N55 Inconsistent/spiking boost

Matticus91 · 11-28-2017, 09:47 AM

On constant throttle, usually not WOT, I'm seeing some peaky boost issues. It usually happens between what I'd say is 50-85% throttle, less than that and I'm not building much boost to matter, more than that and it seems to hold boost just fine. This leads me to believe that it's not a boost leak since it holds a steady 13+psi at WOT. Has anyone had a similar issue with N55? I'm guessing it's the DV as I stated in the title but looking for some input before I upgrade to a GFB DV+.

chris_flies · 11-28-2017, 11:40 AM

My dad had this exact problem on his '17 GTI Sport (Performance Pack, minus heavy luxury items). He got a GoFastBits DV+ (as you seem to be eyeing) and it holds boost at WOT, and it also feels like the engine is more responsive and edgy, it's cool how tiny little things make vast differences in how a car behaves! I'm talking to you, Clutch Delay Valve, Clutch Stop, and Clutch Spring.

Matticus91 · 11-28-2017, 01:42 PM

Quote:

Originally Posted by chris_flies

My dad had this exact problem on his '17 GTI Sport (Performance Pack, minus heavy luxury items). He got a GoFastBits DV+ (as you seem to be eyeing) and it holds boost at WOT, and it also feels like the engine is more responsive and edgy, it's cool how tiny little things make vast differences in how a car behaves! I'm talking to you, Clutch Delay Valve, Clutch Stop, and Clutch Spring.

Ok that's good to hear, I'm hoping the installation isn't too much of a bitch though.

quicksilver3121 · 11-28-2017, 04:32 PM

Wastegate not sealing? You mentioned that you have the rattle at cold starts in a previous post... do you think it's not fully sealing under partial throttle but then closes up when you get on it?

11-28-2017, 09:47 AM	#1
Matticus91 Brigadier General 3475 Rep 3,722 Posts Drives: 2013 135i Join Date: Aug 2015 Location: Washington DC iTrader: (6)	N55 Inconsistent/spiking boost - Diverter Valve issue? On constant throttle, usually not WOT, I'm seeing some peaky boost issues. It usually happens between what I'd say is 50-85% throttle, less than that and I'm not building much boost to matter, more than that and it seems to hold boost just fine. This leads me to believe that it's not a boost leak since it holds a steady 13+psi at WOT. Has anyone had a similar issue with N55? I'm guessing it's the DV as I stated in the title but looking for some input before I upgrade to a GFB DV+. __________________ "Tobias" 2013 135i ///M-Sport 6MT • Pure Stage 1 • XDI 35 HPFP • 404whp/440wtq IG: msteelio91
	Appreciate 0 Tweet Quote

11-28-2017, 11:40 AM	#2
chris_flies Sideways and Smiling 3027 Rep 2,860 Posts Drives: In Exuberance Join Date: Mar 2017 Location: Rosamond, CA USA iTrader: (0) Garage List 2012 BMW E91 328i [0.00]	My dad had this exact problem on his '17 GTI Sport (Performance Pack, minus heavy luxury items). He got a GoFastBits DV+ (as you seem to be eyeing) and it holds boost at WOT, and it also feels like the engine is more responsive and edgy, it's cool how tiny little things make vast differences in how a car behaves! I'm talking to you, Clutch Delay Valve, Clutch Stop, and Clutch Spring. __________________ 2012 BMW 328i 6-Speed Wagon \| Deep Sea Blue with Grey Dakota Leather \| Manual Swap, 330i Intake + Tune, 3.15 Helical LSD, Öhlins R&T (SOLD) 2009 BMW 128i 6-Speed Coupé \| Monaco Blue with Black Sensatec \| chris_flies' 128i thread
	Appreciate 0 Quote

11-28-2017, 04:32 PM	#4
quicksilver3121 Private 30 Rep 74 Posts Drives: 2012 135 M-Sport DCT Join Date: Jun 2016 Location: NJ iTrader: (0)	Wastegate not sealing? You mentioned that you have the rattle at cold starts in a previous post... do you think it's not fully sealing under partial throttle but then closes up when you get on it?
	Appreciate 0 Quote