exhaust causing problems

ridin135 · 01-28-2010, 02:25 PM

I put on my new axle back three days ago and then I took it out for a spin. The first things I noticed was that it made the midpipes hit the suspension brace on the bottom of the car so it would rattle and clunk as you drive. Secondly the turbos made a huge whining sound as you released the gas it overpowered the blow off valve. This noise was coming from the turbos and not from the back of the car. Then I get these huge boost spikes 25+ lbs on my rixster gauge. This happend on the first pull I did on the day of the install. So I go home and do some troulble shooting, the next day I take it out again and it happens again on the second pull. Wensday comes around and I take off the exhaust and the large whine goes away and no matter how hard I try I can't get it to overboost again. So it seems that the exhaust caused these problems but I just dont understand how it did, any ideas?

Robmaster · 01-29-2010, 01:38 AM

what exhaust did you have?

ridin135 · 01-29-2010, 09:59 AM

rather not say dont want to make any company look bad

cn555ic · 01-29-2010, 10:14 AM

I seriously doubt an exhaust would cause you to overboost...and the whine you might be hearing is probably the vibration noise from the exhaust hitting the brace...

ridin135 · 01-29-2010, 10:37 AM

The only thing I am coming up with is that the reduction of back pressure is what is causing it and the wasgates can't open fast enough. Or the bending of the midpipes is makeing and opening somewhere up the exhaust and it overcompensates for the opening to reach proper boost and overshoots.

cn555ic · 01-29-2010, 11:25 AM

Quote:

Originally Posted by ridin135

The only thing I am coming up with is that the reduction of back pressure is what is causing it and the wasgates can't open fast enough. Or the bending of the midpipes is makeing and opening somewhere up the exhaust and it overcompensates for the opening to reach proper boost and overshoots.

Did you check for any leaks? The exhaust touching the brace will give you alot of strange noises and can attribute to the whining noise, but the overboost is strange...Do you have Procede v4?

ridin135 · 01-29-2010, 02:16 PM

Yep, but I dont see it being tune related as it doesn't do it anymore after I removed the exhaust no matter how hard I try

bimmerboy · 01-29-2010, 05:21 PM

what tune are you running?

ridin135 · 01-29-2010, 05:28 PM

Quote:

Originally Posted by bimmerboy

what tune are you running?

Procede

01-28-2010, 02:25 PM	#1
ridin135 Colonel 131 Rep 2,408 Posts Drives: Depends on the day Join Date: Dec 2008 Location: Greenville iTrader: (7)	exhaust causing problems I put on my new axle back three days ago and then I took it out for a spin. The first things I noticed was that it made the midpipes hit the suspension brace on the bottom of the car so it would rattle and clunk as you drive. Secondly the turbos made a huge whining sound as you released the gas it overpowered the blow off valve. This noise was coming from the turbos and not from the back of the car. Then I get these huge boost spikes 25+ lbs on my rixster gauge. This happend on the first pull I did on the day of the install. So I go home and do some troulble shooting, the next day I take it out again and it happens again on the second pull. Wensday comes around and I take off the exhaust and the large whine goes away and no matter how hard I try I can't get it to overboost again. So it seems that the exhaust caused these problems but I just dont understand how it did, any ideas?
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01-29-2010, 01:38 AM	#2
Robmaster Colonel 151 Rep 2,757 Posts Drives: 2010 E82 135, 2005 E87 130i Join Date: Apr 2007 Location: Switzerland iTrader: (3)	what exhaust did you have?
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01-29-2010, 09:59 AM	#3
ridin135 Colonel 131 Rep 2,408 Posts Drives: Depends on the day Join Date: Dec 2008 Location: Greenville iTrader: (7)	rather not say dont want to make any company look bad
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01-29-2010, 10:14 AM	#4
cn555ic 441 Rep 18,331 Posts Drives: 335i Join Date: Jun 2007 Location: US iTrader: (6)	I seriously doubt an exhaust would cause you to overboost...and the whine you might be hearing is probably the vibration noise from the exhaust hitting the brace...
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01-29-2010, 10:37 AM	#5
ridin135 Colonel 131 Rep 2,408 Posts Drives: Depends on the day Join Date: Dec 2008 Location: Greenville iTrader: (7)	The only thing I am coming up with is that the reduction of back pressure is what is causing it and the wasgates can't open fast enough. Or the bending of the midpipes is makeing and opening somewhere up the exhaust and it overcompensates for the opening to reach proper boost and overshoots.
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01-29-2010, 02:16 PM	#7
ridin135 Colonel 131 Rep 2,408 Posts Drives: Depends on the day Join Date: Dec 2008 Location: Greenville iTrader: (7)	Yep, but I dont see it being tune related as it doesn't do it anymore after I removed the exhaust no matter how hard I try
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01-29-2010, 05:21 PM	#8
bimmerboy Captain 23 Rep 601 Posts Drives: 135i Join Date: Jan 2009 Location: Bay Area iTrader: (0)	what tune are you running? __________________ *--2009 BSM 135i--* -Manual, Sport Package, BMW Assist
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