N54 cyl 5 timing drop

SlowE93

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I know its been discussed over the years. Tuned N54s are known for cyl 5 "noise". Some say false knock, others say most N54s blow in cyl 5 (so actual knock). If it is false knock, does it hurt the motor to keep running it with cyl 5 dropping timing while all others look fine ? Ive also read this is more problematic in cars with IJEOS AT. Why is that ?
 
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Its also been discussed that its PCV related and to plug the head ports to prevent oil from entering the intake runners. But even with that done there has been no solid determination on the absolute cause or a permanent solution that I’ve heard of.
 

SlowE93

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How dangerous is it ? If all cylinders maintain except #5 ?
Also, how do 600/700/800 whp cars deal with it ? I have seen that raising boost makes it worse. Lower boost enough and its not there in most cases. Thats why many think its actual knock as opposed to false knock. I saw Terry from BMS post up that most N54 failures are in fact cyl #5 at least from what he has seen. So once again, how risky is a clean overall log with #5 dropping ?
 

SlowE93

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Oh, let me add with a minimum of E65 or better as far as fueling is concerned
 

chrisdfv

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Oh, let me add with a minimum of E65 or better as far as fueling is concerned

I'm on full E85 and I experience timing drops on cyl 5 on 18psi, 20psi, 26psi. Never have perfect timing on cyl 5. I just take it as normal as long as it's not multiple 3* or higher drops in the same or multiple cylinders repeatedly in the same gear. If its one 3/4* pull once in the same gear and it recovers I just ignore it. It's been said it's just part of the DME's torque controlling logic or something along those lines.
 

SlowE93

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I'm on full E85 and I experience timing drops on cyl 5 on 18psi, 20psi, 26psi. Never have perfect timing on cyl 5. I just take it as normal as long as it's not multiple 3* or higher drops in the same or multiple cylinders repeatedly in the same gear. If its one 3/4* pull once in the same gear and it recovers I just ignore it. It's been said it's just part of the DME's torque controlling logic or something along those lines.
Thanks for the response. Does your timing crash more as you raise boost ? At redline/ shift point, how much lower is timing in #5 vs the other cylinders ?
 
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chrisdfv

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Thanks for the response. Does your timing crash more as you raise boost ? At redline/ shift point, how much lower is timing in #5 vs the other cylinders ?

It's the same basically all the time. I'm 6AT so I'm plagued by post shift timing drops most of the time, but timing usually recovers by redline or shift point.

you can check out my tuning venture here:
https://bmw.spoolstreet.com/threads/single-turbo-boostbox-tuning.2854/

I have plenty of logs in there on varying boost levels, E40 fuel and finally e85 once I went above 20psi.
 
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SlowE93

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Any csv. files by chance ? Im more concerned with precise #s vs. graph. Thanks !
 

zmon1300

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I have been trying to answer this for a the longest time also, just gave up. Im on PS2 HiFlow at 27ish psi full e85, ADE pcv and flapper fittings routed to a catch can, then recirculated to the inlets. Always getting timing drops on cyl 5 like -8, -9 degrees. it sucks but car runs great and made 600awhp. Theres no solution for it as far as I know unless you stop logging cyl 5 LOL
 
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SlowE93

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I have been trying to answer this for a the longest time also, just gave up. Im on PS2 HiFlow at 27ish psi full e85, ADE pcv and flapper fittings routed to a catch can, then recirculated to the inlets. Always getting timing drops on cyl 5 like -8, -9 degrees. it sucks but car runs great and made 600awhp. Theres no solution for it as far as I know unless you stop logging cyl 5 LOL
Yeah man, shits annoying as fuck ! So you are not afraid of #5 taking a shit ?
 

SlowE93

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I will check it out again. Im just used to csv. Datazap kinda confuses me lol !
 

veer90

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Yeah man, shits annoying as fuck ! So you are not afraid of #5 taking a shit ?

If you're not worried about possibly breaking the motor, I'd send it at high boost then compression / leakdown / borescope all the cylinders, see if you can tell a difference in #5

also, a good way to check for pre-ignition / detonation is examining the porcelain on the spark plug tip for cracks and other damage, as well as the tip itself for melting. it will be very obvious if you have either.
 
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SlowE93

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Thats why I started this thread. Im not trying to break a motor. Just curious as to what is "normal" for cyl 5 timing drops on say 550 whp +
My plugs come out perfect everytime.
 
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zmon1300

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Yeah man, shits annoying as fuck ! So you are not afraid of #5 taking a shit ?

I mean when you are 550whp+ on a stock motor, anything can happen. Ive been through so many ups and downs with this car that I expect something major to break, if it ever does. My trans is slipping, so thats gonna go eventually. Motor will too, and when that happens, ill just throw in another stock one, and keep on grinding lol
 

SlowE93

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I disagree. I think a well tuned N54 should handle 550whp without issue. That was the purpose of this topic. I mean are all 600/650/700 whp N54s having timing drops in cyl 5 ? If so, then there is no issue as long as the rest of the logs look good. Now if others are running beyond 550 whp and zero timing issues, then thats obviously a safer motor vs one dropping -8* of timing in cyl #5.
 

zmon1300

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I disagree. I think a well tuned N54 should handle 550whp without issue. That was the purpose of this topic. I mean are all 600/650/700 whp N54s having timing drops in cyl 5 ? If so, then there is no issue as long as the rest of the logs look good. Now if others are running beyond 550 whp and zero timing issues, then thats obviously a safer motor vs one dropping -8* of timing in cyl #5.

I partially agree with your statement. A well tuned and maintained N54 should and will handle 550 to 600 no problem. As long as you check it on a weekly or monthly basis to ensure logs and maintenance is up-to-date. I do believe though that past that point there will be timing drops regardless. My logs look great other than the timing drop in cylinder five. So that does mean the car is running good and should hold up for quite some time. But I feel as if though the high horse power builds will keep posting on the boards for a few months and then go ghost. They won’t update them weekly or monthly so I really don’t know if those cars held up or not. I do try to update my thread monthly to check in and show how the car is running at this power level I run my 600 map all day every day on full E 85 even in the winter here in Chicago. I also update the issues I encounter in my thread like the EKPM issue I had a few weeks ago. I hope that changes in a way which we have more documented builds that are updated so we have an understanding on how long these cars hold up at that power level. I think you should be fine as long as you address all the weak points. Just keep an eye on everything and keep us updated on your build! Good luck man!

Z
 

SlowE93

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Thanks for the feed back. Im at 580 whp. I run it like that everyday as well. I dont beat up on it daily of course. My car damn near looks like showroom floor condition. Not 1 leak. Not 1 scratch, etc. I maintain it meticulously. I do all my own work so Im constantly cleaning and over looking things. So cyl 5 seems to be power related and not necessarily boost related. I have seen issues with <20psi on single turbos, and >22psi on hybrids. So its more of a over 500 whp when it begins to happen. So isnt the motor trying to tell us its not happy over 500whp ? Or coincidence ? I dont believe its tuning related as too many people suffer from this at those power levels. Or dont they ? Thats why I started this thread.
So is it safe ?
Slightly risky ?
Extremely risky ?
Again, assuming a pretty much perfect log EXCEPT cyl 5 timing and e65 or higher fuel. Not just my car, im asking in general.