I would like to build my own underseat exhaust pipes,what materials I should use,and what tools.
All the best
Eddie

I experimented with an underseat a couple months back, but decided to go back to a side exhaust because the bodywork was such a ballache to get looking good. Youl need a tig welder for stainless, which is just an inverter with a tig torch & argon bottle.. Cut off saw as well obviously for cutting pipe segments.

When it comes to bends, get a company with a mandrel bender of sorts to do your bends, those non mandrel types oval and crimp the pipe quite badly. I used about 5 or 6, 90', 100-150mm radius bends, and 4, 140' 200mm radius bends. For the more irregular spots you might need to use small segments welded together. Its time consuming, but with some practice can get nice results