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BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > Are downpipes just for performance?



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      09-22-2013, 12:29 PM   #1
tennis_pr0
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Are downpipes just for performance?

I am pretty sure I am going to get downpipes now after hearing so many positive things. My question is, I know downpipes are for performance, but do they also help the longevity of the turbos? Like for example, if a car was pushing high psi numbers, would those turbos be more likely to develop waste gate rattle or turbo failure with stock downpipes?

I am mostly asking this question because I am happy with the mods and power I have, and if the downpipes are just for performance, and it really doesn't affect the reliability of the turbos, then I probably would not get them.
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      09-22-2013, 01:02 PM   #2
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Quote:
Originally Posted by tennis_pr0
I am pretty sure I am going to get downpipes now after hearing so many positive things. My question is, I know downpipes are for performance, but do they also help the longevity of the turbos? Like for example, if a car was pushing high psi numbers, would those turbos be more likely to develop waste gate rattle or turbo failure with stock downpipes?

I am mostly asking this question because I am happy with the mods and power I have, and if the downpipes are just for performance, and it really doesn't affect the reliability of the turbos, then I probably would not get them.
I don't know if there is any evidence to support this, but I would assume at high boost levels that less back pressure would help the turbos in the long run. The ability to hear the turbos spool better is worth it alone, IMO.
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      09-22-2013, 01:13 PM   #3
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Quote:
Originally Posted by AWil335i View Post
I don't know if there is any evidence to support this, but I would assume at high boost levels that less back pressure would help the turbos in the long run. The ability to hear the turbos spool better is worth it alone, IMO.
Yeah I want to get them. Just scared if I do and turbos go they will void the warranty. They are not so easy to just take in and out.
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      09-22-2013, 01:17 PM   #4
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If I was a dealer I wouldn't warranty turbos with downpipes installed. Downpipes will cause the turbos to spin faster and also may promote more oil leaking through the turbo seal due to lack of back pressure.

You'd want to remove the downpipes before going in for warranty work on the turbos.
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      09-22-2013, 01:58 PM   #5
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Quote:
Originally Posted by Jewber View Post
If I was a dealer I wouldn't warranty turbos with downpipes installed. Downpipes will cause the turbos to spin faster and also may promote more oil leaking through the turbo seal due to lack of back pressure.

You'd want to remove the downpipes before going in for warranty work on the turbos.
+1 and no one runs downpipes without a tune, so downpipes are proof positive the car was running higher boost to a dealer and gives them a reason to turn down the warranty work.
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      09-22-2013, 02:26 PM   #6
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Thats why I stuck with high flow chatted downpipes. Can't stand the tin can exhaust sound on cattless DP on so.e cars, not all though
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      09-22-2013, 02:36 PM   #7
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DP's are an automatic turbo warranty fail. They can also cause issues in some state emissions inspections.
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      09-22-2013, 02:56 PM   #8
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Aftermarket DPs remove the huge restriction the factory cats present. Removing this restriction not only improves exhaust flow(less back pressure against the turbine) but also evacuates heat from the turbos and heat is a turbo killer. By themselves they will help to prolong turbo life, however most people begin running more aggressive boost levels after DP installs so in the end it may just be a wash. Running a tune that is designed to provide power but not at the expense of turbo longevity is always an option.

Aftermarket DPs will void your warranty if you do experience turbo failure and they are installed when you visit the dealer. This has more to do with dealers and BMW NA looking for an excuse not to replace your turbos than it does any legitimate claim that the DPs caused the failure. Fortunately, turbo failures are very rarely catastrophic and are usually just a degradation of seals and WG components so it's very easy to just swap the stockers back in if the need ever arises.
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      09-22-2013, 04:00 PM   #9
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Quote:
Originally Posted by tennis_pr0 View Post
Yeah I want to get them. Just scared if I do and turbos go they will void the warranty. They are not so easy to just take in and out.
Just did mine yesterday, only took 2 1/2 hours. That's a relatively quick R&R
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      09-22-2013, 04:45 PM   #10
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Less back pressure so turbos aren't under stress. The coins you get in the exhaust is loud and nice. The. Turbo spool is amazing. The sense in knowing you don't have as much back pressure is a peace of mind. IMO downpipes are awesome of you can get a good deal. Vrsf is a good product IMO. Fitment, quality and sound are amazing.
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