AFR on N54 Tuning

Biggenz

New Member
Jan 11, 2018
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N54 335i
Why are most people tuning the N54 to run around 12afr on WOT when it's a direct injection engine?
 

V8bait

Sergeant
Nov 2, 2016
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Texas
Well that's a rather broad statement and fails to address the use of different fuels, different builds, PI or meth incorporation etc.
 

Biggenz

New Member
Jan 11, 2018
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N54 335i
Well that's a rather broad statement and fails to address the use of different fuels, different builds, PI or meth incorporation etc.

Across the board really but lets say pump only for this.
 

V8bait

Sergeant
Nov 2, 2016
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753
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Texas
Across the board really but lets say pump only for this.

On pump only I target richer than 12's lol. Lets see:

-ACN91 with high boost: low 11's
-Race gas like C16 or E85, DI only: high 12's or low 13's depending on boost like 12.7:1 to 13.1:1, unless you live in Germany
-E85 with PI: mid/low 12's depending on how much PI
-Pump with meth: 11.8 to 12.2:1 depending on situation
-E85/race gas with meth: high 12's low 13's

Going leaner into the 13's works fine with DI if you have good octane but when you start adding things like PI and ACN91 into the mix, DI isn't going to save you from knock. A little richer is a bit safer as the EGT's get cooking on long pulls too so it's something to keep in mind.
 

Biggenz

New Member
Jan 11, 2018
8
9
0
Ride
N54 335i
On pump only I target richer than 12's lol. Lets see:

-ACN91 with high boost: low 11's
-Race gas like C16 or E85, DI only: high 12's or low 13's depending on boost like 12.7:1 to 13.1:1, unless you live in Germany
-E85 with PI: mid/low 12's depending on how much PI
-Pump with meth: 11.8 to 12.2:1 depending on situation
-E85/race gas with meth: high 12's low 13's

Going leaner into the 13's works fine with DI if you have good octane but when you start adding things like PI and ACN91 into the mix, DI isn't going to save you from knock. A little richer is a bit safer as the EGT's get cooking on long pulls too so it's something to keep in mind.

Would you tune exactly the same on a PI engine?
 

V8bait

Sergeant
Nov 2, 2016
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753
0
Texas
Would you tune exactly the same on a PI engine?

No I would tune richer usually assuming it's boosted. ACN91 on a PI engine is high 10's to low 11's, race gas and E85 is 12.1:1, etc.

If it's a build specifically for a certain fuel that can change things, and N/A cars that changes things, and maximum RPM also changes things. Have to run a little richer at very high RPM usually.
 
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V8bait

Sergeant
Nov 2, 2016
493
753
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Texas
Well that one's tough, how much do you trust your meth and what's your base fuel? General rule of thumb with meth is I tune for the base fuel and use it as safety net, but with port meth you're looking for power so probably lean and hope it doesn't have issues.
 
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STE92

Corporal
Mar 3, 2017
170
47
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E92
Sadly 91 ACN, my meth kit is pretty solid. Good pump, all steel braided, solenoid keep system pressurized and also running injectors.
 

PUTC

Corporal
Oct 14, 2017
206
68
0
Ride
08 335xi
I’m still pretty new to tuning. I’m aimim for 12.7-13:1 at high rpm and boost on just 93oct. Tuning the timing is something I’m still trying to figure out. My biggest issue is still not being able to log and busy life, not being able to get onto tunerpro often after changing something. I’ve always felt you can’t go wrong with more fuel though, problems come with too little
 

doublespaces

General of the Army
Oct 18, 2016
8,943
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AZ
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2009 E93 335i
Sadly 91 ACN, my meth kit is pretty solid. Good pump, all steel braided, solenoid keep system pressurized and also running injectors.

I have ACN91, its pure neglect to use it on my car I feel. Since we have E54 from the pump I've never looked back, even my lazy ass who has to drive 30 mins to fuel up.
 
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doublespaces

General of the Army
Oct 18, 2016
8,943
4,150
0
AZ
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2009 E93 335i
Kids these days, that's not even bad. In my day I used to make an hour and a half trek every month to fill up a bunch of gas cans with e85 to mix to e50. Worth it.

I'm 33 on Saturday, its more attributed to my massive lack of motivation for something like fuel.
 

Swedishpowah

Private
Dec 7, 2016
49
27
0
Greer, SC
Ride
LCI e92 - not an M
Man, I feel spoiled here in upstate SC. Got e85 stations all over the place - hurts to read about folks in other parts of the country that don't have easy access to e.
 
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langsbr

Captain
Apr 5, 2017
1,189
677
0
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07 335i 6MT e90
Man, I feel spoiled here in upstate SC. Got e85 stations all over the place - hurts to read about folks in other parts of the country that don't have easy access to e.

Other parts of the country? Hell just in the Midlands it's impossible to find. Damn Brandi replaced all the e85 pumps with ethanol free 85 or 87.