How much boost can the stock motor handle ?

BMW72 · 09-02-2011, 12:15 AM

What are the stock internals rated for ? I see some over double stock boost levels here. How much until meltdown ?

tibra1 · 09-02-2011, 12:18 AM

No one knows for sure..there is no rating..BMW will tell u anything overstock is unsafe..but then again the 335is has an overboost feature..I run 17psi..w no issues..you will inevitably need new turbos but engine internals should be good..the n54 has forged pistons and crank...the n55 doesnt so..?? only time will tell.

plague · 09-02-2011, 12:32 AM

n54 07-08 models have been opened up and found to include forged internals including pistons. 09 and up im really unsure, but guys are making over 510whp with no motor issues so.. once fueling is all worked out people will eventually find out probably.

Brey335i · 09-02-2011, 07:14 AM

The safe thing is to always let there be someone more modded than you. That way you have a better, still not definite though, safety net.

dzenno · 09-02-2011, 08:00 AM

depends on what turbos you're running and where that boost is hitting in the RPMs, what sort of gas you're using, what sort of IATs your engine is seeing and how much exhaust backpressure you've got...its all "relative"

excessive heat and low octane is what melts engine internals not necessarily boost itself

RoundelM3 · 09-02-2011, 09:09 AM

I'd say 14-15 PSI is a conservative limit on 93 octane pump gas for turbo longevity if you don't have full bolt-ons. Opening things up with downpipes, FMIC, etc. might make 17 PSI safe, but it's hard to say. A lot depends on how your tune compensates for the inceased power with higher water pump speeds, timing maps, etc.

SneakyDeeky · 09-02-2011, 05:28 PM

I'll second Dzenno, and roundel's guess is the same thing I'd say.

chrisw335i · 09-02-2011, 05:47 PM

28.768312098 psi

issabmw · 09-02-2011, 06:03 PM

alot

BMW72 · 09-03-2011, 11:18 PM

Quote:

Originally Posted by chrisw335i

28.768312098 psi

Ok...doucher.

tibra1 · 09-04-2011, 12:40 AM

Quote:

Originally Posted by chrisw335i

28.768312098 psi

NO NO its closer to 28.768312098.1 lets be accurate here..

JunkStory · 09-04-2011, 12:48 AM

Wow.. I did not know the N55 doesn't have forged internals like the N54.. thumbs down

onesuperboi · 09-04-2011, 12:54 AM

Probably until 21 pounds of boost with no ignition control.

tibra1 · 09-04-2011, 12:57 AM

Quote:

Originally Posted by JunkStory

Wow.. I did not know the N55 doesn't have forged internals like the N54.. thumbs down

Yep..to be fair its only the early n54s..2007 and 08..BMW cheaped out with cast parts some time in 2009..and ofcourse this includes the n55

Bakeme521 · 09-04-2011, 07:53 AM

I still can't believe BMW went cheapo on us. BUT at least I made it in time and got me a 2007.

DaFish · 09-04-2011, 08:51 AM

Quote:

Originally Posted by Bakeme521

I still can't believe BMW went cheapo on us. BUT at least I made it in time and got me a 2007.

Ya, I completely lucked out and got an 08... no idea I had bought the right car at the time.

Question: Does the 335is, and the 1M have forged pistons and the "good" motor? anybody know... (probably thread jacking here....)

On topic... I would say that the data logs will provide the basis of how far we can go. I will also point out that we have some members with huge boost going with upgraded turbos... we are not seeing any blown motors, and some people have been running this for a while. 20PSI for sure....

Fuel limits seem to be the natural cut off, not seized bottom ends of the motors due to increased stress or pushing too hard.

chrisw335i · 09-04-2011, 12:22 PM

oh yeah, my bad..i was just rounding it off to the nearest whatever that is..hahahahaha

Quote:

Originally Posted by tibra1

NO NO its closer to 28.768312098.1 lets be accurate here..

chrisw335i · 09-04-2011, 12:30 PM

Quote:

Originally Posted by BMW72

Ok...doucher.

CaptainInsano · 09-04-2011, 02:59 PM

Quote:

Originally Posted by plague

n54 07-08 models have been opened up and found to include forged internals including pistons. 09 and up im really unsure, but guys are making over 510whp with no motor issues so.. once fueling is all worked out people will eventually find out probably.

Where did you read that the early N54 pistons are forged? I've been lurking around, but haven't found anything convincing. I have a 2007 335i.

enrita · 09-04-2011, 03:09 PM

Quote:

Originally Posted by CaptainInsano

Where did you read that the early N54 pistons are forged? I've been lurking around, but haven't found anything convincing. I have a 2007 335i.

They are. My engine had and still has forged internal after rebuild.

plague · 09-04-2011, 03:59 PM

Quote:

Originally Posted by CaptainInsano

Where did you read that the early N54 pistons are forged? I've been lurking around, but haven't found anything convincing. I have a 2007 335i.

from this guy lol^ as well as e92fan whos motor was opened

tibra1 · 09-04-2011, 04:13 PM

Yes its confirmed the 07 08 n54 has forged pistons, crank n connecting rods..there are several threads about it

09-02-2011, 12:15 AM	#1
BMW72 Private First Class 15 Rep 178 Posts Drives: 2009 335i XDrive Join Date: Jul 2011 Location: Pittsburgh iTrader: (1) Garage List 2009 BMW 335I X-DRIVE [1.00]	How much boost can the stock motor handle ? What are the stock internals rated for ? I see some over double stock boost levels here. How much until meltdown ? __________________ 2009 BMW 335i X-Drive
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09-02-2011, 12:18 AM	#2
tibra1 Banned 127 Rep 6,773 Posts Drives: 2011 ZCP M3 - 2007 335i crashd Join Date: Apr 2009 Location: NYC iTrader: (4)	No one knows for sure..there is no rating..BMW will tell u anything overstock is unsafe..but then again the 335is has an overboost feature..I run 17psi..w no issues..you will inevitably need new turbos but engine internals should be good..the n54 has forged pistons and crank...the n55 doesnt so..?? only time will tell.
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09-02-2011, 12:32 AM	#3
plague Captain 40 Rep 957 Posts Drives: 335i sold :( / jb 20th AE Join Date: Mar 2011 Location: NJ iTrader: (2)	n54 07-08 models have been opened up and found to include forged internals including pistons. 09 and up im really unsure, but guys are making over 510whp with no motor issues so.. once fueling is all worked out people will eventually find out probably. __________________ 07 335i- SOLD, and will be missed... Parts for sale- PWM meth kit, M steering wheel, M shift knob, perforated e brake handle
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09-02-2011, 07:14 AM	#4
Brey335i Banned 112 Rep 4,771 Posts Drives: e46 ///M3 Join Date: Oct 2009 Location: Austin, TX iTrader: (11)	The safe thing is to always let there be someone more modded than you. That way you have a better, still not definite though, safety net.
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09-02-2011, 08:00 AM	#5
dzenno Banned 273 Rep 5,876 Posts Drives: Join Date: Feb 2006 iTrader: (1)	depends on what turbos you're running and where that boost is hitting in the RPMs, what sort of gas you're using, what sort of IATs your engine is seeing and how much exhaust backpressure you've got...its all "relative" excessive heat and low octane is what melts engine internals not necessarily boost itself
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09-02-2011, 09:09 AM	#6
RoundelM3 Major General 1837 Rep 6,990 Posts Drives: 15 F80 M3, 22 G01 X3 30i Join Date: Apr 2010 Location: Clayton, NC iTrader: (2) Garage List 2022 BMW X3 [9.83] 2015 BMW M3 [6.50]	I'd say 14-15 PSI is a conservative limit on 93 octane pump gas for turbo longevity if you don't have full bolt-ons. Opening things up with downpipes, FMIC, etc. might make 17 PSI safe, but it's hard to say. A lot depends on how your tune compensates for the inceased power with higher water pump speeds, timing maps, etc. __________________ 2015 F80 ///M3 Sedan 7DCT Tanzanite, 2022 X3 sDrive30i 8AT Brooklyn Grey
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09-02-2011, 05:28 PM	#7
SneakyDeeky driver mod in progress 225 Rep 1,858 Posts Drives: with both feet Join Date: Feb 2011 Location: Redondo Beach, CA iTrader: (6) Garage List 2015 VW Golf R [5.50] 2014 Audi SQ5 [10.00]	I'll second Dzenno, and roundel's guess is the same thing I'd say. __________________ '15 VW Golf R \| '14 Audi SQ5 \| '08 Audi Q7 4.2 \| '07 BMW 335i \|
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09-02-2011, 05:47 PM	#8
chrisw335i First Lieutenant 13 Rep 377 Posts Drives: 2007 BMW 335i Coupe Join Date: Jan 2011 Location: Columbus, Ga. iTrader: (3)	28.768312098 psi __________________ 2007 335i Coupe 6AT - Sports Package - Premium Package - Procede V5 Rev 2.5 - Vishnu PWM - Vishnu DCI - Vanguard Exhaust - AR Downpipes - Helix FMIC - 19" Avant Garde M6 Reps - Michelin Pilot Super Sports - Bilstein PSS10 - M3 Suspension Bits - M3 Sway - M3 Strut Brace - GP Thunder -Forge DV -15% Tint - Aero Lip
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09-02-2011, 06:03 PM	#9
issabmw cool beans 63 Rep 1,364 Posts Drives: 325xi Join Date: Mar 2010 Location: FL iTrader: (2)	alot
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09-04-2011, 12:48 AM	#12
JunkStory Major 160 Rep 1,307 Posts Drives: E92 M3, 8V RS3 Join Date: May 2008 Location: 98230 iTrader: (3)	Wow.. I did not know the N55 doesn't have forged internals like the N54.. thumbs down
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09-04-2011, 12:54 AM	#13
onesuperboi Major 52 Rep 1,357 Posts Drives: '08 e92 335i COBB 4.01 Stage 1 Join Date: Aug 2008 Location: Bay Area, CA (Alameda) iTrader: (6)	Probably until 21 pounds of boost with no ignition control. Last edited by onesuperboi; 09-04-2011 at 01:01 AM..
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09-04-2011, 07:53 AM	#15
Bakeme521 Some say... 239 Rep 4,296 Posts Drives: Fresh Join Date: Mar 2010 Location: Baton Rouge n NOLA iTrader: (12) Garage List 2007 BMW 335i [8.24]	I still can't believe BMW went cheapo on us. BUT at least I made it in time and got me a 2007. __________________ I have exhaust and an intake...
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09-04-2011, 04:13 PM	#22
tibra1 Banned 127 Rep 6,773 Posts Drives: 2011 ZCP M3 - 2007 335i crashd Join Date: Apr 2009 Location: NYC iTrader: (4)	Yes its confirmed the 07 08 n54 has forged pistons, crank n connecting rods..there are several threads about it
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