N55

AJG1137 · 08-05-2012, 12:16 PM

Hi all. Looking to change my fuel to get a higher octane and slightly better performance, and am ignorant to the best way to achieve this. I have an N55 335xi with JB4 (no flex fuel wires and no other mods). Would it be best for me to run a 20% e85 mix with 93 octane fuel, mix race gas with 93 octane, or just put 100% race gas in? I would plan to drive this way most of the time, so it wouldn't just be for "track use".
Thanks.

eyim1988 · 08-05-2012, 12:23 PM

Mix e85 with 93 for
The most cost effective , pure race gas for track use

benzy89 · 08-05-2012, 01:35 PM

Mix 93 octane with some E85. You'll get similar results to mixing/running Race Gas at a fraction of the cost.

Newguy123 · 05-22-2014, 10:46 PM

I just tried this tonight E23 mix to be exact. 2.5 gallons of e85 to my full fill of 93. I did my 3 third Gerard pulls in map 5 and it holds 16 psi in fourth. Besides the S2 jb4 and muffler delete my '12 135i is stock. I've read this is ok to do, I did order the FF wires and USB cable so I will log once I have them but couldn't wait to try it. Anyone have comments on this ?

trixdout · 05-22-2014, 11:10 PM

Thing is with race gas is it will do a number on your O2 sensors. Meaning premature failure due to lead content in the race gas. So, get install the flex fuel wires and run at first 40% e85 and then increase your e85 percent based on your logs of injector duty cycle. You shouldn't go higher than 85% duty cycle. That way if you spring a leak while under high boost on a pull, your comp will be able to compensate for it. Always a good idea to play it safe.

1cleann55 · 05-23-2014, 10:39 AM

Quote:

Originally Posted by trixdout

Thing is with race gas is it will do a number on your O2 sensors. Meaning premature failure due to lead content in the race gas. So, get install the flex fuel wires and run at first 40% e85 and then increase your e85 percent based on your logs of injector duty cycle. You shouldn't go higher than 85% duty cycle. That way if you spring a leak while under high boost on a pull, your comp will be able to compensate for it. Always a good idea to play it safe.

Use unleaded race gas.. cam 2 to be more specific... I run 100octane pure occasionally and its insaneeee... but you will need FF wires even to run pure 100octane. the extra boost will cause the car to run sligthy lean so the wires will help richen up

08-05-2012, 12:16 PM	#1
AJG1137 Member 12 Rep 72 Posts Drives: 2011 335i e93 Join Date: Jun 2011 Location: Bloomfield Hills, MI iTrader: (1) Garage List 2011 335i xDrive [0.00]	N55 - e85+93 OR race gas OR race gas+93 Hi all. Looking to change my fuel to get a higher octane and slightly better performance, and am ignorant to the best way to achieve this. I have an N55 335xi with JB4 (no flex fuel wires and no other mods). Would it be best for me to run a 20% e85 mix with 93 octane fuel, mix race gas with 93 octane, or just put 100% race gas in? I would plan to drive this way most of the time, so it wouldn't just be for "track use". Thanks.
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08-05-2012, 12:23 PM	#2
eyim1988 Lieutenant Colonel 98 Rep 1,647 Posts Drives: 2022 BMW M4 Join Date: Feb 2011 Location: Los Angeles, CA iTrader: (5) Garage List 2022 M4 [0.00]	Mix e85 with 93 for The most cost effective , pure race gas for track use __________________ Current: 2021 X3MC Past: 2013 bmw 335i, 2011 bmw 335i coupe, 2016 bmw m3
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08-05-2012, 01:35 PM	#3
benzy89 Banned 79 Rep 2,396 Posts Drives: '08 E90 335i Join Date: Jan 2012 Location: Northern NJ iTrader: (3) Garage List 2008 BMW 335i [7.50]	Mix 93 octane with some E85. You'll get similar results to mixing/running Race Gas at a fraction of the cost.
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05-22-2014, 10:46 PM	#4
Newguy123 Captain 121 Rep 653 Posts Drives: 2008 Nissan Titan Join Date: May 2014 Location: Carlsbad iTrader: (0)	I just tried this tonight E23 mix to be exact. 2.5 gallons of e85 to my full fill of 93. I did my 3 third Gerard pulls in map 5 and it holds 16 psi in fourth. Besides the S2 jb4 and muffler delete my '12 135i is stock. I've read this is ok to do, I did order the FF wires and USB cable so I will log once I have them but couldn't wait to try it. Anyone have comments on this ?
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05-22-2014, 11:10 PM	#5
trixdout Lieutenant 57 Rep 439 Posts Drives: '11 335xi 6mt Join Date: Apr 2014 Location: NNJ iTrader: (1)	Thing is with race gas is it will do a number on your O2 sensors. Meaning premature failure due to lead content in the race gas. So, get install the flex fuel wires and run at first 40% e85 and then increase your e85 percent based on your logs of injector duty cycle. You shouldn't go higher than 85% duty cycle. That way if you spring a leak while under high boost on a pull, your comp will be able to compensate for it. Always a good idea to play it safe.
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