[jpsimon]

before anyone calls me out for hating on running race fuel: this is for educational purposes only (and I'm curious about something......)

So here's the game: dyno appointment for monday at 7am... my catless v3'ed XI with 100 octane fuel.

on this dyno:
- 264whp (uncorrected) stock on 93octane (in cooler weather)
- 364whp (uncorrected) with my current mods on 93octane (in hotter weather)
- _______ on 100 octane with my current mods.



Fill in the blank. What are your predictions?

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*** For v3 users who have dynoed with higher octane fuel... how much higher did you up the torque settings? ***

[jpsimon]

e90AW335i: i'll make sure I get the .drf files for my original runs, and the various stock 335i's and xi's for comparison... (and of course these runs)

[ThePrinzeofcatz]

my guess will be 380ish

[e90AW335i]

Originally Posted by jpsimon

e90AW335i: i'll make sure I get the .drf files for my original runs, and the various stock 335i's and xi's for comparison.

LOL, you already knew I was gonna ask. I would love to add your files to my growing collection of dynos....

Good look bro, I am sure it will be fun....

[jpsimon]

I still have yet to see my corrected numbers from my last dyno there... i think they would be around 370-375. we'll see soon enough!

[1clean335i]

i think you should be in the 390's

[e90AW335i]

Originally Posted by jpsimon

I still have yet to see my corrected numbers from my last dyno there... i think they would be around 370-375. we'll see soon enough!

What were your conditions last time? What temp and humidity?

[AU335]

376rwhp (uncorrected) is my guess

[Mr. 5]

Originally Posted by Railgun

I would think that you'd get just the same running 100 as opposed to the mix. Without tuning for C16, it's hardly worth it. Secondly, even though it may be for a short time, I wouldn't run leaded unless you want to replace O2 sensors.

I don't know about this. I've heard that the C16 will work wonders since the engine would adjust automaticlly.
I've also heard that C16 in an engine that was initially meant to run on unleaded is no bueno. I've brought this up before and people argue that the only thing that C16 will do harm to is the cats if you have them.

I, personally, don't want to find out in my car.
I'll stick with the highest possible unleaded.
MS109 (105 Octane R+M/2) will be good enough.

[E92Pilot]

Originally Posted by Mr. 5

I don't know about this. I've heard that the C16 will work wonders since the engine would adjust automaticlly.
I've also heard that C16 in an engine that was initially meant to run on unleaded is no bueno. I've brought this up before and people argue that the only thing that C16 will do harm to is the cats if you have them.

I, personally, don't want to find out in my car.
I'll stick with the highest possible unleaded.
MS109 (105 Octane R+M/2) will be good enough.

C16 is amazing race fuel. I have run massive amounts of boost with this stuff and have never seen any detonation what so ever. It has a lower specific gravity than unleaded fuels and burns cleaner and hotter. (ala more HP)

One or two times will not be an issue, but on a regular basis will burn up your O2 sensors and the cats. I'm not sure if our O2 sensors are heated or not, but if they are and your car is catless you should have no problems running leaded race fuels. Eventually over time the sensors will have to be replaced.

VP also makes a new blend called Q16, its more expensive than the C but burns even hotter. Supposidly worth a few hundredths on your ET's by just running the Q over the C.

Now with high boost levels and detonation not an issue our stock turbos are once again the limiting factor due to excessive turbine speeds. On most turbo cars usually the reverse is the problem. Not enough motor octane for the compression ratio.

Sometime in the future with aftermarket turbos (either single or twin) big HP will be done on C16.

If you wanna play it safe and make nice power unleaded is the way to go.

P.S. If your not planning on running big boost (i.e. 20psi+) C16 is probabally overkill since it supports 17:1CR
You have to run high boost/timing in order to make power with high motor octane fuels.

[max boost]

Originally Posted by Railgun

I would think that you'd get just the same running 100 as opposed to the mix. Without tuning for C16, it's hardly worth it. Secondly, even though it may be for a short time, I wouldn't run leaded unless you want to replace O2 sensors.

and fast too!

[jpsimon]

I mention C16 because thats what they have available at the shop. If I can find some unleaded (i'm looking for locations right now)... i'm gonna fill up with sunoco 260 GT100

[jpsimon]

apparently there is a location 0.9 miles away from me that has this 100 octane sunoco. Looks like that is what i'll be running

[jpsimon]

Originally Posted by e90AW335i

What were your conditions last time? What temp and humidity?

82.45°, 50% humidity

[jpsimon]

I have half a tank of 93 to kill today before filling up.. I need to go drive around..

[Sniz]

drive the gas out of your car, put some 100 octane in and go beat on the car HARD. You should feel it pep up very quickly.....dont rely on the dyno runs for your car to adapt to the new gas. It took me a good 3 all out 2-4th gear runs for my car to adjust fully....I think.

[ThePrinzeofcatz]

what do we get if we guess correctly?

[jpsimon]

damnit i still have a quarter of a tank.. i gotta go rip around and get rid of this 93 octane

[jpsimon]

step 1: buy 100 octane

[RiXst3r]

How much did those fuel kegs cost ya? I think I found a place near me that sells it...

[jpsimon]

Each one is 5 gallons.... each one was $63. I don't know what the going rate is, but this place was less than a mile away.. so i can't complain

[jpsimon]

Step 2: add fuel to car....
Step 3: do some pulls on the highway....

it definitely feels stronger.... dyno appointment in t-minus 7.5 hours