The Sedan Exhaust Thread
On the hand, im trying to buy the FI RHFC, would you guys recommend i get the 2.25", or the 2.5" since i have the MD? I'm trying to stay away from rasp. The guy told me if i want the 2.5, I'd have to order the one that's for the coupe.
The standard FI catback for the Sedan uses 2.25" piping, unless you upgrade to 2.5" on request. Whereas the Motordyne catback uses 2.5" pipes, period... right?
So if you were to look at this according to the catback you're matching to, get the cats with a 2.5" connector. However, it doesn't really matter, because they use the same flange bolt specs. And as long as you're going from narrow to wide, all should be right with the world. Fitment isn't really the issue.
My cats are 2.25" at the flange, matched up with 2.5" pipes. But I had the cats installed first, a full year before deciding on the catback. If I had known for sure what I was going to get on a later mod, or really thought harder about this, I probably would have asked FI to use 2.5" piping in the cats.
At least, that's how I'm remembering how this went down for me. Getting fuzzy as the years slip by.
So if you were to look at this according to the catback you're matching to, get the cats with a 2.5" connector. However, it doesn't really matter, because they use the same flange bolt specs. And as long as you're going from narrow to wide, all should be right with the world. Fitment isn't really the issue.
My cats are 2.25" at the flange, matched up with 2.5" pipes. But I had the cats installed first, a full year before deciding on the catback. If I had known for sure what I was going to get on a later mod, or really thought harder about this, I probably would have asked FI to use 2.5" piping in the cats.
At least, that's how I'm remembering how this went down for me. Getting fuzzy as the years slip by.
The standard FI catback for the Sedan uses 2.25" piping, unless you upgrade to 2.5" on request. Whereas the Motordyne catback uses 2.5" pipes, period... right?
So if you were to look at this according to the catback you're matching to, get the cats with a 2.5" connector. However, it doesn't really matter, because they use the same flange bolt specs. And as long as you're going from narrow to wide, all should be right with the world. Fitment isn't really the issue.
My cats are 2.25" at the flange, matched up with 2.5" pipes. But I had the cats installed first, a full year before deciding on the catback. If I had known for sure what I was going to get on a later mod, or really thought harder about this, I probably would have asked FI to use 2.5" piping in the cats.
At least, that's how I'm remembering how this went down for me. Getting fuzzy as the years slip by.
So if you were to look at this according to the catback you're matching to, get the cats with a 2.5" connector. However, it doesn't really matter, because they use the same flange bolt specs. And as long as you're going from narrow to wide, all should be right with the world. Fitment isn't really the issue.
My cats are 2.25" at the flange, matched up with 2.5" pipes. But I had the cats installed first, a full year before deciding on the catback. If I had known for sure what I was going to get on a later mod, or really thought harder about this, I probably would have asked FI to use 2.5" piping in the cats.
At least, that's how I'm remembering how this went down for me. Getting fuzzy as the years slip by.
Thanks for the answers man, i appreciate it.

Lol our cars sound exactly the same lol. If we drove next to each other and WOT, that would be insane lol.
But were you letting off the gas while upshifting ? It didn't seem to have that grunt sound to it. But overall, sounds great
Oooooooooo!!! That looks fun. I want to join. 
Lol our cars sound exactly the same lol. If we drove next to each other and WOT, that would be insane lol.
But were you letting off the gas while upshifting ? It didn't seem to have that grunt sound to it. But overall, sounds great

Lol our cars sound exactly the same lol. If we drove next to each other and WOT, that would be insane lol.
But were you letting off the gas while upshifting ? It didn't seem to have that grunt sound to it. But overall, sounds great
Thanks. Already have one of those hard wired in, it’s below the rear view mirror. Yes, my Admin Tuning intakes should finally be arriving Friday which require a tune. I’ll probably wait until spring to do that.
Small update: I noticed I get less MPG with the MD than my ARK
But it might be my foot but I was pretty heavy with my foot with my ARK.
I also think I might have an exhaust leak by the cats as everyone else does. I'm going to check it out when I have more time.
But it might be my foot but I was pretty heavy with my foot with my ARK. I also think I might have an exhaust leak by the cats as everyone else does. I'm going to check it out when I have more time.
The mechanics at the exhaust shop that installed my Motordyne exhaust said they wouldn’t install the supplied gaskets that MD gave because they were cheap and thin and would burn right through. They used the existing gaskets since they were in good shape and of much better quality. My exhaust seems to be running tip top as well.
The mechanics at the exhaust shop that installed my Motordyne exhaust said they wouldn’t install the supplied gaskets that MD gave because they were cheap and thin and would burn right through. They used the existing gaskets since they were in good shape and of much better quality. My exhaust seems to be running tip top as well.
I also noticed that whenever I am WOT, I sometimes notice a tin sort of sound in the rear. It sounds as if their is some sort of vibration due to the exhaust as well in the rear seats. Maybe its something in my trunk.
Also, ever since I got this exhaust compared to my ARK, a lot more random modified / regular cars try to race me like I'm supercharged or some****. Lol, yesterday an M4 came up speeding right up on my *** and let me say... THOSE m4's don't play LOL

I did notice the gaskets seemed a little thinner than the ones that came with my my ark. The thing with my ARK, the gaskets that held the HFC + Y pipe was straight black. Like..... BLACK. And it was only those gaskets too, so I'm assuming their might have been a leak there or the heat was just too much for the gaskets.
I also noticed that whenever I am WOT, I sometimes notice a tin sort of sound in the rear. It sounds as if their is some sort of vibration due to the exhaust as well in the rear seats. Maybe its something in my trunk.
Also, ever since I got this exhaust compared to my ARK, a lot more random modified / regular cars try to race me like I'm supercharged or some****. Lol, yesterday an M4 came up speeding right up on my *** and let me say... THOSE m4's don't play LOL

I also noticed that whenever I am WOT, I sometimes notice a tin sort of sound in the rear. It sounds as if their is some sort of vibration due to the exhaust as well in the rear seats. Maybe its something in my trunk.
Also, ever since I got this exhaust compared to my ARK, a lot more random modified / regular cars try to race me like I'm supercharged or some****. Lol, yesterday an M4 came up speeding right up on my *** and let me say... THOSE m4's don't play LOL


Last edited by Jake85; Dec 7, 2017 at 02:12 PM.






