Best way to fit flanged HKS back box to an unflanged system?

[Amjad]

I've recently picked up a HKS back box for my NA, which currently has a custom cat-back system. The HKS is flanged (2.5"/63mm) but just below the flange there is a slight step down in the pipe to approx 2.25"/57mm.

The current back box is clamped on, and I'm pretty sure the piping is 2.5"

Am I right in thinking I'd need a 2.5" flange and gasket, and a reducer sleeve as pictured below to fit it to my system?

I'm guessing a 2.5" flange cant just be welded on to my mid section as there is a gap in the piping size?

How would the sleeve be fitted? By way of a clamp or welding it in?

Is there a better or easier way of fitting the box?

Thanks

Amjad

[A L 3 X]

How much difference is there between the flange pipe size and yours? You could probably get away with just welding it if its not too much

[Amjad]

I haven't been able to get under the car to check as it's raining at the moment! I'd have thought a 0.5" gap between the flange and pipe would be too much

[A L 3 X]

I remember in an old car I had mate I ordered a reducer to clamp on but the seller got mixed up with the sizes I wanted and it was wrong, took it to a mechanic I know and he tacked it together and then filled with weld, not the best solution but it worked, was only like. 0.5cm gap all the way around on mine though

[Amjad]

Hmm might work, but I don't wanna have to take the old box off match up and flange then to see I'll need a reducer, then have to order it and do it all again.

Anyone else?

[james@cjperformance]

bring it up when your back and ill sort it for you

[Amjad]

To the rescue again haha

Grant was gonna do it but I may as well wait for you because I need to clutch done too!