Hello all, this is my first post on this site, so I'll try not to look stupid. I am currently trying to design a new intake manifold for a turbo 1.6L engine. I have never attempted to this before, but I have a few ideas in mind, and would like some feedback. First, I could use a D-shape pipe for a plenum, and just straight pipe it to the head. My second thought is to use a turbo exhaust manifold, which has even length pipes to each cylinder, and modify it to fit the intake. The thing I am wondering is why every other turbo car uses a plenum style intake instead of a tube design. I understand that the plenum allows a build up of a pressure, but does it then not take longer to pressure up? If you used a header type intake, would it spool up extreemely then? Would you lose top end power because of a volume issue, or would the better, more even flow of air compensate for this. Sorry the post is so long, hope that someone has an answer or two for me.