[wfdeacon88]

Originally Posted by derbo

I was very amazed at the fact even under the actuators there was barely any dust.. I had my air compressor ready to go and everything too!


# Power Bug
Currently, I have been bitten by the power mod bug. I already have an AFE Carbon intake dry filter on the way due to some outrageous pricing from AFE. On the exhaust side of things, I really like my OEM exhaust 4-pipe mod but would like to uncork the exhaust a bit. From what I gathered so far, the stock primary cats are the restrictive portion of the exhaust and that the secondaries can be retained without sacrificing a lot of power. With that in mind, an x-pipe with primaries deleted while retaining secondaries and resonators should increase power levels while keeping odor and sound increases to a minimal.

MotorIQ has a great article about utilizing v-band clamps on both the OE primary cats and test pipes to allow for interchangeability for track use and street/emission testing. I really like this idea and it seems fairly cost effective as well!
https://motoiq.com/project-e90-m3-pa...xhaust-tips/3/





I also heard that Bomiz is in the works creating an X-pipe with HFC secondaries and resonators. With IND possibly bringing back the Challenge sport X-pipe with the HFC secondaries and resonators, there are 3 options that have HFC secondary cats.

1. Rogue Engineering Test pipes + v bands
   Allows for easy replacement of OE Cat again and also probably the cheapest option. It will also require the least amount of storage space since stock x pipe is 1-piece. Spare parts space is a premium here.
2. Bomiz X-Pipe + HFC secondaries
   ETA unknown, probably cheaper than Challenge Sport pipe
3. Challenge Sport X-pipe
   HFC secondaries + secondaries. ETA unknown if IND will bring it back, probably $2k or more

Decisions decisions..

don't forget the Rogue Resonated Test Pipes... an interesting variable to your option #1. I can't decide between resonated and non-resonated but leaning resonated to help with rasp..