RPI only drones between 1500-2000 rpms, that a very rough estimate btw, I can't comment on the the RPI for the 35 because I have never heard one or seen anyone comment about it droning.

 

I guess downpipes it is, it seems cheaper too.

 

Have you purchased COBB tuning yet? That is the best thing you can do for your money. I have it for my Subaru. You can do so many things with it.
BMW 535i, xi, i xDrive

 

I wouldn't recommend downpipes if your still running a stock tune. The tune is by far the best bang for the buck and performance bump you will get out of the N54 motor. Everything else will just compliment the tune.

I'm running the JB3 (newer version is JB4) and you can't go wrong with the Cobb either. Either one will completely change your car.

Good luck and let us know what you go with and how it works out.

 

DP's brother, no brainer.... significantly more power than the exhaust. but if you ask me, the CoBB or JB4 in conjunction with the DP's is the way to do it. Drop in a KN air filter and you will get about 80hp to the wheels.... as in 410-420 bhp. Its been proven time and time again.

 

Thanks for the responses guys. Right now I have a SSTT2 that I got for cheap. I'm planning on getting the DPs next then getting the Cobb after I get the exterior addressed a bit.

 

Check this out


535 E85 Dyno Testing, 146rw delta - N54tech.com | BMW N54 N55 135 335 535 Turbo Performance Forum

 

Here is some links of stock performance with cobb...
click links » Cobb Tuning AccessPort for 2008-2010 BMW 135i, 335i, 535i

i believe this one has exhaust. https://5series.net/forums/e60-parts...-chart-111953/

heres how to install it when you purchase.. Cobb Tuning AccessPort for BMW 135i 335i 535i with N54 engine

 

Keep in mind DP's a lot cheaper but for the install this will cost you around $400-500 it takes at least 5 hours to get this installed.