So I just picked up a new header for my car....

-FGK Fujitsibo J-Spec 4-2-1 (2) piece header......

The measurement at the end is as follows.....

The INSIDE diameter of the end is 2.25"

The OUTSIDE diameter of the end is 2.5"

It also has a big fat donut on it that makes it what looks to be almost 3".....

My dilemma is I am running a Apex'i WSII.....I also removed the cat and have a test pipe... i had a DC Sports 4-1 header on it which fit before and with the test pipe....

So i took my cat converter which is off the car, and tried to see if my new headers would fit the inlet.....no bueno....

so my question is, do i have to get a new test pipe that is bigger to fit the new headers??? BUT....if i get a bigger test pipe, is that going to fit the rest of the exhaust? or do they make a 2.5 to a 2.25 test pipe??? Im trying to figure out what options I have here....

Im going to be crawling underneath her and taking everything apart this week/weekend and see what i got, but i dont think my new headers will fit the test pipe....

heres and example of what it looks like.....


WITHOUT DONUT






WITH DONUT





Thanks for the help guys.....


Dc2

 

exhaust shops, auto parts stores will sell pieces that are bigger on one end to fit a larger diamater pipe.

 

just buy a new donut for your new header and your peice that attached to your previous header should fit to the new

 

but the new header outlet is bigger than the inlet in the test pipe i believe.....with a donut its DEF too big to fit the test pipe....ill have to wait and see when i gt it all apart....i just need to make sure it forms a nice tight seal with no leaks....

 

 

that is excatly what you need i figured you text pipe/cat already had that on there! if you were running your hold header with that donut.sorry

 

are you guys saying to run that in-between the end of the header and the test pipe??? no mod to either piece???

cause each already has the flange on it....so i assume just use a little longer bolt and use this adapter between the two pieces to ensure they fit????

 

the part needs to be welded in the other flanges place

 

cut the small flange off the cat / test pipe or resonator "what ever your runing" and weld that flange onto it