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-   -   Race gas (http://forum.e46fanatics.com/showthread.php?t=745944)

xixixi 03-04-2010 11:58 AM

Race gas
 
can I run higher octane fuel in my 01 330xi? like maybe a mix of 110/93 in a 50/50 ratio or maybe a less then 50/50 anyone?

AdamBath 03-04-2010 11:58 AM

What for? It wouldn't do you much good unless you're extremely modified...

xixixi 03-04-2010 12:19 PM

no damage to motor? or anything?

95blkmax 03-04-2010 12:23 PM

Wont cause any damage to the motor but it wont make a difference really. Only 2 reasons to use that higher octaine gas- to ward off pre-ignition (due to several reasons but include high compression pressures from say boost, or a 12.5:1 NA build) or to allow you to run a very advanced ignition timing map.

xixixi 03-04-2010 12:30 PM

damn so zero gains from the 110/93 mix i just can't believe that. i realize what it is used for i just figured i could get a lil gain with the mix.

330I6SPD 03-04-2010 12:42 PM

Quote:

Originally Posted by xixixi (Post 11413713)
damn so zero gains from the 110/93 mix i just can't believe that. i realize what it is used for i just figured i could get a lil gain with the mix.

:facepalm:Octain is an anti knock index rating, not an energy index rating!

TR_MS3 03-04-2010 12:44 PM

Quote:

Originally Posted by 330i6spd (Post 11413776)
:facepalm:octain is an anti knock index rating, not an energy index rating!

qft

xixixi 03-04-2010 12:51 PM

ok thats kinda what i was thinking what about fuels that have more 02 in em? i'm just here for info nothing more

330I6SPD 03-04-2010 12:56 PM

The close to this thread should be, WITHOUT octane adaptive software, run the LOWEST octane that does not knock!

nickr519 03-04-2010 01:02 PM

I don't know if that's necessarily the best advice, could be slightly misleading but in the context of a stock 3er I suppose its appropriate

xixixi 03-04-2010 01:10 PM

Quote:

Originally Posted by 330I6SPD (Post 11413838)
The close to this thread should be, WITHOUT octane adaptive software, run the LOWEST octane that does not knock!

so you just run cheap gas in your ride right? reg unleaded won;t cause knock... bmw suggest 93 any more info that i could gain on this subject? info i'm seeking would not be in your own words maybe a web page link etc? etc? i'm gonna run 110/93 50/50 mix today i'll let ya know if i FEEL any difference. thanks for your input

330I6SPD 03-04-2010 01:25 PM

Quote:

Originally Posted by xixixi (Post 11413926)
so you just run cheap gas in your ride right? reg unleaded won;t cause knock... bmw suggest 93 any more info that i could gain on this subject? info i'm seeking would not be in your own words maybe a web page link etc? etc? i'm gonna run 110/93 50/50 mix today i'll let ya know if i FEEL any difference. thanks for your input

I never, ever use any cheap gas! BP Ultimate or Shell V-power is all I EVER put in my tank. I am sure however, that there are some E46s on the road that have enough ring and valve/valve seat wear that dropping down to a GOOD (read; NOT CHEAP) mid-grade fuel, would not cause any pre-ignition due to lower compression that the worn rings and valves cause.
Feeling a difference means

xixixi 03-04-2010 01:43 PM

i was being sarcastic about the cheap gas :) i guess what i'm wondering is how far can the vanos go? or does it hit a peak limit at a certain octane level? say it's 93 and anything above does nothing cause it can't adjust the timing past a certain point? maybe i have no idea what i'm talking about, i'm an auto body tech far from a mechanic. ??? my train of thought was coming from.. my car runs considerably better on 93 then low grade gas so i figure maybe it will run better on even higher?

McSpeed 03-04-2010 01:58 PM

Quote:

Originally Posted by xixixi (Post 11413559)
can I run higher octane fuel in my 01 330xi? like maybe a mix of 110/93 in a 50/50 ratio or maybe a less then 50/50 anyone?

If you run race gas make sure it's unleaded or it'll degrade your O2 sensors. Sunoco has 100 octane at the pump at some select locations. You won't get the benefit of a higher octane (better ignition timings = more power) until you run about a tank of it through the engine while driving aggressively so any stored knock adaptation is cleared out (unfortunately the ECU takes its time).

However be aware that, in theory, you'll get more power if you run 93 without knocking because it's less diluted than 100: there's more explosion in it.

Bimmerci330 03-07-2010 10:20 AM

i read somewhere that these cars only run at peak HP on 99 octane?

PEI330Ci 03-07-2010 02:04 PM

Quote:

Originally Posted by xixixi (Post 11414093)
i was being sarcastic about the cheap gas :) i guess what i'm wondering is how far can the vanos go? or does it hit a peak limit at a certain octane level? say it's 93 and anything above does nothing cause it can't adjust the timing past a certain point? maybe i have no idea what i'm talking about, i'm an auto body tech far from a mechanic. ??? my train of thought was coming from.. my car runs considerably better on 93 then low grade gas so i figure maybe it will run better on even higher?

There's a sweet spot with regard to octane for every engine combination. In general, you need to look at the MON (Motor Octane Number) when comparing fuels, as that's what race fuel is most often designed around.

On an N/A engine with under 11:1 compression, you really aren't going to see gains from octane above 95 MON.

What you will see with most race fuels, is a small gain in HP due to the quality of the fuel's vaporization and burn characteristics.

If you are comfortable spending 4 times the cost of regular pump fuel for say VP Streetblaze 99 to get an additional 3rwhp....go ahead and use it.

mrshelley 03-07-2010 06:28 PM

Quote:

Originally Posted by PEI330Ci (Post 11427577)
There's a sweet spot with regard to octane for every engine combination. In general, you need to look at the MON (Motor Octane Number) when comparing fuels, as that's what race fuel is most often designed around.

On an N/A engine with under 11:1 compression, you really aren't going to see gains from octane above 95 MON.

What you will see with most race fuels, is a small gain in HP due to the quality of the fuel's vaporization and burn characteristics.

If you are comfortable spending 4 times the cost of regular pump fuel for say VP Streetblaze 99 to get an additional 3rwhp....go ahead and use it.

Pretty much on target. I run a stock ECU with the Shark Injector and a stock 330 engine in Continental. We have to run Sunoco GTX 260 as Grand-Am requires us to do so. I have dynoed the engine with regular old Sunoco 94 from the pump and what I have to use for Continental. It's around a 3 hp advantage using the GTX 260 at the rear wheels.

The GTX 260 costs me $6.50/gallon. I burn around 100 gallons for a race weekend and run around 12 races per year. As you can see, that 3 hp benefit is pretty expensive.

Here are the specs:
http://www.sunocoinc.com/Site/Consum...noco260GTX.htm

McSpeed 03-07-2010 10:39 PM

Quote:

Originally Posted by McSpeed (Post 11414194)
However be aware that, in theory, you'll get more power if you run 93 without knocking because it's less diluted than 100: there's more explosion in it.

FWIW I've heard this statement^ made in regard to FI - not sure if it applies to NA.

xixixi 03-09-2010 08:41 AM

thanks everyone for the info this was exactly what i was looking for :thanks: :bow:


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