe back out to duals are fractions of a percent less than a full x-pipe setup. If a boosted supercharged vehicle flows well through it (and I have dyno numbers), a N/A 5.4L isn't going to outflow it.

I'm sure a great deal of what you see on the Mustang is because people expect it (true duals) on a Mustang, not because it raises flow enough to make a big cost-benefit difference.

 

Right, a single 3" (trans ams, comaros) will flow more than a dual 2.25" (mustang). But going true dual isn't going to hurt you if it set up with some sort of equalizer (h or x pipe) which was the OP question. Also, IMO, a true dual, regardless of forced induction or naturally aspirated, will always sound better through a true dual than a single exhaust. The supercharger will of course make is sound different, you are making the motor think it is bigger than it is regarding air flow, so the sound IS going to change.

 

That's hard to quantify... depends on what someone thinks "sounds better is". :-)

 

Absolutely, that is why I used "IMO"

 

Exactly. Some folks would think my set up isn't loud enough. Personally, its just a tad too loud but the Roush exhaust note when hooked up to the Dynatech headers is sweet.