Hey was just wondering if I can weld my wastegate dump tube into my test pipe. Is that to far down stream? Because I do not want to cut into my down pipe

 

Why don't you want to go into the down pipe?

 

That's a really long way to run it and I can't think of a good reason why you wouldnt either tie it into the dp earlier or just run it to atmosphere. This seems overcomplicated with no good reason as to why..

 

I'm guessing you want to put it in the test pipe because it's a relatively cheap piece of steel and easily replaceable if something doesn't go right?

Either way, yes it's fine.

HIGHLY suggest doing two things.
1) Add a flex joint. You will crack the dump tube or break the wastegate off the manifold otherwise.
2) Add a vband/flange in the middle of it somewhere. You will have a hell of a time ever disconnecting anything if you don't.