I don't know is there steel wire, but the tube is hard to bend. I had to take the air box out in order to fit it on the tb. I think is safe to say z1 makes good product.
Yes, I did not use hose clamps on the tube. No leak at all.
Edit: yes.. They are wire reinforced. It said on z1 page
http://www.z1motorsports.com/g37_370...oducts_id=5292