agreed .
on the cat back note. magna flow just pushes systems out. incorrectly sized..my 2010 4.6 was the same size as they are claiming the 6.2 to be..just a dumped 3" with a bullet. explain ?

 

It appears that both Magnaflow and Gibson like to use the same parts for a BUNCH of applications(saves on engineering, ya know....).
I find it hard to believe that the same system used for a 4.6 engine will do just as well behind a 6.2.
I noticed that Flowmaster's American Thunder system for Raptors and other F-150's w/ the 6.2 is a full 3-1/2" all the way out (I approve, for what that's worth...) and their American thunder system (louder than ForceII) for 5.0, 4.6, and 5.4 is 3" into the muffler then 3-1/2" out the tailpipe(the muffler has 3" inlet and 3-1/2" outlet). Apparently the 5.0 needs the inlet pipe to be no larger than 3" to scavenge properly. I've actually heard that the 4.6 and 5.4 actually like a 2.5" system for best low-end torque, as they are not as much a real deep-breathing engine like the 5.0 is. Anyway, my .02 worth....

 

oops, I posted this in the wrong forum...here is my redo

sorry I've missed this chat for a while but its been real busy at work. I created a short video showing what I have done with the Dynomax Y pipe. I've found the mod to help a bit in the power loss area, but there is still no improvement in the mpg area. I originally thought I gaind 1 of the 2 mpg I lost, but after driving it more that turned out to be not true. I will do 1 more mob to this thing before I throw the piece of crap in the garbage and put the factory resonator back on........all this just to get a better sound, grrr


Here is the link http://www.youtube.com/watch?v=U3BxNGveHLs&feature=youtu.be

 

08streetglide,

Have you completed your second modification to your Y-pipe yet? I'm still trying to decide if I want to replace my front resonator with a 2-3/4"x3" Y-pipe and install a Doug electric cutout. If there is going to be a power/mpg loss by removing the resonator though, I may not opt for the mod.

Have you taken a look inside the front resonator to see what it consist of? I'm wondering if it is just an open can, a can with a perforated flow-thru pipe, or if it has baffles built in like a traditional muffler.

My other thoughts are, if removing the front resonator causes performance issues, should I just install my cutout after the first resonator...by putting it in the second resonator's place. I'm just not sure how much sound I'd lose due to the first big can.

 

I ventured under my truck yesterday and noticed the exhaust system has banded connections on each side of the 'second resonator'. I will try to disconnect the connection between the two resonators to see if the exhaust note is attractive with only having the first resonator inline.

 

sorry RAPR...

Just got to the mod today (8/12/12), will post the updated video. I wont have any input on this mod until later this week. I see a few others have tried diff. systems that also replace the front resonator. Just curious what their findings have been.

Final Y pipe mod - YouTube

 

OH, and to answer your question....the first resonator is baffled like a muffler, not a flow thru like the smaller second resonator.

 

I like how you made a very smooth transition through the "Y" section of the pipe. I can't help but think it should smooth the flow considerably, thereby eliminating or at least greatly reducing any turbulence that was messing up the flow in the previous setup. This setup even looks very "factory" to me, if you know what I mean. This should work, and I'd bet you even regain, or even improve upon, the "lost" fuel mileage AND low-end torque.
Keep us posted!

 

08streetglide,
If your new y-pipe design works, you might need to go on a short production run It looks really good, regardless of final performance.

 

I agree- it looks production-ready; the line forms to the right(of course...) guys

 

lol, well thank you guys, well, after 2 days of taking it to work, im back up to my 14mpg combo city/highway. and the low end torque is real good again!!! but the one thing that I've failed to mention in all of this is how it sounds. from day 1 of removing the front resonator, and thru the 2 mods, the sound on excel. is off. kind of has the sound of an old rotting out muffler with a hole in it. Maybe the MBRP flow thru muffler isnt the way to go either. I've been so consumed by trying to get the performance back I was hoping the sound would improve as I did the mods.....it has not . maybe a flowmaster baffled muffler would help that out?

 

08streetglide,
You didn't happen by chance get to hear what the exhaust note sounded like coming straight out of the front resonator, without going through the rest of the plumbing?

I thought it was going to be easy disconnecting the piping between the 2 resonators, by loosening the metal band. Well I was wrong. I don't have enough slack to pull the connection completely apart, without removing uninstalling the rest of the factory exhaust.

I see that 'devongarver' did just that in an earlier post, and said that it was a nice deep tone. I'm just wondering on how loud it is, since I'm wanting to go with a cutout. I'd like it to be deep and loud, like the Raptor in the video I posted a while back.

 

not loud enough, thats why I got the Y pipe to eliminate the front resonator hoping for a louder sound. its louder on exceleration, but not a good tone as far as im concerned.

 

Hey man, congrats on the good results! Like you said, now all you have to deal with is getting the right sound. My personal recommendation is a Flowmaster Series 50 or similar. Nice sound, but not TOO noisy. But you use your judgement. Good luck!

 

Well, I finally got my exhaust cutout installed. I swapped out the section with the 2nd (small) resonator and replaced it with the cutout. I left the front resonator in place, as it is a pain to fabricate a custom y-pipe to replace it (as 08streetglide has demonstrated). There is no reason for all you guys to be spending the $ on an exhaust system that cost a few hundred dollars. This cutout produces the deep note that you are looking for. It stays fairly quiet at idle and low accelerator input, but when you give it gas it sounds amazing!

Right now I only have the cutout with a manual block plate, as I won't be able to install the electronic Doug valve until next week. With the cutout blocked, it sounds quiet just like factory.