I need to know what more I can get away with when running C16 as compared to 100 octane.

Basically for 100 octane I take my normal map and offset my fuel -4, zero my timing, and max out my boost map. This is good for 2 more MPH in the 1/4 but honestly I think I'm leaving alot of breathing room on the table. Yesterday I picked up a few gallons of C16 and would like to adjust my current race map to a C16 map.

Basically how much positive timing should I be able to add? How much more offset can I take from the fuel table?

Any suggestions welcomed.

Jeff Jeske

 

Are you running smart?

 

No I am not running smart.

 

Without running smart it is really dangerous to make any further changes. Not knowing what exact Air/Fuel ratio you are running or being able to read knock is a no no when tuning.

 

I have pocket logger and WB so I'm not blind. I was just curious to what others have done with their pump map when going to C16. I assume you can be much more aggressive than what shiv tells us (-4F/0T/MAXB).

 

C16 on a stock turboed car is overkill. If you are after more octane go with vp109 unleaded. Its more expensive than 100 but is the same price as c16 and will make big power. Its highly oxygenated so tune on the conservative side. If you really need some lead in your fuel look at vp110. 110 has 4 grams of lead per gallon and c16 has over 6. C16 will need lots of boost and timing to fire cleanly. To put it in perspective i've seen c16 support 950whp and mid 8's in the quarter mile. With fuel, more isn't always better.

 

C16 is a pure as the driven snow !

 

I wouldnt run c16. We really like the 109, unleaded gas seems to run much better in the evo. It starts up better, idles better, makes good power.

 

So how do I modify my 100 octane map to use 109?

Generally speeking can I toss some positive timing at it?

 

or just run another psi or two

 

and it won't trash your O2 sensors

 

You people worry about O2 sensors more than you should. I ran gallons upon gallons of the stuff in my DSM and never had a problem.

As for the 100 vs 116.....I'm already maxed out on boost on the 100 so I'm looking for some timing numbers.