[cable96]

Wassup,

I just had my AR downpipes installed which goes down to stock exhausts. Now, i understand that there should be a noticeable turbo spooling (whooshing) sound which can be heard in normal traffic while the windows are down. My issue is that i hear a slighly higher pitched, whistling / hissing sound when im giving my car gas going 75+ mph, even when my windows are all rolled up.

For all you veteran AR downpipes guys, is this considered normal? Do you guys hear the same whistling / hissing sound in the cabin while gassing it to 75+ mph on the highway with all the windows closed? or do i have a possible problem in my hands and need to take it back in to be readjusted?

Updated with sound clip:
Excuse the shakiness, and horrible sound quality. The windows are infact CLOSED, i know it may sound that they are open.

At 00:22 - 00:25 you can hear a hissing sound when accelerating from 55-65mph the other times were just too noisy to pinpoint. Usually its more distinctive accelerating at 75+ mph. i just wanted to know if this was "normal".

UPDATE 2/2/2012
Some recent recordings i did that should clear things up. Same hissing sound persists, would appreciate more feedback and what you guys think now.

Sorry in advance for watching them upside down.

Video 1

Video 2

Clearer sound in the first 18 seconds

Video 3

This clip was taken next to a road barrier on purpose so i could amplify the sound, it was hard to capture it with my phone video recorder in the first and second video so this should clear things up. This is exactly how i hear it on the road without a barrier next to me.


Thanks


Update: 3/25/2012
The culprit were the V-Clamps: had them re-adjusted and seems to be the same as the sounds above but slightly lower.

Update: 10/31/2012, Happy Halloween
Sound is now worse again, possible V-Clamps loosened up, might need to purchase a new set, will have to ask the shop to evaluate everything.

[RnmEvo9]

Not normal. Take it back and have them check for exhaust leaks.

[J3NGOe90]

with AR downpipes turbo spool gets louder and 335 drivers actually like it!

[NiVeDh]

Have you heard another car with AR downpipes to compare with?

[roadkillrob]

I have AR Catted pipes, a little bit more turbo noise, but you have to listen to it, nothing like you are describing, the cat's proabably help a bit, but your description sounds like there could be a leak.

[cable96]

Originally Posted by NiVeDh

Have you heard another car with AR downpipes to compare with?

i have sat in one around a year ago but i cant recall exactly, and it was only local, not on the highway.

[335iBoii]

my turbo spool got alotttt louder once i installed my ar catless dps.. when lightly accelerating and then letting the throttle go you can clearly hear the turbos spool down (espiecally with windows down)..i honestly like the sound tho..lol

[thebigragu99]

Originally Posted by cable96

i have sat in one around a year ago but i cant recall exactly, and it was only local, not on the highway.

Any codes or cel?

[cn555ic]

If the car sounds like a helicopter then you have a exhaust leak, other than that you should definitely hear the turbos spool and nothing else...You probably will hear more rasp too for sure since your getting rid of one of the cats.

[cable96]

Haven't checked for codes yet, but I don't hav the dp fix installed yet so something will most likely show up

[taylors335]

normal !

[rader1]

i heard the same noise you were describing when i was running AA catless with cobb stage 2, i switched back to stage 1 V301 and it sounded A LOT better. i know exactly what sound you're describing and it sounds like SHIT, it sounds like a huge rush of air(NOT an exhaust leak) i think it has to do with the wastegate, but idk. im hoping stage 2+ doesnt sound like that

[Brey335i]

You should hear some turbo spool, maybe some intake noises, but nothing loud.

[creaminz]

Im in the same boat, i can hear hissing or even sound like loud static noise when I give it a little gas between 60-80...

[cable96]

ill try to take a vid next time i go out for a cruise, itll probably help.

[805beemer]

doesn't sound normal to me...I had my ar dp's and fmic installed at the same time. But I can only hear the turbos hissing with the windows down at slow speeds. Hope you get it fixed

[rader1]

I've experimented around today and i've come to this conclusion: i think its all about wastegate stiffness/wear/software. The stage 2(linear by default right now) and stage 1 linear sounds the same(loud hiss at partial throttle/until boost comes on). Stage 1 v301 sounds awesome(no hiss) and i think its because of the wategates operation due to tune/bmw software/slop. Thats why it's normal for some and not others.
But, thats just a guess of mine. To be clear, I'm sure as shit no expert.

[cable96]

Quick update, codes i see are 2x H2AD0, thats it. From what i gathered, they arent related to boost leaks or o2 sensor codes. Still working to get a cruising video, my epic 4g's video is nice but sound is bad.

[rader1]

IIRC they are cat ineffeciency codes. If they are it's completely normal.

[cable96]

updated with sound clip

[acdHQK713K]

Sounds normal to me

[335iBoii]

normal. have the exact same sound.. its loudest in 1st gear