|
|
|
|
|
|
BMW Garage | BMW Meets | Register | Today's Posts | Search |
|
BMW 3-Series (E90 E92) Forum
>
Car is hissing after DP installation
|
|
06-13-2013, 12:13 PM | #1 |
First Lieutenant
71
Rep 374
Posts |
Car is hissing after DP installation
I put BMS downpipes on my car a couple weeks ago. Great results and the fittament was spot on. Boost is consistently maxing at about 17psi. My only other performance mod to date is a JB4 G5 (not ISO yet, doing that this weekend, then FMIC next wekend ).
I was expecting the result to still sound like stock, but its anything but. The exhaust note is much deeper/raspier, and when I'm either WOT or halfway on the throttle so that the car is accelerating aggressively i hear a very distinct "hiss". It sounds like a BOV (or a really angry snake). Lasts a bit longer than a BOV purge. I had my indy look at it today. No loose bolts, no leaking lines. Everything seems to be in order. His best guess was air getting sucked through the DV lines was making the sound. Is this a standard thing for our cars? Anyone else have a similar experience? |
06-13-2013, 01:52 PM | #5 |
teh Rider!
12
Rep 488
Posts |
damn those angry snakes, they always make their ways into our cars somehow
on a more serious note, that would be your turbos spooling.. sounds beautiful IMO
__________________
2008 335xi AW/Black MT
383 awhp/410awtq Avant Garde M359 l Hankook Ventus V12 l Kw V1 l M3 Front+sides | Mtec Rear | LCI tails l Cobb Stage2+FMIC l AR DP l ER IC l ER CP l Tial BOV | AFE Stage2 DCI |
Appreciate
0
|
06-13-2013, 02:49 PM | #6 |
Banned
87
Rep 2,854
Posts |
|
Appreciate
0
|
06-13-2013, 02:53 PM | #7 |
2105
Rep 43,350
Posts |
Sounds more like an exhaust leak than the sound of turbo spool. Make sure whoever installed them oriented the pipes correctly, otherwise the torque from the tightening of the rear flanges stretches the v-bands a bit or vice versa.
|
Appreciate
0
|
06-13-2013, 03:16 PM | #8 |
3455
Rep 79,211
Posts
Drives: C6 Z06, 09 335i, 10 335xi
Join Date: Dec 2008
Location: www.TopGearSolutions.com
|
Sounds like an exhaust leak for sure. Most common culprit is near the v-band to the turbo. The orientation is important as well as the orientation of the clamp itself. If the clamp is on incorrectly it will hit the wastegate actuator arm (that's a different problem).
However, if the v band clamp is not seated properly it will not have a good seal but still "appear" to be sealed. Best thing to do is remove both v band clamps and re-install. They should go on smoothly and tighten down smoothly. If they give you trouble the downpipe is not seated correct and or the v band is not seated correct. Also downpipes will not sound like stock anymore. They will have a more aggressive exhaust note and add a bit of rasp. |
Appreciate
0
|
06-13-2013, 04:25 PM | #9 | ||
First Lieutenant
71
Rep 374
Posts |
Ha! I know what turbos sound like
This noise is in addition to the regular spooling sound Quote:
Quote:
Either way, when I'm installing my FMIC (Tiago is fighting with the customs people to make that happen ) I'll have the car on ramps and will try to get a sound clip if i cant figure out what it is. |
||
Appreciate
0
|
06-13-2013, 05:05 PM | #10 |
Major General
161
Rep 7,377
Posts |
Actually have the same sound. Will get it checked for leaks . Sometimes i get as well a lambda code post cat. Can also smell faint exhaust gas near the turbos.
|
Appreciate
0
|
06-13-2013, 07:23 PM | #11 |
Banned
12
Rep 248
Posts |
While on ramps, check for black soot where the downpipes connect to the exhaust. It could be the V-band, but an easy check would be where the dp's connect to the exhaust.
|
Appreciate
0
|
06-15-2013, 12:05 AM | #13 |
First Lieutenant
71
Rep 374
Posts |
|
Appreciate
0
|
Bookmarks |
|
|