I'm trying to help out someone locally that's swapping a TD into an A1. Basically, he's trying to find an answer on whether or not he can use his NA exhaust downpipe to connect to a cast A1 TD turbo downpipe (both clip types).
Has anyone ever tried this combo? I happen to have both types of exhaust downpipes on hand, so I took some pics.
It appears that the TD downpipe is indeed shorter overall than the NA unit and as a consequence, it has a different, sharper bend where it goes into the tunnel.

Here's a shot of them side by side and then stacked. You can see the difference in height and angles...


So... the question is, can he use his NA downpipe (like the one above) with the stock A1 TD cast iron downpipe. I'm thinking it might be possible, but since the NA downpipe is longer / higher, he might have to see if it shifts the whole exhaust down below the car and stresses out the hangers. It'd be simple to do since the whole thing just clips onto the cast piece.
I couldn't really tell if the "bowl" part and clips were the same, but they appeared to be similar.
Another option might be using the stock NA exhaust downpipe pictured with a short section removed. I bet if you removed about 1.5" or so from the "neck" of the NA pipe then rewelded it, it'd work just fine.
Does anyone have any info? I'd let him use my TD downpipe, but it appears to be fused to the stainless exhaust I got with my engine.