Let's Talk Timing Maps

[TwIzTeD_3kGt]

Jeff's Timing Map

What's Jeff's fuel setup? Pump+Meth right?

[kywhitelightning]

Yes, lots of meth. No water, just meth. 20% of my fueling in boost is methanol. 1600ml/min is the flow rate. My 680's are at 65-67%DC at 43.5 psi rail pressure static. I actually tried to run lower timing and it knocked some?????? I knew on my 19t's I was able to get away with 27* up top so I pushed it a little with this setup just to see. This map REALLY likes when I add race gas to the tank he he.

Jeff

[kywhitelightning]

I edited the above post because when I did the fueling calculation I forgot to add in the boost pressure increasing the rail pressure. 20% is what is being injected up to 28psi. I can't get past 25psi with that timing map unless it cools off but the reason I keep it like that is because I don't need a new flash to run race gas. I pour it in and turn up the DSBC.

Jeff

[Toni]

Jeff,

What is the max load that you hit?

[kywhitelightning]

299. As soon as I start a pull it pretty much pegs at 299 and stays there until the end. I refuse to change the MAF size again as it is a global change to the tune and everything would need to be changed all over again.

Jeff

[RealMcCoy]

i edited the above post because when i did the fueling calculation i forgot to add in the boost pressure increasing the rail pressure.

Jeff

wat...?

[kywhitelightning]

A fuel pressure regulators job is to increase rail pressure 1psi for every 1psi increase in the intake manifold. I didn't account for the 25-28 psi of increased rail pressure the fuel injectors were seeing which raises their flow above the on the box rating of 680. To say it short my original figures were skewed quite a bit.

Reality is the figures are, simply put, a guestimate of what is going on in the engine. I have statically tested my meth setup numerous times for 1 minute straight and I always come up with near 1600ml in the container at the end of the min. Sometimes +50ml sometimes -50ml but, it is really difficult to capture a mist and then even more difficult to keep it from evaporating before getting an accurate measurement. If the fuel injectors are actually flowing what their rating is (and they never do) and the logger is seeing 67% duty cycle at the absolute most, I can guestimate my fueling based on what has been measured and what the logger is seeing.

The 20% figure is certainly not a static figure across the board either because the injector duty cycle starts small and I am usually at peak boost within 600RPM's of the original hit of the throttle. The methanol injection is boost based so it maxes way before the IDC's see their max.

Jeff

[Chris@Rvengeperformance]

The injectors flow the same because their flow is dependent on the differential pressure between the intake and the fuel inlet. That is why the FPR is a 1:1 ratio, to keep the injector effective size constant.

So, even at 25 PSI of boost the injectors still act like they are 660s.

[kywhitelightning]

Got it.

Jeff

[J. Fast]

Here's the map I'm currently running.