Well, my final mod for a while was just installed last week. I first did the SCMT then full Airaid, now the Magnaflow 15821. It's the 3" single catback system with rear side exit. The system had a great fit and went on in about 45 minutes. The stock muffler is even bigger once you get it out and on the ground. I cannot believe that thing....it's HUGE. Anyway, everyhing about the fit is perfect except for the tip sticking out about 1" more than I like. It's not bad at all, just more than I prefer. The one thing I don't like about the kit is that it retains a 18" section of stock 2.5" pipe that could have easily been replaced. It's a section about 2 feet in front of the muffler that goes to the back of the Y-pipe. Since there's a slip fit style fit on both ends of this pipe, it should have been replaced with the rest of the system.

Anyway, the sound is pretty good. It's a very deep tone that is very mellow. It can be heard at highway cruise...like 75mph, but very slightly with the radio off or low. You definitely hear it with any load applied to the throttle, but it's still not too bad. It's hard to describe it. If you think flowmasters on a stock mustang are quiet, then this system is going to be quiet for you. If you think the stock exhaust actually has a note to it, you may find this system to be a little loud at first.

I didn't notice much of any power gains. I definitely noticed an bigger gain with the Airaid and the SCMT. I did notice a loss of low end torque. The truck used to bark the tires pretty good every time I'd nail the throttle, but now with the exhaust, it won't spin the tires anymore. Not that it's too bad, because it still feels very torquey down low, just this one aspect is all that I noticed.

Let me know if you have any questions.

 

Thanks for the info on the magnaflow 15821. I had the 03 system on my King Ranch F150 and had a few problems with the system not fitting as well as it should have. I had to heat and bend some of the factory hangers to get it away from the spare. Did the 15821 line up exactly with all the factory hangers? I was also wondering if the midpipe had to be cut. Judging by what you said it doesnt seem like that was the case. My truck is a lease and I want to be able to put the factory system back on in 3 years. In the case of my 03, I was able to get the whole system off. I am hoping that this is the case with this application. I also hope that the factory system can be disconnected from the midpipe and then pushed ahead and up and over the axle and then out and down toward the front of the truck without having to cut the sytem at all. Can you please tell me if you had to cut it? If you did, do you think it could be removed without cutting? Also, with respect to it hanging out the back too far, maybe there is a way to heat the tailpipe hanger slighlty to bring the pipe toward the spare a bit. Thank you very much. Any information on this would be greatly appriciated. You can e-mail me at steveandkathymurphy@yahoo.com

Thanks and good luck with your truck!

 

The system was a direct replacement with great hanger locations. The only problem is that removing the stock system from the truck without cutting it and without a lift, is not easy. The tail pipe has to snake around over the axle, so it is a difficult task without the truck being in the air. You do not have to do any cutting to the stock midpipe. There isn't any issues with the pipe being too close to the spare.

 

hi rob thanks for the info on the exhaust set up , i went ahead and ordered the 15821 and i was wondering if you could tell me how many clamps are included in the kit and what sizes they are , i want to buy stainless clamps to replace the ones they give you in the kit because as i remember with my old truck the clamps were not stainless , there should be 3 included am i right?
if so what sizes are they ? thanks alot for your help Murph

 

my old truck was leased, had exhaust on it, dual straight pipe, gave ford my truck back like that, no probs

 

I have had the magnaflow 15821 on for about 25k miles or better now. The system will get louder after 1k mile. The system lined up great no extra work involved. As far as the clamps they will come with two extra clamps. Thats all you need you will retain the stock on the 2.5 pipe coming off the y pipe (tack welded) on so you dont have to worry about it. Then use the two supplied and it should take you 45 minutes or less start to finish. The only thing I did to make it a little easier for installtion was to hit the rubber hangers with some white lithium grease to make getting the new exhaust in easier.

Robert045.4 I agree I cant figure out why they did not replace that 18" section of stock pipe. The exhaust will get louder, I am waiting for the airfource 1 intake to come out. I have the 1714 tuner just need the intake. Do you have a intake on? I was curoius to see what someone running this exhaust thinks of the noise overall with a cold air intake on. I have read that having one on will make the exhaust louder than a stock intake.

 

I have an Airaid full intake on my truck and I did that first before the exhaust. I don't think it will have an effect on sound of the exhaust at cruising, but may make the exhaust not a tad louder at WOT. The Airaid itself is definitely NOT quiet! It sounds great, but a lot of people don't like the added noise..not me, I love it.

 

Hey Guys,
I had the Dual Catback Magnaflows installed for about a week before I installed my Airaid Cold Intake. It defintely makes it alot more throatie (if that is even a word) sounding when you are accelerating but no difference at idle or cruising speeds. I was a little disappointed in the magnaflow exhaust until I installed my intake now I love it. Just so everybody knows before the exhaust or intake I was getting about 13 mpgs in the city after the two enhancements I got 15.3 mpgs in the city on my last tank of gas.

 

I have the Flowmaster 15821 and love it, you can usually find a used one on ebay or craiglist but I prefer new with a warranty so I got bought from Flowmaster directly here. Flowmaster 15821, or you can try one of the sponsors here on the forum, they are allways having sales/specials. Either way its a great exhaust system, sounds great, and very easy to install.