So i was thinking of buying a Megan headers for a d series engine with a high-flow cat. I want to fit it up a 2.25 inch cat-back exhaust and i need help trying to make it all fit. Any suggestions? The header has a 2 inch outlet.

 

I dont understand this thread

 

Basically i want to know how to run a header into a high-flow cat then to a 2.25 inch cat-back exhaust (already have the cat-back) header has a 2 inch pipping that connects to where that cat goes. and sizes available for a cat are 2 inch 2.25 inch 2.5 inch and 3 inch in/outlets.

 

your best bet is to just take it to midas or a muffler shop and have them weld everything up for you! make sure you have a flex pipe or else your header or something will crack.

 

not true. my friends was not smartly but welded to his header alll the way back one solid piece never broke in 3 years he had it.

you can buy different inlet and outlet size cats...can't remember where though. otherwise exhaust shop weld it up and enjoy it.

 

Your friend got lucky. My DC header broke on the second week. Your torque mounts do not hold the engine in place and therefore when the engine is reved the motor will shift back. If it is a good cat-back system it will utilize all the hangers and fit tightly. When the engine shifts all the movement has to go somewhere; therefore, it will break the hangers off, crack the header, etc....whatever it has to do to get the movement it wants.

Anyways...ignoring that post, the easiest way to do it is to have the muffler shopexpand the 2" aluminized pipe to a little bigger than 2.5"; this way it fits over the 2.5" cat. The 2" pipe I believe wont expand (or is very hard) to 2.5" so they will have to enlarge it in two sections. I could only fit a 2" hole on the CNC piece for the downpie flange of my turbo, so I had to enlarge to 2.5 and it cracked, for mine I just welded it because I didnt have the room.

Have a "smokin'" day CapN' Kronik!