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C16 fuel

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I have a turbo charged that runs on pump gas with 98 ron fuel and i am planning to mix the fuel with c16 fuel, from my knowledge pump gas has stoicmetric value of 14.7 and c16 is 14.77.

Currently my engine runs on 1.4 boost and has igntion timing of 15 degrees, my question is how much timing could i increase if i put 50% c16 and 50% pump gas also, can i use c16 for daily use and how can i tune it? Should i make 2 maps? 1 for if i am only going to use pump gas and the other for when using the mixture? And what afr should i aim for? Currently runing on 11.5


Typically the fuel table will not require much work if you're switching from pump gas to C16 - It's the ignition timing where you'll focus your efforts. I'm not a huge fan of mixing fuel as it opens up to the possibility of inconsistent octane in your blended fuel and potential engine damage if you get it wrong.

I can't tell you how much more timing the engine will take. That's for the dyno to tell you. At 1.4 bar with a 50% C16 mixture it's likely that you won't be knock limited and can tune to MBT but proceed with caution as there are too many variables for me to be able to advise you thoroughly - What is the CR for example? I find that C16 normally works well with similar AFR targets as what you'd expect on pump gas, however due to its higher octane rating you can get away with running a little leaner if the engine responds to this.

C16 can be used for daily driving but it's a pretty expensive way of getting around. It also is heavily leaded and can cause corrosion in the engine and exhaust system if the engine is left for long periods of time. If you're going to be swapping between 100% pump gas and your 50% mix then dual maps are typically the best solution. I'll also caution you that when swapping between fuels it's critical to ensure you have the tank completely empty before refilling otherwise your fuel will end up diluted.

i am also thinking of running the engine on 12 injector, 2 fuel lines and 2 separate fuel tanks, in which c16 will only be supplied on high boost otherwise only the primary inj will supply (pump gas). Give me your opinoin on this andre.

And i dont think i would want to run the engine leaner, little power dose not matter as long as the engine is safe, so i am planning to target 11.2-11.3 afr on high boost when the engine is getting 50% c16 and 50% pump gas

A dual fuel system is probably a nice way of achieving your aim to be honest, although it understandably increases complexity. The likes of Motec's M1 ECU actually provide this functionality in their more recent GPR package. If you're planning on using pure C16 in one tank then it's a safer way of achieving your aim in my opinion.

I'll also add that unless you have a specific reason to use C16, Q16 from VP outperforms C16 in every way and at least here in NZ it ended up cheaper than C16. Q16 is oxygenated though and as a result requires around 5% more fuel to achieve a consistent AFR compared to petrol/C16. Just a little food for though.

Andre i came to a concultion that i would use dual fuel system with Q16 fuel, on high boost i will make the primary injectors supply 70% of pump gas and the secoundary inj 30% of Q16 i will target an AFR of 11. Feedback will be given after project is done.

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