hey Just wondering about down pipe selection. I have noticed that some Dp's have that vented/ flex section in the middle of them and other brands don't. what are the pro's and cons? Also I have noticed on a dp it had an additional tube running off of it. What is the extra pipe for flow, or maybe back pressure? Thanks.. Just trying to learn and familiarize myself in this new scene of the turbo world......

 

The flex pipe shouldn't be needed for an OEM replacement DP. The original design uses a donut gasket with spring-loaded bolts that allow for movement. Some turbo kits will include a DP with flex section as the original components (turbo, O2 housing, DP) are eliminated, but movement still needs to be accounted for.

 

is anyone selling said bolts, i need some

 

I am not sure which company made the dp and not sure on if it was for an 8 or a 9 evo, but I saw one dp with an o2 dump tube on it. Do they work on a 9 and are there more power gaines with that style verses a regular 3" dp? Still learning......

 

An O2 dump has nothing to do with the DP. That would be the O2 housing.
The DP bolts to the O2 housing.

 

Unless it is an o2 eliminator dp.