So, I just bought new 2010 GT. I have a set of 2-1/4" flowmasters that I used on the stock system on my 02 GT. The new car is 2-1/2". The question is, would I gain anything (other than actually being able to hear the exhaust) if I was to weld these in place of the stock mufflers. The pipe on the mufflers will expand that far and I can just weld them in place.

Thanks

 

Mufflers mount in different locations....'02 under the back seat, '10 are axle backs. With that difference, the in and out of the mufflers may be located different. If they are the same, I see no reason why you could not have them installed...... Most just buy axle backs but since you have them already....see what a shop says.

 

Mine are 2 1/4 flowmaster 40's that i had welded up with 3.5in tips. It will work.

 

Ok, thanks. How restrictive are the stock mufflers?

 

I slapped some MBRPs on mine and I didnt feel any gains even though they say they do. Not to say there werent any...but 5 or 10 HP isnt gonna be readily felt. If you plan on doing any other mods, this would be a good place to start though since as the power increases, you dont want the stockers getting in the way in case they do

 

How does the MBRP sound anyway? When I had my 02 mustang they were just doing diesel exhaust. Is it kind of a glass pack?

 

I wouldnt say they were like the glass packs. They are pretty tame when you want em to be, just cruisin, but when you want a little more throatier note, get on it a little and it's got a really nice...for lack of a better word...mature...note to it. Then if you want to blast like they are deletes, just put the hammer down. I really like them. They dont have the drone that I really really hate. And they were a really simple bolt on to boot

 

glasspacks are sick, so are cherry bombs.

 

So I went on ahead and welded the flowmasters in place last weekend. They are surprisingly quieter than I expected. It probably has something to do with how far back they are in the system. It also seems that I've gained 1-2 mpg's according to the display.