i see some downpipes have a flexpipe, like the AMS, ETS and Tomei, but i also see some solid downpipes w/o a flexpipe like invidia and greddy. whats the differensce between the two?

 

You're comparing o2 elim downpipes vs. stock replacement downpipes which still utilize the stock spring bolt/donut gasket flex point.

 

does that mean the stock replacement downpipes dont directly bolt up to the turbo? are there any performance differences? sorry if this is a noob question this is my first car with boost lol

 

Correct, they bolt up to the stock turbo oulet/o2 housing rather than completely replacing it; these type of downpipes are fine for stock turbo setups, but if you plan to upgrade the turbo you'll want an o2 elim version.

 

I gotcha. thanks a lot kracka...you seem to have answers for all my questions so far hahah