[Loboost]

So I have been running my car on map 2 with a 30% mix of E85 and 91 with stock ********* and exhaust the car is a monster. Stage 2 is recommended for *********, but I know many people run the same way as me without issues and have made serious #s on the dyno.

The question is what is the reasoning behind the recommendation to use *********?

Is there simply to much backpressure or is there another reason why?

While I have no issue installing *** I know they work I just don't like the raspy sound with the stock exhaust and I really do not want to spend 5K to correct the raspy sound with probably very minimal gains. Smell is another reason along with puffs of blackish smoke when jumping on it is also a concern.

I drove a friends M4 with *** and Jb4 stage 2 that is also using a 30% E85 mix and while his car certainly spools a little quicker along with having cool turbo whine sounds, I don't think the difference in performance is really worth the compromise.

Am I totally wrong here ? I am asking because I want to learn.

[Terry @ BMS]

For OEM turbos I don't think the *** do much on the S55. With larger turbos they will help.

[Loboost]

Originally Posted by Terry @ BMS

For OEM turbos I don't think the *** do much on the S55. With larger turbos they will help.

So the tune is really not specific too ***, it's just more aggressive with the added boost mainly requiring the use of a suitable fuel more so than less back pressure correct?

[M3kingz]

So for people running meth, would it b worth it to get dp's? Or just leave the oem cats