2.5" axle back exhaust to stock NB1

hejira · Postby **hejira** » Thu Aug 21, 2014 10:21 am

I just had my new 2.5" axle back exhaust delivered at work. I immediately see that the larger pluming may be too big to match up to the stock exhaust.

Before I get a chance to try fitting it up after work, has anyone else tried this bolt on size difference?

Will I have to upsize the rest of the exhaust to be able to fit this or whats the best way to do it/best advice I can give a shop to do it?

hejira · Postby **hejira** » Thu Aug 21, 2014 2:52 pm

anyone?

hks_kansei · Postby **hks_kansei** » Thu Aug 21, 2014 2:57 pm

How much is the difference in size?

It should be fine as long as the gasket faces fit fine and seal.
Just put it on and go for a drive, if it leaks, look into getting an exhaust shop to change it.

Even if it does leak, it's back near the diff so the fumes won't get into the car.

Dupain · Postby **Dupain** » Thu Aug 21, 2014 4:06 pm

Won't be an issue. Flange will bolt on to cat flange.

project.r.racing · Postby **project.r.racing** » Thu Aug 21, 2014 4:12 pm

Dupain wrote:Won't be an issue. Flange will bolt on to cat flange.

it is a axle back system. it wont go anywhere near the cat. cat is at front of the car. axle is at the back.

hks_kansei · Postby **hks_kansei** » Thu Aug 21, 2014 4:18 pm

More the point, the only flange join near the cat on an NB (8a anyway) is at the front, where it attaches to the headers.

All welded from there to the diff.

hejira · Postby **hejira** » Thu Aug 21, 2014 4:50 pm

Its just the 'rear muffler' I'm fitting.

There is a flange near the diff right before the rear muffler that you bolt the rear muffler section onto. I guess I'll just have to attempt the bolt on & if there's too big of a difference in size or the bolt holes don't line up ill have to get an exhaust place to do some cutting/stepping/welding.

hks_kansei · Postby **hks_kansei** » Thu Aug 21, 2014 5:12 pm

pretty much.

I can't see any issues however, the muffler on my car has different sized piping to the midpipe and it fit fine.

Granted, I think my muffler is only 2.25 inch inlet.